Cardiac Resynchronization in Women: A Substudy of the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial

Dominique de Waard; Jaimie Manlucu; Anne M Gillis; John Sapp; Jordan Bernick; Steve Doucette; Anthony Tang; George Wells; Ratika Parkash

doi:10.1016/j.jacep.2019.06.007

Cardiac Resynchronization in Women: A Substudy of the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial

JACC Clin Electrophysiol. 2019 Sep;5(9):1036-1044. doi: 10.1016/j.jacep.2019.06.007. Epub 2019 Jul 31.

Authors

Dominique de Waard¹, Jaimie Manlucu², Anne M Gillis³, John Sapp⁴, Jordan Bernick⁵, Steve Doucette⁶, Anthony Tang², George Wells⁵, Ratika Parkash⁷

Affiliations

¹ Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
² London Health Sciences Center, University of Western Ontario, London, Ontario, Canada.
³ Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.
⁴ Queen Elizabeth II Health Sciences Center, Halifax, Nova Scotia, Canada.
⁵ Ottawa Cardiovascular Research Methods Center, Ottawa, Ontario, Canada.
⁶ Research Methods Unit, Halifax, Nova Scotia, Canada.
⁷ Queen Elizabeth II Health Sciences Center, Halifax, Nova Scotia, Canada. Electronic address: ratika.parkash@nshealth.ca.

PMID: 31537332
DOI: 10.1016/j.jacep.2019.06.007

Abstract

Objectives: This study sought to evaluate the effect of cardiac resynchronization therapy with defibrillator (CRT-D) as compared with implantable cardioverter-defibrillator (ICD) on mortality, heart failure (HF) hospitalization, and ventricular arrhythmia in women versus men.

Background: CRT-D has demonstrated reduced mortality and HF hospitalizations with greater benefit observed in women compared with men. However, whether CRT-D prevented ventricular arrhythmias in women compared with men was unclear.

Methods: The RAFT (Resynchronization-Defibrillation for Ambulatory Heart Failure Trial) study randomized 1,798 patients to an ICD or CRT-D. In this post hoc analysis, women and men were compared by randomized group. By using a multivariable model, the outcomes of death and HF hospitalization and incidence of ventricular arrhythmia were compared between men and women.

Results: There were 1,490 (83%) men (732, ICD; 758, CRT-D) and 308 (17%) women (172, ICD; 136, CRT-D) included in the analysis. Women with CRT-D had a significantly reduced incidence of death and HF hospitalization compared with men with CRT-D (hazard ratio: 0.52; 95% confidence interval: 0.33 to 0.81; p < 0.001) on multivariable analysis. Women with a primary prevention indication and CRT-D had the lowest rate of ventricular arrhythmia compared with men (hazard ratio: 0.59; 95% confidence interval: 0.39 to 0.91; p = 0.016).

Conclusions: Women have improved rates of death and HF hospitalization with CRT-D and were less likely to experience ventricular arrhythmia when compared with men, after adjusting for differences in baseline characteristics over a prolonged follow-up. Whether these improved outcomes reflect inherent sex differences in the underlying myocardial substrate resulting in an enhanced response to CRT-D requires further research.

Keywords: cardiac resynchronization therapy with defibrillator (CRT-D); clinical trial; heart failure; ventricular arrhythmia.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Arrhythmias, Cardiac / epidemiology
Arrhythmias, Cardiac / mortality
Arrhythmias, Cardiac / therapy
Cardiac Resynchronization Therapy* / adverse effects
Cardiac Resynchronization Therapy* / mortality
Cardiac Resynchronization Therapy* / statistics & numerical data
Defibrillators, Implantable* / adverse effects
Defibrillators, Implantable* / statistics & numerical data
Female
Heart Failure* / epidemiology
Heart Failure* / mortality
Heart Failure* / therapy
Hospitalization / statistics & numerical data
Humans
Male
Middle Aged
Treatment Outcome