Prognostic value of changes over time in exercise capacity and echocardiographic measurements in patients with chronic heart failure

Aims This study sought to examine the predictive values of changes over rim e in exercise capacity and echocardiographic measurements of ventricular di mensions or function in predicting mortality in patients with chronic heart failure. Methods and Results Sixty-two patients with chronic heart failure (58 men, mean [ +/- SD] age 60 +/- 10 years, mean peak oxygen consumption (VO2) 18.2 +/- 5.9 ml . kg(-1). min(-1), mean left ventricular ejection fraction 38.9 +/- 15.8%)who underwent both treadmill exercise testing and echocardiograp hic examination on two occasions, separated by 19 +/- 15 months were follow ed-up for a mean of 17 months (interquartile range 9-30 months). During the follow-up period. 19 patients (30%) died and three (4.8%) underwent heart transplantation. Of measurements taken at a single time-point (visit 2) exe rcise duration. peak VO2, ventilatory response to exercise (VE/ VCO2), left atrial diameter and left ventricular ejection fraction were found, by Cox proportional-hazard analysis, to predict the outcome in these patients tall P<0.05). Of the changes in parameters between visit 1 to visit 2, only cha nges in peak VO2 per year (P=0.026) predicted nontransplanted survival (ind ependent of changes in left ventricular ejection fraction and VE/VCO2). Tn Kaplan-Meier survival analysis patients with increased peak VO2 over time ( n=28) showed a better prognosis at 2 years (cumulative survival 75% [95% co nfidence interval: 56-95%] than those with a decrease in peak VO2 (n=34, cu mulative survival 50% [95% confidence interval: 31-68%]). Conclusions Although single estimates of peak VO2 VE/VCO2 and left ventricu lar ejection fraction have significant prognostic importance in patients wi th chronic heart failure, when monitoring changes over time only peak VO2 r emains a significant predictor of outcome. (C) 2000 The European Society of Cardiology.