Association between Baseline Syntax Score and Short-Term Major Adverse Cardiac and Cerebrovascular Events in Patients Undergoing Percutaneous Coronary Intervention or Coronary Artery Bypass Grafting: a Prospective Observational Study

Abstract

Objective: To evaluate the association between baseline SYNTAX score and 90 d major adverse cardiac and cerebrovascular events (MACCE) in patients undergoing percutaneous coronary intervention or coronary artery bypass grafting. Methods: A prospective observational study was conducted at Malla Reddy Narayana Multi-Specialty Hospital. Consecutive patients undergoing PCI or CABG were enrolled. Baseline SYNTAX scores were calculated for all patients. Tertile-based categories were derived from the sample distribution (Low:<16; Intermediate: 17–22; High: ≥23) to facilitate exploratory group comparisons; these categories differ from standard SYNTAX Score-I clinical thresholds and should be interpreted accordingly. The primary outcome was MACCE occurrence at 90 d of follow-up. MACCE was defined as a composite of myocardial infarction (MI), acute kidney injury (AKI), stroke, unstable angina, and cardiac death. Association between SYNTAX tertile and MACCE was assessed using chi-square or Fisher exact test, and binary logistic regression was performed with MACCE occurrence (Yes/No) as the dependent variable. Statistical significance was set at p<0.05. Results: Among 210 patients stratified by baseline SYNTAX score, 90 d MACCE occurred in 2.5%, 28.6%, and 55.0% of patients in the low, intermediate, and high SYNTAX categories, respectively (p<0.001). The baseline SYNTAX score demonstrated good discriminative accuracy for predicting MACCE (AUROC 0.80, 95% CI: 0.73–0.87), with an optimal threshold of>17.5 identified by the Youden Index. On multivariable logistic regression, baseline SYNTAX score (adjusted OR 1.15, 95% CI: 1.08–1.23; p<0.001) and diabetes mellitus (adjusted OR 2.89, 95% CI: 1.35–6.17; p = 0.006) were the only independent predictors of 90 d MACCE. Conclusion: In this prospective observational study, baseline SYNTAX score demonstrated an association with the occurrence of 90 d Major adverse cardiac and cerebrovascular events (MACCE) following coronary revascularization procedures. Higher SYNTAX scores were associated with an increased risk of adverse cardiovascular outcomes, reflecting the impact of coronary lesion complexity on short-term prognosis. However, the findings should be interpreted with caution due to the single center design, limited follow-up duration, and potential residual confounding. Larger multicenter studies with longer follow-up are required to further validate the prognostic utility of the SYNTAX score in patients undergoing PCI and CABG.