LAUSR

BACKGROUND The AdaptivCRT algorithm (aCRT) automatically adjusts atrioventricular delays each minute to achieve ventricular fusion through left ventricular (LV) or biventricular (BiV) pacing. aCRT is associated with superior clinical outcomes compared to standard BiV pacing, but the association of aCRT and subsequent atrial fibrillation (AF) in a real-world population has not been fully evaluated. OBJECTIVE The purpose of this study was to investigate the incidence of AF >48 hours with aCRT vs standard BiV pacing after implant. METHODS Patients implanted with a cardiac resynchronization therapy (CRT) device between 2013 and 2016 were studied via the de-identified Medtronic CareLink database. For univariate and multivariate survival analyses, Kaplan-Meier and Cox proportional hazards were used, respectively. RESULTS Of 37,450 patients (mean age 69.1 ± 11.0 years; 67.9% male) followed for a mean 15.5 ± 9.1 months, 9.7% (n = 3647) developed >48 hours of AF. In univariate analysis, compared with standard BiV pacing, the aCRT BiV+LV mode was associated with a 54% lower risk of >48 hours of AF (P <.001) at 2 years, which persisted after multivariate adjustment (hazard ratio 0.53; 95% confidence interval 0.49-0.57; P <.001), even when stratified by sensed PR interval ≤200 ms and >200 ms. Higher percentages of LV-only pacing with aCRT were associated with lower incidence of AF (comparing >92% LV-only pacing vs 0%-5% LV-only pacing: HR 0.05; 95% CI 0.04-0.06; P <.001). CONCLUSION In a large, real-world population of CRT recipients, aCRT pacing compared to standard BiV pacing was associated with a lower incidence of AF in patients with both long and short PR intervals. A higher percentage of LV-only pacing during aCRT was also associated with lower incidence of AF.