Asymptomatic persistent atrial fibrillation and outcome: results of the RACE study

Background: Symptoms are a major driver for patients with atrial fibrillation (AF) to seek medical attention and are important to titrate AF therapies. However, a large proportion of patients with AF are asymptomatic.

Objective: To investigate the clinical profile and prognosis of patients with asymptomatic recurrent persistent AF in the RAte Control versus Electrical cardioversion for persistent atrial fibrillation study.

Methods: Patients with asymptomatic AF (n = 157 [30%]) were compared with patients with symptomatic AF (n = 365 [70%]). The primary end point was a composite of cardiovascular morbidity and mortality.

Results: Patients with asymptomatic AF were younger and more often men than were patients with symptomatic AF. Cardiac diseases were less common. Quality of life (the Medical Outcomes Study Short-form health survey questionnaire) was better in patients with asymptomatic AF and comparable to healthy controls. At baseline and during follow-up, there were no differences in rate control, antiarrhythmic, or anticoagulant drugs; cardioversions; and time in sinus rhythm. After a follow-up of 2.3 ± 0.6 years, the primary end point occurred in 21 (13%) patients with asymptomatic AF and 83 (23%) patients with symptomatic AF. After adjusting for relevant covariates, asymptomatic AF was associated with a lower risk of the primary end point (hazard ratio 0.51; 95% confidence interval 0.29-0.92; P = .024). This difference was driven by significantly less heart failure hospitalizations (0 vs 21 [6%]) and severe effects of antiarrhythmic drugs or digoxin (1 [0.6%] vs 13 [4%]). Importantly, no difference in the occurrence of thromboembolic complications was observed.

Conclusion: Patients with asymptomatic AF were more often men and had less cardiac disease. During follow-up, in patients with asymptomatic AF, heart failure hospitalizations and severe adverse effects of antiarrhythmic and rate control drugs occurred significantly less frequently.