758-5 Influence of Exercise Training on Skeletal Muscle Vasodilatory Capacity in Chronic Heart Failure

Background Patients with chronic heart failure (CHF) are known to exhibit abnormalities in redistribution of blood flow and vasodilatory capacity during exercise. Exercise training has recently been recognized as an important therapeutic modality for patients with CHF. Training has been shown to improve vasodilatory capacity among normals in training-specific muscle. Methods Seventeen patients with first-diagnosis of CHF due to coronary artery disease (56 ± 5 years, mean EF = 32 ± 6%) were randomized to an exercise training group (N = 8), or a control group (N = 9). At randomization, patients in both groups initiated ace-inhibition therapy. Patients in the training group performed one hour of daily walking along with four sessions per week of high intensity monitored stationary cycling (40 minutes at 70 to 80% peak capacity) at a residential rehabilitation center for a period of two months. Control patients received usual community care. Calf baseline and post-ischemic flow rates were measured by strain gauge plethysmography before and after the study period. Results Training resulted in a 25% increase in maximal oxygen uptake (19.6 ± 3 vs. 24.9 ± 3 ml/kg/min, p l 0.01), whereas control patients did not change significantly (19.6 ± 4 vs. 19.3 ± 5 ml/kg/min). Leg baseline flow was similar in both groups initially and did not change with training (1.3 ± 0.6 vs. 1.6 ± 0.6 m/100 ml in trained patients and 1.8 ± 0.6 vs. 1.9 ± 0.6 ml/l00 ml in controls). Post-ischemic leg flow however, was significantly higher in both groups (14.4 ± 8.0 vs 19.9 ± 8.1 mill 00 ml in trained patients and 15.0 ± 8.1 vs. 20.3 ± 8.1 in controls, p l 0.05 for both groups). Conclusion The trained group improved post-ischemic leg flow, suggesting an improved vasodilatory capacity. However, the control group improved to a similar degree, suggesting that ACE inhibition therapy, not exercise training, causes the improvement. These data underscore the importance of treating these patients with ACE inhibitors.