Single versus Dual Antiplatelet Therapy after CABG Surgery

Abstract

Background: The optimal antiplatelet therapy regimen in the early post-operative CABG period is not well researched. Several studies have proven that use of clopidogrel and aspirin prior to surgery increases bleed risks, but very few studies have examined this therapy post-operatively. Due to the limited amount of data surrounding this topic, the goal of this study was to determine if single or dual antiplatelet therapy had better outcomes in those status-post CABG surgery. Methods: This was a retrospective, single center, cohort study performed at Saint Joseph Hospital in Lexington, Kentucky. Data was reviewed through the Society of Thoracic Surgeons (STS) database, pharmacy medication dispensing records, as well as manual chart review. The primary composite endpoint of the study consisted of in-hospital mortality, ischemic or thrombotic events, bleeding events, restenosis rates, and 30-day readmission rates. Results: The number of events with regard to the primary composite endpoint was 32 events with combination therapy and 39 events with aspirin monotherapy (p = 0.39). A greater decrease in hemoglobin and hematocrit was seen in the aspirin monotherapy group (p = 0.02 and p = 0.047). Patients with prior CVA or TIA were more commonly placed on combination therapy after surgery (p = 0.018). There were no differences in outcomes when type of antiplatelet therapy and type of CABG were analyzed. Conclusions: There was no difference seen between single versus dual antiplatelet therapy regarding the primary composite endpoint. There was an increase in bleeding events with aspirin monotherapy as defined by TIMI criteria as well as a statistically significant decrease in Hgb and HCT with aspirin monotherapy. Patients with previous CVA/TIA were more likely to receive combination therapy. The average number of vessels grafted per surgery was lower in the off-pump surgery cohort.