Eight-month angiographic outcomes and in-stent restenosis in patients undergoing percutaneous coronary intervention on unprotected left main coronary artery

In-stent restenosis (ISR) remains a significant complication of percutaneous coronary intervention (PCI) for left main coronary artery (LMCA) disease, with potentially severe consequences. This study aimed to evaluate the incidence and predictors of ISR and highlight the role of systematic angiographic follow-up in optimizing patient outcomes. We conducted a retrospective cohort study including 229 patients who underwent LMCA PCI between 2013 and 2023 at ASST Spedali Civili di Brescia. All patients underwent systematic angiographic follow-up at 8 months. Data on clinical, angiographic, and procedural characteristics were collected and analyzed using univariate and multivariate logistic regression to identify predictors of ISR. Kaplan-Meier survival analysis was employed to assess outcomes. ISR was identified in 24 patients (10.5%) during angiographic follow-up, with 29.2% being symptomatic. Chronic kidney disease (CKD; odds ratio: 3.84, P = 0.003) and diabetes (odds ratio: 3.18, P = 0.008) emerged as independent predictors of ISR. Multivariate analysis confirmed these associations. Survival rates were high, with 97.7% at 1 year, 92.2% at 2 years, and 81.5% at 4 years. Subanalyses showed trends toward higher mortality among patients with CKD or diabetes but no significant differences between patients with acute and chronic coronary syndromes. In conclusion, ISR remains a clinically significant challenge after LMCA PCI, with CKD and diabetes as key predictors. Systematic angiographic follow-up is essential for early ISR detection, especially in high-risk populations, as the majority of cases are asymptomatic. These findings emphasize the need for tailored surveillance strategies to improve outcomes.