After adjusting for age, New York Heart Association class III-IV, cardiothoracic ratio >0.5, NT-proBNP, persistent atrial fibrillation, DLCO, COPD comorbidity, use of beta-blockers and angiotensin converting enzyme inhibitors, the HR decreased to 1.9 but remained statistically significant (p = 0.039). This evidence concerns the gene ACE and atrial fibrillation.