The outcome of percutaneous coronary intervention in patients with In-Stentrestenosis who failed intracoronary radiation therapy

Objectives This study reports the outcome of patients who failed intracoronary radiation therapy (IRT) for the treatment of in-stent restenosis (ISR). Background Intracoronary radiation therapy has demonstrated a reduction in the recurrence rate of restenosis for patients with ISR. However, 10% to 30% of these patients require repeat intervention to the irradiated site. Methods Of 961 patients who were assigned to gamma or beta radiation for the treatment of diffuse ISR, we evaluated the outcome of 282 (29%) consecutive patients who failed IRT and compared them with the 679 (71%) patients who had successful IRT. For patients who failed radiation, the mean time to the first target vessel revascularization (TVR) was 173 ± 127 days after the index procedure and the total duration of follow-up was 494 ± 304 days. Results Patients who failed IRT were younger (60 ± 10 vs. 63 ± 11 years, P = 0.002) and had a higher incidence of restenting (51% vs. 41%, P = 0.003). The majority (55%) of the restenotic lesions after IRT failure were focal (≤10 mm), with a mean lesion length of 11.9 ± 1.9 mm. Of the 257 patients who had subsequent TVR after failed IRT, 68 (26%) underwent coronary artery bypass grafting and 189 (74%) underwent percutaneous coronary intervention using balloon in 61%, restenting in 26%, atheroablation in 11%, and the cutting balloon in 2% of cases. At six months, 6% of patients died, 1% had Q-wave MI, 17% had repeat TVR, and the overall rate of major adverse cardiac events was 21%. Conclusions The predominant angiographic pattern of lesions in patients who failed IRT is focal restenosis, with these lesions responding well to conventional revascularization methods.