Exercise training in advanced heart failure patients: Discordance between improved exercise tolerance and unchanged NT-proBNP levels

Abstract

Background Exercise training can improve aerobic capacity and symptoms in congestive heart failure (CHF) patients. Aims To test the feasibility of exercise training in advanced CHF patients, and examine the potential benefit from peripheral vascular and muscular conditioning as well as improved central hemodynamic and neurohumoral status. Methods and results Thirty NYHA functional class III, CHF patients (mean age 61 ± 13 yr, ejection fraction 27 ± 4%, VO2max 11.3 ± 3.9 ml/kg/min) were enrolled. Exercise capacity, cardiovascular parameters and serum levels of brain natriuretic peptide (NT-proBNP) were determined at baseline and after 18 weeks of moderate intensity exercise training. Twenty eight (93%) patients, who completed the exercise program, experienced marked improvements in the 6 min walk (+ 39%) and exercise duration on the modified Bruce protocol (+ 66%). Smaller improvements were recorded in the cardiac index (a 15% increase), in the maximal oxygen consumption (a 13% increase in VO2max), in the left ventricular ejection fraction (an 11% increase) and in the systemic vascular resistance and pulmonary artery pressure (an 11% decrease). NT-proBNP levels were not significantly affected. They correlated with exercise capacity and VO2max on baseline measurement, but these correlations were not found after training. Conclusion Rehabilitation is feasible, even in advanced CHF, and leads to markedly improved exercise performance, but does not affect the level of the principal neurohumoral marker of prognosis — NT-proBNP. Resting cardiovascular performance and maximal oxygen consumption improve less than functional capacity, suggesting that an important benefit is derived from muscle conditioning and improved peripheral vascular response to exercise.