Dr. William Hiesinger is an assistant professor in the Department of Cardiothoracic Surgery at Stanford University. There, he serves as the Surgical Director of the Mechanical Circulatory Support (MCS) Program, where he leads and directs the surgical implantation of ventricular assist devices (VADs) in patients with end-stage heart failure. In addition, he runs a basic science laboratory investigating bioengineered devices and the application of angiogenic cytokine therapy and tissue engineering for the treatment of ischemic heart failure. Originally from Philadelphia, PA, Dr. Hiesinger was an undergraduate at Dartmouth College, where he received his B.A. in Psychological and Brain Sciences. He went on to receive his medical degree from the University of Pennsylvania School of Medicine and remained on at the Hospital of the University of Pennsylvania for both his general surgery and cardiothoracic surgery trainings. He has received research fundings from the National Institutes of Health (NIH) and the Thoracic Surgery Foundation (TSF).
- Heart Transplantation
- Mechanical Circulatory Support
- Mitral Valve Repair
- Aortic Aneurysm
- Minimally Invasive Cardiac Surgery
- Cardiac Surgery
- Complex Valve Repair Surgery
- Aortic Valve Repair
- Valve Replacement Surgery
- Surgical Treatments of Cardiomyopathy
- Heart Failure
- Ventricular Assist Device
- Heart-Lung Transplantation
- Coronary Artery Bypass
- Coronary Artery Bypass, Off-pump
- Reoperative Cardiac Surgery
- Clinical Device Trials
- Lung Transplantation
- Thoracic and Cardiovascular Surgery
- Thoracic Surgery
Honors & Awards
Keith Reemtsma Surgical Resident of the Year Award, Department of Surgery, University of Pennsylvania (2014)
Jonathan E. Rhoads Research Award, Department of Surgery, University of Pennsylvania (2011)
Vivien Thomas Young Investigator Award Finalist, American Heart Association (2010)
Alpha Omega Alpha (AOA) Honor Medical Society, University of Pennsylvania (2007)
Clyde F. Baker Research Prize, Department of Surgery, University of Pennsylvania (2007)
First Place, Medical Student Research Day Basic Science Research, University of Pennsylvania (2007)
I. S. Ravdin Prize, Department of Surgery, University of Pennsylvania (2007)
Boards, Advisory Committees, Professional Organizations
Member, Society of Thoracic Surgeons Workforce on Surgical Treatment of End-Stage Cardiopulmonary Disease, National Committee (2017 - Present)
Reviewer, Circulation (2017 - Present)
Member, American Heart Association, Council for Cardiothoracic & Vascular Surgery (2017 - Present)
Member, Society of Thoracic Surgeons (2017 - Present)
Fellowship:Hospital of the University of Pennsylvania Dept of CTS (2016) PA
Residency:Hospital of the University of Pennsylvania General Surgery Residency (2014) PA
Medical Education:Perelman School of Medicine University of Pennsylvania (2007) PA
Board Certification: Thoracic Surgery, American Board of Thoracic Surgery (2017)
Board Certification: General Surgery, American Board of Surgery (2015)
M.D., University of Pennsylvania (2008)
Postdoctoral Faculty Sponsor
Graduate and Fellowship Programs
The Incremental Value of Right Ventricular Size and Strain in the Risk Assessment of Right Heart Failure Post - Left Ventricular Assist Device Implantation.
Journal of cardiac failure
2018; 24 (12): 823–32
BACKGROUND: Right heart failure (RHF) after left ventricular assist device (LVAD) implantation is associated with high morbidity and mortality. Existing risk scores include semiquantitative evaluation of right ventricular (RV) dysfunction. This study aimed to determine whether quantitative evaluation of both RV size and function improve risk stratification for RHF after LVAD implantation beyond validated scores.METHODS AND RESULTS: From 2009 to 2015, 158 patients who underwent implantation of continuous-flow devices who had complete echocardiographic and hemodynamic data were included. Quantitative RV parameters included RV end-diastolic (RVEDAI) and end-systolic area index, RV free-wall longitudinal strain (RVLS), fractional area change, tricuspid annular plane systolic excursion, and right atrial area and pressure. Independent correlates of early RHF (<30 days) were determined with the use of logistic regression analysis. Mean age was 56 ± 13 years, with 79% male; 49% had INTERMACS profiles ≤2. RHF occurred in 60 patients (38%), with 20 (13%) requiring right ventricular assist device. On multivariate analysis, INTERMACS profiles (adjusted odds ratio 2.38 [95% confidence interval [CI] 1.47-3.85]), RVEDAI (1.61 [1.08-2.32]), and RVLS (2.72 [1.65-4.51]) were independent correlates of RHF (all P < .05). Both RVLS and RVEDAI were incremental to validated risk scores (including the EUROMACS score) for early RHF after LVAD (all P < .01).CONCLUSIONS: RV end-diastolic and strain are complementary prognostic markers of RHF after LVAD implantation.
View details for PubMedID 30539717
Planned Concomitant Left and Right Ventricular Assist Device Insertion to Avoid Long-term Biventricular Mechanical Support: Bridge to Right Ventricular Recovery.
The heart surgery forum
2018; 21 (5): E412–E414
INTRODUCTION: The planned use of a temporary right ventricular assist device (RVAD) at the time of left ventricular assist device (LVAD) implantation may prevent the need for a permanent biventricular assist device (BiVAD). Herein we describe our RVAD weaning protocol that was effectively employed in 4 patients to prevent the need for permanent BiVAD.METHODS: Four patients in refractory cardiogenic shock underwent planned RVAD insertion during LVAD implantation due to severely depressed right ventricular function with dilation preoperatively. A standardized RVAD weaning protocol was employed in these 4 patients in preparation for decannulation.RESULTS: Temporary RVADs were successfully placed in all 4 patients at the time of LVAD implantation. All patients survived to RVAD decannulation and discharge and were alive at the time of most recent follow-up (range, 528-742 days post-RVAD decannulation).CONCLUSION: Planned implantation of a temporary RVAD in high risk patients may avoid the need for biventricular mechanical support in the future.
View details for PubMedID 30311895
Right ventricular load adaptability metrics in patients undergoing left ventricular assist device implantation.
The Journal of thoracic and cardiovascular surgery
OBJECTIVE: Several right load adaptability metrics have been proposed as predictors of right heart failure (RHF) following left ventricular assist device implantation. This study sought to validate and compare the prognostic value of these indices.METHODS: This retrospective study included 194 patients undergoing continuous-flow left ventricular assist device implantation. The primary end point was unplanned right atrial assist device (RVAD) need within 30days after left ventricular assist device implantation; the secondary end points included clinical RHF syndrome without RVAD need and the composite of RHF or RVAD need. Load adaptability indices or interventricular ratios were divided into surrogates of ventriculoarterial coupling (RV area change:end-systolic area), indices reflecting adaptation proportionality (Dandel's index=tricuspid regurgitation velocity-time integral normalized for average RV radius in diastole or systole), and simple ratios (eg, pulse pressure:right atrial pressure or right arterial pressure:pulmonary arterial wedge pressure).RESULTS: Mean age was 55±13years with 77% of men. RHF occurred in 75 patients with 30 patients requiring RVAD implantation. Among right heart metrics, right arterial pressure (normalized odd ratio, 1.62; 95% confidence interval, 1.15-2.38), right arterial pressure:pulmonary arterial wedge pressure (normalized odds ratio, 1.59; 95% confidence interval, 1.08-2.32) and pulse pressure:right arterial pressure<2.0 (normalized odds ratio, 2.56; 95% confidence interval, 1.16-5.56) were associated with RVAD need (all P values<.02). These 3 metrics significantly added incremental prognostic value to the Interagency Registry for Mechanically Assisted Circulatory Support classification score in a similar range, whereas only RAP was incremental to the Michigan score. Correlates of RHF not requiring RVAD included RV end-systolic area index and the Dandel indices, which provided similar incremental value to the Interagency Registry for Mechanically Assisted Circulatory Support, Michigan, and European Registry for Patients with Mechanical Circulatory Support scores.CONCLUSIONS: Although associated with outcome, right load adaptability indices do not appear to provide strong incremental value when compared with simple metrics.
View details for PubMedID 30482529
Transplant Outcomes in Destination Therapy vs Bridge to Transplant LVAD Patients
ELSEVIER SCIENCE INC. 2018: S434–S435
View details for Web of Science ID 000430727300515
- RIGHT VENTRICULAR LOAD ADAPTABILITY IN PATIENTS UNDERGOING CONTINUOUS-FLOW LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION ELSEVIER SCIENCE INC. 2018: 1624
Prolonged veno-arterial extracorporeal life support for cardiac failure.
The International journal of artificial organs
In intractable cardiogenic shock, extracorporeal life support frequently is the last treatment option. Outcomes of prolonged veno-arterial extracorporeal life support for cardiac failure are poorly defined.We retrospectively analyzed 10 patients (4 females, age = 36 ± 16 years) who underwent prolonged extracorporeal life support (≥7 days) from December 2015 to March 2017 for cardiogenic shock. The primary endpoint was survival to hospital discharge.Etiologies included ischemic cardiomyopathy with non ST-segment elevation myocardial infarction (n = 1), dilated (n = 3), hypertrophic (n = 1), postpartum cardiomyopathy (n = 1), and others (n = 4). Heart failure was left or biventricular in 80.0% (left ventricular ejection fraction = 15.6 ± 5.5%). Among the 10 patients, 80.0% underwent femoral and 20.0% central cannulation, 40.0% required changes in the cannulation strategy, and 80.0% underwent left ventricular venting. No technical malfunctions occurred, but 50.0% required circuit exchanges for thrombus formation. 80.0% suffered from infections. 60.0% could be decannulated after 717 ± 830 (168-2301) h of support, and survival to hospital discharge was 40.0%. Longest follow-up available is 160 ± 175 (12-409) days after discharge, with 30.0% alive and in satisfying functional condition.Prolonged veno-arterial extracorporeal life support for cardiac failure is feasible with low technical complication rates. Survival rates are acceptable, yet inferior to short-term support. We observed a shift from initial shock-related complications to infections during prolonged support. Since recovery and thus weaning is rather unlikely after a prolonged need for extracorporeal life support, this form of support should be limited to centers offering the full spectrum of interdisciplinary cardiac care including ventricular assist device implantation and transplantation.
View details for PubMedID 29896993
Injectable Bioengineered Hydrogel Therapy in the Treatment of Ischemic Cardiomyopathy.
Current treatment options in cardiovascular medicine
2017; 19 (4): 30-?
Over the past two decades, the field of cardiovascular medicine has seen the rapid development of multiple different modalities for the treatment of ischemic myocardial disease. Most research efforts have focused on strategies aimed at coronary revascularization, with significant technological advances made in percutaneous coronary interventions as well as coronary artery bypass graft surgery. However, recent research efforts have shifted towards ways to address the downstream effects of myocardial infarction on both cellular and molecular levels. To this end, the broad application of injectable hydrogel therapy after myocardial infarction has stimulated tremendous interest. In this article, we will review what hydrogels are, how they can be bioengineered in unique ways to optimize therapeutic potential, and how they can be used as part of a treatment strategy after myocardial infarction.
View details for DOI 10.1007/s11936-017-0530-x
View details for PubMedID 28337717
Operative technique and pitfalls in donor heart procurement.
Asian cardiovascular & thoracic annals
2017; 25 (1): 80-82
We describe a simple and reproducible donor heart procurement technique in sequential steps. A detailed understanding of procurement and organ preservation techniques should be an essential part of a heart transplant training program.
View details for DOI 10.1177/0218492316678716
View details for PubMedID 28074702
An innovative biologic system for photon-powered myocardium in the ischemic heart.
2017; 3 (6): e1603078
Coronary artery disease is one of the most common causes of death and disability, afflicting more than 15 million Americans. Although pharmacological advances and revascularization techniques have decreased mortality, many survivors will eventually succumb to heart failure secondary to the residual microvascular perfusion deficit that remains after revascularization. We present a novel system that rescues the myocardium from acute ischemia, using photosynthesis through intramyocardial delivery of the cyanobacterium Synechococcus elongatus. By using light rather than blood flow as a source of energy, photosynthetic therapy increases tissue oxygenation, maintains myocardial metabolism, and yields durable improvements in cardiac function during and after induction of ischemia. By circumventing blood flow entirely to provide tissue with oxygen and nutrients, this system has the potential to create a paradigm shift in the way ischemic heart disease is treated.
View details for PubMedID 28630913
Biochemically engineered stromal cell-derived factor 1-alpha analog increases perfusion in the ischemic hind limb.
Journal of vascular surgery
2016; 64 (4): 1093-1099
Despite promising therapeutic innovation over the last decade, peripheral arterial disease remains a prevalent morbidity, as many patients are still challenged with peripheral ischemia. We hypothesized that delivery of engineered stromal cell-derived factor 1-alpha (ESA) in an ischemic hind limb will yield significant improvement in perfusion.Male rats underwent right femoral artery ligation, and animals were randomized to receive a 100 μL injection of saline (n = 9) or 6 μg/kg dosage of equal volume of ESA (n = 12) into the ipsilateral quadriceps muscle. Both groups of animals were also given an intraperitoneal injection of 40 μg/kg of granulocyte macrophage colony-stimulating factor (GMCSF). Perfusion was quantified using a laser Doppler imaging device preoperatively, and on postoperative days 0, 7, and 14. Immunohistochemistry was performed to quantify angiogenesis on day 14, and an mRNA profile was evaluated for angiogenic and inflammatory markers.Compared with the saline/GMCSF group at day 14, the ESA/GMCSF-injected animals had greater reperfusion ratios (Saline/GMCSF, 0.600 ± 0.140 vs ESA/GMCSF, 0.900 ± 0.181; group effect P = .006; time effect P < .0001; group×time effect P < .0001), elevated capillary density (10×; Saline/GMCSF, 6.40 ± 2.01 vs ESA/GMCSF, 18.55 ± 5.30; P < .01), and increased mRNA levels of vascular endothelial growth factor-A (Saline/GMCSF [n = 6], 0.298 ± 0.205 vs ESA/GMCSF [n = 8], 0.456 ± 0.139; P = .03).Delivery of ESA significantly improves perfusion in a rat model of peripheral arterial disease via improved neovasculogenesis, a finding which may prove beneficial in the treatment strategy for this debilitating disease.
View details for DOI 10.1016/j.jvs.2015.06.140
View details for PubMedID 26372192
Cell transplantation in heart failure: where do we stand in 2016?
EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY
2016; 50 (3): 396–99
View details for PubMedID 27587719
- Hybrid coronary revascularization: Ready for prime time, but who should star? JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 2016; 151 (4): 1090–91
- Building a better bridge: Remodeling, recovery, and a better understanding of the biologic foundation of mechanical circulatory support JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 2015; 150 (5): 1342–43
A Tissue-Engineered Chondrocyte Cell Sheet Induces Extracellular Matrix Modification to Enhance Ventricular Biomechanics and Attenuate Myocardial Stiffness in Ischemic Cardiomyopathy
TISSUE ENGINEERING PART A
2015; 21 (19-20): 2515-2525
There exists a substantial body of work describing cardiac support devices to mechanically support the left ventricle (LV); however, these devices lack biological effects. To remedy this, we implemented a cell sheet engineering approach utilizing chondrocytes, which in their natural environment produce a relatively elastic extracellular matrix (ECM) for a cushioning effect. Therefore, we hypothesized that a chondrocyte cell sheet applied to infarcted and borderzone myocardium will biologically enhance the ventricular ECM and increase elasticity to augment cardiac function in a model of ischemic cardiomyopathy (ICM). Primary articular cartilage chondrocytes of Wistar rats were isolated and cultured on temperature-responsive culture dishes to generate cell sheets. A rodent ICM model was created by ligating the left anterior descending coronary artery. Rats were divided into two groups: cell sheet transplantation (1.0 × 10(7) cells/dish) and no treatment. The cell sheet was placed onto the surface of the heart covering the infarct and borderzone areas. At 4 weeks following treatment, the decreased fibrotic extension and increased elastic microfiber networks in the infarct and borderzone areas correlated with this technology's potential to stimulate ECM formation. The enhanced ventricular elasticity was further confirmed by the axial stretch test, which revealed that the cell sheet tended to attenuate tensile modulus, a parameter of stiffness. This translated to increased wall thickness in the infarct area, decreased LV volume, wall stress, mass, and improvement of LV function. Thus, the chondrocyte cell sheet strengthens the ventricular biomechanical properties by inducing the formation of elastic microfiber networks in ICM, resulting in attenuated myocardial stiffness and improved myocardial function.
View details for DOI 10.1089/ten.tea.2014.0155
View details for PubMedID 26154752
A "Repair-All" Strategy for Degenerative Mitral Valve Disease Safely Minimizes Unnecessary Replacement
ANNALS OF THORACIC SURGERY
2015; 99 (6): 1983-1991
We examined the feasibility and efficacy of a "repair-all" strategy applied in all patients with degenerative mitral regurgitation, regardless of valve complexity, risk profile, and surgical approach.Between 2002 and 2011, 4,241 patients underwent mitral operations at our institution. Analysis was limited to 525 consecutive patients with mitral regurgitation due to leaflet prolapse (posterior, 75%; anterior, 5%; bileaflet, 20%) who underwent isolated mitral operations. A right minithoracotomy was used in 46% of procedures. Propensity scores identified 153 well-matched patient pairs for evaluation of the effect of surgical approach on valve reparability.Mitral repair was successful in 99% (520 of 525) of patients. The location of the leaflet prolapse did not significantly influence the repair rate or the need for intraoperative revision of the initial repair. The repair rate and the need for intraoperative repair revision also did not significantly differ by surgical approach. Intraoperative revision did not confer a greater risk of perioperative morbidity or longer length of stay. At 8 years, freedom from severe mitral regurgitation was 97% ± 2%. Development of residual mitral regurgitation did not differ by location of the leaflet prolapse, need for repair revision, or surgical approach. After discharge, the survival trend did not differ between patients who did and did not require intraoperative repair revision.In experienced centers, a "repair-all" strategy for degenerative mitral regurgitation can be used with nearly 100% repair rates and excellent outcomes, regardless of valve complexity. When necessary, intraoperative revision of the initial repair may be performed in most patients without a significant incremental risk, thereby further enhancing repair rates.
View details for DOI 10.1016/j.athoracsur.2014.12.076
View details for Web of Science ID 000357521600028
View details for PubMedID 25865766
Ventricular assist device implantation in the elderly.
Annals of cardiothoracic surgery
2014; 3 (6): 570-572
Dramatic advances in ventricular assist device (VAD) design and patient management have made mechanical circulatory support an attractive therapeutic option for the growing pool of elderly heart failure patients.A literature review of all relevant studies was performed. No time or language restrictions were imposed, and references of the selected studies were checked for additional relevant citations.In concordance with the universal trend in mechanical circulatory support, continuous flow devices appear to have particular benefits in the elderly. In addition, the literature suggests that early intervention before the development of cardiogenic shock, important in all patients, is particularly paramount in older patients.The ongoing refinement of patient selection, surgical technique, and post-operative care will continue to improve surgical outcomes, and absolute age may become a less pivotal criterion for mechanical circulatory support. However, clear guidelines for the use of mechanical circulatory support in the elderly remain undefined.
View details for DOI 10.3978/j.issn.2225-319X.2014.09.07
View details for PubMedID 25512896
Bioengineered Stromal Cell- Derived Factor-1 alpha Analogue Delivered as an Angiogenic Therapy Significantly Restores Viscoelastic Material Properties of Infarcted Cardiac Muscle
JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME
2014; 136 (8)
Ischemic heart disease is a major health problem worldwide, and current therapies fail to address microrevascularization. Previously, our group demonstrated that the sustained release of novel engineered stromal cell-derived factor 1-a analogue (ESA) limits infarct spreading, collagen deposition, improves cardiac function by promoting angiogenesis in the region surrounding the infarct, and restores the tensile properties of infarcted myocardium. In this study, using a well-established rat model of ischemic cardiomyopathy, we describe a novel and innovative method for analyzing the viscoelastic properties of infarcted myocardium. Our results demonstrate that, compared with a saline control group, animals treated with ESA have significantly improved myocardial relaxation rates, while reducing the transition strain, leading to restoration of left ventricular mechanics.
View details for DOI 10.1115/1.4027731
View details for Web of Science ID 000338507000012
A bioengineered hydrogel system enables targeted and sustained intramyocardial delivery of neuregulin, activating the cardiomyocyte cell cycle and enhancing ventricular function in a murine model of ischemic cardiomyopathy.
Circulation. Heart failure
2014; 7 (4): 619-626
Neuregulin-1β (NRG) is a member of the epidermal growth factor family possessing a critical role in cardiomyocyte development and proliferation. Systemic administration of NRG demonstrated efficacy in cardiomyopathy animal models, leading to clinical trials using daily NRG infusions. This approach is hindered by requiring daily infusions and off-target exposure. Therefore, this study aimed to encapsulate NRG in a hydrogel to be directly delivered to the myocardium, accomplishing sustained localized NRG delivery.NRG was encapsulated in hydrogel, and release over 14 days was confirmed by ELISA in vitro. Sprague-Dawley rats were used for cardiomyocyte isolation. Cells were stimulated by PBS, NRG, hydrogel, or NRG-hydrogel (NRG-HG) and evaluated for proliferation. Cardiomyocytes demonstrated EdU (5-ethynyl-2'-deoxyuridine) and phosphorylated histone H3 positivity in the NRG-HG group only. For in vivo studies, 2-month-old mice (n=60) underwent left anterior descending coronary artery ligation and were randomized to the 4 treatment groups mentioned. Only NRG-HG-treated mice demonstrated phosphorylated histone H3 and Ki67 positivity along with decreased caspase-3 activity compared with all controls. NRG was detected in myocardium 6 days after injection without evidence of off-target exposure in NRG-HG animals. At 2 weeks, the NRG-HG group exhibited enhanced left ventricular ejection fraction, decreased left ventricular area, and augmented borderzone thickness.Targeted and sustained delivery of NRG directly to the myocardial borderzone augments cardiomyocyte mitotic activity, decreases apoptosis, and greatly enhances left ventricular function in a model of ischemic cardiomyopathy. This novel approach to NRG administration avoids off-target exposure and represents a clinically translatable strategy in myocardial regenerative therapeutics.
View details for DOI 10.1161/CIRCHEARTFAILURE.113.001273
View details for PubMedID 24902740
Preclinical evaluation of the engineered stem cell chemokine stromal cell-derived factor 1a analog in a translational ovine myocardial infarction model.
2014; 114 (4): 650-659
After myocardial infarction, there is an inadequate blood supply to the myocardium, and the surrounding borderzone becomes hypocontractile.To develop a clinically translatable therapy, we hypothesized that in a preclinical ovine model of myocardial infarction, the modified endothelial progenitor stem cell chemokine, engineered stromal cell-derived factor 1α analog (ESA), would induce endothelial progenitor stem cell chemotaxis, limit adverse ventricular remodeling, and preserve borderzone contractility.Thirty-six adult male Dorset sheep underwent permanent ligation of the left anterior descending coronary artery, inducing an anteroapical infarction, and were randomized to borderzone injection of saline (n=18) or ESA (n=18). Ventricular function, geometry, and regional strain were assessed using cardiac MRI and pressure-volume catheter transduction. Bone marrow was harvested for in vitro analysis, and myocardial biopsies were taken for mRNA, protein, and immunohistochemical analysis. ESA induced greater chemotaxis of endothelial progenitor stem cells compared with saline (P<0.01) and was equivalent to recombinant stromal cell-derived factor 1α (P=0.27). Analysis of mRNA expression and protein levels in ESA-treated animals revealed reduced matrix metalloproteinase 2 in the borderzone (P<0.05), with elevated levels of tissue inhibitor of matrix metalloproteinase 1 and elastin in the infarct (P<0.05), whereas immunohistochemical analysis of borderzone myocardium showed increased capillary and arteriolar density in the ESA group (P<0.01). Animals in the ESA treatment group also had significant reductions in infarct size (P<0.01), increased maximal principle strain in the borderzone (P<0.01), and a steeper slope of the end-systolic pressure-volume relationship (P=0.01).The novel, biomolecularly designed peptide ESA induces chemotaxis of endothelial progenitor stem cells, stimulates neovasculogenesis, limits infarct expansion, and preserves contractility in an ovine model of myocardial infarction.
View details for DOI 10.1161/CIRCRESAHA.114.302884
View details for PubMedID 24366171
- Therapeutic potential of Rb phosphorylation in atherosclerosis CELL CYCLE 2014; 13 (3): 352
Sustained release of engineered stromal cell-derived factor 1-a from injectable hydrogels effectively recruits endothelial progenitor cells and preserves ventricular function after myocardial infarction.
2013; 128 (11): S79-86
Exogenously delivered chemokines have enabled neovasculogenic myocardial repair in models of ischemic cardiomyopathy; however, these molecules have short half-lives in vivo. In this study, we hypothesized that the sustained delivery of a synthetic analog of stromal cell-derived factor 1-α (engineered stromal cell-derived factor analog [ESA]) induces continuous homing of endothelial progenitor cells and improves left ventricular function in a rat model of myocardial infarction.Our previously designed ESA peptide was synthesized by the addition of a fluorophore tag for tracking. Hyaluronic acid was chemically modified with hydroxyethyl methacrylate to form hydrolytically degradable hydrogels through free-radical-initiated crosslinking. ESA was encapsulated in hyaluronic acid hydrogels during gel formation, and then ESA release, along with gel degradation, was monitored for more than 4 weeks in vitro. Chemotactic properties of the eluted ESA were assessed at multiple time points using rat endothelial progenitor cells in a transwell migration assay. Finally, adult male Wistar rats (n=33) underwent permanent ligation of the left anterior descending (LAD) coronary artery, and 100 µL of saline, hydrogel alone, or hydrogel+25 µg ESA was injected into the borderzone. ESA fluorescence was monitored in animals for more than 4 weeks, after which vasculogenic, geometric, and functional parameters were assessed to determine the therapeutic benefit of each treatment group. ESA release was sustained for 4 weeks in vitro, remained active, and enhanced endothelial progenitor cell chemotaxis. In addition, ESA was detected in the rat heart >3 weeks when delivered within the hydrogels and significantly improved vascularity, ventricular geometry, ejection fraction, cardiac output, and contractility compared with controls.We have developed a hydrogel delivery system that sustains the release of a bioactive endothelial progenitor cell chemokine during a 4-week period that preserves ventricular function in a rat model of myocardial infarction.
View details for DOI 10.1161/CIRCULATIONAHA.112.000343
View details for PubMedID 24030424
Predicting Right Ventricular Failure in the Modern, Continuous Flow Left Ventricular Assist Device Era
59th Annual Meeting of the Southern-Thoracic-Surgical-Association (STSA)
ELSEVIER SCIENCE INC. 2013: 857–64
In the era of destination continuous flow left ventricular assist devices (LVAD), the decision of whether a patient will tolerate isolated LVAD support or will need biventricular support (BIVAD) can be challenging. Incorrect decision making with delayed right ventricular (RV) assist device implantation results in increased morbidity and mortality. Continuous flow LVADs have been shown to decrease pulmonary hypertension and improve RV function. We undertook this study to determine predictors in the continuous flow LVAD era that identify patients who are candidates for isolated LVAD therapy as opposed to biventricular support.We reviewed demographic, hemodynamic, laboratory, and echocardiographic variables for 218 patients who underwent VAD implant from 2003 through 2011 (LVAD=167, BIVAD=51), during the era of continuous flow LVADs.Fifty preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BIVAD. Seventeen variables demonstrated statistical significance by univariate analysis. Multivariable logistic regression analysis identified central venous pressure>15 mmHg (OR 2.0, "C"), severe RV dysfunction (OR 3.7, "R"), preoperative intubation (OR 4.3, "I"), severe tricuspid regurgitation (OR 4.1, "T"), heart rate>100 (OR 2.0, Tachycardia-"T")-CRITT as the major criteria predictive of the need for biventricular support. Utilizing these data, a highly sensitive and easy to use risk score for determining RV failure was generated that outperformed other established risk stratification tools.We present a preoperative risk calculator to determine suitability of a patient for isolated LVAD support in the current continuous flow ventricular assist device era.
View details for DOI 10.1016/j.athoracsur.2013.03.099
View details for Web of Science ID 000323940200026
View details for PubMedID 23791165
Rapid onset of fulminant myocarditis portends a favourable prognosis and the ability to bridge mechanical circulatory support to recovery
EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY
2013; 43 (2): 379-382
Fulminant myocarditis with cardiogenic shock is fatal without mechanical circulatory support. Once haemodynamic stability has been established with a ventricular assist device (VAD), the decision to wait for myocardial recovery as opposed to listing for an orthotopic heart transplant (OHT) can be difficult. We have undertaken this study to establish the criteria for determining the need for heart transplantation following VAD implant for fulminant myocarditis.A total of 442 VADs were implanted between 1993 and 2011. Twenty-four VADs were implanted for fulminant myocarditis with refractory cardiogenic shock. We retrospectively analysed the variables and the pathology for this cohort. Patients who had a full recovery of myocardial function and subsequent VAD explant (Explant) were compared with those bridged to OHT. There was one acute death.There was no difference in the past medical history between the groups. Explant patients had a more acute onset of heart failure with a median of 7 days between the onset of symptoms and VAD implant, when compared with 22 days for OHT (P = 0.01). A rapid recovery in myocardial function was seen in the Explant group, with recovery of myocardial function (ejection fraction = 53 ± 24%) in 14 ± 7 days. Myocardial function was sustained for 5 years following the VAD explant. The female gender favoured myocardial recovery and VAD explantability. Two patients had giant cell myocarditis, neither of whom had a recovery of function, and they were bridged to heart transplant with a VAD.Fulminant myocarditis is a fatal condition without mechanical support. The rapid onset of symptoms is associated with a complete recovery of myocardial function and VAD explant. The absence of rapid recovery of myocardial function should prompt listing for a heart transplant.
View details for DOI 10.1093/ejcts/ezs242
View details for Web of Science ID 000313829300031
View details for PubMedID 22564805
Mathematically engineered stromal cell-derived factor-1 alpha stem cell cytokine analog enhances mechanical properties of infarcted myocardium
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
2013; 145 (1): 278-284
The biomechanical response to a myocardial infarction consists of ventricular remodeling that leads to dilatation, loss of contractile function, abnormal stress patterns, and ultimately heart failure. We hypothesized that intramyocardial injection of our previously designed pro-angiogenic chemokine, an engineered stromal cell-derived factor-1α analog (ESA), improves mechanical properties of the heart after infarction.Male rats (n = 54) underwent either sham surgery (n = 17) with no coronary artery ligation or ligation of the left anterior descending artery (n = 37). The rats in the myocardial infarction group were then randomized to receive either saline (0.1 mL, n = 18) or ESA (6 μg/kg, n = 19) injected into the myocardium at 4 predetermined spots around the border zone. Echocardiograms were performed preoperatively and before the terminal surgery. After 4 weeks, the hearts were explanted and longitudinally sectioned. Uniaxial tensile testing was completed using an Instron 5543 Microtester. Optical strain was evaluated using custom image acquisition software, Digi-Velpo, and analyzed in MATLAB.Compared with the saline control group at 4 weeks, the ESA-injected hearts had a greater ejection fraction (71.8% ± 9.0% vs 55.3% ± 12.6%, P = .0004), smaller end-diastolic left ventricular internal dimension (0.686 ± 0.110 cm vs 0.763 ± 0.160 cm, P = .04), greater cardiac output (36 ± 11.6 mL/min vs 26.9 ± 7.3 mL/min, P = .05), and a lower tensile modulus (251 ± 56 kPa vs 301 ± 81 kPa, P = .04). The tensile modulus for the sham group was 195 ± 56 kPa, indicating ESA injection results in a less stiff ventricle.Direct injection of ESA alters the biomechanical response to myocardial infarction, improving the mechanical properties in the postinfarct heart.
View details for DOI 10.1016/j.jtcvs.2012.09.080
View details for Web of Science ID 000312386300047
View details for PubMedID 23244259
Re-Engineered Stromal Cell-Derived Factor-1 alpha and the Future of Translatable Angiogenic Polypeptide Design
TRENDS IN CARDIOVASCULAR MEDICINE
2012; 22 (6): 139-144
Smaller engineered analogs of angiogenic cytokines may provide translational advantages, including enhanced stability and function, ease of synthesis, lower cost, and, most important, the potential for modulated delivery via engineered biomaterials. In order to create such a peptide, computational molecular modeling and design was employed to engineer a minimized, highly efficient polypeptide analog of the stromal cell-derived factor-1α (SDF) molecule. After removal of the large, central β-sheet region, a designed diproline linker connected the native N-terminus (responsible for receptor activation and binding) and C-terminus (responsible for extracellular stabilization). This yielded energetic and conformational advantages resulting in a small, low-molecular-weight engineered SDF polypeptide analog (ESA) that was shown to have angiogenic activity comparable to or better than that of recombinant human SDF both in vitro and in a murine model of ischemic heart failure.
View details for Web of Science ID 000311065900001
View details for PubMedID 22902182
Myocardial tissue elastic properties determined by atomic force microscopy after stromal cell-derived factor 1 alpha angiogenic therapy for acute myocardial infarction in a murine model
37th Annual Meeting of the Western-Thoracic-Surgical-Association
MOSBY-ELSEVIER. 2012: 962–66
Ventricular remodeling after myocardial infarction begins with massive extracellular matrix deposition and resultant fibrosis. This loss of functional tissue and stiffening of myocardial elastic and contractile elements starts the vicious cycle of mechanical inefficiency, adverse remodeling, and eventual heart failure. We hypothesized that stromal cell-derived factor 1α (SDF-1α) therapy to microrevascularize ischemic myocardium would rescue salvageable peri-infarct tissue and subsequently improve myocardial elasticity.Immediately after left anterior descending coronary artery ligation, mice were randomly assigned to receive peri-infarct injection of either saline solution or SDF-1α. After 6 weeks, animals were killed and samples were taken from the peri-infarct border zone and the infarct scar, as well as from the left ventricle of noninfarcted control mice. Determination of tissues' elastic moduli was carried out by mechanical testing in an atomic force microscope.SDF-1α-treated peri-infarct tissue most closely approximated the elasticity of normal ventricle and was significantly more elastic than saline-treated peri-infarct myocardium (109 ± 22.9 kPa vs 295 ± 42.3 kPa; P < .0001). Myocardial scar, the strength of which depends on matrix deposition from vasculature at the peri-infarct edge, was stiffer in SDF-1α-treated animals than in controls (804 ± 102.2 kPa vs 144 ± 27.5 kPa; P < .0001).Direct quantification of myocardial elastic properties demonstrates the ability of SDF-1α to re-engineer evolving myocardial infarct and peri-infarct tissues. By increasing elasticity of the ischemic and dysfunctional peri-infarct border zone and bolstering the weak, aneurysm-prone scar, SDF-1α therapy may confer a mechanical advantage to resist adverse remodeling after infarction.
View details for DOI 10.1016/j.jtcvs.2011.12.028
View details for Web of Science ID 000301609200036
View details for PubMedID 22264415
Oxygen-dependent quenching of phosphorescence used to characterize improved myocardial oxygenation resulting from vasculogenic cytokine therapy
JOURNAL OF APPLIED PHYSIOLOGY
2011; 110 (5): 1460-1465
This study evaluates a therapy for infarct modulation and acute myocardial rescue and utilizes a novel technique to measure local myocardial oxygenation in vivo. Bone marrow-derived endothelial progenitor cells (EPCs) were targeted to the heart with peri-infarct intramyocardial injection of the potent EPC chemokine stromal cell-derived factor 1α (SDF). Myocardial oxygen pressure was assessed using a noninvasive, real-time optical technique for measuring oxygen pressures within microvasculature based on the oxygen-dependent quenching of the phosphorescence of Oxyphor G3. Myocardial infarction was induced in male Wistar rats (n = 15) through left anterior descending coronary artery ligation. At the time of infarction, animals were randomized into two groups: saline control (n = 8) and treatment with SDF (n = 7). After 48 h, the animals underwent repeat thoracotomy and 20 μl of the phosphor Oxyphor G3 was injected into three areas (peri-infarct myocardium, myocardial scar, and remote left hindlimb muscle). Measurements of the oxygen distribution within the tissue were then made in vivo by applying the end of a light guide to the beating heart. Compared with controls, animals in the SDF group exhibited a significantly decreased percentage of hypoxic (defined as oxygen pressure ≤ 15.0 Torr) peri-infarct myocardium (9.7 ± 6.7% vs. 21.8 ± 11.9%, P = 0.017). The peak oxygen pressures in the peri-infarct region of the animals in the SDF group were significantly higher than the saline controls (39.5 ± 36.7 vs. 9.2 ± 8.6 Torr, P = 0.02). This strategy for targeting EPCs to vulnerable peri-infarct myocardium via the potent chemokine SDF-1α significantly decreased the degree of hypoxia in peri-infarct myocardium as measured in vivo by phosphorescence quenching. This effect could potentially mitigate the vicious cycle of myocyte death, myocardial fibrosis, progressive ventricular dilatation, and eventual heart failure seen after acute myocardial infarction.
View details for DOI 10.1152/japplphysiol.01138.2010
View details for Web of Science ID 000290472400043
View details for PubMedID 21292844
View details for PubMedCentralID PMC3098666
Computational Protein Design to Re-Engineer Stromal Cell-Derived Factor-alpha (SDF) Generates a Supra-Efficient Angiogenic Polypeptide Analog
LIPPINCOTT WILLIAMS & WILKINS. 2010
View details for Web of Science ID 000208231600703
Acute Myocardial Rescue with Endogenous Endothelial Progenitor Cell Therapy
HEART LUNG AND CIRCULATION
2010; 19 (11): 644-654
Post-myocardial infarction heart failure is a major health concern with limited therapy. Molecular revascularisation utilising granulocyte-macrophage colony stimulating factor (GMCSF) mediated endothelial progenitor cell (EPC) upregulation and stromal cell derived factor-1α (SDF) mediated myocardial EPC chemokinesis, may prevent myocardial loss and adverse remodelling. Vasculogenesis, viability, and haemodynamic improvements following therapy were investigated.Lewis rats (n=91) underwent LAD ligation and received either intramyocardial SDF and subcutaneous GMCSF or saline injections at the time of infarction. Molecular and haemodynamic assessments were performed at pre-determined time points following ligation.SDF/GMCSF therapy upregulated EPC density as shown by flow cytometry (0.12±0.02% vs. 0.06±0.01% circulating lymphocytes, p=0.005), 48hours following infarction. A marked increase in perfusion was evident eight weeks after therapy, utilising confocal angiography (5.02±1.7×10(-2)μm(3)blood/μm(3)myocardial tissue vs. 2.03±0.710(-2)μm(3)blood/μm(3)myocardial tissue, p=0.00004). Planimetric analysis demonstrated preservation of wall thickness (0.98±0.09mm vs. 0.67±0.06mm, p=0.003) and ventricular diameter (7.81±0.99mm vs. 9.41±1.1mm, p=0.03). Improved haemodynamic function was evidenced by echocardiography and PV analysis (ejection fraction: 56.4±18.1% vs. 25.3±15.6%, p=0.001; pre-load adjusted maximal power: 6.6±2.6mW/μl(2) vs. 2.7±1.4mW/μl(2), p=0.01).Neovasculogenic therapy with GMCSF-mediated EPC upregulation and SDF-mediated EPC chemokinesis maybe an effective therapy for infarct modulation and preservation of myocardial function following acute myocardial infarction.
View details for DOI 10.1016/j.hlc.2010.06.1056
View details for Web of Science ID 000283908600002
View details for PubMedID 20719564
View details for PubMedCentralID PMC3235678
Spliced stromal cell-derived factor-1 alpha analog stimulates endothelial progenitor cell migration and improves cardiac function in a dose-dependent manner after myocardial infarction
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
2010; 140 (5): 1174-1180
Stromal cell-derived factor (SDF)-1α is a potent endogenous endothelial progenitor cell (EPC) chemokine and key angiogenic precursor. Recombinant SDF-1α has been demonstrated to improve neovasculogenesis and cardiac function after myocardial infarction (MI) but SDF-1α is a bulky protein with a short half-life. Small peptide analogs might provide translational advantages, including ease of synthesis, low manufacturing costs, and the potential to control delivery within tissues using engineered biomaterials. We hypothesized that a minimized peptide analog of SDF-1α, designed by splicing the N-terminus (activation and binding) and C-terminus (extracellular stabilization) with a truncated amino acid linker, would induce EPC migration and preserve ventricular function after MI.EPC migration was first determined in vitro using a Boyden chamber assay. For in vivo analysis, male rats (n = 48) underwent left anterior descending coronary artery ligation. At infarction, the rats were randomized into 4 groups and received peri-infarct intramyocardial injections of saline, 3 μg/kg of SDF-1α, 3 μg/kg of spliced SDF analog, or 6 μg/kg spliced SDF analog. After 4 weeks, the rats underwent closed chest pressure volume conductance catheter analysis.EPCs showed significantly increased migration when placed in both a recombinant SDF-1α and spliced SDF analog gradient. The rats treated with spliced SDF analog at MI demonstrated a significant dose-dependent improvement in end-diastolic pressure, stroke volume, ejection fraction, cardiac output, and stroke work compared with the control rats.A spliced peptide analog of SDF-1α containing both the N- and C- termini of the native protein induced EPC migration, improved ventricular function after acute MI, and provided translational advantages compared with recombinant human SDF-1α.
View details for DOI 10.1016/j.jtcvs.2010.08.012
View details for Web of Science ID 000283057600043
View details for PubMedID 20951261
Stromal Cell-Derived Factor-1 alpha Activation of Tissue-Engineered Endothelial Progenitor Cell Matrix Enhances Ventricular Function After Myocardial Infarction by Inducing Neovasculogenesis
82nd National Conference and Exhibitions and Annual Scientific Session of the American-Heart-Association
LIPPINCOTT WILLIAMS & WILKINS. 2010: S107–S117
Myocardial ischemia causes cardiomyocyte death, adverse ventricular remodeling, and ventricular dysfunction. Endothelial progenitor cells (EPCs) have been shown to ameliorate this process, particularly when activated with stromal cell-derived factor-1α (SDF), known to be the most potent EPC chemokine. We hypothesized that implantation of a tissue-engineered extracellular matrix (ECM) scaffold seeded with EPCs primed with SDF could induce borderzone neovasculogenesis, prevent adverse geometric remodeling, and preserve ventricular function after myocardial infarction.Lewis rats (n=82) underwent left anterior descending artery ligation to induce myocardial infarction. EPCs were isolated, characterized, and cultured on a vitronectin/collagen scaffold and primed with SDF to generate the activated EPC matrix (EPCM). EPCM was sutured to the anterolateral left ventricular wall, which included the region of ischemia. Control animals received sutures but no EPCM. Additional groups underwent application of the ECM alone, ECM primed with SDF (ECM+SDF), and ECM seeded with EPCs but not primed with SDF (ECM+SDF). At 4 weeks, borderzone myocardial tissue demonstrated increased levels of vascular endothelial growth factor in the EPCM group. When compared to controls, Vessel density as assessed by immunohistochemical microscopy was significantly increased in the EPCM group (4.1 versus 6.2 vessels/high-powered field; P<0.001), and microvascular perfusion measured by lectin microangiography was enhanced 4-fold (0.7% versus 2.7% vessel volume/section volume; P=0.04). Comparisons to additional groups also showed a significantly improved vasculogenic response in the EPCM group. Ventricular geometry and scar fraction assessed by digital planimetric analysis of sectioned hearts exhibited significantly preserved left ventricular internal diameter (9.7 mm versus 8.6 mm; P=0.005) and decreased infarct scar formation expressed as percent of total section area (16% versus 7%; P=0.002) when compared with all other groups. In addition, EPCM animals showed a significant preservation of function as measured by echocardiography, pressure-volume conductance, and Doppler flow.Extracellular matrix seeded with EPCs primed with SDF induces borderzone neovasculogenesis, attenuates adverse ventricular remodeling, and preserves ventricular function after myocardial infarction.
View details for DOI 10.1161/C1RCULATIONAHA.109.930404
View details for Web of Science ID 000282294800017
View details for PubMedID 20837901
- Rapid Onset of Fulminant Myocarditis Portends a Favorable Prognosis and Ability To Bridge Mechanical Support to Recovery CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 2010: S51
Early planned institution of biventricular mechanical circulatory support results in improved outcomes compared with delayed conversion of a left ventricular assist device to a biventricular assist device
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
2009; 137 (4): 971-977
It is generally accepted that patients who require biventricular assist device support have poorer outcomes than those requiring isolated left ventricular assist device support. However, it is unknown how the timing of biventricular assist device insertion affects outcomes. We hypothesized that planned biventricular assist device insertion improves survival compared with delayed conversion of left ventricular assist device support to biventricular assist device support.We reviewed and compared outcomes of 266 patients undergoing left ventricular assist device or biventricular assist device placement at the University of Pennsylvania from April 1995 to June 2007. We subdivided patients receiving biventricular assist devices into planned biventricular assist device (P-BiVAD) and delayed biventricular assist device (D-BiVAD) groups based on the timing of right ventricular assist device insertion. We defined the D-BiVAD group as any failure of isolated left ventricular assist device support.Of 266 patients who received left ventricular assist devices, 99 (37%) required biventricular assist device support. We compared preoperative characteristics, successful bridging to transplantation, survival to hospital discharge, and Kaplan-Meier 1-year survival between the P-BiVAD (n = 71) and D-BiVAD (n = 28) groups. Preoperative comparison showed that patients who ultimately require biventricular support have similar preoperative status. Left ventricular assist device (n = 167) outcomes in all categories exceeded both P-BiVAD and D-BiVAD group outcomes. Furthermore, patients in the P-BiVAD group had superior survival to discharge than patients in the D-BiVAD group (51% vs 29%, P < .05). One-year and long-term Kaplan-Meier survival distribution confirmed this finding. There was also a trend toward improved bridging to transplantation in the P-BiVAD (n = 55) versus D-BiVAD (n = 22) groups (65% vs 45%, P = .10).When patients at high risk for failure of isolated left ventricular assist device support are identified, proceeding directly to biventricular assist device implantation is advised because early institution of biventricular support results in dramatic improvement in survival.
View details for DOI 10.1016/j.jtcvs.2008.09.021
View details for Web of Science ID 000264562000028
View details for PubMedID 19327526
View details for PubMedCentralID PMC3232461
Off-pump, minimally invasive and robotic coronary revascularization yield improved outcomes over traditional on-pump CABG
INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY
2009; 5 (1): 1-12
Coronary artery disease is a global health concern, with increasing morbidity and mortality. Surgical coronary artery bypass grafting has been performed on cardiopulmonary bypass for nearly four decades, with excellent long-term durability. Beating-heart coronary surgery has been increasing in frequency in an attempt to decrease cardiopulmonary bypass-related morbidity. Furthermore, with increasing expertise and technology, minimally invasive and robotic techniques have been developed to enhance post-operative recovery, patient satisfaction and cosmesis. Several clinical trials have demonstrated decreased morbidity and more rapid recovery following off-pump, minimally invasive and robotic procedures when compared to on-pump coronary artery bypass grafts (CABGs). An equivalent extent of revascularization and medium-term anastomotic patency has been demonstrated among all approaches. Furthermore, for a large number of patients who do not have anatomy amenable to traditional coronary revascularization, adjunctive molecular therapies may provide alternative myocardial micro-revascularization.
View details for DOI 10.1002/rcs.230
View details for Web of Science ID 000263998300001
View details for PubMedID 19117020
Cardiac retransplantation is an efficacious therapy for primary cardiac allograft failure
JOURNAL OF CARDIOTHORACIC SURGERY
Although orthotopic heart transplantation has been an effective treatment for end-stage heart failure, the incidence of allograft failure has increased, necessitating treatment options. Cardiac retransplantation remains the only viable long-term solution for end-stage cardiac allograft failure. Given the limited number of available donor hearts, the long term results of this treatment option need to be evaluated.709 heart transplants were performed over a 20 year period at our institution. Repeat cardiac transplantation was performed in 15 patients (2.1%). A retrospective analysis was performed to determine the efficacy of cardiac retransplantation. Variables investigated included: 1 yr and 5 yr survival, length of hospitalization, post-operative complications, allograft failure, recipient and donor demographics, renal function, allograft ischemic time, UNOS listing status, blood group, allograft rejection, and hemodynamic function.Etiology of primary graft failure included transplant arteriopathy (n = 10), acute rejection (n = 3), hyperacute rejection (n = 1), and a post-transplant diagnosis of metastatic melanoma in the donor (n = 1). Mean age at retransplantation was 45.5 +/- 9.7 years. 1 and 5 year survival for retransplantation were 86.6% and 71.4% respectively, as compared to 90.9% and 79.1% for primary transplantation. Mean ejection fraction was 67.3 +/- 12.2% at a mean follow-up of 32.6 +/- 18.5 mos post-retransplant; follow-up biopsy demonstrated either ISHLT grade 1A or 0 rejection (77.5 +/- 95.7 mos post-transplant).Cardiac retransplantation is an efficacious treatment strategy for cardiac allograft failure.
View details for DOI 10.1186/1749-8090-3-26
View details for Web of Science ID 000262855000001
View details for PubMedID 18462494
View details for PubMedCentralID PMC2432055
Ischemic heart failure enhances endogenous myocardial apelin and APJ receptor expression
CELLULAR & MOLECULAR BIOLOGY LETTERS
2007; 12 (1): 127-138
Apelin interacts with the APJ receptor to enhance inotropy. In heart failure, apelin-APJ coupling may provide a means of enhancing myocardial function. The alterations in apelin and APJ receptor concentrations with ischemic cardiomyopathy are poorly understood. We investigated the compensatory changes in endogenous apelin and APJ levels in the setting of ischemic cardiomyopathy.Male, Lewis rats underwent LAD ligation and progressed into heart failure over 6 weeks. Corresponding animals underwent sham thoracotomy as control. Six weeks after initial surgery, the animals underwent hemodynamic functional analysis in the presence of exogenous apelin-13 infusion and the hearts were explanted for western blot and enzyme immunoassay analysis. Western blot analysis of myocardial APJ concentration demonstrated increased APJ receptor protein levels with heart failure (1890750+/-133500 vs. 901600+/-143120 intensity units, n=8, p=0.00001). Total apelin protein levels increased with ischemic heart failure as demonstrated by enzyme immunoassay (12.0+/-4.6 vs. 1.0+/-1.2 ng/ml, n=5, p=0.006) and western blot (1579400+/-477733 vs. 943000+/-157600 intensity units, n=10, p=0.008). Infusion of apelin-13 significantly enhanced myocardial function in sham and failing hearts. We conclude that total myocardial apelin and APJ receptor levels increase in compensation for ischemic cardiomyopathy.
View details for DOI 10.2478/s11658-006-0058-7
View details for Web of Science ID 000244632300011
View details for PubMedID 17119870