Baseline differences in the HF-ACTION trial by sex.

Area of Science:

• Cardiology
• Exercise Physiology
• Heart Failure Research

Background:

• Functional capacity assessment is crucial for heart failure (HF) prognosis and transplant eligibility.
• Historically, HF trials have underrepresented women, leading to male-centric prognostic cutoffs.
• Peak oxygen uptake (VO2) is lower in women, and this difference may be exacerbated in HF.

Purpose of the Study:

• To investigate sex-based differences in functional capacity measures in patients with HF.
• To examine the interaction of sex with cardiopulmonary exercise testing parameters.
• To inform the interpretation of prognostic markers and transplant criteria for women with HF.

Main Methods:

• Analysis of 2,331 HF patients (28% women) from the HF-ACTION trial.
• Comparison of functional capacity metrics including peak VO2, VE/VCO2, VO2 at ventilatory threshold, and 6-minute walk distance between sexes.
• Investigation of the interaction between sex and covariates in exercise testing models.

Main Results:

• Women with HF were younger, more likely to have non-ischemic etiology, and higher ejection fraction.
• Women had significantly lower peak VO2 and 6-minute walk distance compared to men.
• Peak VO2 was notably lower in women than men with comparable ventricular function and health status.

Conclusions:

• Stable, well-medicated women with class II-IV HF demonstrate significantly lower peak VO2 and 6-minute walk distance than men.
• These sex-based differences highlight the need for careful consideration of prognostic markers in women.
• Current transplant listing criteria may require re-evaluation to accurately reflect female patient capabilities.