Three-year follow-up after intracoronary gamma radiation therapy for in-stent restenosis

Background: The Washington Radiation for In-Stent Restenosis Trial (WRIST) is a double-blinded randomized study evaluating the effects of intracoronary radiation therapy (IRT) in patients with in-stent restenosis (ISR). Methods: One hundred and thirty patients with ISR (100 native coronary and 30 vein grafts) underwent PTCA, laser ablation, rotational atherectomy, and/or additional stenting (36% of lesions). Patients were randomized to either Iridium-192 IRT or placebo, with a prescribed dose of 15 Gy to a 2-mm radial distance from the center of the source. Results: Angiographic restenosis (27% vs. 56%, P =.002) and target vessel revascularization (TVR; 26% vs. 66%, P P =.002) and TVR (IRT=17% vs. placebo=3%, P =.009). At 3 years, the major adverse cardiac event (MACE) rate was significantly reduced with IRT (39% vs. 65%, P =.003). Conclusions: In WRIST, patients with ISR treated with IRT using 192 Ir had a marked reduction in the need for repeat target lesion and vessel revascularization at 6 months, with the clinical benefit maintained at 3 years.