A comparison of clinical presentations, angiographic patterns and outcomes of in-stent restenosis between bare metal stents and drug eluting stents

Abstract

This paper studies in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) following bare-metal stent (BMS) and drug-eluting stent (DES) in all consecutive patients between 2004 and 2007 undergoing PCI for ISR lesions at our centre. We compared the clinical presentation, pattern and angiographic outcomes in 838 patients with BMS ISR (487) and SES ISR (351). About 18% of the patients presented with acute coronary syndrome with 2% presenting as ST elevation myocardial infarction, similar in both groups. Angiographic pattern was predominantly focal with SES ISR (47%SES ISR vs. 19% BMS ISR; p<0.001) and diffuse with BMS ISR (SES ISR 16% vs. BMS ISR 36%; p=0.003). In our series the use of balloon angioplasty was higher for the treatment of SES ISR patients as compared to BMS ISR (41.6% vs. 18.3%; p<0.001) and the usage of stent was higher in BMS ISR patients (38.6% vs. 23.4%; p<0.001). Angiographic recurrent restenosis with conventional treatment in a consecutive series of patients was 38.6% and target lesion revascularisation was seen in 33.6%. These outcomes were seen slightly higher in SES ISR group (41.1% vs. 36.9%, p=ns). We have identified unstable angina at presentation (OR 3.02; 95%CI: 1.58-5.77, p=0.001), focal pattern of ISR (OR 0.50; 95% CI: .25-.99, p=0.04), stent usage (OR .25; 95% CI .13-.47, p<0.001), and baseline% diameter stenosis (OR1.03; 95%CI: 1.03-1.06, p=0.01) as independent predictors of BMS ISR recurrent restenosis. Unstable angina, focal pattern of ISR, reference vessel diameter, and% diameter stenosis were shown to be independent predictors of SES ISR. ISR is not a benign condition, and one fifth of the patients presented with acute coronary syndrome. The pattern of restenosis is predominantly non-focal with BMS ISR and focal with SES ISR. Recurrent restenosis rates are high following conventional treatment and further optimal therapies mainly with SES ISR needs to defined.