Abstract 2476: Eight-Year Clinical Outcome After Radioactive Stent Implantation: a Matched-Propensity Controlled Cohort Study
Radioactive stent (RS) implantation has been proposed as a modality to prevent restenosis. Its unfavourable short-term outcome, due to edge restenosis prohibited its therapeutic use and the long-term outcome of patients who underwent RS implantation is a cause of concern.
Objectives: To determine the long-term outcome of patients after RS implantation in comparison to a control patient group who underwent bare metal stenting (BMS).
Methods: The RS study population consisted of 133 consecutive patients who underwent RS implantation between November 1997 and July 2000. They were matched by using the propensity score method with 266 patients who underwent bare metal stenting in the same period. Long-term survival status was assessed by written inquires to the Municipal Civil Registries and long-term information on MACE [defined as death, myocardial infarction (MI) and any re-intervention] was obtained from an electronic database of hospital records and questionnaires sent to the patients and the referring physicians. The Kaplan-Meier method was used for computing the survival curves and differences between groups were assessed by the log-rank test of significance.
Results: Complete follow-up was available for all patients in the RS group (mean: 6.4±1.4 years) and 258 (97%) patients in the BMS group (mean: 6.4±1.6 years). The cumulative target lesion revascularisation (TLR) rate at six months in the RS group was 30%, mainly due to edge restenosis, and at one year 36.8%. Eight-year cumulative survival (95% vs. 92%, p=0.4) and death/MI-free survival (80% vs. 79%, p=1) were similar between the RS and BMS group respectively. Eight-year cumulative MACE-free survival rate was significantly lower in RS patients (42% vs. 60%, p<0.001) due to the difference in events during the first year of follow-up, while there was no difference in the MACE rate after the first year (p=0.3).
Conclusions: A high incidence of re-intervention and MACE was observed during the first year following radioactive stent implantation, mainly related to TLR for edge restenosis. After the first year, the clinical outcome of RS patients is comparable to that of patients treated with BMS indicating that there are no late adverse effects related to low dose-rate intracoronary radiation therapy.