Clinical Focus

  • Thoracic and Cardiac Surgery

Academic Appointments

Professional Education

  • Fellowship: University of Alberta Cardiology Fellowships (2017) Canada
  • Fellowship: UCSF Adult Congenital Cardiac Fellowship (2015) CA
  • Board Certification: Royal College of Physicians and Surgeons of Canada, Cardiovascular Surgery (2014)
  • Residency: University of Calgary Cardiac Surgery Residency (2014) Canada
  • Residency: Dalhousie University Cardiac Surgery Residency (2009) Canada
  • Medical Education: University of Alberta (2005) Canada

All Publications

  • Tricuspid regurgitation in Hypoplastic Left Heart Syndrome: Three-dimensional echocardiography provides additional information in describing jet location. Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography Mah, K., Khoo, N. S., Tham, E., Yaskina, M., Maruyama, M., Martin, B., Alvarez, S., Alami, N., Rebeyka, I. M., Smallhorn, J., Colen, T. 2020


    BACKGROUND: Twenty-five percent of hypoplastic left heart syndrome (HLHS) patients require tricuspid valve (TV) repair. Location of tricuspid regurgitation (TR) is important in determining the type of repair performed. Three-dimensional echocardiography (3DE) studies report a high incidence of error in 2DE identification of TV leaflets. This study compares 3DE and 2DE assessment of TR in HLHS (jet location, TR grade, reproducibility).METHODS: We performed a retrospective, single center review. Fifty-six HLHS patients with available 2DEs and 3DEs, and mild or greater TR, were included. TR location, grade, vena contracta (VC) area, and TV annulus diameter were measured from 2DE and 3DE. Reproducibility was assessed by blinded reviewers.RESULTS: 3DE identified primary jet location as central (57%), followed by antero-septal (36%). There was poor agreement between 3DE and 2DE findings for jet location (kappa 0.05; CI: -0.08 to 0.19). Interobserver reproducibility for 3DE location was excellent (kappa 0.8), whereas 2DE reproducibility was poor (kappa 0.32). The most common jet location pre-Norwood and pre-Glenn is central (70%); whereas pre-Fontan and post-Fontan the location is central (45%) and anterior-septal (48%). 2DE VC area correlated moderately with 3DE VC area (r = 0.60, p<0.0001). 2DE and 3DE TV annulus diameter for lateral (r = 0.85, p<0.0001) and anterior-posterior (r= 0.74, p= 0.001) dimensions were strongly correlated.CONCLUSIONS: In children with HLHS, 2DE assessment of TR location has poor agreement with 3DE and was poorly reproducible. In contrast, 3DE TR jet location was highly reproducible. Pre-Glenn, a central TR jet was the most common, while post-Glenn central and anteroseptal locations were equal, highlighting the importance of pre-operative identification of TR jet location in HLHS patients.

    View details for DOI 10.1016/j.echo.2020.12.010

    View details for PubMedID 33373699

  • Functional Popliteal Artery Entrapment Syndrome as a Mimicker of Musculoskeletal, Rheumatologic, and Myofascial Lower Extremity Pain Amlani, A., Cantle, P., Martin, B., Martin, L. J RHEUMATOL PUBL CO. 2020: 1119
  • Predicting Post-Fontan Length of Stay: The Limits of Measured Variables. Pediatric cardiology Martin, B., McBrien, A., Marchak, B. E., Atallah, J., Al Aklabi, M., Mackie, A. S. 2019


    Post-operative length of stay (LOS) is an important metric for both healthcare providers and patients and their families. Predicting LOS is a challenge as it is sensitive to multitudinous patient and system factors. All subjects undergoing a Fontan from 1996-2016 who survived to hospital discharge were included. Details about the pre-operative status, operative conduct, and post-operative course of each patient were obtained. The association between patient characteristics and post-Fontan LOS were determined using stepwise multivariable regression models. Of 320 subjects who underwent a Fontan, 314 (98.1%) survived to hospital discharge. Median age at Fontan was 3.3years (IQR 2.8, 4.0) and the most common underlying diagnosis was hypoplastic left heart syndrome (106, 33.8%). Median post Fontan LOS was 11days (IQR 8, 17). Univariable risk factors for longer LOS included number of previous surgeries, post-Glenn LOS, cardiopulmonary bypass time, post-operative chylothorax, and failure to extubate in the operating room (all p<0.05). In multivariable models, number of previous operations, extubation in the operating room, and postoperative complications predicted LOS (R2=0.5185 for full model). The proportion of patients discharged on week days (14.7-18.8% per day) was significantly higher than the proportion discharged on weekend days (5.1-9.9% per weekend day). Pre-operative variables have limited use in predicting post-Fontan length of stay. The most important predictors of post-operative LOS are extubation in the operating room and the occurrence of post-operative complications. However, a significant proportion of variability in LOS was not explained by available measurable variables.

    View details for DOI 10.1007/s00246-019-02134-y

    View details for PubMedID 31230092

  • Cardiac rehabilitation in people with peripheral arterial disease: A higher risk population that benefits from completion INTERNATIONAL JOURNAL OF CARDIOLOGY Devrome, A. N., Aggarwal, S., McMurtry, M., Southern, D., Hauer, T., Lamb, B., Arena, R., Moore, R. D., Wilton, S. B., Stone, J., Martin, B. 2019; 285: 108–14
  • Neonatal Tracheal and Intracardiac Repair in a High-Risk Premature Infant Requiring Preoperative ECMO Transport WORLD JOURNAL FOR PEDIATRIC AND CONGENITAL HEART SURGERY Martin, B., Holinski, P., Noga, M., El-Hakim, H., Al Aklabi, M. 2019; 10 (3): 380–83
  • Cardiac rehabilitation in people with peripheral arterial disease: A higher risk population that benefits from completion. International journal of cardiology Devrome, A. N., Aggarwal, S., McMurtry, M. S., Southern, D., Hauer, T., Lamb, B., Arena, R., Moore, R. D., Wilton, S. B., Stone, J., Martin, B. 2019


    BACKGROUND: Peripheral arterial disease (PAD) is common in people referred for cardiac rehabilitation (CR). However, the associations between PAD diagnosis and CR attendance and mortality remain to be defined.METHODS: All patients referred to a 12-week exercise-based CR program were included. Associations between PAD diagnosis and starting CR as well as between PAD diagnosis and completing CR were measured using multivariable logistic regression. Associations between CR completion and mortality were measured using adjusted Cox proportional hazards models, and a propensity-based matching sensitivity analysis was performed.RESULTS: 23,215 patients (mean age 61.3 years; 21.6% female) were referred to CR; 1366 (5.9%) had PAD. Those with PAD were less likely to start CR (57.0% vs 68.2%, adjusted OR 0.81, 95%CI 0.72, 0.91) and complete CR if they started (70.6% vs 76.7%, adjusted OR 0.80, 95%CI 0.68, 0.94). Patients with PAD completing CR had lower exercise capacity at baseline (6.6 vs. 7.6 METs, p < 0.0001) and completion (7.5 vs 8.6 METs, p < 0.0001). There were 3510 deaths over follow-up; 10-year survival was lower in those with PAD (66.9 vs 84.5%; p < 0.0001). CR completion was associated with lower mortality for all (adjusted HR 0.62 (95%CI 0.57, 0.67)), and the magnitude of the association was independent of PAD status.CONCLUSIONS: Patients with PAD referred to CR had a higher mortality than those without, and were less likely to start and complete CR. Completion of CR was associated with improved fitness and survival for PAD patients. These data support broader use of CR by those with PAD.

    View details for PubMedID 30857844

  • Driveline Site Is Not a Predictor of Infection After Ventricular Assist Device Implantation ASAIO JOURNAL Martin, B., Luc, J. Y., Maruyama, M., MacArthur, R., Bates, A. R., Buchholz, H., Freed, D. H., Conway, J. 2018; 64 (5): 616–22
  • Driveline Site Is Not a Predictor of Infection After Ventricular Assist Device Implantation. ASAIO journal (American Society for Artificial Internal Organs : 1992) Martin, B., Luc, J. G., Maruyama, M., MacArthur, R., Bates, A. R., Buchholz, H., Freed, D. H., Conway, J. 2018; 64 (5): 616–22


    Driveline infections (DLIs) remain a major source of morbidity for patients requiring long-term ventricular assist device (VAD) support. We aimed to assess whether VAD driveline exit site (DLES) (abdomen versus chest wall) is associated with DLI. All adult patients who underwent insertion of a HeartWare HVAD or HeartMate II (HMII) between 2009 and 2016 were included. Driveline infection was defined as clinical evidence of DLI accompanied by a positive bacterial swab and need for antibiotics. Competing risks analysis was used to assess the association between patient characteristics and DLI. Ninety-two devices (59 HMII) were implanted in 85 patients (72 men; median age 57.4 years) for bridge to transplant or destination therapy. VAD DLES was chest in 28 (30.4%) devices. Median time on VAD support was 347.5 days (IQR 145.5, 757.5), with 28 transplants and 29 deaths (27 on device). DLI occurred in 24 patients (25 devices) at a median of 140 days (IQR 67, 314) from implant. Staphylococcus aureus accounted for 15 infections (60%). Freedom from infection was 72.8% (95% confidence interval [CI] 53.1-78.0%) at 1 year and 41.9% (95% CI 21.1-61.5%) at 3 years. In competing risks regression, abdominal DLES was not predictive of DLI (hazard ratio, HR 1.65 [95% CI 0.63, 4.29]), but body mass index (BMI) >30 kg/m was (HR 2.72 [95% CI 1.25, 5.92]). In conclusion, risk of DLI is high among patients on long-term VAD support, and a nonabdominal DLES does not reduce this risk. The only predictor of DLI in this series was an elevated BMI.

    View details for PubMedID 29035899

  • Factors Associated With Cardiorespiratory Fitness at Completion of Cardiac Rehabilitation: Identification of Specific Patient Features Requiring Attention CANADIAN JOURNAL OF CARDIOLOGY Laddu, D., Ozemek, C., Lamb, B., Hauer, T., Aggarwal, S., Stone, J. A., Arena, R., Martin, B. 2018; 34 (7): 925–32


    We aimed to determine and compare predictors of postcardiac rehabilitation (CR) cardiorespiratory fitness (CRF), improvements in a large cohort of subjects with varying baseline CRF levels completing CR for ischemic heart disease and to refine prediction models further by baseline CRF.The Alberta Provincial Project for Outcomes Assessment in Coronary Heart disease (APPROACH) and TotalCardiology (TotalCardiology, Inc, Calgary, Alberta, Canada) databases were used retrospectively to obtain information on 10,732 (1955 [18.2%] female; mean age 60.4, standard deviation [SD] 10.5 years) subjects who completed the 12-week comprehensive CR program between 1996 and 2016. Peak metabolic equivalents (METs) were determined at program start and completion and identified patients at baseline with low fitness (L-Fit) (< 5 METs), moderate fitness (M-Fit, 5-8 METs), or high fitness (H-Fit, > 8 METs). Multivariable linear regression models were developed to predict METs at completion of the program.Across all fitness groups, mean baseline METs was the strongest predictor of CRF at completion of CR. Other factors-including sex, age, current smoking status, obesity, and diabetes-were highly predictive of post-CR CRF (all P < 0.05). Compared with H-fit patients, coronary artery bypass graft and chronic obstructive pulmonary disease in L-Fit patients, and cerebrovascular disease in M-Fit patients had an additional negative effect on the overall model variance in post-CR CRF.Expected CRF at the end of CR is highly predictable, with several key patient factors being clear determinants of CRF. Although most identified patient factors are not modifiable, our analysis highlights populations that may require extra attention over the course of CR to attain maximal benefit.

    View details for PubMedID 29861207

  • Deterioration of functional abilities in children surviving the Fontan operation CARDIOLOGY IN THE YOUNG Ricci, M., Martin, B., Joffe, A. R., Dinu, I. A., Alton, G. Y., Guerra, G. G., Robertson, C. T., Western Canadian Complex Pediat Th 2018; 28 (6): 868–75


    Functional abilities are needed for activities of daily living. In general, these skills expand with age. We hypothesised that, in contrast to what is normally expected, children surviving the Fontan may have deterioration of functional abilities, and that peri-Fontan stroke is associated with this deterioration. All children registered in the Western Canadian Complex Pediatric Therapies Follow-up Program who survived a Fontan operation in the period 1999-2016 were eligible for inclusion. At the age of 2 years (pre-Fontan) and 4.5 years (post-Fontan), the Adaptive Behavior Assessment System-II general adaptive composite score was determined (population mean: 100, standard deviation: 15). Deterioration of functional abilities was defined as ⩾1 standard deviation decrease in pre- to post-Fontan scores. Perioperative strokes were identified through chart review. Multivariable logistic regression analysis determined predictors of deterioration of functional abilities. Of 133 children, with a mean age at Fontan of 3.3 years (standard deviation 0.8) and 65% male, the mean (standard deviation) general adaptive composite score was 90.6 (17.5) at 2 years and 88.3 (19.1) at 4.5 years. After Fontan, deterioration of functional abilities occurred in 34 (26%) children, with a mean decline of 21.8 (7.1) points. Evidence of peri-Fontan stroke was found in 10 (29%) children who had deterioration of functional abilities. Peri-Fontan stroke (odds ratio 5.00 (95% CI 1.74, 14.36)) and older age at Fontan (odds ratio 1.67 (95% CI 1.02, 2.73)) predicted functional deterioration. The trajectory of functional abilities should be assessed in this population, as more than 25% experience deterioration. Efforts to prevent peri-Fontan stroke, and to complete the Fontan operation at an earlier age, may lead to reduction of this deterioration.

    View details for PubMedID 29690942

  • Hypoplastic Left Heart Syndrome Is Not a Predictor of Worse Intermediate Mortality Post Fontan Martin, B., Mah, K., Eckersley, L., Harder, J., Pockett, C., Schantz, D., Dyck, J., Al Aklabi, M., Rebeyka, I. M., Ross, D. B. ELSEVIER SCIENCE INC. 2017: 2037–44


    An increasing proportion of those living with single ventricle physiology have hypoplastic left heart syndrome (HLHS). Our objective was to assess the association between HLHS and outcomes post Fontan operation.All pediatric patients who underwent a Fontan procedure at the University of Alberta between 1996 and 2016 were included. Follow-up clinical data collected included early and late surgical or catheter reintervention, echocardiography, and long-term transplant-free survival. Characteristics were compared between those with and without HLHS, and the association between outcomes and HLHS were assessed.A total of 320 children (median age 3.3 years, interquartile range 2.8 to 3.9 years; 121 [43.4%] female) underwent a Fontan procedure over the course of the study. Nearly one third of subjects had HLHS (107, 33.4%). Patients with HLHS were more likely to have abnormal ventricular function (19.6% versus 7.0%, p = 0.003) and worse than mild atrioventricular valve (AVV) regurgitation (23.4 versus 9.2%, p = 0.001) preoperatively. HLHS was not predictive of in-hospital Fontan failure (odds ratio 0.82, 95% CI 0.28, 2.39), late reintervention (hazard ratio [HR] 1.08, 95% CI 0.66, 1.76), or transplant-free survival (HR 1.58, 95% CI 0.72, 3.44). Subjects with HLHS were more likely to have more than mild AVV regurgitation (31.6% versus 13.3%, p = 0.028) and abnormal ventricular function (29.8% versus 10.7%, p < 0.0001) at late follow-up.Patients with HLHS who survive to the Fontan procedure do no worse with the operation than those with other anatomy. Given worse late ventricular function and AVV regurgitation, equivalent survival may not persist throughout a patient's life course.

    View details for PubMedID 29096870

  • Post-operative Outcomes in Children Undergoing Fontan Palliation in a Regionalized Surgical System PEDIATRIC CARDIOLOGY Martin, B., Ross, D. B., Al Aklabi, M., Harder, J., Dyck, J. D., Rebeyka, I. M. 2017; 38 (8): 1654–62


    Evidence suggests that outcomes in pediatric cardiac surgery are improved by consolidating care into centers of excellence. Our objective was to determine if outcomes are equivalent in patients across a large regional referral base, or if patients from centers without on-site surgery are at a disadvantage. Since 1996, all pediatric cardiac surgery has been offered at one of two centers within the region assessed, with the majority being performed at Stollery Children's Hospital. All patients who underwent a Fontan between 1996 and 2016 were included. Follow-up data including length of stay (LOS), repeat surgical interventions, and transplant-free survival were acquired for each patient. The association between post-operative outcomes and home center was assessed using Kaplan-Meier survival analysis and Cox proportional Hazards models. 320 children (median age 3.3 years, IQR 2.8-4.0) were included; 120 (37.5%) had the surgical center as their home center. Cardiac anatomy was hypoplastic left heart syndrome in 107 (33.4%) subjects. Median LOS was 11 days (IQR, 8-17), and there were 8 in-hospital deaths. There were 17 deaths and 11 transplants over the course of follow-up. Five-year transplant-free survival was 92.5%. There was no difference in hospital re-intervention, late re-intervention, or survival by referral center (all p > 0.05). In multivariable analysis, home center was not predictive of either LOS (R 2 = -0.40, p = 0.87) or transplant-free survival (1.52, 95%CI 0.66, 3.54). In children with complex congenital heart disease, a regionalized surgical care model achieves good outcomes, which do not differ according to a patient's home base.

    View details for PubMedID 28831564

  • Tricuspid Valve Repair in Infancy Using Neochordae: Three-Dimensional Echocardiographic Imaging WORLD JOURNAL FOR PEDIATRIC AND CONGENITAL HEART SURGERY Martin, B., Khoo, N. S., Smallhorn, J., Al Aklabi, M. 2017; 8 (6): 740–42


    Tricuspid regurgitation (TR) in infancy poses a surgical challenge. Both two- and three-dimensional echocardiography (3DE) can provide detailed information about the mechanism(s) of valve failure and insights into valve adaptation during follow-up. We report two patients who underwent tricuspid valve repair using Gore-Tex neochordae, repairs which were facilitated by and assessed with 3DE. Both infants had less than mild residual TR and no valve tethering at hospital discharge. Furthermore, follow-up 3DEs have helped to confirm valve competence, lack of tethering, and growth of the valve and valve apparatus.

    View details for PubMedID 29187115

  • Hypoplastic Left Heart Syndrome is not Associated with Worse Clinical or Neurodevelopmental Outcomes Than Other Cardiac Pathologies After the Norwood-Sano Operation. Pediatric cardiology Martin, B. J., De Villiers Jonker, I. n., Joffe, A. R., Bond, G. Y., Acton, B. V., Ross, D. B., Robertson, C. M., Rebeyka, I. M., Atallah, J. n. 2017; 38 (5): 922–31


    There is evidence to suggest that patients undergoing a Norwood for non-HLHS anatomy may have lower mortality than classic HLHS, but differences in neurodevelopmental outcome have not been assessed. Our objective was to compare survival and neurodevelopmental outcome during the same surgical era in a large, well-described cohort. All subjects who underwent a Norwood-Sano operation between 2005 and 2014 were included. Follow-up clinical, neurological, and developmental data were obtained from the Western Canadian Complex Pediatric Therapies Follow-up Program database. Developmental outcomes were assessed at 2 years of age using the Bayley Scales of Infant and Toddler Development (Bayley-III). Survival was assessed using Kaplan-Meier analysis. Baseline characteristics, survival, and neurodevelopmental outcomes were compared between those with HLHS and those with non-HLHS anatomy (non-HLHS). The study comprised 126 infants (75 male), 87 of whom had HLHS. Five-year survival was the same for subjects with HLHS and those with non-HLHS (HLHS 71.8%, non-HLHS 76.9%; p = 0.592). Ninety-three patients underwent neurodevelopmental assessment including Bayley-III scores. The overall mean cognitive composite score was 91.5 (SD 14.6), language score was 86.6 (SD 16.7) and overall mean motor composite score was 85.8 (SD 14.5); being lower than the American normative population mean score of 100 (SD 15) for each (p-value for each comparison, <0.0001). None of the cognitive, language, or motor scores differed between those with HLHS and non-HLHS (all p > 0.05). In the generalized linear models, dominant right ventricle anatomy (present in 117 (93%) of patients) was predictive of lower language and motor scores. Comparative analysis of the HLHS and non-HLHS groups undergoing single ventricle palliation including a Norwood-Sano, during the same era, showed comparable 2-year survival and neurodevelopmental outcomes.

    View details for PubMedID 28341901

  • An Unusual Cause of Hemopericardium 22 Years After a Fontan Procedure. The Annals of thoracic surgery Martin, B. J., Seaman, C. n., Windram, J. D., Rebeyka, I. M. 2017; 103 (2): e187–e189


    Late tamponade after cardiac operations is rare but reasonably well described. We report a case of exceedingly late tamponade secondary to a spontaneous coronary bleed 22 years after a Fontan operation, which was repaired with catheter intervention.

    View details for PubMedID 28109386

  • A Unique Intracardiac Shunt: Identifying Complex Anatomy in Reoperative Adult Congenital Heart Disease. World journal for pediatric & congenital heart surgery Martin, B. J., Rebeyka, I. M., Smallhorn, J. F., Taylor, D. A., Vonder Muhll, I. F. 2017: 2150135116685031


    Adult patients with repaired congenital heart disease are presenting with previously unseen types of residual lesions and consequences of prior repair. Patients with d-transposition of the great arteries repaired with atrial switch operations are returning with dysrhythmias and atrioventricular valve disease requiring intervention. We present the challenging case of a young adult with a residual shunt identified on preoperative three-dimensional transthoracic echocardiography, the precise anatomy of which was only characterized intraoperatively.

    View details for DOI 10.1177/2150135116685031

    View details for PubMedID 28466690

  • Glutaraldehyde Treatment of Allografts and Aortic Outcomes Post-Norwood: Challenging Surgical Decision. The Annals of thoracic surgery Martin, B. J., Kaestner, M. n., Peng, M. n., Ross, D. B., Urschel, S. n., West, L. J., Rebeyka, I. M. 2017; 104 (4): 1395–1401


    Glutaraldehyde (GA) treatment of allografts used for arch reconstruction prevents the immunologic sensitization that occurs with untreated allografts, but its use may cause tissue changes that predispose to recurrent obstruction. The objective was to determine whether GA treatment of allografts used in Norwood procedures increases the risk of recurrent aortic obstruction.All infants who underwent a Norwood procedure between 2000 and 2015 were included. Cryopreserved pulmonary allografts were used for all arch reconstructions; starting in 2005 all were treated with GA before use. Complete follow-up was obtained, including survival, transplantation, and all repeat procedures. Competing risks analyses were used to assess for differences in aortic reintervention over time.Two hundred six infants (132 male) were included. There were 60 deaths and 14 transplantations; 5-year transplantation-free survival was 71.9%. GA treatment of patches (n = 142, 68.9%) was not predictive of death (hazard ratio [HR] 1.38, 95% confidence interval [CI]: 0.61 to 3.08). Fifty-five patients had at least one aortic reintervention and 31 patients (15.0%) required surgical aortic reintervention. At 1-year, freedom from all aortic reintervention was similar between patients with and without treated patches, but freedom from surgical aortic reintervention was lower in the treated group (87.6% versus 95.3%, p = 0.0256). GA treatment was not associated with the combined end point of catheter-based or surgical reintervention but was associated with specific need for surgical reintervention (HR 4.05, 95% CI: 1.19 to 13.77).GA treatment is associated with increased late surgical aortic reintervention. The advantages of decreased sensitization with GA treatment need to be balanced against the risk of aortic reobstruction.

    View details for PubMedID 28577843

  • Neonatal Tracheal and Intracardiac Repair in a High-Risk Premature Infant Requiring Preoperative ECMO Transport. World journal for pediatric & congenital heart surgery Martin, B. J., Holinski, P. n., Noga, M. n., El-Hakim, H. n., Aklabi, M. A. 2017: 2150135117696490


    Congenital tracheal stenosis is an uncommon malformation that portends a poor outcome in children who are symptomatic in the neonatal period. Over time, the management of significant tracheal disease has been consolidated at high-volume centers, and increasingly complex patients have undergone surgical repair. We present a premature newborn boy who was diagnosed with critical multi-level airway and cardiac disease who decompensated at a remote site, requiring extracorporeal membrane oxygenation support for transport. He underwent a complete repair including a slide tracheoplasty and was successfully discharged home, with no residual stenosis at follow-up.

    View details for PubMedID 28825386

  • Shunt Lesions Part II: Anomalous Pulmonary Venous Connections and Truncus Arteriosus. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Martin, B. J., Karamlou, T. B., Tabbutt, S. 2016; 17 (8 Suppl 1): S310-4


    The objectives of this review are to describe the anatomy, pathophysiology, perioperative therapeutic strategies, and operative procedures for patients with anomalous pulmonary venous connections and truncus arteriosus.MEDLINE and PubMed.An understanding of the anatomy and pathophysiology of anomalous pulmonary venous connections and truncus arteriosus is essential for the optimal perioperative management of these complex and challenging congenital lesions.

    View details for DOI 10.1097/PCC.0000000000000822

    View details for PubMedID 27490615

  • Rehabilitation Therapy in Peripheral Arterial Disease. The Canadian journal of cardiology Aggarwal, S. n., Moore, R. D., Arena, R. n., Marra, B. n., McBride, A. n., Lamb, B. n., Martin, B. J., Stone, J. n. 2016; 32 (10 Suppl 2): S374–S381


    Peripheral arterial disease (PAD) is the result of atherosclerosis in the lower limb arteries, which can give rise to intermittent claudication (IC), limb ulceration, infections, and, in some circumstances, amputation. As a result of PAD, patients are frequently limited in both walking duration and speed. These ambulatory deficits impact both functional capacity and quality of life. The prevalence of PAD is increasing, and patients with this diagnosis have high cardiovascular morbidity and mortality. A comprehensive approach is required to improve outcomes in patients with PAD and include tobacco cessation, pharmacologic management of metabolic fitness, risk-factor modification, and exercise training. Supervised exercise programs significantly improve functional capacity and quality of life in addition to reducing IC. These programs reduce morbidity and mortality and are cost-effective; yet they are uncommonly prescribed. Supervised exercise training is an accepted intervention in the PAD population and has been included in both Canadian and American guidelines for PAD management. This review describes (1) key background information related to PAD, (2) the initial approach to PAD diagnosis, (3) pharmacologic management options, (4) risk-factor modification, and (5) the currently accepted approach to exercise training. Key recommendations for enhancing PAD care in a Canadian context are also discussed.

    View details for PubMedID 27692118

  • Clinical and Functional Developmental Outcomes in Neonates Undergoing Truncus Arteriosus Repair: A Cohort Study. The Annals of thoracic surgery Martin, B. J., Ross, D. B., Alton, G. Y., Joffe, A. R., Robertson, C. M., Rebeyka, I. M., Atallah, J. n. 2016; 101 (5): 1827–33


    Truncus arteriosus (TA) is an uncommon congenital cardiac lesion that portends an exceedingly poor prognosis if not repaired. The objective of this study was to assess the clinical and developmental outcomes in a prospective cohort of patients who underwent TA repair.All patients who underwent a TA repair between 1996 and 2012 were included. Follow-up clinical, neurologic, and developmental data were obtained from the Western Canadian Complex Pediatric Therapies Follow-up Program database. Functional developmental outcomes were assessed at 21.1 ± 2.5 months of age with the Adaptive Behavior Assessment System-II, General Adaptive Composite (GAC) score. Survival and outcomes were compared between those with and without chromosomal abnormalities (CA). Survival and freedom from reintervention were assessed by Kaplan-Meier analysis.The study comprised 36 infants (19 male). CA was identified in 13, with 22q11.2 deletion in 10 patients. Patients underwent TA repair at a median age of 10 days; 5 patients underwent concomitant interrupted arch repair. There were 8 deaths, 2 of which occurred in the hospital. The 5-year survival was 79.4%. Survival was similar between those with and without CA. At 5 years, freedom from reoperation was 77.2%. The mean GAC was higher in the patients without CA (93.6 ± 12.8 vs 76.1 ± 13.1, p = 0.0016).Patients with surgically repaired TA continue to have significant postoperative mortality. Reoperation and cardiac catheterization are eventualities for a quarter of patients in the first 5 years of life. Functional developmental outcome in patients without CA is good, although it is significantly impaired in those with CA.

    View details for PubMedID 26952297

  • Repair of recoarctation after the Norwood operation: The right-sided posterior approach. The Journal of thoracic and cardiovascular surgery Martin, B. J., Maruyama, M. n., Rebeyka, I. M. 2016; 152 (6): 1622–24

    View details for PubMedID 27464578

  • Role of vascular function in predicting arteriovenous fistula outcomes: an observational pilot study. Canadian journal of kidney health and disease MacRae, J. M., Ahmed, S., Hemmelgarn, B., Sun, Y., Martin, B. J., Roifman, I., Anderson, T. 2015; 2: 19


    Many arteriovenous fistula (AVF) fail prior to use due to lack of maturation or thrombosis. Determining vascular function prior to surgery may be helpful to predict subsequent AVF success. This is a feasibility study to describe the vascular function in a cohort of chronic kidney disease (CKD) patients who are awaiting AVF creation.A prospective cohort of 28 CKD patients expected to progress to HD underwent arterial stiffness (pulse wave velocity, PWV) and endothelial function testing (flow mediated dilation FMD, and peripheral arterial tonometry, PAT) one week prior to AVF creation. AVF success was defined as maintaining patency and achieving maturation. Post operative fistula assessment at 8 weeks evaluated maturation (clinical assessment of adequate fistula flowand ultrasound diameter ≥ 0.5 cm).The median age 72 years (62 - 78), 75% males, eGFR 15 ml/min/1.73 m(2) (12 - 18). 20 (71%) patients had successful AVF surgery with a mature AVF at 8 weeks. Patients with AVF success had higher mean PAT values 1.87 ± 0.52 than those with failed AVF 1.41 ± 0.24 p = 0.03.Microvascular endothelial function as measured using PAT may be useful as a predictor of AVF maturation and function. This simple non invasive marker of vascular function may be a useful tool to predict AVF outcomes.

    View details for DOI 10.1186/s40697-015-0055-8

    View details for PubMedID 25949818

    View details for PubMedCentralID PMC4422532

  • Cardiac rehabilitation completion is associated with reduced mortality in patients with diabetes and coronary artery disease. Diabetologia Armstrong, M. J., Sigal, R. J., Arena, R., Hauer, T. L., Austford, L. D., Aggarwal, S., Stone, J. A., Martin, B. J. 2015; 58 (4): 691-8


    Cardiac rehabilitation (CR) reduces the risks of mortality and hospitalisation in patients with coronary artery disease and without diabetes. It is unknown whether patients with diabetes obtain the same benefits from CR.We retrospectively examined patients referred to a 12 week CR programme between 1996 and 2010. Associations between CR completion vs non-completion and death, hospitalisation rate and cardiac hospitalisation rate were assessed by survival analysis.Over the study period, 13,158 participants were referred to CR (mean ± SD, age 59.9 ± 11.1 years, 28.9% female, 2,956 [22.5%] with diabetes). Patients with diabetes were less likely to complete CR than those without diabetes (41% vs 56%, p < .0001). Over a median follow-up of 6.6 years, there were 379 deaths in patients with diabetes vs 941 deaths among those without diabetes (12.8% vs 8.9%). Of the non-completers, patients with diabetes had a higher mortality rate compared with those without diabetes (17.7% vs 11.3%). In patients who completed CR, mortality was lower: 11.1% in patients with diabetes vs 7.0% in those without diabetes. In patients with diabetes, CR completion was associated with reduced mortality (HR 0.46 [95% CI 0.37, 0.56]), reduced hospitalisation (HR 0.86 [95% CI 0.76, 0.96]) and reduced cardiac hospitalisation (HR 0.67 [95% CI 0.54, 0.84]). The protective associations were similar to those of patients without diabetes. In multivariable adjusted analyses, all of these associations remained significant.Patients with diabetes were less likely to complete CR than those without diabetes. However, patients with diabetes who completed CR derived similar apparent reductions in mortality and hospitalisation to patients without diabetes.

    View details for DOI 10.1007/s00125-015-3491-1

    View details for PubMedID 25742772

  • Optimizing Value From Cardiac Rehabilitation: A Cost-Utility Analysis Comparing Age, Sex, and Clinical Subgroups. Mayo Clinic proceedings Leggett, L. E., Hauer, T. n., Martin, B. J., Manns, B. n., Aggarwal, S. n., Arena, R. n., Austford, L. D., Meldrum, D. n., Ghali, W. n., Knudtson, M. L., Norris, C. M., Stone, J. A., Clement, F. n. 2015; 90 (8): 1011–20


    To assess the cost utility of a center-based outpatient cardiac rehabilitation program compared with no program within patient subgroups on the basis of age, sex, and clinical presentation (acute coronary syndrome [ACS] or non-ACS).We performed a cost-utility analysis from a health system payer perspective to compare cardiac rehabilitation with no cardiac rehabilitation for patients who had a cardiac catheterization. The Markov model was stratified by clinical presentation, age, and sex. Clinical, quality-of-life, and cost data were provided by the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and TotalCardiology.The incremental cost per quality-adjusted life-year (QALY) gained for cardiac rehabilitation varies by subgroup, from $18,101 per QALY gained to $104,518 per QALY gained. There is uncertainty in the estimates due to uncertainty in the clinical effectiveness of cardiac rehabilitation. Overall, the probabilistic sensitivity analysis found that 75% of the time participation in cardiac rehabilitation is more expensive but more effective than not participating in cardiac rehabilitation.The cost-effectiveness of cardiac rehabilitation varies depending on patient characteristics. The current analysis indicates that cardiac rehabilitation is most cost effective for those with an ACS and those who are at higher risk for subsequent cardiac events. The findings of the current study provide insight into who may benefit most from cardiac rehabilitation, with important implications for patient referral patterns.

    View details for PubMedID 26149321

  • Cardiac rehabilitation referral, attendance and mortality in women. European journal of preventive cardiology Colbert, J. D., Martin, B. J., Haykowsky, M. J., Hauer, T. L., Austford, L. D., Arena, R. A., Knudtson, M. L., Meldrum, D. A., Aggarwal, S. G., Stone, J. A. 2015; 22 (8): 979–86


    Cardiac rehabilitation (CR) reduces mortality in women and men with coronary artery disease (CAD). The objective of this study was to examine sex differences in long-term mortality, based on CR referral rates and attendance patterns in a large CAD population.This is a retrospective cohort study.The Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) and Cardiac Wellness Institute of Calgary (CWIC) databases were used to obtain information on all patients. Rates of referral to and attendance at CR were compared by sex. Logistic regression models were constructed to assess whether sex predicted CR referral or completion. The association between referral, completion, and survival was assessed by sex using Cox proportional hazard models.25,958 subjects (6374-24.6%-were women) with at least one vessel CAD were included. Females experienced reduced rates of CR referral (31.1% vs 42.2%, p < 0.0001) and completion (50.1 vs 60.4%, p < 0.0001). Adjusting for demographic and clinical characteristics, relative to men, CR referral was significantly lower in women (adjusted odds ratio (OR) 0.74, 95% CI 0.69, 0.79) as was CR completion (adjusted OR 0.73, 95% CI 0.66, 0.81). Women completing CR experienced the greatest reduction in mortality (HR 0.36, 95% CI 0.28, 0.45) with a relative benefit greater than men (HR 0.51, 95% CI 0.46, 0.56).This is the first large cohort study to demonstrate that referral to and attendance at CR is associated with a significant mortality reduction in women, comparatively better than that in men.

    View details for PubMedID 25278001

  • Microvascular dysfunction in schizophrenia: a case-control study. NPJ schizophrenia Vetter, M. W., Martin, B. J., Fung, M. n., Pajevic, M. n., Anderson, T. J., Raedler, T. J. 2015; 1: 15023


    Schizophrenia is a mental illness associated with cardiovascular disease at a younger age than in the general population. Endothelial dysfunction has predictive value for future cardiovascular events; however, the impact of a diagnosis of schizophrenia on this marker is unknown.We tested the hypothesis that subjects with schizophrenia have impaired endothelial function.A total of 102 subjects (34.5±7.5 years) participated in this study. This sample consisted of 51 subjects with a diagnosis of schizophrenia and 51 healthy subjects, who were matched for age (P=0.442), sex (P>0.999), and smoking status (P=0.842). Peripheral artery microvascular and conduit vessel endothelial function was measured using hyperemic velocity time integral (VTI), pulse arterial tonometry (PAT), and flow-mediated dilation (FMD).Significantly lower values of VTI were noted in subjects with schizophrenia (104.9±33.0 vs. 129.1±33.8 cm, P<0.001), whereas FMD (P=0.933) and PAT (P=0.862) did not differ between the two groups. A multivariable-linear-regression analysis, built on data from univariate and partial correlations, showed that only schizophrenia, sex, lipid-lowering medications, antihypertensive medications, and low-density lipoprotein (LDL)-cholesterol were predictive of attenuated VTI, whereas age, ethnicity, family history of cardiovascular disease, smoking status, systolic blood pressure, waist circumference, HDL-cholesterol, triglycerides, C-reactive protein, and homeostatic model assessment-insulin resistance (HOMA-IR), antidiabetic medications, antidepressant medications, mood stabilizers, benzodiazepines, and anticholinergic medications did not predict VTI in this model (adjusted R (2)=0.248).Our findings suggest that a diagnosis of schizophrenia is associated with impaired microvascular function as indicated by lower values of VTI, irrespective of many other clinical characteristics. It might be an early indicator of cardiovascular risk in schizophrenia, and might help to identify high-risk individuals.

    View details for PubMedID 27336034

    View details for PubMedCentralID PMC4849449

  • Patients with diabetes in cardiac rehabilitation: attendance and exercise capacity. Medicine and science in sports and exercise Armstrong, M. J., Martin, B. J., Arena, R., Hauer, T. L., Austford, L. D., Stone, J. A., Aggarwal, S., Sigal, R. J. 2014; 46 (5): 845-50


    Diabetes increases mortality after myocardial infarction, but participation in cardiac rehabilitation (CR) reduces this risk. Our objectives were to examine whether attendance at CR and changes in cardiorespiratory fitness differed according to diabetic status and sex.Retrospective cohort study of patients referred for CR in Calgary between 1996 and 2010. Cardiorespiratory fitness in metabolic equivalents (METs) was estimated by maximal exercise testing at baseline, at the end of the 12-wk CR program, and 1-yr after CR.Among 7036 nondiabetic and 1546 diabetic patients who started, 84.9% of nondiabetic versus 79.5% of diabetic patients completed CR (P < 0.0001). The difference between diabetic and nondiabetic patients was greater in women (81.7% vs 72.1%, P < 0.0001) than that in men (86.0% vs 82.5%, P = 0.004). Patients without diabetes were more likely to return for the 1-yr assessment (53.7% vs 42.7%, P < 0.0001), and nondiabetic women were more likely than diabetic women to attend the 1-yr follow-up (44.3% vs 31.7%, P < 0.0001). Change in cardiorespiratory fitness from baseline to 12 wk was +1.0 METs in nondiabetic men, +0.9 METS in diabetic men, +0.9 METs in nondiabetic women, and +0.7 METs in diabetic women (within-group change; P = 0.0009). Changes in cardiorespiratory fitness at 1 yr compared with baseline were +0.9, +0.6, +0.9, and +0.5 METS, respectively (within-group change, P = 0.0001).Patients with diabetes, especially females, were less likely than patients without diabetes to complete CR and attend follow-up. Among patients who attended 1-yr follow-up, changes in cardiorespiratory fitness were not as well maintained in diabetic patients as in nondiabetic patients. Identifying barriers and targeting CR adherence interventions to patients with diabetes may help improve outcomes.

    View details for DOI 10.1249/MSS.0000000000000189

    View details for PubMedID 24126968

  • Supervision of exercise testing by nonphysicians: a scientific statement from the American Heart Association. Circulation Myers, J., Forman, D. E., Balady, G. J., Franklin, B. A., Nelson-Worel, J., Martin, B. J., Herbert, W. G., Guazzi, M., Arena, R. 2014; 130 (12): 1014-27

    View details for DOI 10.1161/CIR.0000000000000101

    View details for PubMedID 25223774

  • Coding of obesity in administrative hospital discharge abstract data: accuracy and impact for future research studies. BMC health services research Martin, B. J., Chen, G., Graham, M., Quan, H. 2014; 14: 70


    Obesity is a pervasive problem and a popular subject of academic assessment. The ability to take advantage of existing data, such as administrative databases, to study obesity is appealing. The objective of our study was to assess the validity of obesity coding in an administrative database and compare the association between obesity and outcomes in an administrative database versus registry.This study was conducted using a coronary catheterization registry and an administrative database (Discharge Abstract Database (DAD)). A Body Mass Index (BMI) ≥30 kg/m2 within the registry defined obesity. In the DAD obesity was defined by diagnosis codes E65-E68 (ICD-10). The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of an obesity diagnosis in the DAD was determined using obesity diagnosis in the registry as the referent. The association between obesity and outcomes was assessed.The study population of 17380 subjects was largely male (68.8%) with a mean BMI of 27.0 kg/m2. Obesity prevalence was lower in the DAD than registry (2.4% vs. 20.3%). A diagnosis of obesity in the DAD had a sensitivity 7.75%, specificity 98.98%, NPV 80.84% and PPV 65.94%. Obesity was associated with decreased risk of death or re-hospitalization, though non-significantly within the DAD. Obesity was significantly associated with an increased risk of cardiac procedure in both databases.Overall, obesity was poorly coded in the DAD. However, when coded, it was coded accurately. Administrative databases are not an optimal datasource for obesity prevalence and incidence surveillance but could be used to define obese cohorts for follow-up.

    View details for DOI 10.1186/1472-6963-14-70

    View details for PubMedID 24524687

    View details for PubMedCentralID PMC3996078

  • Characterizing types of readmission after acute coronary syndrome hospitalization: implications for quality reporting. Journal of the American Heart Association Southern, D. A., Ngo, J. n., Martin, B. J., Galbraith, P. D., Knudtson, M. L., Ghali, W. A., James, M. T., Wilton, S. B. 2014; 3 (5): e001046


    Thirty-day readmission rates have been tied to hospital reimbursement in the United States, but remain controversial as measures of healthcare quality. We profile the timing, main diagnoses, and survival outcomes of inpatient and emergency department readmissions after acute coronary syndrome (ACS), based on a large regional database.Patients enrolled in the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) registry with an ACS hospitalization between April 2008 and March 2010 (n=3411) were included. Primary outcomes were inpatient and emergency department-only readmissions, at 30 days and 1 year. Predictors of 30-day readmission were identified, and the association between 30-day readmission status and mortality was evaluated. A total of 1170 (34.3%) patients had ≥1 hospital readmission within 30 days, reaching 2106 (61.7%) within 1 year of ACS discharge. Of first readmissions, 45% were emergency department only and 53% were for cardiovascular or possibly related diagnoses. Renal disease and diabetes predicted all-cause readmissions at 30 days and 1 year, but there were no robust predictors of cardiovascular readmissions. Thirty-day inpatient, but not emergency department, readmissions were associated with increased mortality.Hospital readmissions within 30 days after discharge for ACS are common, and associated with increased mortality. However, our findings underline that readmissions are quite heterogeneous in nature, and that many readmissions are unrelated to index stay and thus not easily predicted with common clinical variables. All-cause 30-day readmission rates may be too simplistic, and perhaps even misleading, as a hospital performance metric.

    View details for PubMedID 25237046

    View details for PubMedCentralID PMC4323836

  • The effect of ischemia-reperfusion injury on measures of vascular function. Clinical hemorheology and microcirculation Alhejily, W. n., Aleksi, A. n., Martin, B. J., Anderson, T. J. 2014; 56 (3): 265–71


    Ischemia-reperfusion injury results in conduit vessel endothelial dysfunction as assessed by flow-mediated dilatation (FMD). The effect on the potentially more important microvascular circulation has not been well studied. The objective of our study was to assess the effect of ischemia-reperfusion injury on microvascular function including peripheral arterial tonometry (PAT) hyperemic index.45 healthy volunteers free of cardiovascular disease were recruited (mean age 35 ± 14 yrs, 29 men). Using ultrasound, the flow-mediated dilation (FMD) and hyperemic velocity (VTI) of the brachial artery were measured following a 5-minute forearm cuff occlusion. Simultaneously, the PAT hyperemic index was measured. Ischemia was then induced by a 15-minute upper arm occlusion and within 15 minutes of recovery the vascular measures were repeated.Ischemia caused a significant reduction in FMD (7.9 ± 4.0 to 4.7 ± 3.5, p = 0.0001). The hyperemic VTI, a measure of microvascular function, was unaffected following ischemia-reperfusion (92 ± 30 vs. 97 ± 37 cm, p = 0.236). Finally, PAT index was also unchanged by the intervention (2.07 ± 0.8 vs. 2.04 ± 0.7, p = 0.742).Ischemia-reperfusion caused conduit and not resistance vessel endothelial dysfunction. The PAT-index was unchanged suggesting that this measure is more closely aligned with resistance than conduit vessel function. This has implications for its use as a measure of vascular function in clinical research.

    View details for PubMedID 23719421

  • Delirium and cardiac surgery: progress - and more questions. Critical care (London, England) Martin, B. J., Arora, R. C. 2013; 17 (2): 140


    Post-operative delirium is a common and dangerous complication of cardiac surgery. Many risk factors for delirium have been identified, but its pathogenesis remains largely elusive. A study by Kazmierski and colleagues investigates a more recently considered risk factor for delirium: perturbations in the hypothalamic pituitary axis and depression. This and further work may help define novel prevention and treatment strategies for delirium.

    View details for DOI 10.1186/cc12610

    View details for PubMedID 23659704

    View details for PubMedCentralID PMC3672483

  • The relationship between peripheral arterial tonometry and classic measures of endothelial function. Vascular medicine (London, England) Martin, B. J., Gurtu, V., Chan, S., Anderson, T. J. 2013; 18 (1): 13-8


    The aim of this study was to assess the association between peripheral arterial tonometry (PAT) and two more traditional measures of endothelial function - flow-mediated dilation (FMD) and its hyperemic stimulus, hyperemic peak velocity time integral (VTI). We related three vascular function measures (natural log transformed PAT, FMD, and VTI) from 304 patients (mean age 48.9 ± 12.5 years), including 105 with coronary artery disease (CAD). Using linear regression, we studied the relationships between lnPAT, FMD, and VTI, and compared differences in these parameters in those with and without CAD. Although FMD and lnPAT both had a correlation with VTI (Pearson's r = 0.119, p = 0.039 and r = 0.167, p = 0.004, respectively), lnPAT had no correlation with FMD (r = -0.0471, p = 0.414). lnPAT was also lower in patients with CAD compared to controls (mean 0.51 ± 0.19 versus 0.65 ± 0.26, respectively, p < 0.0001). In multivariate analysis, VTI remained associated with lnPAT (standardized β = 0.1369, p = 0.04). Among this group of subjects with and without CAD, lnPAT was found to be unrelated to FMD but correlated with VTI. This would suggest that lnPAT is a measure of microvascular function. Although it is unrelated to FMD, lnPAT is decreased in patients with pre-existing cardiovascular disease. Further studies are required to determine if this can be used clinically as a tool for cardiac risk stratification and prediction of CAD.

    View details for DOI 10.1177/1358863X12468194

    View details for PubMedID 23263153

  • Cardiovascular fitness and mortality after contemporary cardiac rehabilitation. Mayo Clinic proceedings Martin, B. J., Arena, R. n., Haykowsky, M. n., Hauer, T. n., Austford, L. D., Knudtson, M. n., Aggarwal, S. n., Stone, J. A. 2013; 88 (5): 455–63


    To assess the association between cardiorespiratory fitness (CRF) and outcomes in a cardiac rehabilitation (CR) cohort.We conducted a retrospective study of 5641 patients (4282 men [76%] and 1359 women [24%]; mean ± SD age, 60.0±10.3 years) with coronary artery disease who participated in CR between July 1, 1996, and February 28, 2009. Based on peak metabolic equivalents (METs), patients were classified as low fitness (LFit) (<5 METs), moderate fitness (5-8 METs), or high fitness (>8 METs).Baseline fitness predicted long-term mortality: relative to the LFit group, patients with moderate fitness had an adjusted hazard ratio of 0.54 (95% CI, 0.42-0.69), and those with high fitness a hazard ratio of 0.32 (95% CI, 0.24-0.44). Improvement in CRF at 12 weeks was associated with decreased overall mortality, with a 13% point reduction with each MET increase (P<.001) and a 30% point reduction in those who started with LFit. At 1 year, each MET increase in CRF was associated with a 25% point reduction in overall mortality in the whole group (P<.001).In this study of contemporary CR patients, higher baseline fitness predicted lower mortality. The novel finding was that improvement in fitness during a CR program and improvements that persisted at 1 year were also associated with decreased mortality, most strongly in patients who start with LFit.

    View details for PubMedID 23639499

  • The relationship between anthropometric indexes of adiposity and vascular function in the FATE cohort. Obesity (Silver Spring, Md.) Martin, B. J., Verma, S. n., Charbonneau, F. n., Title, L. M., Lonn, E. M., Anderson, T. J. 2013; 21 (2): 266–73


    Numerous indexes of adiposity have been proposed and are currently in use in clinical practice and research. However, the correlation of these indexes with measures of vascular health remain poorly defined. This study investigated which measure of adiposity is most strongly associated with endothelial function.Data from the Firefighters And Their Endothelium (FATE) study was used. The relationships between three measures of vascular function: flow-mediated dilation (FMD), hyperemic velocity time integral (VTI), and hyperemic shear stress (HSS), and five measures of adiposity: BMI, waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and body adiposity index (BAI) were tested. Univariate comparisons were made, and subsequently models adjusted for traditional risk factors were constructed.A total of 1,462 male firefighters (mean age 49 ± 9) without cardiovascular disease comprised the study population. No measure of adiposity correlated with FMD; all five measures of adiposity were negatively correlated with VTI and HSS (P values <0.0001), with WHtR most strongly correlated with VTI, and WC most strongly correlated with HSS (both P < 0.05). In models including all five measures of obesity simultaneously, BMI, WC, and WHtR were all predictive of HSS (all P values <0.05), and BMI and WHR were both predictive of VTI (P values <0.05).Anthropometric measures of adiposity may help refine estimations of atherosclerotic burden. BMI was most consistently associated with endothelial dysfunction, but measures of adiposity that reflect distribution of mass were additive.

    View details for PubMedID 23532989

  • Cardiac rehabilitation attendance and outcomes in coronary artery disease patients. Circulation Martin, B. J., Hauer, T., Arena, R., Austford, L. D., Galbraith, P. D., Lewin, A. M., Knudtson, M. L., Ghali, W. A., Stone, J. A., Aggarwal, S. G. 2012; 126 (6): 677-87


    Cardiac rehabilitation (CR) is an efficacious yet underused treatment for patients with coronary artery disease. The objective of this study was to determine the association between CR completion and mortality and resource use.We conducted a prospective cohort study of 5886 subjects (20.8% female; mean age, 60.6 years) who had undergone angiography and were referred for CR in Calgary, AB, Canada, between 1996 and 2009. Outcomes of interest included freedom from emergency room visits, hospitalization, and survival in CR completers versus noncompleters, adjusted for clinical covariates, treatment strategy, and coronary anatomy. Hazard ratios for events for CR completers versus noncompleters were also constructed. A propensity model was used to match completers to noncompleters on baseline characteristics, and each outcome was compared between propensity-matched groups. Of the subjects referred for CR, 2900 (49.3%) completed the program, and an additional 554 subjects started but did not complete CR. CR completion was associated with a lower risk of death, with an adjusted hazard ratio of 0.59 (95% confidence interval, 0.49-0.70). CR completion was also associated with a decreased risk of all-cause hospitalization (adjusted hazard ratio, 0.77; 95% confidence interval, 0.71-0.84) and cardiac hospitalization (adjusted hazard ratio, 0.68; 95% confidence interval, 0.55-0.83) but not with emergency room visits. Propensity-matched analysis demonstrated a persistent association between CR completion and reduced mortality.Among those coronary artery disease patients referred, CR completion is associated with improved survival and decreased hospitalization. There is a need to explore reasons for nonattendance and to test interventions to improve attendance after referral.

    View details for DOI 10.1161/CIRCULATIONAHA.111.066738

    View details for PubMedID 22777176

  • Delirium: a cause for concern beyond the immediate postoperative period. The Annals of thoracic surgery Martin, B. J., Buth, K. J., Arora, R. C., Baskett, R. J. 2012; 93 (4): 1114–20


    Delirium is a common neurologic complication after cardiac surgery, and may be associated with increased morbidity and mortality. Research has focused on potential causes of delirium, with little attention to its sequelae.Perioperative data were collected prospectively on all isolated cases of coronary artery bypass grafting (CABG) performed from 1995 to 2006 at a single center. The definition of delirium used in the study was that of the Society of Thoracic Surgeons. Characteristics of patients who became delirious postoperatively were compared with those of patients who did not. The outcomes of interest were long-term all-cause mortality, hospital admission for stroke, and in-hospital mortality, examined in all three cases through multivariate analysis.Of 8,474 patients who underwent CABG within the defined period, 496 (5.8%) developed postoperative delirium and 229 (2.7%) died while in the hospital. At baseline, patients who developed delirium were more likely to be older and to have a greater burden of comorbid illness. Delirium was an independent predictor of perioperative stroke (odds ratio [OR]; 1.96; 95% confidence interval [CI], 1.22 to 3.16), but was not associated with in-hospital mortality (OR, 0.81; 95%CI, 0.49 to 1.34). Delirious patients had a median postoperative hospital stay of 12 days (interquartile range [IQR], 8 to 21 days) versus 6 days (IQR, 5 to 8 days) for those who were nondelirious. Delirium was identified as an independent predictor of all-cause mortality (hazard ratio [HR], 1.52; 95%CI, 1.29 to 1.78) and hospitalization for stroke (HR, 1.54; 95%CI, 1.10 to 2.17).There was an association between delirium and adverse outcomes after CABG that persisted beyond the immediate perioperative period. Patients with delirium after CABG appear to have an increased long-term risk of death and stroke. The advancing age and rising rates of delirium in the CABG population make it necessary to address the prevention and management of delirium in this population.

    View details for PubMedID 22200370

  • Obesity negatively impacts aerobic capacity improvements both acutely and 1-year following cardiac rehabilitation. Obesity (Silver Spring, Md.) Martin, B. J., Aggarwal, S. G., Stone, J. A., Hauer, T. n., Austford, L. D., Knudtson, M. n., Arena, R. n. 2012; 20 (12): 2377–83


    Cardiac rehabilitation (CR) produces a host of health benefits related to modifiable cardiovascular risk factors. The purpose of the present investigation was to determine the influence of body weight, assessed through BMI, on acute and long-term improvements in aerobic capacity following completion of CR. Three thousand nine hundred and ninety seven subjects with coronary artery disease (CAD) participated in a 12-week multidisciplinary CR program. Subjects underwent an exercise test to determine peak estimated metabolic equivalents (eMETs) and BMI assessment at baseline, immediately following CR completion and at 1-year follow-up. Normal weight subjects at 1-year follow-up demonstrated the greatest improvement in aerobic fitness and best retention of those gains (gain in peak METs: 0.95 ± 1.1, P < 0.001). Although the improvement was significant (P < 0.001), subjects who were initially classified as obese had the lowest aerobic capacity and poorest retention in CR fitness gains at 1-year follow-up (gain in peak eMETs: 0.69 ± 1.2). Subjects initially classified as overweight by BMI had a peak eMET improvement that was also significantly better (P < 0.05) than obese subjects at 1-year follow-up (gain in peak eMETs: 0.82 ± 1.1). Significant fitness gains, one of the primary beneficial outcomes of CR, can be obtained by all subjects irrespective of BMI classification. However, obese patients have poorer baseline fitness and are more likely to "give back" fitness gains in the long term. Obese CAD patients may therefore benefit from additional interventions to enhance the positive adaptations facilitated by CR.

    View details for PubMedID 22627915

  • The optimal measure of microvascular function with velocity time integral for cardiovascular risk prediction. Vascular medicine (London, England) Lee, V. n., Martin, B. J., Fung, M. n., Anderson, T. J. 2012; 17 (5): 287–93


    Recent evidence suggests that microvascular function may be important in cardiovascular risk prediction. One measure of microvascular function is hyperaemic velocity time integral (VTI). We assessed whether the VTI of more than one beat of reactive hyperaemia would provide a stronger correlate to traditional cardiovascular risk factors using a subset of subjects from the Firefighters and Their Endothelium (FATE) study. Vascular function was assessed by measurement of hyperaemic blood velocity with high-resolution ultrasound of the brachial artery. We evaluated three measures in the current analysis: the VTI of the first beat, average VTI of 10 beats, and maximum VTI of 10 beats post-cuff release. A total of 399 male subjects (45.5 ± 10 years) were included in this analysis. Univariate correlations between the three end points and cardiovascular risk factors were calculated, and multivariable regression models constructed. Intra-observer variability was approximately equal for all VTI end points (coefficient of variation: first = 1.6%, average = 1.4%, maximum = 1.4%). Univariate correlations between VTI and cardiovascular risk factors were similar across all three end points. In multivariable analyses, there were no differences in the relationships between cardiovascular risk factors and the various VTI end points (R(2) from 0.090 to 0.102). Age, systolic blood pressure, and BMI were predictors of the three VTI end points (p < 0.05). In conclusion, the first beat of reactive hyperaemia remains the suitable measure of microvascular function.

    View details for PubMedID 22815000

  • Long-term retention of aerobic fitness improvements following participation in cardiac rehabilitation. International journal of cardiology Stone, J. A., Arena, R., Hauer, T., Martin, B. J., Austford, L. D., Aggarwal, S. 2011; 150 (3): 355-6

    View details for DOI 10.1016/j.ijcard.2011.05.041

    View details for PubMedID 21652095

  • Outcomes associated with bilateral internal thoracic artery grafting: the importance of age. The Annals of thoracic surgery Kieser, T. M., Lewin, A. M., Graham, M. M., Martin, B. J., Galbraith, P. D., Rabi, D. M., Norris, C. M., Faris, P. D., Knudtson, M. L., Ghali, W. A. 2011; 92 (4): 1269–75; discussion 1275–76


    Although bilateral internal thoracic artery (BITA) grafting in coronary artery bypass grafting (CABG) is associated with low morbidity and good long-term results, controversy exists about the age after which BITA grafting is no longer beneficial. We sought to determine if such an age cutoff point exists.The study cohort consisted of 5,601 consecutive patients from a cardiac surgery registry who underwent isolated CABG (1,038 [19%] BITA grafts, 4,029 [72%] single internal thoracic artery [SITA] grafts, 534 [10%] vein-only grafts) between 1995 and 2008. A Cox model was used to compare survival by use of bilateral, single, or no internal thoracic artery (ITA) grafts, adjusting for baseline clinical and demographic characteristics.Mean follow-up was 7.1 years. Patients undergoing BITA grafting had the lowest 1-year mortality (2.4% versus 4.3% SITA grafting and 8.2% vein-only grafting; p < 0.0001). Relative to SITA grafting, a crude survival benefit of 54% existed for BITA grafting (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.37 to 0.57; p < 0.0001) with worse survival for vein-only grafts (HR, 1.16; 95% CI, 0.99 to 1.37; p = 0.07). After adjustment, the benefit of BITA grafting was no longer statistically significant (HR, 0.87; 95% CI, 0.69 to 1.08; p = 0.2). However age may be an effect modifier: a spline analysis plotting HR (BITA grafting versus SITA grafting) against age suggested a potential survival advantage associated with BITA grafting in patients younger than 69.9 years.Bilateral internal thoracic artery grafting is a reasonable revascularization strategy in suitable patients up to age 70 years. As benefits of arterial grafting become more obvious over time, a longer period of follow-up will be needed to confirm the advantage of a BITA grafting strategy. In the meantime the BITA grafting advantage for patients older than 70 years is not clear.

    View details for PubMedID 21958771

  • Systematic review and meta-analysis: anti-tumor necrosis factor α therapy and cardiovascular events in rheumatoid arthritis. Arthritis care & research Barnabe, C. n., Martin, B. J., Ghali, W. A. 2011; 63 (4): 522–29


    Control of rheumatoid arthritis (RA) may reduce the risk of cardiovascular events. We sought to systematically assess the association between anti-tumor necrosis factor α (anti-TNFα) therapy in RA and cardiovascular event rates.Observational cohorts and randomized controlled trials (RCTs) reporting on cardiovascular events (all events, myocardial infarction [MI], congestive heart failure, and cerebrovascular accident [CVA]) in RA patients treated with anti-TNFα therapy compared to traditional disease-modifying antirheumatic drugs were identified from a search of PubMed (1950 to November 2009), EMBase (1980 to November 2009), and conference abstracts. Relative risks (RRs) or hazard ratios and 95% confidence intervals (95% CIs) were extracted. If the incidence was reported, additional data were extracted to calculate an incidence density ratio and its variance.The systematic review and meta-analysis include 16 and 11 publications, respectively. In cohort studies, anti-TNFα therapy was associated with a reduced risk for all cardiovascular events (pooled adjusted RR 0.46; 95% CI 0.28, 0.77), MI (pooled adjusted RR 0.81; 95% CI 0.68, 0.96), and CVA (pooled adjusted RR 0.69; 95% CI 0.53, 0.89). Meta-analysis of RCTs also produced a point estimate indicating lower risk of cardiovascular events, but this was not statistically significant (pooled RR 0.85; 95% CI 0.28, 2.59).Anti-TNFα therapy is associated with a reduced risk of all cardiovascular events, MI, and CVA in observational cohorts. There was heterogeneity among cohort studies and possible publication bias. The point estimate of the effect from RCTs is underpowered with wide 95% CIs, and cardiovascular events were secondary outcomes, but RCTs also demonstrated a trend toward decreased risk.

    View details for PubMedID 20957658

  • Delirium as a predictor of sepsis in post-coronary artery bypass grafting patients: a retrospective cohort study. Critical care (London, England) Martin, B. J., Buth, K. J., Arora, R. C., Baskett, R. J. 2010; 14 (5): R171


    Delirium is the most common neurological complication following cardiac surgery. Much research has focused on potential causes of delirium; however, the sequelae of delirium have not been well investigated. The objective of this study was to investigate the relationship between delirium and sepsis post coronary artery bypass grafting (CABG) and to determine if delirium is a predictor of sepsis.Peri-operative data were collected prospectively on all patients. Subjects were identified as having agitated delirium if they experienced a short-term mental disturbance marked by confusion, illusions and cerebral excitement. Patient characteristics were compared between those who became delirious and those who did not. The primary outcome of interest was post-operative sepsis. The association of delirium with sepsis was assessed by logistic regression, adjusting for differences in age, acuity, and co-morbidities.Among 14,301 patients, 981 became delirious and 227 developed sepsis post-operatively. Rates of delirium increased over the years of the study from 4.8 to 8.0% (P = 0.0003). A total of 70 patients of the 227 with sepsis, were delirious. In 30.8% of patients delirium preceded the development of overt sepsis by at least 48 hours. Multivariate analysis identified several factors associated with sepsis, (receiver operating characteristic (ROC) 79.3%): delirium (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.6 to 3.4), emergent surgery (OR 3.3, CI 2.2 to 5.1), age (OR 1.2, CI 1.0 to 1.3), pre-operative length of stay (LOS) more than seven days (OR 1.6, CI 1.1 to 2.3), pre-operative renal insufficiency (OR 1.9, CI 1.2 to 2.9) and complex coronary disease (OR 3.1, CI 1.8 to 5.3).These data demonstrate an association between delirium and post-operative sepsis in the CABG population. Delirium emerged as an independent predictor of sepsis, along with traditional risk factors including age, pre-operative renal failure and peripheral vascular disease. Given the advancing age and increasing rates of delirium in the CABG population, the prevention and management of delirium need to be addressed.

    View details for DOI 10.1186/cc9273

    View details for PubMedID 20875113

    View details for PubMedCentralID PMC3219273

  • Frail patients are at increased risk for mortality and prolonged institutional care after cardiac surgery. Circulation Lee, D. H., Buth, K. J., Martin, B. J., Yip, A. M., Hirsch, G. M. 2010; 121 (8): 973-8


    Frailty is an emerging concept in medicine yet to be explored as a risk factor in cardiac surgery. Where elderly patients are increasingly referred for cardiac surgery, the prevalence of a frail group among these is also on the rise. We assessed frailty as a risk factor for adverse outcomes after cardiac surgery.Functional measures of frailty and clinical data were collected prospectively for all cardiac surgery patients at a single center. Frailty was defined as any impairment in activities of daily living (Katz index), ambulation, or a documented history of dementia. Of 3826 patients, 157 (4.1%) were frail. Frail patients were older, were more likely to be female, and had risk factors for adverse surgical outcomes. By logistic regression, frailty was an independent predictor of in-hospital mortality (odds ratio 1.8, 95% CI 1.1 to 3.0), as well as institutional discharge (odds ratio 6.3, 95% CI 4.2 to 9.4). Frailty was an independent predictor of reduced midterm survival (hazard ratio 1.5, 95% CI 1.1 to 2.2).Frailty is a risk for postoperative complications and an independent predictor of in-hospital mortality, institutional discharge, and reduced midterm survival. Frailty screening improves risk assessment in cardiac surgery patients and may identify a subgroup of patients who may benefit from innovative processes of care.

    View details for DOI 10.1161/CIRCULATIONAHA.108.841437

    View details for PubMedID 20159833

  • Risk prediction in cardiovascular disease: the prognostic significance of endothelial dysfunction. The Canadian journal of cardiology Martin, B. J., Anderson, T. J. 2009; 25 Suppl A: 15A-20A


    The role of new and emerging biomarkers in risk prediction has become a topic of significant interest and controversy in recent times. Currently, available models for risk prediction are reasonably good yet still misclassify a not insignificant portion of the population. The sheer number of new potential risk markers is daunting, and it is difficult to assess the importance of each one over and above the traditional risk factors. Endothelial function is one potential biomarker of risk that has been extensively studied. However, while it has demonstrated some utility in risk prediction, its use in daily clinical practice is yet to be clearly defined. The present review assesses the prognostic significance of measures of endothelial function.

    View details for PubMedID 19521569

    View details for PubMedCentralID PMC2787006

  • Long-term results of heart operations performed by surgeons-in-training. Circulation Stoica, S. C., Kalavrouziotis, D., Martin, B. J., Buth, K. J., Hirsch, G. M., Sullivan, J. A., Baskett, R. J. 2008; 118 (14 Suppl): S1-6


    We investigated the association between trainees performing supervised operations and late outcomes of patients undergoing cardiac surgery.Data were prospectively collected on patients who underwent coronary artery bypass graft surgery, aortic valve replacement, or a combination of these between 1998 and 2005 at the Maritime Heart Center, Halifax, Canada. In-hospital mortality and a composite outcome of in-hospital mortality, stroke, bleeding, intra-aortic balloon pump insertion, renal failure, and sternal infection was compared between teaching (n=1054) and nonteaching cases (n=5877). Late survival and cardiovascular hospital readmissions were also examined. To adjust for baseline risk disparities, we used logistic regression for dichotomous in-hospital outcomes and Cox proportional hazards regression for survival data. Resident cases were significantly more likely to have high-risk features such as depressed ventricular function, redo operation, and urgent or emergent procedure. Resident as primary operator was not independently associated with in-hospital mortality (OR, 1.09; 95% CI, 0.75 to 1.58; P=0.66) or with the composite outcome (OR, 1.01; 95%, CI 0.82 to 1.26; P=0.90). The Kaplan-Meier event-free survival of the 2 groups was equivalent at 1, 3, and 5 years (log-rank P=0.06). By Cox regression, resident cases were not associated with late death or cardiovascular rehospitalization (hazard ratio, 1.05; 95% CI, 0.94 to 1.17; P=0.42).Cases performed by senior-level cardiac surgery residents were more likely to have greater acuity and complexity than staff surgeon-performed cases. However, clinical outcomes were similar in the short- and long-term. Allowing residents to perform cardiac surgery is not associated with adverse patient outcomes.

    View details for DOI 10.1161/CIRCULATIONAHA.107.756379

    View details for PubMedID 18824740

  • The sustainability of exercise capacity changes in home versus center-based cardiac rehabilitation. Journal of cardiopulmonary rehabilitation and prevention Ramadi, A. n., Haennel, R. G., Stone, J. A., Arena, R. n., Threlfall, T. G., Hitt, E. n., Aggarwal, S. G., Haykowsky, M. n., Martin, B. J. ; 35 (1): 21–28


    Although participation in either center- or home-based cardiac rehabilitation (CR) can improve exercise capacity, the sustainability of this improvement following completion of the CR program is challenging. The purpose of this study was to compare the immediate and 1-year effectiveness of center- versus home-based CR on exercise capacity in cardiac patients who were given the choice of participating in a center-based or home-based CR program.This was a retrospective study, which relied on the database from a large multidisciplinary CR program. A sample of 3488 cardiac patients participated either in center-based (n = 2803) or home-based (n = 685) CR. Participants underwent exercise testing at baseline, after 12 weeks of CR and again 1 year after completion of the CR programs.Following CR, exercise capacity (ie, peak metabolic equivalents [METs]) increased significantly in both groups (P < .05). From post-CR to the 1-year followup, exercise capacity remained unchanged in home-based CR participants (P = .183), whereas the center-based CR group demonstrated a decline in exercise capacity (P < .05).Although at the 1-year followup exercise capacity decreased in the center-based group, the observed decline did not seem to be clinically significant. The present findings indicate that when the patients were given a choice as to the delivery model (center- vs home-based) used for their CR program, they were relatively successful in retaining the improvement in exercise capacity 1 year post-CR irrespective of the exact location for their exercise training.

    View details for PubMedID 25313452

  • The independent effect of traditional cardiac rehabilitation and the LEARN program on weight loss: a comparative analysis. Journal of cardiopulmonary rehabilitation and prevention Aggarwal, S. n., Arena, R. n., Cuda, L. n., Hauer, T. n., Martin, B. J., Austford, L. n., Stone, J. A. ; 32 (1): 48–52


    Despite its numerous other benefits, cardiac rehabilitation (CR) has not consistently proven to be an effective, although much needed, intervention for weight loss in the cardiovascular disease (CVD) population. Comparatively, the LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) program appears to be an effective intervention for weight loss. The purpose of the present investigation was to compare changes in body weight in a CVD cohort consecutively participating in traditional CR and the LEARN program.Forty-four patients diagnosed with CVD (22 men/22 women) participated in a 12-week multidisciplinary CR program. All patients successfully completed the LEARN program following CR. Body mass index (BMI) and body weight were recorded immediately prior to and following both CR and LEARN.The peak metabolic equivalents were significantly higher following CR (7.3 ± 1.6 vs 8.5 ± 1.6, P < .001), while body weight (203.5 ± 32.6 vs 201.8 ± 32.5 lbs, P > .10) and BMI (32.1 ± 4.0 vs 31.8 ± 3.9 kg/m, P > .05) were unchanged. All subjects then successfully completed the LEARN program, participating in an average of 10 sessions. There was a significant reduction in body weight (203.3 ± 30.7 vs 190.1 ± 30.4 lbs, P < .001) and BMI (32.0 ± 3.9 vs 29.5 ± 3.8 kg/m, P < .001) following the LEARN program.Our results support the independent value of the LEARN program in eliciting weight loss for CR patients. Clinicians delivering CR services should consider integrating a focused weight loss program, such as LEARN, into their usual CR programs.

    View details for PubMedID 22207088