In-Hospital Outcomes of Acute Coronary Syndrome in Patients with Prior Coronary Artery Bypass Grafting: Experience from a Tertiary Cardiac Care Center in Pakistan

Abstract

Objectives: To assess in-hospital outcomes and identify factors associated with mortality among patients with a prior history of coronary artery bypass grafting (CABG) presenting with acute coronary syndrome (ACS) at a tertiary cardiac care center in Pakistan. Methodology: This cross-sectional study was conducted at Tabba Heart Institute, Karachi, from February 2025 to August 2025. Consecutive patients aged 40–80 years with a documented history of CABG presenting with ACS were enrolled. Demographic characteristics, cardiovascular risk factors, clinical variables, and echocardiographic parameters, including left ventricular ejection fraction (LVEF), were recorded. The primary outcome was all-cause in-hospital mortality. Logistic regression analyses were performed to identify factors associated with mortality. Results: A total of 334 patients were included in the final analysis. The median age was 66 years, and most patients were male. The overall in-hospital mortality rate was 3.9%. In univariate analysis, reduced LVEF was significantly associated with mortality. In multivariable logistic regression, LVEF remained the only independent predictor of in-hospital death, with each 1% increase in LVEF associated with an 8% reduction in the odds of mortality. Conclusion: Among patients with prior CABG presenting with ACS, in-hospital mortality was relatively low; however, reduced LVEF was independently associated with death. Assessment of ventricular function may provide important prognostic information in this high-risk population.