Abstract P224: Completeness of Revascularization Predicts Long-Term Survival Benefit in CABG Surgery

Abstract

Objectives: The primary objective of this study was to examine the effect of complete vs. incomplete revascularization in CABG surgery on long-term mortality. The secondary objective of this study was to examine the effect of variable grafting strategies on long-term mortality. Methods: All consecutive CABG surgeries performed at a single tertiary care center between 1995-2007 were reviewed. Long-term survival rates were compared among patients based on completeness of revascularization, the use of no arterial graft (all saphenous vein), single arterial graft, and multiple arterial grafts. Groups were also stratified based on the type of arterial grafts used (bilateral internal mammary arteries (BIMA) vs. multiple arterial grafts with only one IMA). Cox proportional Hazards ratio models were generated to adjust for differences in clinical presentation between the CABG groups. Results: A total of 8977 isolated CABG operations were preformed at our institution during that period. These patients were followed for a median time of 3.5 years (IQR=1.1-6.4). In this patient population, incomplete revascularization predicted an increased risk of mortality (HR=1.25; CI=1.12-1.39). A single arterial graft was performed in the majority of patients (63%; n=5637) with 28% of patients (n=2532) receiving multiple arterial grafts. Patients who received multiple arterial grafts were more likely to be younger, male, and undergo non-urgent surgery. After adjusting for these differences, patients who received an arterial graft (LIMA, RIMA, or radial) were shown to have improved survival when compared to patients who did not (HR=0.74; CI=0.65-0.83). Among patients who received multiple arterial grafts, percent survival for patients with BIMA grafts at 10 years was 70.4% compared to 66.1% for patients with single arterial grafts. Furthermore, patients who received BIMA grafts had the lowest predicted mortality among arterial graft patients when compared to patients who did not receive an arterial graft (HR=0.63; CI=0.51-0.77). Conclusions: We were able to show that after adjusting for differences in clinical presentation, both completeness of revascularization and BIMA grafting are strong independent predictors of long-term survival among CABG patients.