Effects of exercise training in patients with chronic heart failure and advanced left ventricular systolic dysfunction receiving β-blockers

Abstract

Background: It remains unclear whether patients with chronic heart failure (CHF) and advanced left ventricular (LV) dysfunction on β-blocker therapy benefit from exercise training (ET). Methods and Results: We studied 45 CHF patients with advanced LV dysfunction [ejection fraction (LVEF) <25%] and impaired exercise tolerance [normalized peak oxygen uptake (PV O2) <70%] receiving a β-blocker: 33 patients participated in a cardiac rehabilitation program with ET (ET group) and 12 did not (inactive control group). Exercise capacity, LV dimension and plasma B-type natriuretic peptide (BNP) were assessed before and after a 3-month study period. At baseline, both groups had markedly reduced LVEF (ET group 18±4% vs. Control group 18±5%, NS) and impaired exercise capacity (normalized PV · O2 51±10% vs. 55±9%, NS). Although one patient in the ET group withdrew from the program due to worsening CHF, no serious cardiac events occurred during the ET sessions. After 3 months, the ET group (n=24) had significantly improved PV · O2 by 16±15% (1,005± 295 to 1,167±397 ml/min, P<0.001), while the PV · O2 of the control group was unchanged. LV end-diastolic dimension decreased in both groups to a similar extent, but plasma BNP was significantly decreased only in the ET group (432 to 214 pg/ml, P<0.05). Conclusions: The data indicate that in CHF patients with advanced LV dysfunction on β-blocker therapy, ET successfully improves exercise capacity and BNP without adversely affecting LV remodeling or causing serious cardiac complications.