Author + information
- Received December 19, 2019
- Revision received April 20, 2020
- Accepted April 30, 2020
- Published online September 21, 2020.
- Jagmeet P. Singh, MD, DPhila,∗ (, )
- Ronald D. Berger, MD, PhDb,
- Rahul N. Doshi, MDc,
- Michael Lloyd, MDd,
- Douglas Moore, DOe,
- James Stone, MDf,
- Emile G. Daoud, MDg,
- for the ENHANCE CRT Study Group
- aMassachusetts General Hospital, Boston, Massachusetts
- bJohns Hopkins University, Baltimore, Maryland
- cUniversity of Southern California, Los Angeles, California
- dEmory University Hospital, Atlanta, Georgia
- eSt. John Hospital and Medical Center, Detroit, Michigan
- fNorth Mississippi Medical Center, Tupelo, Mississippi
- gThe Ohio State University, Columbus, Ohio
- ↵∗Address for correspondence:
Dr. Jagmeet P. Singh, Massachusetts General Hospital, 55 Fruit Street, GRB 109, Boston, Massachusetts 02114.
Objectives This study compared clinical outcomes between an increased electrical delay in the left ventricular region (QLV)-based LV lead implantation approach (QLV arm) and anatomical implantation approach (control arm) in patients with non-left bundle branch block.
Background Limited data exist on cardiac resynchronization therapy effectiveness in patients with non-left bundle branch block. Clinicians generally deliver cardiac resynchronization therapy through an anatomical implantation approach; however, targeting the QLV may serve as an individualized implantation strategy in non-left bundle branch block patients.
Methods The study enrolled 248 subjects at 29 U.S. centers. Subjects were randomized in a 2:1 ratio between a QLV-based implantation approach and anatomical implantation approach and were implanted with a St. Jude Medical quadripolar cardiac resynchronization therapy defibrillator system. The primary endpoint was the clinical composite score after 12 months of follow-up.
Results The study analyzed 191 available subjects at 12 months of follow-up (128 QLV arm, 63 control arm). Of these, 39 subjects (26 in the QLV arm and 13 in the control arm) had heart failure events (8 cardiac deaths and 31 heart failure hospitalizations). Aside from New York Heart Association functional class, there were no other significant differences in baseline characteristics between the 2 arms. The responder rate at 12 months measured by the clinical composite score was 67.2% in the QLV arm and 73.0% in the control arm (p = 0.506).
Conclusions Although patient-tailored left ventricular lead placement guided by QLV is promising, we observed no difference in outcome between the QLV-based implantation approach and the conventional anatomical implantation approach.
- cardiac resynchronization therapy
- left bundle branch block
- longest electrical delay
- non-left bundle branch block
- right bundle branch block
Supported by Abbott. Dr. Singh has consulted for Biotronik, Boston Scientific, Medtronic, Abbott, Microport, EBR Systems, Respicardia, Impulse Dynamics, BackBeat, and Toray. Dr. Berger has consulted for Abbott. Dr. Doshi has consulted for Abbott, Biosense Webster, Boston Scientific, Respicardia, and Zoll Medical. Dr. Lloyd has consulted for Abbott, Boston Scientific, and Medtronic; has received research funding from Medtronic and Boston Scientific; and has served on the Steering Committee of Boston Scientific. Dr. Stone has consulted for Boston Scientific and Biotronik. Dr. Daoud has consulted for Abbott, Boston Scientific, Biotronik, and Biosense Webster. Dr. Moore has reported that he has no relationships relevant to the contents of this paper to disclose. Jean-Claude Deharo, MD, served as Guest Editor for this paper. Katja Zeppenfeld, MD, served as Guest Editor-in-Chief for this paper.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received December 19, 2019.
- Revision received April 20, 2020.
- Accepted April 30, 2020.
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