Background: Long-term follow-up studies revealed a significant decline in the benefits of intracoronary radiation for in-stent restenosis.
Methods and results: A total of 25 study and 25 contemporaneous control patients with diffuse in-stent restenosis who underwent cutting balloon angioplasty (CBA) transradially, followed by subsequent intracoronary irradiation with a liquid β-emitter Rhenium-188 (¹⁸⁸Re)-filled balloon were enrolled in the study. The mean clinical follow-up durations were 64.9 ± 13.0 and 66.3 ± 13.8 months for the irradiated and control patients, respectively. Six-month angiographic restenosis was observed in 16% (4 of 25) of the patients in the irradiated group and 48% (12 of 25) of the patients in the control groups (P = 0.03). The 6-month major adverse cardiac events (MACE) rate was 12% and 44%, respectively (P = 0.025). The 3-year follow-up angiography was performed in 16 of 21 (76%) irradiated patients and in 4 of 13 (31%) control patients who had no significant restenosis at the 6-month angiographic follow-up. Restenosis occurred in 1 of 16 (7%) irradiated patients and 2 of 4 (50%) control patients. Late target lesion revascularization was performed in 1 irradiated and 2 control patients. The MACE rate within 6 years was significantly reduced in the irradiated group (20% vs. 56%, P = 0.019).
Conclusions: Brachytherapy using ¹⁸⁸Re-filled balloon following CBA for diffuse in-stent restenotic native coronary arteries is effective in reducing target lesion restenosis and improving long-term outcomes.