Embolic and Other Adverse Outcomes in Symptomatic Versus Asymptomatic Patients With Atrial Fibrillation (from the ORBIT-AF Registry)

Asymptomatic atrial fibrillation (AF) is being increasingly diagnosed via implantable devices, screening, and inpatient telemetry. Management of asymptomatic AF is controversial, in part, because the associated risks have not been well described. We examined the incidence of major adverse outcomes in patients with asymptomatic versus symptomatic AF using Outcomes Registry for Better Informed Treatment of Atrial, a nationwide US registry of AF patients. We compared stroke and/or non-central nervous system (CNS) embolism, major adverse cardiovascular and neurologic events, bleeding, and death in 9,319 asymptomatic (defined by European Heart Rhythm Association score = 1 or “no symptoms”) versus symptomatic patients. Overall, median (interquartile) age was 75 (67 to 82) years, 3,944 (42%) were women, and 38% versus 37% were asymptomatic based on physician versus patient-reported symptoms. Compared with those with symptoms, physician-defined asymptomatic patients were less likely to be woman (35%/47%) or be on an antiarrhythmic agent (22%/33%), but were more likely to have permanent and/or persistent AF (51%/40%). CHA₂DS₂-VASc scores did not vary by symptom status. After adjustment, risk of first stroke and/or non-CNS embolism (hazard ratio [HR] 0.85 [95% confidence interval {CI} 0.63 to 1.16], p = 0.32), major adverse cardiovascular and neurologic events (HR 0.88 [95% CI 0.76 to 1.03], p = 0.11), bleeding (HR 0.85 [95% CI 0.72 to 1.00], p = 0.05), and death (HR 0.99 [95% CI 0.87 to 1.13], p = 0.88) were similar in asymptomatic (European Heart Rhythm Association = 1) and symptomatic AF, respectively. Prospective, randomized studies are needed to further define associated adverse events and delineate optimal prophylactic therapies in patients with asymptomatic AF.