The impact of lesion length and reference vessel diameter on angiographic restenosis and target vessel revascularization in treating in-stent restenosis with radiation

OBJECTIVES The study assessed the influence of lesion length and reference vessel diameter (RVD) on recurrent restenosis after gamma intracoronary radiation therapy (ICRT) for in-stent restenosis (IRS). BACKGROUND Intracoronary radiation therapy reduces angiographic and clinical restenosis in patients with ISR. The impact of ICRT on challenging subgroups, such as long lesions and small vessels, 9 has not been established. METHODS Six-month quantitative coronary angiography and clinical follow-up were conducted to evaluate the influence of lesion length and RVD in patient with ISR treated with ICRT who were enrolled in gamma radiation trials. Angiographic binary restenosis (similar to50% diameter stenosis) and clinical events were assessed in 311 patients treated with gamma ICRT and 105 patients who received placebo, RESULTS Baseline demographic, angiographic and procedural details were similar in the two treatment groups. The ICRT group had reduced binary restenosis in vessels of ass sizes (30% vs. 66%, p < 0.001), with the most benefit seen in small A trend toward reduced restenosis with ICRT was found across all lesion lengths, At six months, major adverse cardiac events (MACE) were reduced in the ICRT group compared to placebo (34% vs. 71%) p < 0.0001), driven by reduced target vessel revascularization (27% vs 71%, p < 0.0001), The independent predictors of angiographic restenois include ICRT (OR [odd ratio] 0.16 CI [confidence interval] 0.10 to 0.28, p < 0.001), lesion length (OR 1.03; CI 1.01 to 1.05, p = 0.004) and RVD (OR 0.40; CI 0.23 to 0.617, p < 0.001). CONCLUSIONS Intracoronary, radiation therapy, compared to placebo, result, in a significant reduction of angiographic restenosis across all vessel sizes, with it trend toward reduction of angiographic restenosis across all lesion length; this effect is seen predominantly in small vessels and diffuse lesions. (C) 2002 by the American College of Cardiology Foundation.