Abstract 4001: Ventilatory Efficiency and Systolic Blood Pressure, Not Peak Oxygen Consumption, Are Predictive of Long-term Mortality in Patients Being Evaluated for Cardiac Transplantation
Introduction: Peak oxygen consumption (VO2) measured during cardiopulmonary exercise testing is commonly used to assess prognosis in heart failure patients and triage for possible cardiac transplantation. However, the literature lacks long-term studies of ventilatory efficiency (VE/VCO2 slope).
Hypothesis: The purpose of this study was to determine the prognostic ability of exercise variables over a 10 year period.
Methods: We prospectively estimated the ability of cardiopulmonary exercise test variables to predict death or urgent transplantation in 399 patients. All exercise tests and blood pressure assessments were measured at one center with the same equipment by one investigator.
Results: There were 195 deaths, 6 urgent transplants, 21 LVADs, and 29 censored non-urgent transplants. The mean ±SD were: VE/VCO2 slope =37.3 ±10.7, peak VO2 =16.3 ±4.9 ml·kg·min−1, SBP=114±19 mm Hg. By Cox Regression, the most predictive model included Log VE/VCO2 slope (Hazard Ratio (HR)=61.5,p=0.00), and SBP≤100mm Hg (HR=2.0,p=0.00). No other variables added to the model, including peak VO2 (HR=1.0,p=0.12), invasive hemodynamics, heart rate, age, NYHA, and LVEF. The figure⇓ shows survival curves of the VE/VCO2 slope and dichotomous SBP.
Conclusions: Ventilatory efficiency and SBP, and not peak VO2, provided valuable long-term prognostic information.