In-hospital and 1-Year Outcomes of Repeated Percutaneous Coronary Intervention for In-stent Restenosis With Acute Coronary Syndrome Presentation

In-stent restenosis (ISR) is the Achilles' heel of percutaneous coronary intervention (PCI). There have been controversial data about outcomes of repeated PCI (redo-PCI) for ISR. This study aims to determine the predictors of major adverse cardiac events (MACE) in patients underwent redo-PCI for ISR.In this retrospective study, all patients with acute coronary syndrome who were underwent successful PCI for ISR at Tehran Herat Center (between 2004 and 2019) were eligible for inclusion. Patients with moderate to severe valvular heart disease and/or hematological disorders were excluded. Participants were divided into 2 groups based on the occurrence of the MACE [composite of cardiovascular death, myocardial infarction (MI), coronary artery bypass grafting, target vessel revascularization, and target lesion revascularization]; then, the study variables were compared between the 2 groups. Finally, the predictors of MACE were identified using Cox regression analysis.Of 748 redo-PCI patients (mean age: 65.2 ± 10.1; 71.0% males), 631 patients had met the inclusion criteria. Fifty-four patients (9.8%) developed MACE within a 1-year follow-up period. Multivessel disease, primary PCI, Ad-hoc PCI, history of non-ST-segment elevation MI, and diabetes mellitus were independent predictors for MACE. In a subgroup analysis, 30 patients who experienced third PCI (target lesion revascularization/target vessel revascularization) were followed more as 1-year MACE. Among these patients, 14 MACEs were observed during the last follow-up (till June 2020).Multivessel disease, primary PCI, and history of non-ST-segment elevation MI were the predictors of higher 1-year MACE, whereas Ad-hoc PCI and diabetes mellitus had a protective effect on MACE.