Asymptomatic Atrial Fibrillation in Contemporary Clinical Practice: Insights from the REGUEIFA Registry

Background: Asymptomatic atrial fibrillation (AF) represents a substantial proportion of diagnosed AF cases; however, its prognostic implications remain controversial. This study aimed to compare clinical characteristics, treatment strategies, and outcomes between asymptomatic and symptomatic AF patients in a contemporary real-world registry. Methods: This observational subanalysis included 997 patients from the prospective multicenter REGUEIFA registry with 2-year follow-up. Patients were classified as asymptomatic if they had a baseline European Heart Rhythm Association (EHRA) score of I. Clinical characteristics, therapeutic strategies, and the incidence of a composite endpoint including cardiovascular death, stroke, major bleeding, or worsening heart failure were analyzed. Results: Overall, 33.7% of patients were asymptomatic. Compared with symptomatic patients, asymptomatic patients had a lower prevalence of heart failure, hypertension, and cardiomyopathy, lower CHA₂DS₂-VASc scores, and a higher prevalence of preserved left ventricular ejection fraction. Rhythm control strategies were less frequently used in asymptomatic patients (58.33% vs. 65.96%; p = 0.018), despite similar arrhythmia recurrence rates after treatment (p = 0.490). The incidence of the composite endpoint was lower in asymptomatic patients (8.39 [6.53-10.78] vs. 12.12 [10.43-14.09] per 100 person-years; p = 0.013), mainly driven by lower cardiovascular mortality. No significant differences were observed in stroke, major bleeding, worsening heart failure, or all-cause mortality. In multivariable analysis adjusted for clinically relevant covariates, symptomatic patients exhibited a higher incidence of the composite endpoint. Conclusions: In this contemporary real-world registry, asymptomatic AF patients exhibited a lower burden of cardiovascular comorbidities and lower cardiovascular mortality than symptomatic patients, while rates of stroke, heart failure worsening, major bleeding, and arrhythmia recurrence were similar. These findings suggest that prognosis is influenced predominantly by baseline comorbidity burden, and the independent contribution of symptom status itself, although statistically significant, appears modest and should be interpreted with caution given the observational design.