Two-year follow-up after catheter-based radiotherapy to inhibit coronary restenosis

Background-Although early trials indicate the treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new t echnology has been questioned. The possibility of late untoward consequence s, such as aneurysm formation, perforation, and accelerated vascular diseas e, is of significant concern. Furthermore, it is not known whether the bene ficial effects of radiation therapy will be durable or whether radiation wi ll only delay restenosis. Methods and Results-A double-blind, randomized trial was undertaken to comp are <SUP>192</SUP>Ir with placebo sources in patients with previous resteno sis after coronary angioplasty. Patients were randomly assigned to receive a 0.76-mm (0.03-in) ribbon containing sealed sources of either <SUP>129</SU P>Ir or placebo. All patients underwent repeat coronary angiography at 6 mo nths. All living patients were contacted 24 months after their index study procedure. Patients were assessed with respect to the need for target-lesio n revascularization or nontarget-lesion revascularization, occurrence of my ocardial infarction, or death. Over a 9-month period, 55 patients were enro lled; 26 were randomized to <SUP>192</SUP>Ir<SUP></SUP> and 29 to placebo. Follow-up was obtained in 100% of living patients at a minimum of 24 months . Target-lesion revascularization was significantly lower in the <SUP>192</ SUP>Ir group (15.4% versus 44.8%; P<0.01). Nontarget-lesion revascularizati on was similar in <SUP>192</SUP>Ir and placebo patients (19.2% versus 20.7% ; P=NS). There were 2 deaths in each group. The composite end point of deat h, myocardial infarction, or target-lesion revascularization was significan tly lower in <SUP>192</SUP>Ir-treated versus placebo-treated patients (23.1 % versus 51.7%; P=0.03). No patient in the <SUP>192</SUP>Ir group sustained a target-lesion revascularization later than 10 months. Conclusions-At 2-year clinical follow-up, treatment with Ir-192 demonstrate s significant clinical benefit. Although further follow-up (including late angiography) will be necessary, no clinical events have occurred to date in the Ir-192 group to suggest major untoward effects of vascular radiotherap y. At the intermediate follow-up time point, vascular radiotherapy continue s to be a promising new treatment for restenosis.