Higher SII and FAR levels associated with poorly-developed coronary collateral circulation in CTO patients.

BackgroundCoronary collateral circulation (CCC) plays a vital compensatory role in maintaining myocardial perfusion in patients with chronic total occlusion (CTO) of the coronary arteries. Systemic inflammation and nutritional status are known to influence arteriogenesis; however, the roles of the systemic immune-inflammation index (SII) and the fibrinogen-to-albumin ratio (FAR) in CCC formation remain underexplored.ObjectiveThis study aimed to evaluate the association between SII and FAR levels and the development of CCC in patients with CTO.MethodsA retrospective analysis was conducted on 469 patients with coronary chronic total occlusion who underwent elective coronary angiography. Patients were stratified into poorly-developed and well-developed CCC groups based on the Rentrop collateral grading system. Baseline clinical characteristics, laboratory biomarkers, and angiographic findings were compared between groups. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of poorly-developed CCC. The predictive value of SII and FAR, both individually and in combination, was evaluated using receiver operating characteristic (ROC) curve analysis.ResultsPatients with poorly-developed CCC exhibited significantly higher levels of SII and FAR compared to those with well-developed CCC. In multivariate logistic regression, both SII [odds ratio [OR] = 3.121, 95% confidence interval [CI]: 1.827–5.537, P