Five-Year Follow-Up of the Medicine, Angioplasty, or Surgery Study (MASS) : A Prospective, Randomized Trial of Medical Therapy, Balloon Angioplasty, or Bypass Surgery for Single Proximal Left Anterior Descending Coronary Artery Stenosis

Abstract

Background-Although coronary angioplasty and myocardial bypass surgery are routinely used, there is no conclusive evidence that these interventional methods offer greater benefit than medical therapy alone. This study is intended to evaluate, in a prospective, randomized, and comparative analysis, the benefit of the 3 current therapeutic strategies for patients with stable angina and single proximal left anterior descending coronary artery stenosis. Methods and Results-In a single institution, 214 patients with stable angina, normal ventricular function, and severe proximal stenosis (Ͼ80%) on the left anterior descending artery were selected for the study. After random assignment, 70 patients were referred to surgical treatment, 72 to angioplasty, and 72 to medical treatment. The primary end points were the occurrence of acute myocardial infarction or death and presence of refractory angina. After a 5-year follow-up, these combined events were reported in only 6 patients referred to surgery as compared with 29 patients treated with angioplasty and 17 patients who only received medical treatment (Pϭ0.001). However, no differences were noted in relation to the occurrence of cardiac-related death in the 3 treatment groups (Pϭ0.622). No patient assigned to surgery needed repeat operation, whereas 8 patients assigned to angioplasty and 8 patients assigned to medical treatment required surgical bypass after the initial random assignment. Surgery and angioplasty reduced anginal symptoms and stress-induced ischemia considerably. However, all 3 treatments effectively improved limiting angina. Conclusions-Bypass surgery for single-vessel coronary artery disease is associated with a lower incidence of medium-term and long-term events as well as fewer anginal symptoms than that found in the patients who underwent angioplasty or medical therapy. In this study, coronary angioplasty was only superior to medical strategies in relation to the anginal status. However, the 3 treatment regimens yielded a similar incidence of acute myocardial infarction and death. Such information should be useful when choosing the best therapeutic option for similar patients. (Circulation. 1999;100[suppl II]:II-107-II-113.)

Trials and tribulations associated with angina and traditional therapeutic approaches

“…Of the many subgroups previously identified as being at high-risk, only the subgroup with involvement of the proximal-LAD was subsequently evaluated in a prospective manner in the medicine, angioplasty or surgery study-1 (MASS-1). 29,30 Additional studies were conducted in the 1990s, which evaluated the role of CABGS, PTCA, or medical treatment in patients with stable CAD. These include the asymptomatic cardiac ischemia pilot (ACIP) 31,32 and the MASS trials.…”

“…These include the asymptomatic cardiac ischemia pilot (ACIP) 31,32 and the MASS trials. 29,30,33 The ACIP study 31,32 evaluated the effects of medical or revascularization (PTCA or CABGS) treatment strategies in patients with stable angiographic CAD (> = 50% stenosis) with or without angina, myocardial ischemia on ambulatory electrocardiography (AECG), and evidence of ischemia on an exercise treadmill test or pharmaceutical stress perfusion study. In this complex, partly blinded study, the three treatment strategies were angina-guided medical therapy; angina-guided plus AECG ischemiaguided medical therapy; and myocardial revascularization of major coronary arteries.…”

“…Although, mortality rates were similar between the two medical treatment arms and between the revascularization and angina-guided plus AECG-guided medical therapy (1.6%). 31,32 The MASS trial compared the effect of these therapies in patients with proximal-LAD (MASS-1) 29,30 and in patients with multi-vessel CAD (MASS-2). 33 In the Clinical Cardiology DOI:10.1002/clc MASS trials, all patients were placed on an optimal medical regimen that included: nitrates, aspirin, betablockers, CCBs, ACEI, or a combination of these drugs.…”

“…29,30,33 In the prospective MASS-1 trial 29,30 in patients with p-LAD involvement (> = 0.80 stenosis) compared to PTCA and medical therapy, CABGS was associated with a modest benefit on the combined outcome that consisted of cardiac death, MI, or angina requiring revascularization (the benefit was predominantly related to a less frequent need for subsequent revascularization). 29,30 It is important to note that compared to CABGS, medical therapy was associated with a similar reduction in the risk of hard events (mortality or MI). Treatment with PTCA appeared to be an inferior option compared to the other treatment strategies.…”

<![CDATA[Ministernotomy in off-pump coronary artery bypass surgery]]>

“…Recent studies have demonstrated that patients with isolated lesions of the proximal left anterior descending artery (LAD) achieve greater clinical benefits when submitted to surgical treatment using the left internal thoracic artery (LITA) [1][2][3]. Observational data, over the last decade, demonstrated that there is a lower incidence of cardiovascular events and greater survival when the LITA is utilized in coronary artery bypass grafting.…”