Long-term outcome of patients treated with repeat percutaneous coronary intervention after failure of γ-brachytherapy for the treatment of in-stent restenosis

Background - Although ¹⁹²Ir intracoronary brachytherapy has been demonstrated to dramatically reduce the recurrence of in-stent restenosis, up to 24% of these patients will still require repeat target-vessel revascularization. The short- and long-term outcomes of repeat percutaneous intervention in this population have not been characterized. Methods and Results - Analysis was performed of all patients enrolled in the GAMMA-I and GAMMA-II brachytherapy trials who underwent repeat percutaneous target lesion revascularization (TLR) because of restenosis. Subjects were divided into 2 cohorts: those who had received ¹⁹²Ir brachytherapy and those randomized to placebo. Forty-five (17.6%) of a total of 256 patients whose index treatment was intracoronary radiation therapy and 36 (29.8%) of 121 patients whose index treatment was placebo required repeat percutaneous TLR. The mean time to this first TLR was 295±206 days in the irradiated group and 202±167 days in the placebo group (P=0.03). Acute procedural success occurred in 100% of irradiated patients and 94% of placebo controls (P=0.19). After the first TLR, a subsequent TLR was required in 15 (33.3%) of 45 brachytherapy patients versus 17 (47.2%) of 36 placebo failure patients (P=0.26). There was no significant difference in time to second TLR between the 2 groups. Other long-term major adverse event rates in both groups were comparable to those of other contemporary angioplasty/stenting series. Conclusions -In those patients who "fail" ¹⁹²Ir intracoronary brachytherapy for in-stent restenosis, treatment with ¹⁹²Ir delays the time to first TLR. Additionally, repeat percutaneous intervention in these patients is safe and efficacious in the short term, with acceptable long-term results.