Practice Variation in Anticoagulation Prescription and Outcomes after Device-Detected Atrial Fibrillation: Insights from the Veterans Health Administration.
BACKGROUND: Device-detected atrial fibrillation (AF) is associated with increased risk of stroke. However, there are no clearly-defined thresholds of AF burden for which to initiate oral anticoagulation (OAC). We sought to describe OAC prescription practice variation in response to new device-detected AF and the association to outcomes.METHODS: We performed a retrospective cohort study using data from the Veterans Health Administration linked to remote monitoring data that included day-level AF burden. We included patients with cardiac implantable electronic devices (CIED) and remote monitoring from 2011-2014, CHA2DS2-VASc ≥2, and no prior stroke or OAC receipt in the preceding 2 years. We determined the proportion of patients prescribed OAC within 90-days following new device-detected AF across a range of AF thresholds (≥6 minutes to >24 hours), and examined site variation in OAC prescription. We used multivariable Cox proportional hazards regressions to determine the association of OAC prescription with stroke by device-detected AF burden.RESULTS: Among 10,212 patients with CIEDs, 4,570 patients (45%), 3,969 patients (39%), 3,263 patients (32%), and 2,469 patients (24%) had device-detected AF >6 minutes, >1 hour, >6 hours, and >24 hours, respectively. For device-detected AF >1 hour, 1,712 patients met inclusion criteria (72±10 years; 1.5% female; CHA2DS2-VASc 4.0±1.4; HAS-BLED 2.6±1.1). The proportion receiving OAC varied based on device-detected AF burden (≥6 minutes: 272/2,101 (13%); >1 hour: 273/1,712 (16%); >6 hours: 263/1,279 (21%); >24 hours: 224/818 (27%)). Across 52 sites (N=1,329 patients), there was substantial site-level variation in OAC prescription after device-detected AF >1 hour (median: 16%; range: 3%-67%; median odds ratio: 1.56 [95% credible interval 1.49-1.71]). In adjusted models, OAC prescription after device-detected AF >24 hours was associated with reduced stroke risk (HR 0.28, 95% CI 0.10-0.81, p=0.02), although the propensity-adjusted model was significant when AF lasted at least 6 minutes.CONCLUSIONS: Among Veterans with CIEDs, device-detected AF is common. There is large practice variation in 90-day OAC initiation after new device-detected AF with low rates of treatment overall, even for episodes >24 hours. The strongest association of OAC with reduction in stroke was observed after device-detected AF >24 hours. Randomized trials are needed to confirm these observational findings.
View details for PubMedID 30880434
Appropriateness of Direct Oral Anticoagulant Dosing in Patients With Atrial Fibrillation: Insights From the Veterans Health Administration.
Journal of pharmacy practice
BACKGROUND:: Direct oral anticoagulants (DOACs) have strict dosing guidelines, but recent studies indicate that inappropriate dosing is common, particularly in chronic kidney disease (CKD), for which it has been reported to be as high as 43%. Since 2011, the Veterans Health Administration (VA) has implemented anticoagulation management programs for DOACs, generally led by pharmacists, which has previously been shown to improve medication adherence.OBJECTIVE:: We investigated the prevalence of overdosing and underdosing of DOACs in the VA.METHODS:: Using data from the TREAT-AF cohort study (The Retrospective Evaluation and Assessment of Therapies in AF), we identified VA patients with newly diagnosed atrial fibrillation (AF) and receipt of a DOAC between 2003 and 2015. We classified dosing as correct, overdosed, or underdosed based on the Food and Drug Administration-approved dosing criteria.RESULTS:: Of 230 762 patients, 5060 received dabigatran (77.3%) or rivaroxaban (22.7%) within 90 days of AF diagnosis (age 69 [10[ years; CHA2DS2-VASc 1.6 [1.4]), of which 1312 (25.9%) had CKD based on estimated glomerular filtration rate <60. Overall, 93.6% of patients, 83.2% with CKD, received appropriate DOAC dosing. Incorrect dosing increased with worsening renal function.CONCLUSION:: Compared to recent studies of commercial payers and health-care systems, incorrect dosing of DOACs is less common across the VA. Pharmacist-led DOAC management or similar anticoagulation management interventions may reduce the risk of incorrect dosing across health-care systems.
View details for PubMedID 30791808
Efficacy of Ablation Lesion Sets in Addition to Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation: Findings From the SMASH - AF Meta-Analysis Study Cohort.
Journal of the American Heart Association
2019; 8 (1): e009976
Background The objective was to explore the efficacy of ablation lesion sets in addition to pulmonary vein isolation ( PVI ) for paroxysmal atrial fibrillation. The optimal strategy for catheter ablation of paroxysmal atrial fibrillation is debated. Methods and Results The SMASH-AF (Systematic Review and Meta-analysis of Ablation Strategy Heterogeneity in Atrial Fibrillation) study cohort includes trials and observational studies identified in PubMed, Scopus, and Cochrane databases from January 1 1990, to August 1, 2016. We included studies reporting single procedure paroxysmal atrial fibrillation ablation success rates. Exclusion criteria included insufficient reporting of outcomes, ablation strategies that were not prespecified and uniform, and a sample size of fewer than 40 patients. We analyzed lesion sets performed in addition to PVI ( PVI plus) using multivariable random-effects meta-regression to control for patient, study, and procedure characteristics. The analysis included 145 total studies with 23263 patients ( PVI- only cohort: 115 studies, 148 treatment arms, 16500 patients; PVI plus cohort: 39 studies; 46 treatment arms, 6763 patients). PVI plus studies, as compared with PVI -only studies, included younger patients (56.7years versus 58.8years, P=0.001), fewer women (27.2% versus 32.0% women, P=0.002), and were more methodologically rigorous with longer follow-up (29.5 versus 17.1months, P 0.004) and more randomization (19.4% versus 11.8%, P<0.001). In multivariable meta-regression, PVI plus studies were associated with improved success (7.6% absolute improvement [95% CI, 2.6-12.5%]; P<0.01, I2=88%), specifically superior vena cava isolation (4 studies, 4 treatment arms, 1392 patients; 15.1% absolute improvement [95%CI, 2.3-27.9%]; P 0.02, I2=87%). However, residual heterogeneity was large. Conclusions Across the paroxysmal atrial fibrillation ablation literature, PVI plus ablation strategies were associated with incremental improvements in success rate. However, large residual heterogeneity complicates evidence synthesis.
View details for PubMedID 30587059
Secular trends in success rate of catheter ablation for atrial fibrillation: The SMASH-AF cohort.
American heart journal
BACKGROUND: Approaches, tools, and technologies for atrial fibrillation (AF) ablation have evolved significantly since its inception. We sought to characterize secular trends in AF ablation success rates.METHODS: We performed a systematic review and meta-analysis of AF ablation from January 1, 1990, to August 1, 2016, searching PubMed, Scopus, and Cochrane databases. Major exclusion criteria were insufficient outcome reporting and ablation strategies that were not prespecified and uniform. We stratified treatment arms by AF type (paroxysmal AF; nonparoxysmal AF) and analyzed single-procedure outcomes. Multivariate meta-regressions analyzed effects of study, patient, and procedure characteristics on success rate trends. Registered in PROSPERO (CRD42016036549).RESULTS: A total of 180 trials and observational studies with 28,118 patients met inclusion. For paroxysmal AF ablation studies, unadjusted success rate summary estimates ranged from 73.1% in 2003 to 77.1% in 2016, increasing by 0.9%/year (95% CI 0.4%-1.4%; P = .001; I2 = 90%). After controlling for study design and patient demographics, rate of improvement in success rate summary estimate increased (1.6%/year; 95% CI 0.9%-2.2%; P = .001; I2 = 87%). For nonparoxysmal AF ablation studies, unadjusted success rate summary estimates ranged from 70.0% in 2010 to 64.3% in 2016 (1.1%/year; 95% CI -1.3% to 3.5%; P = .37; I2 = 85%), with no improvement in multivariate analyses.CONCLUSIONS: Despite substantial research investment and health care expenditure, improvements in AF ablation success rates have been incremental. Meaningful improvements may require major paradigm or technology changes, and evaluation of clinical outcomes such as mortality and quality of life may prove to be important going forward.
View details for PubMedID 30502925
- ALTERNATIVE METRICS BY SYSTEMATIC REVIEW INCLUSION STATUS OF STUDIES OF CATHETER ABLATION FOR ATRIAL FIBRILLATION: FINDINGS FROM THE SMASH-AF META-ANALYSIS STUDY COHORT ELSEVIER SCIENCE INC. 2018: 342
Geographic and racial representation and reported success rates of studies of catheter ablation for atrial fibrillation: Findings from the SMASH-AF meta-analysis study cohort.
Journal of cardiovascular electrophysiology
INTRODUCTION: We performed a systematic review and meta-analysis of geographic and racial representation and reported success rates of studies of catheter ablation for atrial fibrillation (AF).METHODS AND RESULTS: We searched PubMed, Scopus, and Cochrane databases from 1/1/1990 to 8/1/2016 for trials and observational studies reporting AF ablation outcomes. Major exclusion criteria were insufficient reporting of outcomes, non-English language articles, and ablation strategies that were not prespecified and uniform. We described geographic and racial representation and single-procedure ablation success rates by country, controlling for patient demographics and study design characteristics. The analysis cohort included 306 studies (49,227 patients) from 28 countries. Over half of the paroxysmal (PAF) and nonparoxysmal AF (NPAF) treatment arms were conducted in 5 and 3 countries, respectively. Reporting of race or ethnicity demographics and outcomes were rare (1 study, 0.3%) and nonexistent, respectively. Unadjusted success rates by country ranged from 63.5% to 83.0% for PAF studies and 52.7% to 71.6% for NPAF studies, with substantial variation in patient demographics and study design. After controlling for covariates, South Korea and the United States had higher PAF ablation success rates, with large residual heterogeneity. NPAF ablation success rates were statistically similar by country.CONCLUSIONS: Studies of AF ablation have substantial variation in patient demographics, study design, and reported outcomes by country. There is limited geographic representation of trials and observational studies of AF ablation and a paucity of race- or ethnicity-stratified results. Future AF ablation studies and registries should aim to have broad representation by race, geography, and ethnicity to ensure generalizability.
View details for PubMedID 29364570
Patient and facility variation in costs of catheter ablation for atrial fibrillation.
Journal of cardiovascular electrophysiology
Cost-effectiveness or value of cardiovascular therapies may be undermined by unwarranted cost variation, particularly for heterogeneous procedures such as catheter ablation for atrial fibrillation (AF). We sought to characterize cost variation of AF ablation in the U.S. health care system and the relationship between cost and outcomes.We performed a retrospective cohort study using data from the MarketScan® commercial claims and Medicare supplemental databases including patients who received an AF ablation from 2007 through 2011. We aggregated encounter cost, reflecting total payments received for the encounter, to the facility level to calculate median facility cost. We classified procedures as outpatient or inpatient and assessed for association between cost and 30-day and one-year outcomes. The analysis cohort included 9,415 AF ablations (59±11 years; 28% female; 52% outpatient) occurring at 327 facilities, with large cost variation across facilities (median: $25,100; 25th percentile: $18,900, 75th percentile: $35,600, 95th percentile: $57,800). Among outpatient procedures, there was reduced health care utilization in higher cost quintiles with reductions in rehospitalization at 30-days (Quintile 1: 16.1%, Quintile 5: 8.8%, p < 0.001) and one-year (Quintile 1: 34.8%, Quintile 5: 25.6%, p < 0.001), which remained significant in multivariate analysis.Although median costs of AF ablation are below amounts used in prior cost-effectiveness studies that demonstrated good value, large facility variation in cost suggests opportunities for cost reduction. However, for outpatient encounters, association of cost to modestly improved outcomes suggests cost containment strategies could have variable effects. This article is protected by copyright. All rights reserved.
View details for PubMedID 29864193
Association of Healthcare Plan with Atrial Fibrillation Prescription Patterns.
Atrial fibrillation (AF) is treated by many types of physician specialists, including primary care physicians (PCPs). Health plans have different policies for how patients encounter these providers, and these may affect selection of AF treatment strategy.We hypothesized that healthcare plans with PCP-gatekeeping to specialist access may be associated with different pharmacologic treatments for AF.We performed a retrospective cohort study using a commercial pharmaceutical claims database. We utilized logistic regression models to compare odds of prescription of oral anticoagulant (OAC), non-vitamin K-dependent oral anticoagulant (NOAC), rate control, and rhythm control medications used to treat AF between patients with PCP-gated healthcare plans (e.g. HMO, EPO, POS) and patients with non-PCP-gated healthcare plans (e.g. PPO, CHDP, HDHP, Comprehensive) between 2007 and 2012. We also calculated median time to receipt of therapy within 90 days of index AF diagnosis.We found similar odds of OAC prescription at 90 days following new AF diagnosis in patients with PCP-gated plans compared to those with non-PCP-gated plans (OR: OAC 1.01, p=0.84; warfarin 1.05, p=0.08). Relative odds were similar for rate control (1.17, p<0.01) and rhythm control agents (0.93, p=0.03). However, PCP-gated plan patients had slightly lower likelihood of being prescribed NOACs (0.82, p=0.001) than non-gated plan patients. Elapsed time until receipt of medication was similar between PCP-gated and non-gated groups across drug classes.Pharmaceutical claims data do not suggest that PCP-gatekeeping by healthcare plans is a structural barrier to AF therapy, although it was associated with lower use of NOACs.
View details for PubMedID 30098034
Treating Specialty and Outcomes in Newly Diagnosed Atrial Fibrillation From the TREAT-AF Study
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2017; 70 (1): 78–86
Atrial fibrillation (AF) occurs in many clinical contexts and is diagnosed and treated by clinicians across many specialties. This approach has resulted in treatment variations.The goal of this study was to evaluate the association between treating specialty and AF outcomes among patients newly diagnosed with AF.Using data from the TREAT-AF (Retrospective Evaluation and Assessment of Therapies in AF) study from the Veterans Health Administration, patients with newly diagnosed, nonvalvular AF between 2004 and 2012 were identified who had at least 1 outpatient encounter with primary care or cardiology within 90 days of the AF diagnosis. Cox proportional hazards regression was used to evaluate the association between treating specialty and AF outcomes.Among 184,161 patients with newly diagnosed AF (age 70 ± 11 years; 1.7% women; CHA2DS2-VASc score 2.6 ± 1.7), 40% received cardiology care and 60% received primary care only. After adjustment for covariates, cardiology care was associated with reductions in stroke (hazard ratio [HR]: 0.91; 95% confidence interval [CI]: 0.86 to 0.96; p < 0.001) and death (HR: 0.89; 95% CI: 0.88 to 0.91; p < 0.0001) and increases in hospitalizations for AF/supraventricular tachycardia (HR: 1.38; 95% CI: 1.35 to 1.42; p < 0.0001) and myocardial infarction (HR: 1.03; 95% CI: 1.00 to 1.05; p < 0.04). The propensity-matched cohort had similar results. In mediation analysis, oral anticoagulation prescription within 90 days of diagnosis may have mediated reductions in stroke but did not mediate reductions in survival.In patients with newly diagnosed AF, cardiology care was associated with improved outcomes, potentially mediated by early prescription of oral anticoagulation therapy. Although hypothesis-generating, these data warrant serious consideration and study of health care system interventions at the time of new AF diagnosis.
View details for PubMedID 28662810
Amiodarone and risk of death in contemporary patients with atrial fibrillation: Findings from The Retrospective Evaluation and Assessment of Therapies in AF study.
American heart journal
2015; 170 (5): 1033-1041 e1
There are limited data on mortality outcomes associated with use of amiodarone in atrial fibrillation and flutter (AF).We evaluated the association of amiodarone use with mortality in patients with newly diagnosed AF using complete data from the Department of Veterans Affairs national health care system. We included patients seen in an outpatient setting within 90 days of a new diagnosis for nonvalvular AF between Veterans Affairs fiscal years 2004 and 2008. Multivariate analysis and propensity-matched Cox proportional hazards regression were used to evaluate the association of amiodarone use to death.Of 122,465 patients (353,168 person-years of follow-up, age 72.1 ± 10.3 years, 98.4% males), amiodarone was prescribed in 11,655 (9.5%). Cumulative, unadjusted mortality rates were higher for amiodarone recipients than for nonrecipients (87 vs 73 per 1,000 person-years, P < .001). However, in multivariate and propensity-matched survival analyses, there was no significant difference in mortality (multivariate hazard ratio 1.01, 95% CI 0.97-1.05, P = .51, and propensity-matched hazard ratio 1.02, 95% CI 0.97-1.07, P = .45). The hazard of death was not modified by age, sex, heart failure, kidney function, β-blocker use, or warfarin use, but there was evidence of effect modification among patients diagnosed with AF as an inpatient versus outpatient.In a national health care system population of newly diagnosed AF, overall use of amiodarone as an early treatment strategy was not associated with mortality.
View details for DOI 10.1016/j.ahj.2015.07.023
View details for PubMedID 26542514
The long-term prognostic value of the Q wave criteria for prior myocardial infarction recommended in the universal definition of myocardial infarction.
Journal of electrocardiology
2015; 48 (5): 798-802
We sought to characterize the prognostic value of the third universal definition of myocardial infarction (UDMI) and ≥40msec Q wave criteria.We evaluated hazard ratios (HR) with 95% confidence intervals (CI) for cardiovascular (CV) death for computerized Q wave measurements from the electrocardiograms of 43,661 patients collected from 1987 to 1999 at the Palo Alto VA. There were 3929 (9.0%) CV deaths over a mean follow-up of 7.6 (±3.8) years.The risk of CV death for Q waves ≥40msec in any two contiguous leads in any lead group was equivalent to or higher than that for contiguous UDMI Q waves, with HR 2.44 (95% CI 2.15-4.11) and HR 2.42 (95% CI (2.18-3.42), respectively.The UDMI Q wave criteria do not provide an advantage over ≥40msec Q waves at predicting CV death.
View details for DOI 10.1016/j.jelectrocard.2015.07.004
View details for PubMedID 26233646
Evaluating the Cost-effectiveness of Catheter Ablation of Atrial Fibrillation.
Arrhythmia & electrophysiology review
2014; 3 (3): 177-183
Atrial fibrillation (AF) is one of the most common cardiac conditions treated in primary care and specialty cardiology settings, and is associated with considerable morbidity, mortality and cost. Catheter ablation, typically by electrically isolating the pulmonary veins and surrounding tissue, is more effective at maintaining sinus rhythm than conventional antiarrhythmic drug therapy and is now recommended as first-line therapy. From a value standpoint, the cost-effectiveness of ablation must incorporate the upfront procedural costs and risks with the benefits of longer term improvements in quality of life (QOL) and healthcare utilisation. Here, we present a primer on cost-effectiveness analysis (CEA), review the data on cost-effectiveness of AF ablation and outline key areas for further investigation.
View details for DOI 10.15420/aer.2014.3.3.177
View details for PubMedID 26835088
Association Between Success Rate and Citation Count of Studies of Radiofrequency Catheter Ablation for Atrial Fibrillation Possible Evidence of Citation Bias
CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES
2014; 7 (5): 687-692
The preferential citation of studies with the highest success rates could exaggerate perceived effectiveness, particularly for treatments with widely varying published success rates such as radiofrequency catheter ablation for atrial fibrillation.We systematically identified observational studies and clinical trials of radiofrequency catheter ablation of atrial fibrillation between 1990 and 2012. Generalized Poisson regression was used to estimate association between study success rate and total citation count, adjusting for sample size, journal impact factor, time since publication, study design, and whether first or last author was a consensus-defined pre-eminent expert. We identified 174 articles meeting our inclusion criteria (36 289 subjects). After adjustment only for time since publication, a 10-point increase above the mean in pooled reported success rates was associated with a 17.8% increase in citation count at 5 years postpublication (95% confidence interval, 7.1-28.4%; P<0.001). After additional adjustment for impact factor, sample size, randomized trial design, and pre-eminent expert authorship, the association remained significant (18.6% increase in citation count; 95% confidence interval, 7.6-29.6%; P<0.0001). In this full model, time since publication, impact factor, and pre-eminent expert authorship were significant covariates, whereas randomized control trial design and study sample size were not.Among studies of radiofrequency catheter ablation of atrial fibrillation, high success rate was independently associated with citation count, which may indicate citation bias. To readers of the literature, radiofrequency catheter ablation of atrial fibrillation could be perceived to be more effective than the data supports. These findings may have implications for a wide variety of novel cardiovascular therapies.
View details for DOI 10.1161/CIRCOUTCOMES.114.000912
View details for Web of Science ID 000342365200011
The long-term prognostic value of the ST depression criteria for ischemia recommended in the universal definition of myocardial infarction in 43,661 veterans
INTERNATIONAL JOURNAL OF CARDIOLOGY
2014; 173 (3): 494-498
The third Universal Definition of Myocardial Infarction (UDMI) includes electrocardiographic criteria for ischemia, specifying horizontal or down-sloping ST depression ≥0.05 mV in two contiguous electrocardiogram (ECG) leads. We used the surrogate of cardiovascular (CV) death to evaluate the criteria.We collected computerized ST amplitude measurements, in different lead groupings, from the resting ECGs of 43,661 patients collected between 1987 and 1999 at the Palo Alto VA. There were 3929 (9.0%) cardiac deaths over a mean follow-up of 7.6 (SD 3.8) years.We found that horizontal or down-sloping ST depressions in contiguous leads, depending upon the lead groupings, had sensitivities ranging from 1% to 5%, specificities exceeding 99%, and relative risks for CV death ranging from 3.1 to 7.0 (p<0.001 for each individual relative risk) while horizontal or down-sloping ST depressions in a single lead had comparable values. We found that up-sloping ST depressions had greater sensitivities than horizontal or down-sloping ST depressions. Additionally, we found that ST depressions isolated to the inferior or anterior leads, without concomitant lateral depressions, were poor predictors of CV death.These findings reinforce and further characterize the value of ST depressions for predicting CV death. Furthermore, if these findings can be reproduced in the acute setting, they would undermine the requirement for contiguous lead depressions with slope assessment as well as prioritize ST depression in V4, V5, and V6 when assessing for myocardial ischemia.
View details for DOI 10.1016/j.ijcard.2014.03.091
View details for PubMedID 24704413
Comparison of a Safety Strategy Using Transradial Access and Dual-Axis Rotational Coronary Angiography with Transfemoral Access and Standard Coronary Angiography
JOURNAL OF INTERVENTIONAL CARDIOLOGY
2013; 26 (5): 524-529
We sought to investigate the radiation exposure and contrast utilization associated with using a strategy of transradial access and rotational angiography (radial-DARCA) compared to the traditional approach of transfemoral access and standard angiography (femoral-SA).There is an increased focus on optimizing patient safety during cardiac catheterization procedures. Professional guidelines have highlighted physician responsibility to minimize radiation doses and contrast volume. Dual axis rotational coronary angiography (DARCA) is the most recently investigated type of rotational angiography. This new technique permits complete visualization of the left or right coronary tree with a single injection, and is felt to reduce contrast and radiation exposure.A total of 56 consecutive patients who underwent radial-DARCA were identified. From the same time period, an age- and gender-matched group of 61 patients who had femoral-SA were selected for comparison. Total volume of contrast agent used, fluoroscopy time, and 2 measures of radiation dose (dose area product and air kerma) were recorded for each group.Mean contrast agent use and patient radiation exposure of the radial-DARCA group were significantly less than that of the femoral-SA group. There was no significant difference in fluoroscopy time between the 2 groups.Physicians can successfully employ an innovative safety strategy of transradial access combined with DARCA that is feasible and is associated with lower radiation doses and contrast volume than femoral artery access and traditional coronary angiography approach.
View details for DOI 10.1111/joic.12054
View details for Web of Science ID 000325478600012
View details for PubMedID 23952684