Cardiopulmonary exercise measures of men and women with HFrEF differ in their relationship to prognosis: The Henry Ford Hospital Cardiopulmonary Exercise Testing (FIT-CPX) project
Ehrman JK, Brawner CA, Shafiq A, Lanfear DE, Saval M, Keteyian SJ. Cardiopulmonary Exercise Measures of Men and Women with HFrEF Differ in Their Relationship to Prognosis: The Henry Ford Hospital Cardiopulmonary Exercise Testing (FIT-CPX) Project. J Card Fail. 2018;24(4):227-233. doi: 10.1016/j.cardfail.2018.02.005.
BACKGROUND: This study evaluated if different prognostic characteristics exist for peak oxygen consumption (VO2), percent predicted peak VO2 (ppVO2), and the slope of the change in minute ventilation to volume of carbon dioxide produced (VE-VCO2) slope between men and women with heart failure and reduced ejection fraction (HFrEF).
METHODS: Analysis of the Henry Ford Hospital Cardiopulmonary Exercise Testing database (n = 1085; 33% women, 55% black) of individuals with HFrEF who completed a physician-referred cardiopulmonary exercise testing (CPX) between 1997 and 2010. Primary outcome was a composite of all-cause death, left ventricular assist device placement, and orthotopic heart transplant . Logistic and Cox regressions were performed and Kaplan-Meier survival curves were developed to describe relationships of the CPX variables and the composite outcome within and between men and women.
RESULTS: All patients were followed-up for a minimum of 5 years, during which there were 643 combined events (62%; 499 deaths, 64 left ventricular assist device implants, 80 orthotopic heart transplant). Each CPX variable was significantly related to event-free survival among both men and women. Log-rank assessment of Kaplan-Meier curves noted survival differences for peak VO2 and VE-VCO2 slope (p ≤ .002), but not ppVO2 (P = .32), between men and women.
CONCLUSIONS: Prognostic values for peak VO2 and the VE-VCO2 slope might be considered separately for men and women, whereas the ppVO2 value corresponding to 1- and 3-year survival rates may not be different between the sexes.