Abstract 16395: Comparing Cardiopulmonary Exercise Measures of Men and Women With HFrEF and Their Relationship to Prognosis: The Henry Ford HospITal CardioPulmonary Exercise Testing (FIT-CPET) Project

Abstract

Introduction: Several cardiopulmonary exercise test (CPET) variables (e.g., peak oxygen consumption (VO2), ventilatory efficiency (VE-VCO2) slope, and % predicted peak VO2 (%pVO2)) are regularly used to estimate prognosis in patients with systolic heart failure (HFrEF). Although known sex differences in physiology (i.e., muscle mass, lung volume) result in lower peak VO2 values in healthy women vs. men, this influence on CPET variables and subsequent prognosis in patients with HFrEF is not well described. Purpose: Compare the peak VO2, VE-VCO2 slope and %pVO2 values in men and women that correspond to prognosis using the International Society of Heart Transplant (ISHT) reported North American 1 and 3-y cardiac transplant survival rates (i.e., 86% and 79%, respectively). Methods: Patients with a CPET between 1997 and 2010 were identified. HFrEF was confirmed through a manual query of the medical record. Deaths through December 2011 were identified from the National Death Index. Receiver operator characteristic (ROC) curves were developed for each CPET measure and the threshold values and area under the curve (AUC) values associated with 86% and 79% specificity for each sex were determined. Results: A total of 1,201 patients (33% female; 55% Black; 33% ischemic; age = 55 + 13 y; BMI = 31 +7 kg.m-2; EF = 22 + 9%) were included in this analysis. Specificity threshold values and the corresponding AUC, for each CPX variable, are shown in the Table. At 1-y there were 167 (14%) deaths with a 10% event rate for women and 16% for men. At 3-y there were 335 (31%) deaths with a 25% event rate for women and 35% for men. Conclusions: In this large, racially diverse population both peak VO2 and %pVO2 had clinically meaningful differences for risk stratification thresholds depending on sex. This was not true for VE-VCO2 slope. Clinical decisions regarding the need for advanced therapies such as transplant or ventricular assist devices, when based on peak VO2 or %pVO2, might consider the patient’s sex.