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.