Background: Following conventional treatment of in-stent restenosis, clinical restenosis may be as high as 60% in long lesions. Results of the START (Stents and Radiation Therapy) trial indicate that intracoronary beta radiation yields significant reductions in the incidence of recurrent in-stent restenosis as compared with placebo.
Methods and results: In a subgroup of the START trial, results in patients with coronary lesions > 15 mm in length (n = 239) were analyzed to assess treatment with a 30 mm, beta radiation source train. Patients received an intracoronary catheter with (90)Strontium/(90)Yttrium (n = 128) or placebo (n = 111). Clinical and angiographic parameters were evaluated at 8 months. Patient demographics and angiographic lesion characteristics were similar between the 2 groups. The mean lesion lengths were comparable in the radiation and placebo groups (21.5 5.2 mm versus 22.1 5.5 mm, respectively; p = 0.3873). A total of 14.1% and 22.5% of patients in the radiation and placebo groups, respectively, received new stents (p = 0.09). At 8 months, radiation therapy yielded significant reductions in major adverse cardiac events (16.4% versus 29.7%; p = 0.014), target vessel revascularization (14.8% versus 28.8%; p = 0.0085) and target lesion revascularization (11.7% versus 27.9%; p = 0.0015). There was no stent thrombosis, and binary restenosis rates were significantly lower in the radiation group compared to placebo.
Conclusion: Intracoronary beta radiation may prevent early recurrent restenosis in long lesions. Additional study is required to determine if the reduction persists throughout mid- to long-term follow-up.