Resumption of sinus rhythm in patients with heart failure and permanent atrial fibrillation undergoing cardiac resynchronization therapy: a longitudinal observational study

Aims To investigate the temporal patterns, predictors, and prognostic impact of spontaneous sinus rhythm resumption (SRR) of heart failure (HF) patients with permanent atrial fibrillation (AF) treated with cardiac resynchronization therapy (CRT). Methods and results This multicentre, retrospective, longitudinal study analysed 330 consecutive HF patients with permanent AF treated with a CRT device (mean age 70 +/- 9 years, male 83%, ischaemic aetiology 44%, NYHA class III-IV 93%, mean QRS duration 167 +/- 40 ms, and mean ejection fraction 26 +/- 7%). Clinical, echocardiographic, and outcome data were collected during follow-up. Thirty-four patients experienced SRR after CRT (10.3%) at a median 4-month follow-up. The strongest independent predictors were end-diastolic diameter (EDD) [hazard ratios (HR) 4.03, 95% confidence intervals (95% Cl) 1.43-11.36, P = 0.008], post-CRT QRS <= 150 ms (HR 2.63, 95% Cl 1.02-6.67, P = 0.05), left atrium (LA) diameter <= 50 mm (HR 4.76, 95% Cl 1.72-11.82, P = 0.002), and atrioventricular junction (AVJ) ablation (HR 4.27, 95% Cl 1.54-11.84, P = 0.02). The coexistence of three predictors vs. zero to two predictors increased by 3.5-fold the likelihood of SRR; while the presence of all four factors improves the probability by a factor of 5.7-fold. Sinus rhythm resumption was associated with a significantly better long-term survival (log rank P = 0.03). Conclusion Keywords One in every 10 HF patients with permanent AF may experience SRR after CRT. Baseline EDD <= 65 mm, CRT-paced QRS <= 150 ms, LA <= 50 mm, and AVJ ablation appear to be predictive of this phenomenon.