Sex-specific mortality differences in heart failure patients with ischemia receiving cardiac resynchronization therapy
July
Sex-specific mortality differences in heart failure patients with ischemia receiving cardiac resynchronization therapy
Zhonglin Han 0 1
Zheng Chen 0 1
Rongfang Lan 0 1
Wencheng Di 0 1
Xiaohong Li 0 1
Hongsong Yu 0 1
Wenqing Ji 0 1
Xinlin Zhang 0 1
Biao Xu 0 1
Wei Xu 0 1
0 Editor: Doan TM Ngo, University of Adelaide , AUSTRALIA
1 Department of Cardiology, Nanjing University Medical School Affiliated Nanjing Drum Tower Hospital , Nanjing , China
Recent studies have reported prognosis differences between male and female heart failure patients following cardiac resynchronization therapy (CRT). However, the potential clinical factors that underpin these differences remain to be elucidated. A meta-analysis was performed to investigate the factors that characterize sex-specific differences following CRT. This analysis involved searching the Medline (Pubmed source) and Embase databases in the period from January 1980 to September 2016.
Background
Results
OPEN ACCESS
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: This work was supported by National
Natural Science Foundation of China (No.
81600267) to Zhonglin Han. The funders had no
role in study design, data collection and analysis,
decision to publish, or preparation of the
manuscript.
Competing interests: The authors have declared
that no competing interests exist.
Fifty-eight studies involving 33445 patients (23.08% of whom were women) were analyzed
as part of this study. Only patients receiving CRT with follow-up greater than six months
were included in our analysis. Compared with males, females exhibited a reduction of 33%
(hazard ratio, 0.67; 95% confidence interval, 0.62±0.73; P < 0.0001) and 42% (hazard ratio,
0.58; 95% confidence interval, 0.46±0.74; P = 0.003) in all-cause mortality and heart failure
hospitalization or heart failure, respectively. Following a stratified analysis of all-cause
mortality, we observed that ischemic causes (p = 0.03) were likely to account for most of the
sex-specific differences in relation to CRT.
Conclusion
These data suggest that women have a reduced risk of all-cause mortality and heart failure
hospitalization or heart failure following CRT. Based on the results from the stratified
analysis, we observed more optimal outcomes for females with ischemic heart disease. Thus,
ischemia are likely to play a role in sex-related differences associated with CRT in heart
failure patients. Further studies are required to determine other indications and the potential
mechanisms that might be associated with sex-specific CRT outcomes.
Introduction
Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure patients
exhibiting wide QRS complexes and reduced systolic left ventricular ejection fractions (LVEF).
Although CRT devices are routinely implanted according to ACCF/AHA/HRS guidelines,
approximately 20% of CRT patients fail to benefit from CRT [
1
]. Recently, sex-specific
differences in relation to heart failure (HF) epidemiology, clinical presentation, response to CRT,
and post-CRT prognosis have been reported. However, the mechanisms that underlie these
differences are not well understood. An AHA Statistical Update from 2016 [
2
] reported that
heart failure mortality was higher in women than men; however, no obvious sex-specific
differences were observed in relation to the prevalence of heart failure. Therefore, these data
suggest that sex-specific factors may cause differences in CRT response between males and
females. Indeed, most studies and meta-analyses performed in this area report that women
who received CRT experienced greater benefits and reduced mortality compared with men
[
3
]. Studies evaluating the differential effects of clinical factors, including ischemic events, left
bundle branch block (LBBB), age, LVEF, and atrial fibrillation on male and female clinical
outcomes are limited. Thus, it is important that we attempt to identify and characterize factors
that might help us to improve clinical responses to CRT for both male and female HF patients.
The aim of this meta-analysis was to assess sex-specific differences in all-cause mortality in patients who received CRT. We also aimed to examine the effect of clinical factors on sexrelated outcomes.
Methods
This meta-analysis was performed according to the Preferred Reporting Items for Systematic
Reviews and Meta-Analyses Statement [4]. No participation of human subjects were involved in this analysis.
Literature search
A computer-based literature search by two reviewers (Z.H. and Z.C.) was performed to iden
tify English-language publications listed in the Medline (Pubmed source) and Embase
electronic databases from January 1980 to September 2016. The search terms and algorithm for
the literature search were as follows: cardiac resynchronization therapy OR CRT OR pace
maker AND (female OR women OR gender). The detailed search strategy were uplo (...truncated)