Stents or Surgery?

Coronary angioplasty and coronary bypass surgery are mechanical approaches to atherosclerotic obstructions that impede coronary blood flow. In bypass surgery, arterial and venous conduits are placed beyond the proximal obstructions. By contrast, in angioplasty, the area of narrowing is expanded and now usually buttressed with a stent. Neither mechanical approach addresses the fundamental disease process, however, which needs to be treated with medications and lifestyle changes.Article p 381 The perennial question is whether angioplasty or surgery yields better clinical outcomes. Even without randomized clinical trials, it is obvious that angioplasty is a less invasive procedure and that patients recover more quickly. Individual randomized trials have been large enough to show that bypass surgery generally reduces angina and repeat interventions to a greater extent than angioplasty does. But for the most important clinical outcome, mortality, single randomized clinical trials have not been large enough to provide definitive results. Because mortality is infrequent after contemporary coronary revascularization, lengthy follow-up is required to provide an adequate comparison of surgery and angioplasty. Large numbers of patients are required to ensure sufficient statistical power to detect clinically meaningful differences in mortality. Trials of the needed size and duration are difficult to organize and highly expensive. The results of every such trial are important pieces of the puzzle.The Stent or Surgery (SoS) trial is one of the largest randomized comparisons of coronary angioplasty and bypass surgery. Investigators at 53 study centers in 11 countries between 1996 and 1999 randomized 988 patients with multivessel coronary disease to undergo either conventional coronary bypass surgery or angioplasty with a bare-metal stent. The initial report of the SoS trial1 was based on a median of 2 years of follow-up, after which 22 patients assigned to angioplasty had died compared with 8 patients assigned to surgery (hazard ratio …