Predictive Value Analysis of in-Stent Restenosis Within Three Years in Older Acute Coronary Syndrome Patients: A Two-Center Retrospective Study.

We aimed to investigate prognostic factors of in-stent restenosis (ISR) within 3 years in older acute coronary syndrome (ACS) patients after drug-eluting stent (DES) implantation and establish a clinical model for predicting ISR. We retrospectively collected 215 older ACS patients who followed coronary angiography (CAG) after DES implantation, divided into ISR group and non in-stent restenosis (non-ISR) group according to the results of reviewed CAG. Logistic regression analysis was performed to screen independent predictors related to ISR and build the clinical predictive model, which clinical application was assessed by decision curve analysis (DCA) and clinical impact curve (CIC). Kaplan-Meier survival curves for ISR by independent predictors. In multivariate logistic regression analysis showed that the red cell distribution width (RDW) was higher in ISR group compared with non-ISR (odds ratio (OR) = 1.54, 95% confidence interval (CI): 1.14-2.08, p < 0.01). Instead, a negative correlation was observed between minimum stent diameter and ISR (OR = 0.28, 95%CI:0.09-0.86, p = 0.03). A novel nomogram composed of these significant features presented a concordance index (C-index) of 0.710, DCA and CIC suggested that the predictive nomogram had clinical utility. Schoenfeld residuals showed the model RDW ≥ 12.6% with minimum stent diameter <3 mm was consistent with the proportional risk assumption. The Kaplan-Meier estimate for ISR showed statistical significance. Higher levels of RDW and lower minimum stent diameter were associated with incidence of ISR within 3 years in older ACS patients after DES implantation.