Exercise Training for Angina

Abstract & Commentary

Synopsis: A 12-month program of regular exercise in selected patients with chronic stable angina and significant CAD resulted in a higher event-free survival and exercise capacity at lower costs than PCI.

Source: Hambrecht R, et al. Circulation. 2004;109: 1371-1378.

Although percutaneous coronary interventions (PCI) are highly efficacious in acute coronary syndromes, their benefit in chronic stable exercise-induced angina is less clear. Thus, Hambrecht and associates from Leipzig, Germany, randomized 101 men with class I-III angina younger than 70 years of age to 20 minutes of exercise per day or PCI after routine coronary angiography showed significant coronary artery disease (CAD). Exclusion criteria included negative stress tests for ischemia, recent myocardial infarction, left main or proximal left anterior descending disease, ejection fraction < 40%, and insulin-dependent diabetes. Over 12 months, exercise training exhibited a higher event-free survival as compared to PCI (88 vs 70%; P = .023). The difference in events was mainly due to rehospitalizations for ischemic events and revascularization. There were no deaths. Repeat angiography showed that 32% of exercise patients had CAD progression vs 45% of the PCI patients (P = .035). Significant improvements in stress myocardial perfusion were observed in both groups, but the increase in exercise oxygen consumption was greater in the exercise group (16% vs 2%; P < .001). The cost needed to gain one angina class was $3,429 in the exercise group vs $6,956 in the PCI group (P < .001). Hambrecht et al concluded that a 12-month program of regular exercise in selected patients with chronic stable angina and significant CAD resulted in a higher event-free survival and exercise capacity at lower costs than PCI.

Comment by Michael H. Crawford, MD

Previous single-center experience has shown increased survival and exercise tolerance in CAD patients treated with exercise training, but no randomized trials have been done. For that reason, this trial is of interest. It generally agrees with other medical vs revascularization trials, and it is not surprising that exercise training increased exercise tolerance more than PCI, since most CAD patients are sedentary despite our advice to exercise. Interestingly, both groups experienced a reduction in angina, which is consistent with other studies of revascularization, but less well established for exercise training. Since coronary lesion regression was not seen with exercise training, the mechanism of this benefit is unclear but may be due to improved vasomotor tone. That the reduced total direct costs were less in the exercise-training group is not surprising because of the cost of the initial PCI. However, the decrease in subsequent hospitalizations and procedures in the exercise group is less expected. This suggests that in such low-risk patients, the complications of PCI end up negating its benefits as compared to conservative therapy. Of course, drug-eluting stents were not used. Perhaps they would have significantly reduced the 15% restenosis rate observed in the PCI group and altered the conclusions of this study. Also, this is a small trial, so the conclusions must be tempered. In addition, these were very low-risk patients as evidenced by the zero death rate. Thus, the major implication of this small, randomized trial is that medical therapy with exercise training is a viable alternative to PCI in low-risk patients with chronic stable angina due to CAD. Of course, only selected patients will be able to adhere to this consistent exercise program, but for those who are motivated, exercise training plus maximal medical therapy may be highly effective. The COURAGE trial is testing the hypothesis that maximal medical therapy plus PCI will be better for patients with CAD than maximal medical therapy alone, but this trial does not include formal exercise training. I believe American physicians have given up on getting Americans, especially women, to exercise regularly. Perhaps this approach will only work in Europe and other places where regular exercise is more accepted. It is interesting to speculate on what PCI, maximal medical therapy, and exercise could do.

Dr. Crawford is Professor of Medicine, Associate Chief of Cardiology for Clinical Programs, University of California, San Francisco.