Complete atrioventricular block does not reduce long-term mortality in patients with permanent atrial fibrillation treated with cardiac resynchronization therapy

Aims A maximum percentage of ventricular pacing is mandatory to obtain a good response to CRT. Atrioventricular junction (AVJ) ablation has been recommended to attain this objective in patients with AF. The aims of our study were: (i) to determine whether the presence of complete AVJ block (induced or spontaneous) improves survival in patients with permanent AF treated with CRT and (ii) to analyse the predictors of mortality in AF patients treated with CRT. Methods and results From a series of 608 patients treated with CRT in our centre from 2000 to 2011, a cohort of 155 patients with permanent AF was analysed. Patients in AF were divided into two groups, AF + AVJ block [76 (49%)] and AF non-AVJ block [79 (51%)]. Mean follow-up was 30 months (interquartile range 13-51 months). During the follow-up, 62 patients died. Overall and cardiovascular mortality were similar between both groups: hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.51-1.39, P = 0.51 and HR 0.94, 95% CI 0.52-1.68, P = 0.82. Multivariate analysis identified three independent predictors of mortality: basal NYHA functional class IV (HR 2.25, 95% CI 1.12-4.22, P = 0.03), glomerular filtration rate (HR 0.98, 95% CI 0.96-0.99, P = 0.03), and LVEF (HR 0.94, 95% CI 0.89-0.99, P = 0.02). Conclusions AVJ block did not improve survival for patients in AF treated with CRT. Basal NYHA functional class IV, poor renal function, and LVEF were the independent predictors of mortality.