Ventilatory variables are strong prognostic markers in elderly patients with heart failure

Abstract

OBJECTIVE: To evaluate the safety and prognostic capacity of cardiopulmonary exercise testing in patients > or = 60 years old who are hospitalised with heart failure caused by left ventricular dysfunction. DESIGN: Prospective study. SETTING: University hospital. PATIENTS: Study participants were 67 patients (66% men) with clinical heart failure stabilised on medical treatment. The study is a part of a nursing intervention study. Mean (SD) age was 74 (6) years, New York Heart Association functional class II-III, and ejection fraction 0.36 (0.11). INTERVENTIONS: Cardiopulmonary exercise testing and echocardiography. MAIN OUTCOME MEASURES: Peak oxygen consumption (VO2), peak ventilatory equivalents for carbon dioxide (VE/VCO2) and oxygen (VE/VO2), left ventricular volumes, and mortality. RESULTS: Mean (SD) peak VO2 was 11.7 (3.7) ml/kg/min, peak VE/VCO2 43 (9), and peak VE/VO2 46 (11). During 12-59 months of follow up, 14 patients died. In univariate analyses peak VO2, VE/VO2, and VE/VCO2 were all strongly related (p < 0.01) to mortality. In a multivariate Cox regression analysis, peak VE/VCO2 was the strongest predictor of mortality (p < 0.001), followed by left ventricular end systolic volume (p < 0.001). A cut off of peak VE/VCO2 at > or = 45 gave a univariate hazard ratio of 6.7 for death during follow up. No adverse events occurred during the exercise test. CONCLUSION: These findings extend results found in selected middle aged patients to elderly patients with heart failure and show that ventilatory parameters from a cardiopulmonary exercise test, such as peak VO2, VE/O2, and VE/VCO2 are powerful predictors of mortality.