Twelve versus six months of clopidogrel to reduce major cardiac events in patients undergoing γ-radiation therapy for in-stent restenosis: Washington radiation for in-stent restenosis trial (WRIST) 12 versus WRIST PLUS

Background— Intracoronary γ-radiation reduces recurrent in-stent restenosis (ISR). Late thrombosis was attenuated with 6 months of aspirin and clopidogrel. We aimed to find out whether 12 months of aspirin plus clopidogrel is superior to a strategy of 6 months after radiation therapy for patients with ISR. Methods and Results— One hundred twenty consecutive patients with diffuse ISR in native coronaries and vein grafts with lesions <80 mm in length underwent PTCA, laser ablation, or rotational atherectomy. Additional stents were placed in 39 patients (33%). After the intervention, a ribbon with different trains of radioactive 192Ir seeds was positioned to cover the treated site, and a dose of 14 Gy to 2 mm was prescribed. Patients were discharged with clopidogrel and aspirin for 12 months and followed up clinically. The cardiac clinical event rates at 15 months were compared with the γ-treated (n=120) patients of the WRIST PLUS study (only 6 months of antiplatelet therapy). Whereas the late thrombosis rat...