Impact of Atrial Fibrillation on Long-Term Outcomes of Aortic Stenosis.

BACKGROUND: Atrial fibrillation (AF) is common in patients with aortic stenosis (AS), but its independent long-term prognostic impact on outcomes remains uncertain. We examined the association between AF and mortality risk across the full spectrum of AS. METHOD: In this retrospective cohort study, we included 1592 patients with at least mild AS and preserved left ventricular ejection fraction (≥50%). Patients were stratified by AF status. Primary and secondary end points were all-cause and cardiovascular mortality, respectively. RESULTS: Of 1592 patients, including the full spectrum of AS severity, 254 (16%) had AF. AF was more prevalent in patients with severe paradoxical low-flow low-gradient (36%) compared with severe normal-flow (12%), severe high-gradient (10%), and mild-to-moderate (16%) AS (P<0.001). During a median follow-up of 7.2 (interquartile range, 3.6-11.0) years, 885 deaths occurred (49% cardiovascular-related). AF was associated with an increased risk of all-cause and cardiovascular mortality (both P<0.001). In multivariable Cox models, AF independently predicted a higher risk of all-cause (hazard ratio [HR], 1.78 [95% CI, 1.34-2.36], P<0.001) and cardiovascular (HR, 1.77 [95% CI, 1.20-2.62], P=0.004) mortality. The prognostic impact was greatest for permanent/persistent AF (HR, 2.04) and significant for paroxysmal AF (HR, 1.69). The association of AF with outcomes remained consistent across various subgroups, including AS flow-gradient patterns (all interaction P>0.05). CONCLUSION: In this large cohort with AS, AF was independently associated with an increased risk of both all-cause and cardiovascular mortality, regardless of treatment strategy or AS flow-gradient pattern. AF should be integrated into risk stratification algorithms in AS, beyond parameters of AS severity.