Three-year clinical and angiographic follow-up after intracoronary radiation - Results of a randomized clinical trial

Background-Although several early trials indicate treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The objective of this report is to document angiographic and clinical outcome 3 years after treatment of restenotic stented coronary arteries with catheter-based Ir-192. Methods and Results-A double-blind, randomized trial compared Ir-192 with placebo sources in patients with previous restenosis after coronary angioplasty, Over a 9-month period. 55 patients were enrolled; 26 were randomized to Ir-192 and 29 to placebo. At 3-year follow-up, target-lesion revascularization was significantly lower in the Ir-192 group (15.4% versus 48.3%; P<0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in Ir-192 patients (33% versus 64%; P<0.05), In a subgroup of patients with 3-year angiographic follow-up not subjected to target-lesion revascularization by the 6-month angiogram, the mean minimal luminal diameter between 6 months and 3 years decreased from 2.49+/-0.81 to 2.12+/-0.73 mm in Ir-192 patients but was unchanged in placebo patients. Conclusions-The early clinical benefits observed after treatment of coronary restenosis with Ir-192 appeal durable at late follow-up. Angiographic restenosis continues to be significantly reduced in Ir-192-treated patients, but a small amount of late loss was observed between the 6-month and 3-year follow-up time points. No events occurred in the Ir-192 group to suggest major untoward effects of vascular radiotherapy. At 3-year follow-up, vascular radiotherapy continues to be a promising new treatment for restenosis.