Lower Afib Risk With AdaptivCRT vs Conventional Cardiac Resynchronization Therapy

The use of the AdaptivCRT (aCRT) synchronized left ventricular pacing algorithm is associated with a lower risk for atrial fibrillation (AF) in patients with heart failure compared with conventional cardiac resynchronization therapy (convCRT), according to study findings published in Heart Rhythm.

In the AdaptResponse trial (ClinicalTrials.gov identifier: NCT02205359), investigators examined data from the Adaptive CRT trial, which randomly assigned patients 2:1 indicated for CRT defibrillation to aCRT or convCRT pacing (N=478). Specifically, researchers compared the long-term effect of the aCRT algorithm vs convCRT pacing on AF risk. The primary outcome for this subanalysis was AF incidence >48 hours.

At 20.2±5.9 months, the primary outcome occurred in 16.2% of convCRT patients and 8.7% of aCRT patients (hazard ratio [HR], 0.54; 95% CI, 0.31-0.93; P =.03). A significantly greater proportion of convCRT patients with prolonged baseline atrioventricular intervals experienced the primary outcome compared with aCRT patients (27.4% vs 12.8%, respectively; HR, 0.45; 95% CI, 0.24-0.85; P =.01).

In addition, AF incidence was more common in convCRT patients vs aCRT patients (12.7% vs 4.3%, respectively; HR, 0.39; 95% CI, 0.19–0.79; P =.01). In patients whose left atrial area decreased by <20% by 6 months, AF risk was significantly lower with aCRT (HR, 0.18; 95% CI, 0.37-0.91; P =.02).

Because this study is a post hoc analysis and included a somewhat small sample size, the investigators believe the findings are limited.

Although the investigators failed to discover an explanation for the reduced incidence of AF with aCRT, they suggested that “more physiological [atrioventricular] intervals may in part explain the benefit of the algorithm.”

Disclosures: Several researchers report financial relationships with Medtronic, Inc, which funded the study.

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Birnie D, Hudnall H, Lemke B, et al. Continuous optimization of cardiac resynchronization therapy reduces atrial fibrillation in heart failure patients: results of the Adaptive Cardiac Resynchronization Therapy Trial [published online September 8, 2017]. Heart Rhythm. doi:10.1016/j.hrthm.2017.08.017