Comparison of Outcomes in Patients Undergoing Coronary Bypass of Patent Versus Restenosed Bare Metal Stented Coronary Arteries

It is unclear whether bypass of a patent stented artery affects clinical outcomes. We sought to compare the survival of patients who, as part of multisystem coronary artery bypass grafting, underwent revascularization of arteries with patent stents (<50% stenosis) or in-stent restenosis (>50% diameter stenosis). Of 550 consecutive patients with previously placed stents who underwent coronary artery bypass grafting from May 1995 to October 2003, we studied 399 who had only 1 stented vessel bypassed at surgery. Of these, 128 had coronary bypass to an artery with a patent stent and 271 had bypass to an artery with in-stent restenosis. Nonparametric survival estimates were obtained using the Kaplan-Meier method. A propensity-adjusted multivariate hazard model of group differences was generated using variables identified by bootstrap bagging. The unadjusted survival rate at 1 month, 1 year, and 5 years was 99.7%, 97.3%, and 89.1%, respectively, for the patent stent group and 96.6%, 93.9%, and 86.2%, respectively, for the in-stent restenosis group, a result of high early risk in the latter group. After adjusting for clinical variables, neither stent patency (p = 0.9) nor interval (p = 0.3) from stent placement was a risk factor, although advanced age, increased blood urea nitrogen, and preoperative atrial fibrillation were associated with poorer survival. In conclusion, survival after bypassing a patent stented coronary artery is comparable to that after bypassing a stented restenotic coronary artery.