Effects of Exercise Training on Left Ventricular Function and Peripheral Resistance in Patients With Chronic Heart Failure

Abstract

Context  Exercise training in patients with chronic heart failure improves work capacity by enhancing endothelial function and skeletal muscle aerobic metabolism, but effects on central hemodynamic function are not well established.

Objective  To evaluate the effects of exercise training on left ventricular (LV) function and hemodynamic response to exercise in patients with stable chronic heart failure.

Design  Prospective randomized trial conducted in 1994-1999.

Setting  University department of cardiology/outpatient clinic in Germany.

Patients  Consecutive sample of 73 men aged 70 years or younger with chronic heart failure (with LV ejection fraction of approximately 0.27).

Intervention  Patients were randomly assigned to 2 weeks of in-hospital ergometer exercise for 10 minutes 4 to 6 times per day, followed by 6 months of home-based ergometer exercise training for 20 minutes per day at 70% of peak oxygen uptake (n=36) or to no intervention (control group; n=37).

Main Outcome Measures  Ergospirometry with measurement of central hemodynamics by thermodilution at rest and during exercise; echocardiographic determination of LV diameters and volumes, at baseline and 6-month follow-up, for the exercise training vs control groups.

Results  After 6 months, patients in the exercise training group had statistically significant improvements compared with controls in New York Heart Association functional class, maximal ventilation, exercise time, and exercise capacity as well as decreased resting heart rate and increased stroke volume at rest. In the exercise training group, an increase from baseline to 6-month follow-up was observed in mean (SD) resting LV ejection fraction (0.30 [0.08] vs 0.35 [0.09]; P=.003). Mean (SD) total peripheral resistance (TPR) during peak exercise was reduced by 157 (306) dyne/s/cm⁻⁵ in the exercise training group vs an increase of 43 (148) dyne/s/cm⁻⁵ in the control group (P=.003), with a concomitant increase in mean (SD) stroke volume of 14 (22) mL vs 1 (19) mL in the control group (P=.03). There was a small but significant reduction in mean (SD) LV end diastolic diameter of 4 (6) mm vs an increase of 1 (4) mm in the control group (P<.001). Changes from baseline in resting TPR for both groups were correlated with changes in stroke volume (r=−0.76; P<.001) and in LV end diastolic diameter (r=0.45; P<.001).

Conclusions  In patients with stable chronic heart failure, exercise training is associated with reduction of peripheral resistance and results in small but significant improvements in stroke volume and reduction in cardiomegaly.