According to TheHeart.org, a European multi-center randomized clinical trial comparing angioplasty and stenting to a regimen of exercise training for the treatment of patients with stable angina (the multi-center PET study) has ended in failure, due to a lack of enthusiasm among potential study participants.
The multi-center PET study was based on a smaller, single-center PET study whose results were reported in Circulation in 2004. In this original study, 102 patients with stable angina were randomized to either exercise therapy or angioplasty/stenting. Both groups showed significant improvements in symptoms, and the exercise group showed clear trends (without statistical significance) toward improved long-term outcomes. Because of this intriguing trend, the multicenter PET trial was begun in medical centers in Germany, Austria, Switzerland, and Romania.
Unfortunately, this larger trial had to be stopped after only 100 of the projected 400 patients were enrolled, because of insurmountable difficulties in getting enough patients to sign up for the trial.
At the recent European Society of Cardiology meetings in Barcelona, the principal investigator, Dr Rainer Hambrecht from Bremen, Germany, reported on the combined results of the two PET trials (with approximately 100 patients from each trial). Pooling the results, patients randomized to exercise therapy had significantly fewer coronary artery "events" (heart attacks, or the need for further invasive treatment) than patients randomized to angioplasty/stenting. That is, it appears that exercise training is actually superior to angioplasty/stenting in patients with stable angina.
Dr. Hambrecht suggested that these results can be explained by the fact that exercise provides more "global" benefits to the cardiovascular system than the local effects provided by stenting.
It is not likely that this conclusion will win widespread recognition, since it was achieved by pooling results from two separate trials. And it is unlikely that a trial like this will be undertaken again in the forseeable future, given the inability of even these very entusiastic investigators to find enough patients willing to commit to a rigorous exercise program to allow for the completion of their study. Interventional cardiologists, the stent industry, and the patients who otherwise would have been cajoled (by their doctors and their insurers) into embarking on exercise programs, are all saved.
Sources:
Hambrecht R, Walther C, Möbius-Winkler S, et al. Percutaneous coronary angioplasty compared with exercise training in patients with stable coronary artery disease: a randomized trial. Circulation 2004; 109:1371-1378.
