Objective To evaluate the 2-year clinical improvement after 'Ablate and Pace' therapy and to identify the variables able to influence the efficacy of this therapy in patients with permanent atrial fibrillation (AF).

Design Prospective multicentre observational study.

Setting Cardiology departments of 19 general hospitals in Italy, Spain and Greece.

Patients 171 patients with drug-refractory severely symptomatic permanent AF considered for AV junction ablation.

Interventions Patients underwent AV junction ablation, received a right ventricular (RV) pacing or echo-guided cardiac resynchronisation (CRT) pacing and were followed-up to 24 months.

Main outcome measures Non-responders to Ablate and Pace therapy were defined those patients who, during the follow-up period had clinical failure (defined as death or hospitalisation due to heart failure, or worsening heart failure) or showed no improvement in their clinical condition.

Results Responders were 63% of RV-paced patients and 83% of CRT-paced patients. Another 27% showed no clinical improvement (7%) or worsened (20%) (non-responders group). On multivariable Cox regression analysis, CRT mode and echo-optimised CRT were the only independent protective factors against non-response (HR=0.24, 95% CI 0.10–0.58, p=0.001 and HR=0.22, 95% CI 0.07–0.77, p=0.018 respectively). On comparing freedom from non-response, a trend in favour of echo-optimised CRT versus simultaneous biventricular pacing (p=0.077) was seen.

Conclusions In patients affected by severely symptomatic permanent AF, Ablate and Pace therapy yielded a clinical benefit in 63% of RV-paced patients and 83% of CRT-paced patients. CRT pacing and echo-optimised CRT were the only independent predictor of clinical benefit.