Relationship Between Syntax Score and Cystatin C in Patients with Acute Coronary Syndrome

Introduction: The SYNTAX (SYNergy between PCI with TAXUS and Cardiac Surgery) score (SS) is an angiographic scoring system to determine the severity of coronary artery disease (CAD). As far as we know, studies examining the relationship between SYNTAX Score and Cystatin C (Cys-C) are limited in the literature. In this study, we aimed to investigate the relationship between Cys-C level and SS in patients presenting with ST-elevation myocardial infarction (STEMI). Patients and Methods: One hundred ninety-two patients who underwent coronary angiography for STEMI between June 2021 and December 2021 in our center were included in the study. The patients were divided into two groups according to their SS values: Group 1 included patients with SS<22, and Group 2 included patients with SS≥ 22. The two groups were compared in terms of baseline characteristics and serum Cys-C levels. Results: Patients in Group 2 had significantly higher Cys-C levels than those in Group 1 (1.7 ± 0.53 vs 1.3 ± 0.29; p= 0.006). In the correlation analysis, SS showed a positive correlation with the Cys-C level (r= 0.189, p= 0.015). Multivariate logistic regression analysis showed that Cys-C level was an independent predictor of high SS (β=0.306, p= 0.006). When receiver operating characteristic (ROC) curve analysis was performed, the optimal cut-off value of Cys-C to predict severe coronary artery disease (indicating high SS) was Cys-C≥ 1.56, which was predictive for severe coronary artery disease with 74% sensitivity and 72% specificity [area under the curve (AUC)= 0.745, 95% confidence interval (CI)= 0.624-0.835, p<0.001). Conclusion: Cystatin C levels are independently associated with high SS in STEMI patients. In summary, our findings show that Cys-C is a promising clinical biomarker that can be used to assess the severity of coronary artery lesions, potentially providing additional information to established risk markers.