What are the predictors that affect the excellent long-term benefits of redo coronary artery bypass grafting?

ABSTRACT

OBJECTIVE: Recurrent angina refractory to medical therapy in patients having undergone prior coronary artery bypass grafting (CABG) is an indication for repeat surgical revascularisation. The primary aim of this retrospective study was to determine the benefit of redo surgery over the longer term with regards to survival and freedom from cardiac symptoms/events. Our secondary aim was to identify risk factors that compromise surgical efficacy of redo revascularisation. METHODS: Patients were identified through case note review. Survivors were interviewed by telephone according to a defined protocol. Actuarial freedom from cardiac symptoms/events and survival were determined. A composite outcome for cardiac symptoms/events was used and defined as angina class> or =2 or NYHA> or =2 or myocardial infarction or need for percutaneous intervention. Univariate and multivariate analysis was performed. Survival was assessed using a Kaplan-Meier method, and determinants of survival with the Cox proportional hazards model. RESULTS: Between January 1st, 1996 and February 1st, 2004, 101 consecutive patients underwent redo CABG at our institution under the care of a single surgeon. There were 91 men and 10 women, 64% (65/101) had an age> or =70 years. 30-Day mortality was 1.2% (2/101). Mean time to follow-up was 5.3+/-3.8 years. Poor left ventricular function and pre-operative NYHA> or =2 status were independent predictors of decreased survival with hazard ratios (HR) of 2.12 (1.042-4.31) and 3.98 (1.39-11.39) respectively. The use of a radial artery graft at re-operation was an independent predictor of peri-operative death OR=18 (1-346). Actuarial survival at 1, 5 and 8 years was 90.1%, 84.4% and 76.9% and freedom from cardiac symptoms/events was 100%, 95% and 68% respectively. CONCLUSION: This study shows acceptable short- and long-term survival and freedom from symptoms/events in patients undergoing redo coronary artery bypass grafting at a single institution. The apparent association between radial arterial grafts and impaired early clinical outcome warrants further investigation.