Abstract P133: Effect of Prior Cardiac Surgery on Survival After CABG Surgery

Abstract

Background: We examined a recent regional experience to determine the impact of a prior cardiac surgery on short and long-term outcomes following coronary artery bypass grafting (CABG) surgery. Methods: We identified 20,504 patients undergoing non-emergent CABG surgery at 8 centers in northern New England from 2000-2008, of whom 818 (4.0%) had undergone prior cardiac surgery. Prior CABG and/or valve surgery utilizing a mini- or full sternotomy was considered a prior sternotomy. Survival data was obtained by linkage to the Social Security Administration Death Index. Hazard ratios were estimated using a Cox Proportional Hazards regression model while adjusted survival curves were estimated using inverse probability weighting. Models were adjusted for age, sex, ejection fraction, acuity, vascular disease, diabetes, prior myocardial infarction, renal failure or creatinine >2 mg/dl, left main disease, chronic obstructive pulmonary disease, body mass index, medical center and year. We conducted a nearest-neighbor propensity matched analysis among a subset of 1,568 patients who were matched 1:1 having a prior cardiac procedure based on their history of a cardiac surgical procedure and aforementioned patient and disease characteristics. Results: In both instances, prior sternotomy was associated with increased risk of mortality for patients undergoing CABG: [adjusted unmatched HR: 1.68, (CI 95% 1.46, 1.93)]; [propensity matched HR: 1.44, (CI 95% 1.12, 1.86)]. Conclusions In our recent regional experience with non-emergent CABG, a prior cardiac surgery was associated with a nearly two-fold increased hazard of mortality at up to 4 years of follow-up.