Practice Variation in Anticoagulation Prescription and Outcomes After Device-Detected Atrial Fibrillation.

BACKGROUND: Device-detected atrial fibrillation (AF) is associated with increased risk of stroke; however, there are no clearly defined thresholds of AF burden at which to initiate oral anticoagulation (OAC). We sought to describe OAC prescription practice variation in response to new device-detected AF and the association with 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 and remote monitoring from 2011 to 2014, CHA2DS2-VASc score ≥2, and no prior stroke or OAC receipt in the preceding 2 years. We determined the proportion of patients prescribed OAC within 90 days after 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 cardiac implantable electronic devices, 4570 (45%), 3969 (39%), 3263 (32%), and 2469 (24%) had device-detected AF >6 minutes, >1 hour, >6 hours, and >24 hours, respectively. For device-detected AF >1 hour, 1712 patients met inclusion criteria (72±10 years; 1.5% female; CHA2DS2-VASc score 4.0±1.4; HAS-BLED score 2.6±1.1). The proportion receiving OAC varied based on device-detected AF burden (≥6 minutes: 272/2101 [13%]; >1 hour: 273/1712 [16%]; >6 hours: 263/1279 [21%]; >24 hours: 224/818 [27%]). Across 52 sites (N=1329 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 (hazard ratio, 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 cardiac implantable electronic devices, 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 that last >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.

Patient and facility variation in costs of catheter ablation for atrial fibrillation.

BACKGROUND: 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 US healthcare system and the relationship between cost and outcomes. METHODS AND RESULTS: 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 to 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 1-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 healthcare utilization in higher cost quintiles with reductions in rehospitalization at 30-days (Quintile 1: 16.1%, Quintile 5: 8.8%, P < 0.001) and 1-year (Quintile 1: 34.8%, Quintile 5: 25.6%, P < 0.001), which remained significant in multivariate analysis. CONCLUSIONS: 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.

Amiodarone and risk of death in contemporary patients with atrial fibrillation: Findings from The Retrospective Evaluation and Assessment of Therapies in AF study.

BACKGROUND: There are limited data on mortality outcomes associated with use of amiodarone in atrial fibrillation and flutter (AF). METHODS: 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. RESULTS: 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, ß-blocker use, or warfarin use, but there was evidence of effect modification among patients diagnosed with AF as an inpatient versus outpatient. CONCLUSION: 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.

Evaluating the Cost-effectiveness of Catheter Ablation of Atrial Fibrillation.

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.