Cardiac resynchronization therapy in patients undergoing atrioventricular junction ablation for permanent atrial fibrillation: a randomized trial.

AIMS: On the basis of the current knowledge, cardiac resynchronization therapy (CRT) cannot be recommended as a first-line treatment for patients with severely symptomatic permanent atrial fibrillation undergoing atrioventricular (AV) junction ablation. We examined whether CRT was superior to conventional right ventricular (RV) pacing in reducing heart failure (HF) events.

METHODS AND RESULTS: In this prospective, multi-centre study, we randomly assigned 186 patients, in whom AV junction ablation and CRT device implantation had been successfully performed, to receive optimized echo-guided CRT (97 patients) or RV apical pacing (89 patients). The data were analysed according to the intention-to-treat principle. During a median follow-up of 20 months (interquartile range 11-24), the primary composite endpoint of death from HF, hospitalization due to HF, or worsening HF occurred in 11 (11%) patients in the CRT group and 23 (26%) patients in the RV group [CRT vs. RV group: sub-hazard ratio (SHR) 0.37 ( 95% CI 0.18-0.73), P = 0.005]. In the CRT group, compared with the RV group, fewer patients had worsening HF [SHR 0.27 (95% CI 0.12-0.58), P = 0.001] and hospitalizations for HF [SHR 0.20 (95% CI 0.06-0.72), P = 0.013]. Total mortality was similar in both groups [hazard ratio (HR) 1.57 (95% CI 0.58-4.27), P = 0.372]. The beneficial effects of CRT were consistent in patients who had ejection fraction ≤35%, New York Heart Association Class ≥III and QRS width ≥120 and in those who did not. At multi-variable Cox regression, only CRT mode remained an independent predictor of absence of clinical failure during the follow-up [HR = 0.23 (95% CI 0.08-0.66), P = 0.007].

CONCLUSIONS: In patients undergoing 'Ablate and Pace' therapy for severely symptomatic permanent atrial fibrillation, CRT is superior to RV apical pacing in reducing the clinical manifestations of HF. (ClinicalTrials.gov number: NCT00111527).