Outcomes and prognostic factors of patients treated for in-stent restenosis: a retrospective single-center experience

Background: The incidence of in-stent restenosis (ISR) remains relatively common despite the use of drug-eluting stents. Outcomes and prognostic factors following ISR revascularization are still being investigated. We aimed to describe the outcomes following different ISR treatment strategies in order to identify prognostic factors associated with worse outcomes. Results: In a retrospective cohort study, we included patients who were admitted to our department and treated for ISR, from January 2017 to December 2018. All patients were followed up for a median period of 24 months. Major cardiac adverse event (MACE) was a composite outcome of the following events: myocardial infarction, target vessel revascularization, target lesion revascularization or cardiovascular death. MACEs were collected during follow-up. Our population consisted of 116 patients. Mean age was 60 years old with a sex ratio of 2.8. During follow-up, 44 patients (37.9%) had at least one MACE. Independent factors identified by multivariate logistic regression were ISR of the proximal left anterior descending artery [Odds ratio (OR) = 1.29; 95% confidence interval (95% CI) 1.16-1.81; p= 0.05], diffuse ISR [OR= 2.16; 95% CI 1.1-3.47; p = 0.022], double or triple vessel disease [OR = 2.97; 95% CI 1.2-6.8; p= 0.008], two or more stents per lesion [OR = 1.82; 95% CI 1.14-2.21,p= 0.031] and absence of post-dilatation in the initial angioplasty [OR= 1.32; 95% CI 1-1.35; p= 0.04]. Conclusions: Our study suggested that ISR is related to poor outcomes. Identifying prognostic factors would play a key role in the refinement of interventional techniques.