Symptoms are a major driver for patients with atrial fibrillation to seek medical attention and are important to titrate atrial fibrillation therapies. However, a large proportion of patients with atrial fibrillation are asymptomatic.
Researchers have investigated the clinical profile and prognosis of patients with asymptomatic recurrent persistent atrial fibrillation in the RACE ( RAte Control versus Electrical cardioversion for persistent atrial fibrillation ) trial.
Patients with asymptomatic atrial fibrillation ( n = 157 [ 30% ] ) were compared with patients with symptomatic atrial fibrillation ( n = 365 [ 70% ] ).
The primary end point was a composite of cardiovascular morbidity and mortality.
Patients with asymptomatic atrial fibrillation were younger and more often men than were patients with symptomatic atrial fibrillation.
Cardiac diseases were less common.
Quality of life ( the Medical Outcomes Study Short-form health survey questionnaire ) was better in patients with asymptomatic atrial fibrillation 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 endpoint occurred in 21 ( 13% ) patients with asymptomatic atrial fibrillation and 83 ( 23% ) patients with symptomatic atrial fibrillation.
After adjusting for relevant covariates, asymptomatic atrial fibrillation was associated with a lower risk of the primary end point ( hazard ratio, HR=0.51; 95% confidence interval 0.29–0.92; P = 0.024 ).
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.
In conclusion patients with asymptomatic atrial fibrillation were more often men and had less cardiac disease.
During follow-up, in patients with asymptomatic atrial fibrillation, heart failure hospitalizations and severe adverse effects of antiarrhythmic and rate control drugs occurred significantly less frequently. ( Xagena )
Rienstra M et al, Heart Rhythm 2014; 11: 939–945