Prognostic role of atrial fibrillation in patients affected by chronic heart failure : data from the MECKI score research group

Background: Atrial fibrillation (AF) is common in heart failure (HF). It is unclear whether AF has an independent prognostic role in HF. The aim of the present study was to assess the prognostic role of AF in HF patients with reduced ejection fraction (EF). Methods: HF patients were followed in 17 centers for 3.15years (1.51-5.24). Study endpoints were the composite of cardiovascular (CV) death and heart transplant (HTX) and all-cause death. Data analysis was performed considering the entire population and a 1 to 1 match between sinus rhythm (SR) and AF patients. Match process was done for age±5, gender, left ventricle EF±5, peakVO2 ±3 (ml/min/kg) and recruiting center. Results: A total of 3447 patients (SR=2882, AF=565) were included in the study. Considering the entire population, CV death and HTX occurred in 114 (20%) AF vs. 471 (16%) SR (p=0.026) and all-cause death in 130 (23%) AF vs. 554 (19.2%) SR patients (p=0.039). At univariable Cox analysis, AF was significantly related to prognosis. Applying a multivariable model based on all variables significant at univariable analysis (EF, peakVO2, ventilation/carbon dioxide relationship slope, sodium, kidney function, hemoglobin, beta-blockers and digoxin) AF was no longer associated with adverse outcomes. Matching procedure resulted in 338 couples. CV death and HTX occurred in 63 (18.6%) AF vs. 74 (21.9%) SR (p=0.293) and all-cause death in 71 (21%) AF vs. 80 (23.6%) SR (p=0.406), with no survival differences between groups. Conclusion: In systolic HF AF is a marker of disease severity but not an independent prognostic indicator.