In a trial comparing coronary-artery bypass surgery with stenting for the treatment of multivessel coronary disease, Serruys et al. (April 12 issue) 1 conclude that both treatments offer protection against death, stroke, and myocardial infarction. We disagree. Whether there is "protection" can be determined only through comparison with a group of patients who are assigned to medical therapy alone.To date, no clinical trial comparing angioplasty with medical therapy for angina has demonstrated a protective effect of angioplasty in multivessel disease.2,3 Indeed, in the second Randomised Intervention Treatment of Angina (RITA-2) trial, 3 patients who underwent angioplasty had a significant 91 percent increase (a 3 percent absolute difference) in the rate of death or myocardial infarction during a median of 2.7 years of follow-up. The early randomized, controlled trials comparing coronary surgery with medical treatment also failed to show an improvement in prognosis among patients without stenosis of the left main coronary artery and with good left ventricular function. 4 Neither of these treatment options has been shown to offer protection against myocardial infarction or stroke. These results can be explained by the fact that risk of plaque rupture is determined not by the patency of the vessel but by the stability of the atheromatous plaque: most episodes of acute coronary occlusion occur in vessels with stenoses that are not flow-limiting (those resulting in a reduction of less than 70 percent in the luminal diameter).5 These two treatments are palliative, and to portray them as protective is misleading.