The RACE study in perspective of randomized studies on management of persistent atrial fibrillation

Atrial fibrillation is the most common sustained cardiac arrhythmia. Treatment strategies are focused on reducing symptoms and minimizing the risks of atrial fibrillation like stroke and heart failure. First choice therapy is the rhythm control strategy, with restoration of sinus rhythm. Drawback of this approach is the low success rate for maintenance of sinus rhythm. Outcome will improve with the use of antiarrhythmic drugs after electrical cardioversion, unfortunately exposing the patient to the risks of life threatening pro-arrhythmia. The second alternative, a rate control strategy, is easy to achieve but it is unknown whether this treatment strategy results in higher morbidity and mortality rates. RACE (RAte Control versus Electrical cardioversion for persistent atrial fibrillation) was a prospective randomized trial comparing both strategies. The primary end point was a composite of death from cardiovascular causes, heart failure, thromboembolic complications, bleeding, pacemaker implants and severe adverse effects of drugs. After a mean follow-up of 2.3 years, the primary end point occurred in 44 of the 256 rate control patients (17.2%) and 60 of the 266 rhythm control patients (22.6%). Other trials as the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management), PIAF (Pharmacological Intervention in Atrial Fibrillation) and STAF (Strategies of Treatment of Atrial Fibrillation) also found that rate control was not inferior to rhythm control in terms of morbidity, mortality and quality of life. These four randomized trials demonstrated that a rate control strategy is an acceptable alternative to rhythm control in patients with recurrent atrial fibrillation. For those with severely symptomatic atrial fibrillation, continued rhythm control is unavoidable. For these patients, safer and more effective methods of maintaining sinus rhythm are needed to reduce morbidity related to palpitations and atrial fibrillation-induced heart failure.Furthermore, the randomized studies showed that rhythm control therapy does not prevent stroke. It was observed from RACE that 21 of the 35 thromboembolic complications occurred under rhythm control, the majority while receiving inadequate anticoagulation therapy. Also in AFFIRM, with patients with one or more stroke risk factors, more strokes were present under rhythm control. Therefore, one of the main lesson learned from the randomized studies is that anticoagulation must be continued if stroke risk factors are present even if patients maintain sinus rhythm.