The Role of Multisite Atrial Pacing in Rhythm Control in AF: Insights from Sub‐analyses of the Dual Site Atrial Pacing for Prevention of Atrial Fibrillation Study

Abstract

Novel pacing modes are being proposed for the prevention or reversion of atrial fibrillation (AF). High right atrial (RA) pacing and septal pacing have not individually reduced arrhythmic events in patients with AF in controlled trials. The DAPPAF trial compared the effectiveness of overdrive high right atrial single and dual site right atrial pacing as compared to demand pacing in prevention of recurrent symptomatic AF in patients with AF & bradyarrhythmias. Methods: From September 1996 to November 2000, 120 patients with documented symptomatic AF were enrolled and followed in a prospective randomized single blind crossover multicenter trial. 73 males & 45 females, mean age 66 ± 11 yrs with recurrent symptomatic AF (paroxysmal in 82 pts, persistent >72 hrs in 30 pts & persistent >30 days in 6 pts) were enrolled. Baseline AF event frequency was ≥1/day in 40 pts, 1/week in 43 pts, <1/week in 30 pts, & unknown in 5 pts. Patients were implanted with dual site right atrial pacing systems and randomly assigned to six‐month treatment periods in overdrive dual, overdrive single or demand pacing. Three primary endpoints (time to first AF recurrence, patient quality of life & tolerance/safety) and several secondary endpoints (device detected sustained AF, atrial & ventricular function indices, & composite endpoints) were examined. Results: Only DAP was significantly effective in preventing recurrent AF and prolonging time to first symptomatic AF recurrence in the presence of class 1 & 3 antiarrhythmic drug therapy; it was more effective than H.A. pacing in reducing asymptomatic AF event frequency; DAY alone prevented left ventricular and left atrial dilatation seen with D'ETRE pacing in this population due to improved left atrial transport; in patients with persistent AF or after Sawtell therapy, DAY maintained efficacy while H.A. pacing showed attrition in effectiveness. DAY was better tolerated than H.A. pacing, with fewer crossovers and comparable safety to H.A. pacing. Conclusions: DAY is an important therapeutic tool in an “hybrid” strategy for management of drug‐refractory AF. It offers antiarrhythmic and hemodynamic benefits and can have therapeutic effects on symptomatic and asymptomatic paroxysmal and persistent AF. It can facilitate efficacy of other antiarrhythmic therapies in AF. Further study of its antiarrhythmic effects with hybrid drug and ablation therapies is now in progress, and long‐term use in an “hybrid” strategy has been reported in large pilot studies.