There is evidence of superiority of AV junction ablation strategy over pharmacological therapy only for symptoms of atrial fibrillation, but not for heart failure, hospitalization, morbidity and mortality. Hypothesis of trial is that AV junction ablation is superior to pharmacological therapy as regard hospitalization and mortality

Prospective randomized, controlled, investigator-initiated trial which consists of two specific consecutive(overlapped) phases:

"Morbidity trial" (APAF-CRT morbidity). Small size (280 pts), follow-up 24 months. Primary endpoint: combined of mortality due to heartfailure, hospitalization for heart failure or atrial fibrillation or worsening heart failure. Predefined subgroup analysis for patients with ejection fraction ≤35% versus >35%

"Mortality trial" (APAF-CRT mortality). Large size (pts included in morbidity trial plus additional ~1500 pts, long-term follow-up (at least 4 years). Primary endpoint: total mortality. Predefined subgroup analysis for patients with ejection fraction ≤35% versus >35%

Inclusion Criteria:

To be eligible, each patient must be in the following condition:

1. Permanent atrial fibrillation (>6 months) which has been considered unsuitable for ablation or failed ablation
2. Narrow QRS ≤ 110 ms
3. Severely symptomatic (atrial fibrillation-related symptoms), refractory to drug therapy for rate control
4. At least one hospitalization related to atrial fibrillation and/or heart failure in the previous year (see definition below)

Exclusion Criteria:

1. New York Heart Association (NYHA) class IV and systolic blood pressure <80 mmHg despite optimized therapy;
2. severe concomitant non-cardiac disease;
3. need for surgical intervention;
4. myocardial infarction within the previous 3 months;
5. previous implanted devices (PM/ICD/CRT)