Association of Permanent Atrial Fibrillation With Mortality and Heart Failure Progression in Low Thromboembolic Risk Patients.

BACKGROUND Although atrial fibrillation (AF) is a well-established risk factor for thromboembolic events, patients with a low CHA₂DS₂-VASc score are generally considered at low risk. However, permanent AF may independently worsen outcomes via non-embolic mechanisms such as myocardial remodeling and progression of heart failure (HF). MATERIAL AND METHODS This retrospective observational sub-study used data from the CRAFT study (NCT02987062), a multicenter registry of AF patients hospitalized between 2011 and 2016. We included 418 patients with CHA₂DS₂-VASc ≤2 for women and with ≤1 for men, of whom 63 had permanent AF as defined by ESC guidelines. The primary endpoint was all-cause mortality; secondary endpoints included ischemic events and bleeding during a mean follow-up of 4 years. RESULTS Patients with permanent AF had significantly higher all-cause mortality (39.7% vs 8.7%; P<0.0001) and a comparable rate of ischemic events (12.7% vs 8.5%; P=0.12) despite similarly low thromboembolic risk profiles. They were older (64 vs 60 years; P<0.0001), more frequently had heart failure (48.4% vs 15.5%; P<0.0001) and, lower left ventricular ejection fraction (LVEF) (43.5% vs 55%; P=0.0005), and more often had cardiac devices. CONCLUSIONS Our findings suggest that permanent AF is associated with worse long-term outcomes, even in patients with low thromboembolic risk score. These results show the importance of early rhythm control in preventing AF progression and irreversible structural remodeling.