Treatment of diffuse in-stent restenosis with rotational atherectomy followed by radiation therapy with a rhenium-188–mercaptoacetyltriglycine-filled balloon

OBJECTIVES This study was done to evaluate the feasibility and efficacy of beta-radiation therapy with a rhenium-188–mercaptoacetyltriglycine (188Re-MAG3)-filled balloon after rotational atherectomy for diffuse in-stent restenosis (ISR). BACKGROUND Rotational atherectomy has been shown to be safe and efficient for the treatment of ISR, but the recurrence rate is still high. Intracoronary beta-irradiation after rotational atherectomy may be a reasonable approach to prevent recurrent ISR. METHODS Fifty consecutive patients with diffuse ISR (length >10 mm) in native coronary arteries underwent rotational atherectomy and adjunctive balloon angioplasty, followed by beta-irradiation using a 188Re-MAG3–filled balloon catheter. The radiation dose was 15 Gy at a depth of 1.0 mm into the vessel wall. RESULTS The mean lengths of the lesion and irradiated segment were 25.6 ± 12.7 mm and 37.6 ± 11.2 mm, respectively. Radiation was delivered successfully to all patients, with a mean irradiation time of 201.8 ± 61.7 s. No adverse event, including myocardial infarction, death or stent thrombosis, occurred during the follow-up period (mean 10.3 ± 3.7 months), and nontarget vessel revascularization was needed in one patient. The six-month binary angiographic restenosis rate was 10.4%, and the loss index was 0.17 ± 0.31. CONCLUSIONS Beta-irradiation using a 188Re-MAG3–filled balloon after rotational atherectomy is safe and feasible in patients with diffuse ISR, and it may improve their clinical and angiographic outcomes. Further prospective, randomized trials are warranted to evaluate the synergistic effect of debulking and irradiation in patients with diffuse ISR.