P6544A real world study of high frequency atrial anti-tachycardia pacing in new algorithm for atrial arrhythmia

Background Advanced pacemakers feature atrial antitachycardia pacing (aATP) therapies for terminating atrial arrhythmia. Previous studies showed the efficacy of combined atrial preventive pacing and aATP in patients with pacemakers. The independent effect of aATP and the impact for patients outside the clinical trials has not been well elucidated. Methods In a single center, prospective, all-comers trial, we enrolled 567 patients implanted cardiac devices with Reactive ATP function. History of permanent atrial fibrillation (AF) was not included. After device interrogation of the AF burden and the longest AF duration in the last 6 months, aATP was programmed as a bit more aggressive setting than MINERVA trial (time interval was set as every 2 hours). As for newly implanted devices, aATP was activated after at least 3 months run-in period. Primary and secondary outcomes were the longest AF duration and cumulative percentage of progression into permanent AF, respectively. Results Of 541 eligible patients, aged 75.3±10.7 years, 356 pacemaker, 82 ICD and 103 CRT patients, the longest single episode of AF lasted ≤6 min in 439 patients (81.1%), >6 min to 6 h in 43 (8.0%), >6–24 h in 33 (6.1%), and >24 h in 26 (4.8%) at the enrollment. During mean follow-up of 1.9 years, the longest AF episode lasted >24 h in 49 patients (9.1%) and 14 patients (2.6%) progressed into permanent AF. According with baseline longest single episode of AF, patients with AF ≤6 min developed an episode >24 h in 0.8% at 1 year and 3.2% at 2 years follow up; patients with AF >6 min to 6 h developed an episode >24 h in none at 1 year and 7% at 2 years follow up; and patients with AF >6–24 h developed an episode >24 h in 19% at 1 year and 42% at 2 years follow up, respectively. In a subgroup analysis of in 192 patients with at least 1 aATP, 46 patients with high efficacy (>44%) did not developed an episode >24 h. Only one patient developed into permanent AF without aATP therapy. On multivariate analysis, neither ICD nor CRT was independent risk factor for developing the longest AF episode >24 h. Conclusions The independent use of aATP without atrial preventive pacing was effective for preventing AF progression in a real world cohort. Even without the previous AF episodes, aATP could prevent AF development, especially in patients showing high aATP efficacy. Future research is required to enhance the aATP success rate.