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- CABG, coronary artery bypass graft
- ISR, in-stent restenosis
- MACE, major adverse cardiac events
- PCI, percutaneous coronary intervention
- SES, sirolimus eluting stent
- VBT, vascular brachytherapy
- percutaneous coronary intervention
- sirolimus eluting stent
- in-stent restenosis
- vascular brachytherapy
Since they were first introduced 17 years ago,1 bare metallic stents have improved the outcome of angioplasty.2 However, in-stent restenosis (ISR) remains a major limitation with an incidence of additional revascularisation of 17–21 %. Among the several approaches proposed to address this problem, vascular brachytherapy (VBT) has given the best results, with an incidence of major cardiac events at nine months from 18–28 %.3 The preliminary results reported with the use of sirolimus eluting stents (SES) in de novo lesions were encouraging.4 We report our results with both techniques in patients with ISR.
Between April 2001 and mid April 2002 all patients with ISR were treated with VBT, and from mid April to November 2002 they received one or several SES within the previous stent. The data from these patients were included in a prospective registry. All patients were pre-treated with aspirin 100 mg/day. Intravenous heparin was given initially and a 300 mg loading dose of clopidogrel was administered at the end. In the VBT group, we used the Beta-Cath with a 40 mm Sr-Y90 β source train. The radiation dose was calculated after the diameter of the vessel was determined by computer based quantitative coronary angiography, in order to deliver 18–25 Gy at 2 mm from the source. Additional stent implantation was avoided. In the SES group direct stenting was applied whenever possible. A successful procedure was defined as a residual stenosis < 20% and no major cardiac event during the in-hospital stay.
After the procedure patients were monitored and discharged less than 24 hours after the intervention. Aspirin 100 mg/day was given long term and clopidogrel 75 mg/day was prescribed for 3–12 months. For patients with angiographic follow up, restenosis was defined as a 50% or more reduction of the luminal diameter.
Clinical follow up was obtained by a visit or by telephone contact. Control angiography was performed only when clinically required. Cardiac death, myocardial infarction, and additional revascularisation were considered as major adverse cardiac events (MACE). The mean (SD) follow up time was 11 (2) months.
A total of 76 patients were included in the registry. Thirty eight patients were treated with VBT and 38 patients received one or several SES. An additional stent was required in six patients in the VBT group. The demographic and angiographic baseline characteristics were similar in both groups, as well as the classification (Mehran classification) of the ISR. A platelet glycoprotein IIb/IIIa inhibitor was used in 12% of the patients. There was no in-hospital death, myocardial infarction, or need for emergency revascularisation, and no acute or subacute stent thromboses. Early procedure clinical success rate was 100% in both groups and no patient experienced an increased creatine kinase value. Follow up was obtained in 76 patients (100%). Twenty nine patients (38%) underwent control, clinically driven, angiography (VBT = 16, SES = 13). MACE occurred in nine patients (24%) in the VBT group and in two patients (5%) in the SES group, (p = 0.048) (table 1). One patient died suddenly seven days after VBT. However, at necropsy no stent thrombosis was found. The additional procedures in the VBT group were: two coronary artery bypass grafts (CABGs) and six percutaneous coronary interventions (PCIs); and in the SES group two PCIs. No patients in either group experienced myocardial infarction. Angina class was comparable although more patients were in class I in the SES group (74% v 92%).
This registry, which compares VBT with drug eluting stents for the therapy of ISR, suggests that SES are associated with a significantly lower MACE rate at 11 months than VBT, primarily because of a lower requirement for further revascularisation procedures.
ISR leading to repeat revascularisation remains the major limitation following successful PCI. No single pharmacological regimen has been shown to be effective. Only VBT has been shown, in several randomised controlled trials, to have a positive impact at 6–12 months. The residual incidence of MACE is still 19–28%; however, this is largely determined by a need for further target lesion revascularisation. Recently, preliminary data with the use of drug eluting stents were reported as encouraging in selected groups of patients and in patients with ISR.5 Our current data are not randomised, a limitation of the trial, and therefore cannot be considered as definite proof that SES is superior, or indeed equivalent, to VBT, but suggest a real benefit of SES over VBT for the treatment of ISR in an unselected patient population. Based on these positive results we have now changed our policy and use SES to treat all our patients with ISR. More definitive conclusions must await the results of ongoing randomised trials.