Chronic heart failure in the elderly: Value of cardiopulmonary exercise testing in risk stratification

Abstract

Objective - To assess the value of cardiopulmonary exercise testing in predicting prognosis in a cohort of elderly patients with chronic heart failure (CHF). Design - A retrospective cohort study of all patients with CHF over the age of 70 years assessed between January 1992 and May 1997. Setting - Tertiary centre. Patients - 50 patients (mean (SD) age 75.9 (4.5) years, 8 women) with CHF New York Heart Association (NYHA) class I (3 patients), II (25 patients), III (20 patients), and IV (2 patients). Follow up was complete for two years in all patients. Results - The patients underwent cardiopulmonary exercise testing (peak oxygen consumption 15.2 (4.5)ml/kg/min, minute ventilation/carbon dioxide production (VE/VCO2) slope 38.7 (11.8)); radionucleide ventriculography (left ventricular ejection fraction 32.8 (14.3)%); serum sodium measurement (139 (2.8) mmol/l); and echocardiography (left ventricular end diastolic dimension 6.1 (1.1) cm, left ventricular end systolic dimension 4.7 (1.5) cm). At the end of follow up in May 1999, 26 patients had died. The median follow up of the survivors was 47.7 months (interquartile range 31.5-53.5 months). On univariate analysis VE/VCO2 slope (p < 0.0001), NYHA class (p < 0.001), peak oxygen uptake (VO2) (p < 0.01), left ventricular end systolic dimension (p < 0.05), and serum sodium concentration (p < 0.05) had significant predictive power. Stepwise multivariate analysis identified only VE/VCO2 slope (p < 0.01), NYHA class (p < 0.05), and peak VO2 (p< 0.05) as conveying significant independent prognostic information. Conclusion - Elderly patients with CHF have a high mortality, with the majority dead within two years. Cardiopulmonary exercise testing provides important information for risk stratification within this group and its use should not be neglected.