Intracoronary Radiation Therapy Improves the Clinical and Angiographic Outcomes of Diffuse In-Stent Restenotic Lesions

Abstract

Background— The Washington Radiation for In-Stent Restenosis Trial for long lesions (Long WRIST) was designed to determine the safety and efficacy of vascular brachytherapy for the treatment of diffuse in-stent restenosis. Methods and Results— A total of 120 patients with diffuse in-stent restenosis in native coronary arteries (lesion length, 36 to 80 mm) were randomized for either radiation with ¹⁹² Ir with 15 Gy at 2 mm from the source axis or placebo. After enrollment, 120 additional patients with the same inclusion criteria were treated with ¹⁹² Ir with 18 Gy and included in the Long WRIST High Dose registry. Antiplatelet therapy was initially prescribed for 1 month and was extended to 6 months in the last 60 patients of the Long WRIST High Dose registry. At 6 months, the binary angiographic restenosis rate was 73%, 45%, and 38% in the placebo, 15 Gy, and 18 Gy radiated groups, respectively ( P P P Conclusions— Vascular brachytherapy with ¹⁹² Ir is safe and reduces the rate of recurrent restenosis in diffuse in-stent restenosis. The efficacy of vascular brachytherapy on angiographic and clinical outcomes is enhanced with a radiation dose of 18 Gy and prolonged antiplatelet therapy.