Influence of preoperative renal dysfunction on one-year bypass graft patency and two-year outcomes in patients undergoing coronary artery bypass surgery

Abstract

Limited information exists on the impact of preoperative renal dysfunction on internal thoracic artery and saphenous vein graft failure and 2-year clinical outcomes in patients undergoing coronary artery bypass surgery. We studied the impact of preoperative renal dysfunction (creatinine clearance < 60 mL/min) on 1-year internal thoracic artery and saphenous vein graft failure (defined as > or = 75% angiographic stenosis) and 2-year clinical events (death; death or myocardial infarction; and death, myocardial infarction, or revascularization) in 3014 patients undergoing coronary artery bypass surgery enrolled in the Project of Ex-vivo Vein Graft Engineering via Transfection-IV study. Of 2973 patients (98.6%) with preoperative measurement of renal function, 440 (14.8%) had renal dysfunction. Most baseline comorbidities were higher in these patients. Two-year clinical events were higher in patients with preoperative renal dysfunction (adjusted death, myocardial infarction, or revascularization, hazard ratio 1.21, 95% confidence interval 0.97-1.50; adjusted death or myocardial infarction, hazard ratio 1.35, 95% confidence interval 1.05-1.74; adjusted death, hazard ratio 1.47, 95% confidence interval 0.98-2.21). However, saphenous vein graft (odds ratio 1.02, 95% confidence interval 0.79-1.33) and internal thoracic artery (odds ratio 0.76, 95% confidence interval 0.40-1.44) failure were similar in the 2 groups. Although the risk of adverse clinical events is higher in patients with preoperative renal dysfunction, that of internal thoracic artery and saphenous vein graft failure is not. This suggests that factors other than graft failure account for the worse clinical outcomes in this high-risk cohort. Further studies are needed to identify other mechanisms of these worse outcomes so that appropriate measures can be developed to improve long-term outcomes in patients with renal dysfunction undergoing coronary artery bypass surgery.