Introduction and objectives: The prognostic value of a single measurement of ejection fraction and peak oxygen uptake in chronic heart failure has been extensively investigated. The aim of our study was to evaluate the prognostic significance of serial changes in ejection fraction and exercise performance in moderate to severe chronic heart failure.
Methods: 182 patients (156 men, 53 [47-58] years) underwent echocardiography and cardiopulmonary exercise testing at baseline and after 10 [8-12] months. Most patients had idiopathic dilated cardiomyopathy (69%) and all patients presented left ventricular ejection fraction <45%. Median follow-up was 21 [14-34] months; cardiac death and heart transplantation were the end-points. Hazard ratio (HR, per unit) is presented with its 95% confidence interval (CI).
Results: During follow-up 18 patients (9.9%) died and 14 (7.7%) underwent heart transplantation. Baseline ejection fraction (HR, 0.94, 95% CI, 0.89-0.98 P=.006) and mitral regurgitation (HR, 4.22, 95% CI, 1.63-10.92, P=.003), and delta (second examination-baseline) ejection fraction (HR, 0.93, 95% CI, 0.88-0.98, P=.01) were the only significant variables at univariate analysis. Both ejection fraction and delta ejection fraction remained independently associated with events at multivariate analysis. The prognostic power significantly increased between a model including ejection fraction alone and another one including ejection fraction plus delta ejection fraction.
Conclusions: In clinically stable patients with chronic heart failure, ejection fraction and its changes were independently associated with outcome; on the contrary, serial cardiopulmonary exercise testing did not provide significant prognostic value. Baseline plus changes in ejection fraction showed better prognostic performance than baseline ejection fraction alone.