Atrial fibrillation is common in patients with heart failure, but outcomes of patients with both conditions who receive cardiac resynchronization therapy with defibrillator (CRT-D) compared with an implantable cardioverter-defibrillator (ICD) alone are unclear.Methods and Results—
Using the National Cardiovascular Data Registry’s ICD Registry linked with Medicare claims, we identified 8951 patients with atrial fibrillation who were eligible for CRT-D and underwent first-time device implantation for primary prevention between April 2006 and December 2009. We used Cox proportional hazards models and inverse probability-weighted estimates to compare outcomes with CRT-D versus ICD alone. Cumulative incidence of mortality (744 [33%] for ICD; 1893 [32%] for CRT-D) and readmission (1788 [76%] for ICD; 4611 [76%] for CRT-D) within 3 years and complications within 90 days were similar between groups. After inverse weighting for the probability of receiving CRT-D, risks of mortality (hazard ratio, 0.83; 95% confidence interval, 0.75–0.92), all-cause readmission (hazard ratio, 0.86; 95% confidence interval, 0.80–0.92), and heart failure readmission (hazard ratio, 0.68; 95% confidence interval, 0.62–0.76) were lower with CRT-D compared with ICD alone. There was no significant difference in the 90-day complication rate (hazard ratio, 0.88; 95% confidence interval, 0.60–1.29). We observed hospital-level variation in the use of CRT-D among patients with atrial fibrillation.Conclusions—
Among eligible patients with heart failure and atrial fibrillation, CRT-D was associated with lower risks of mortality, all-cause readmission, and heart failure readmission, as well as with a similar risk of complications compared with ICD alone.