Semiurgent CABG after Successful PTCA: Should a Patent Stented Coronary Artery Be By-Passed?

Abstract

Background: After a successful primary percutaneous transluminal coronary angioplasty (PTCA)/stent placement, performing bypass surgery to an artery with a patent stent during semiurgent coronary artery bypass grafting (CABG) surgeries may protect the patient against ischemic complications due to acute stent occlusion. This issue, however, is controversial. Loss of bypass graft function may occur in the early stages due to the competition between native flow and graft flow. In the present study, the effects of bypass surgery to an artery with a patent stent on the outcomes were investigated. Methods: Fifty nine patients who had undergone isolated CABG surgery within 6 weeks after a successful primary PTCA/stent placement were included in the study. Patients who had undergone emergency operation due to suspicion of acute stent occlusion and the redo cases were excluded in the study. Patients were divided into two groups; those with (Group P, protected) and without (Group NP; non-protected) coronary bypass to an artery with a patent stent. Preoperative, operative and postoperative data were collected retrospectively from the patient files. The need for urgent revascularization was recorded postoperatively. Mann-Whitney U test was used for the analysis of continuous variables, whereas categorical variables were analyzed either using Pearson's chisquare test or Fisher's exact test. Results: Of 59 patients, 35 underwent bypass surgery to the artery with patent stent, whereas bypass was not performed on 24 patients. It was observed that dual antiplatelet therapy had been performed on 20% of the patients in Group P and 87.5% of those in Group NP (p = 0.001). No acute ischemic change due to stent occlusion was determined in Group P, whereas it was observed in one patient in Group NP (p = 0.4). The prevalence of hospital mortality was found to be 8.6% and 8.3% in Group P and Group NP, respectively (p = 1). Conclusions: Although it was not statistically significant, it was observed that bypass surgery might have a protective effect against stent occlusion in patients who underwent bypass surgery. However, postoperative dual antiplatelet therapy substantially prevented stent occlusion in those without bypass surgery. On the other hand, stent-supported coronary circulation may be unsafe in case of discontinuation of clopidogrel therapy. Therefore, it was suggested that performing bypass surgery to an artery with a patent stent would be more reasonable in patients who underwent semi-urgent CABG surgery.