Cardiac Resynchronization Therapy in Patients With Atrial Fibrillation. The CERTIFY Study (Cardiac Resynchronization Therapy in Atrial Fibrillation Patients Multinational Registry).

Objectives: The purpose of this study is to determine whether, in patients with atrial fibrillation (AF) undergoing cardiac resynchronization therapy (CRT), atrioventricular junction ablation (AVJA) is associated with a better outcome than treatment with rate-slowing drugs. Background: Different trials have demonstrated that CRT is effective in treating heart failure (HF) patients who are in sinus rhythm (SR). No trials have addressed whether CRT confers similar benefits on AF patients, with or without AVJA. Methods: The clinical outcomes of CRT for patients with permanent AF undergoing CRT combined with either AVJA (n= 443) or rate-slowing drugs (n= 895) were compared with those of SR patients (n= 6,046). Results: Median follow-up was 37 months. Total mortality (6.8 vs. 6.1 per 100 person-years) and cardiac mortality (4.2 vs. 4.0) were similar for patients with AF+AVJA and patients in SR (both p= NS). In contrast, the AF+drugs group hada higher total and cardiac mortality than the SR group and the AF+AVJA group (11.3 and 8.1, respectively; p<0.001). On multivariable analysis, AF+AVJA had total mortality (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.74 to 1.67) and cardiac mortality (HR: 0.88, 95% CI: 0.66 to 1.17) similar to that of the SR group, independent of known confounders. The AF+drugs group, however, had a higher total mortality (HR: 1.52, 95% CI: 1.26 to 1.82) and cardiac mortality (HR: 1.57, 95% CI: 1.27 to 1.94) than both the SR group and the AF+AVJA group (both p<0.001). Conclusions: Long-term survival after CRT among patients with AF+AVJA is similar to that observed among patients in SR. Mortality is higher for AF patients treated with rate-slowing drugs.