Mortality Associated with the Number of Diseased Vessels and Therapeutic Strategies for Coronary Artery Disease: Long-Term Follow-Up

Abstract

Background: The number of coronary arteries affected by atherosclerosis is believed to impact the prognosis of coronary artery disease, resulting in a higher incidence of cardiac events. However, conclusive results on the relationship between the extent of coronary atherosclerosis and outcomes are lacking. Methods: This retrospective, single-center, observational cohort study included patients with stable coronary artery disease and preserved ventricular function who had the option of any of the three therapeutic strategies (medicine, angioplasty, or surgery) included in the MASS-Trials database. Patients were stratified according to the number of diseased arteries forming single-vessel, double-vessel, and triple-vessel disease groups. The atherosclerotic burden was assessed using the SYNTAX Score. Each group was eligible for any of the three therapeutic strategies. The primary endpoint was overall mortality. Secondary endpoints included the combination of all-cause death, nonfatal myocardial infarction, and additional coronary interventions. Results: Between May 1998 and June 2009, 2,000 patients who met the inclusion criteria in the MASS-Trial database were included. The study enrolled 1,855 patients. Of these, 224(12%) had single-vessel disease (SVD), 536(29%) had double-vessel disease (2VD), and 1,095(59%) had triple-vessel disease (3VD). The entire follow-up of our sample was 5 years. Overall mortality for SVD, 2VD, and 3VD was 9(4%), 33(6.3%), and 43(3.9%), respectively (P=0.054). Pairwise comparison of mortality at 5-year follow-up showed no significant differences between SVD x 2VD, SVD x 3VD, and 2VD x 3VD (hazard ratio [HR] 1.41, 95% CI: 0.81-2.44). The secondary endpoints (combination of overall mortality, nonfatal infarction, and additional revascularization) also revealed no significant differences (P=0.2). Conclusions: Overall mortality was similar regardless of the number of diseased arteries and the degree of arterial involvement. These data suggest that optimized medical treatment as an initial strategy is safe and has a similar rate of events in any applied therapeutic option.