Effects of exercise training on left ventricular function and peripheral resistance in patients with chronic heart failure - A randomized trial

Context Exercise training in patients with chronic heart failure improves w ork capacity by enhancing endothelial function and skeletal muscle aerobic metabolism, but effects on central hemodynamic function are not well establ ished. 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 ergo meter 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 pe ak oxygen uptake (n=36) or to no intervention (control group; n=37). Main Outcome Measures Ergospirometry with measurement of central hemodynami cs by thermodilution at rest and during exercise; echocardiographic determi nation 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 statist ically significant improvements compared with controls in New York Heart As sociation functional class, maximal ventilation, exercise time, and exercis e capacity as well as decreased resting heart rate and increased stroke vol ume 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 (T PR) during peak exercise was reduced by 157 (306) dyne/s/cm(-5) in the exer cise training group vs an increase of 43 (148) dyne/s/cm-5 in the control g roup (P=.03), with a concomitant increase in mean (SD) stroke volume of 14 (22) mt vs 1 (19) mL in the control group (P=.03). There was a small but si gnificant reduction in mean (SD) LV end diastolic diameter of 4 (6) mm vs a n 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 volu me (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 trainin g is associated with reduction of peripheral resistance and results in smal l but significant improvements in stroke volume and reduction in cardiomega ly.