The Impact of the PR Interval in Patients Receiving Cardiac Resynchronization Therapy: Results From the REVERSE Study
Jeffrey Senfield, Claude Daubert, William T Abraham, Stefano Ghio, Martin St John Sutton, Jeffrey Cerkvenik, Cecilia Linde, Michael R Gold, Jeffrey Senfield, Claude Daubert, William T Abraham, Stefano Ghio, Martin St John Sutton, Jeffrey Cerkvenik, Cecilia Linde, Michael R Gold
Abstract
Objectives: This study sought to evaluate the impact of baseline PR interval on cardiac resynchronization therapy (CRT) outcomes in the REVERSE (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction) study.
Background: The baseline electrocardiogram has important prognostic value to determine response to CRT. Specifically, QRS duration and morphology are strong predictors of response and outcomes; however, the prognostic importance of the PR interval is less clear.
Methods: REVERSE was a double-blinded, randomized study of CRT in mild heart failure (HF). The primary endpoint was the analysis of patients in sinus rhythm (n = 582) of the time-to-first HF hospitalization or death during the 2-year randomized period of the trial. In addition, the long-term impact of PR interval was assessed in the cohort actively on CRT during the pre-planned 5-year follow-up. Subjects were analyzed by PR interval, grouped by the median (180 ms) in 20-ms bins or as a continuous variable depending on the analysis performed. Secondary endpoints included the clinical composite score and echocardiographic measures of reverse remodeling.
Results: During the randomized phase of the study, CRT had similar effectiveness for both PR <180 ms (hazard ratio [HR]: 0.34) and PR >180 ms (HR: 0.57) subgroups (interaction p = 0.33). Similar results were observed when PR interval was grouped in 20-ms bins or treated as a continuous variable. In multivariable analysis of the long-term follow-up, left bundle branch block morphology, New York Heart Association functional class, HF etiology, and QRS duration, but not PR interval, predicted HF hospitalization or death.
Conclusions: Baseline PR interval does not affect clinical outcomes or reverse remodeling with CRT in mild HF. (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction [REVERSE]; NCT00271154).
Keywords: PR interval; cardiac resynchronization therapy; defibrillator; electrocardiogram; heart failure; implantable cardioverter-defibrillator.
Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Source: PubMed