Improving outcomes in patients with atrial fibrillation: rationale and design of the Early treatment of Atrial fibrillation for Stroke prevention Trial

BACKGROUND: Even on optimal therapy including anticoagulation and rate control, major cardiovascular complications (stroke, cardiovascular death, and acute heart failure) are common in patients with atrial fibrillation (AF). Conceptually, maintenance of sinus rhythm could prevent adverse outcomes related to AF. Rhythm control therapy has been only moderately effective in published trials, and its potential benefit was offset by side effects of repeated interventions.

RATIONALE: Rhythm control therapy applied early after the first diagnosis of AF could preserve atrial structure and function and maintain sinus rhythm more effectively than the current practice of delayed rhythm control (when symptoms persist after otherwise effective rate control). Furthermore, catheter ablation and new antiarrhythmic drugs have enhanced the potential effectiveness and safety of rhythm control therapy. The EAST will test whether an early, modern rhythm control therapy can reduce cardiovascular complications in AF.

DESIGN: The EAST (Early treatment of Atrial fibrillation for Stroke prevention Trial) will randomize approximately 3,000 patients with recent onset AF at risk for stroke (CHA₂DS₂VASc score ≥2) to either guideline-mandated usual care or to usual care plus early rhythm control therapy in a prospective, randomized, open, blinded outcome assessment trial. All patients will be followed up until the end of the trial for the composite primary outcome of cardiovascular death, stroke, worsening of heart failure, and myocardial infarction. Nights spent in hospital will be counted as a coprimary outcome. Usual care will consist of anticoagulation, therapy of underlying heart disease, and rate control as an initial approach. Early rhythm control therapy will consist of usual care plus rhythm control therapy by antiarrhythmic drugs, catheter ablation, and a patient-operated electrocardiographic device to monitor the ongoing rhythm. Key secondary outcomes include cognitive function and quality of life.

CONCLUSION: EAST will determine whether rhythm control therapy, when applied early after the initial diagnosis of AF, can prevent cardiovascular complications associated with AF.