OUTCOMES AMONG PATIENTS WITH CORONARY ARTERY BYPASS GRAFTS PRESENTING WITH ACUTE CORONARY SYNDROME: ROLE OF PERCUTANEOUS CORONARY INTERVENTION

Abstract

<h3>BACKGROUND</h3> Patients with complex coronary artery disease (CAD) are treated with coronary artery bypass graft surgery (CABG). Due to progressive atherosclerotic CAD, patients with previous CABG can present with an acute coronary syndrome (ACS). Robust data demonstrating prognostic benefit for revascularization over medical management in this patient population is lacking. Therefore, we evaluated patients with previous CABG presenting with ACS, to identify the long-term outcomes of repeat revascularization vs. medical management. <h3>METHODS AND RESULTS</h3> Using the Manitoba Center for Health Policy repository, we identified patients treated with CABG, who subsequently presented with ACS from January 1, 2000 to March 31, 2018. Patients were divided into 3 groups: 1) not investigated by cardiac catheterization and managed medically; investigated by cardiac catheterization and 2a) treated medically, and 2b) treated with percutaneous coronary intervention (PCI). An inverse probability treatment weighted survival in a propensity-matched cohort was calculated, 90 days post-discharge from hospital. A total of 20297 CABG patients were included. Nearly 25% of patients with previous CABG presented with an ACS at a median of 7.2 years (3.4-11.5 years) post-CABG. In propensity-matched cohorts, treatment with PCI [N=741, median age 70 years (62-77 years); 581/741 (78.4%) male] was associated with improved survival in comparison to those investigated by catheterization but treated medically [N=546, median age 71 years (62-78 years); 418/546 (76.6%) male] at 10-years of follow-up; adjusted hazard ratio HR: 0.87 (95% CI 0.77 - 0.97); p=0.02 (Table 1, Figure 1). Patients treated medically and not referred for cardiac catheterization [N=742, median age 78 years (71-84 years); 518/742 (69.8%) male] were older and had significantly higher mortality in comparison to those treated with PCI. Mortality benefit associated with PCI may be secondary to underlying coronary anatomy and severity of disease, however, we do not have individual patient level angiographic data. <h3>CONCLUSION</h3> ACS is not uncommon following CABG. Suitable patients should be revascularized given the association with improved outcomes; however, this may be accounted for by inherent differences in the patient populations and coronary anatomy. Further individual patient level data is required to identify observed mortality differences.