Women are underrepresented in cardiac resynchronization therapy trials

Area of Science:

• Cardiology
• Clinical Trials
• Heart Failure

Background:

• Current cardiac resynchronization therapy (CRT) guidelines do not differentiate by sex.
• Women are historically underrepresented in randomized controlled trials (RCTs) for CRT.
• This study investigates if women's participation in CRT trials reflects their real-world prevalence in heart failure (HF).

Purpose of the Study:

• To assess gender representation in CRT clinical trials.
• To determine if women with heart failure derive differential benefits from CRT compared to men.
• To evaluate the generalizability of current CRT evidence for women.

Main Methods:

• Systematic review of 10 CRT trials (8107 patients) referenced in the 2012 EHRA/HRS expert consensus statement.
• Analysis of gender representation within these trials.
• Evaluation of sex-based outcome reporting and subgroup analyses.

Main Results:

• Women constituted only 23% of participants across the studied CRT trials.
• Sex-based outcome analysis was reported in only 5 of the 10 trials.
• The MADIT-CRT and RAFT trials, with lower ejection fraction inclusion criteria (≤30%), indicated greater CRT benefit in women, who also presented with less ischemic cardiomyopathy and more left bundle branch block (LBBB).

Conclusions:

• Women remain underrepresented in CRT clinical trials.
• Evidence suggests women may experience greater benefits from CRT, particularly those with specific characteristics like lower ejection fraction and LBBB.
• Increased female participation in future CRT trials is crucial for robust, generalizable evidence.