Impact of Internal Mammary Artery Conduit on Long-term Outcomes After Percutaneous Intervention of Saphenous Vein Graft

Abstract

Background— The influence of an internal mammary artery (IMA) graft on long-term outcomes after percutaneous saphenous vein graft (SVG) intervention is currently unknown. Methods and Results— To examine the impact of IMA on outcomes in patients undergoing SVG interventions, we analyzed 2119 patients from the Duke Cardiovascular Disease Database (1986–2003) with prior coronary artery bypass surgery undergoing cardiac catheterization who had at least 1 SVG graft. Patients were categorized into 4 groups: group I, SVG intervention and patent IMA; group II, no SVG intervention and patent IMA; group III, SVG intervention without patent IMA; and group IV, no SVG intervention without patent IMA. At a median follow-up of 4.8 years (interquartile range, 2.1 to 8.8 years), adjusted survival rates in groups I, II, III, and IV were 72.8%, 72.3%, 64.5%, and 58.9%, respectively. Multivariate Cox proportional hazards modeling showed similar survival for groups I and II ( P =0.63) and for groups III and IV ( P =0.33). The presence of IMA graft was related to lower long-term mortality (adjusted hazard ratio [HR], 0.69; 95% CI, 0.58 to 0.82), whereas SVG intervention was not associated with long-term mortality (adjusted HR, 0.94; 95% CI, 0.81 to 1.10). In contrast, the adjusted event-free rates for nonfatal myocardial infarction were lower in the SVG intervention groups (groups I and III) than in the non-SVG intervention groups (groups II and IV) (HR for SVG intervention versus no SVG intervention, 3.19; 95% CI, 2.18 to 4.66), with the presence of patent IMA conferring no significant benefit on this outcome (HR, 1.37; 95% CI, 0.91 to 2.08). Conclusions— In patients undergoing SVG interventions, survival, but not nonfatal myocardial infarction, is favorably influenced by the presence of patent IMA. In contrast, SVG intervention had no measurable survival benefit but was associated with an increased risk of nonfatal myocardial infarction.