Aims: 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.
Methods and results: 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.
Conclusions: 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.