[Intracoronary beta-radiotherapy in high-risk in-stent restenosis. Prospective results of a single center registry].

Background: The aim of the study was to evaluate, on single center prospective data, long-term angiographic and clinical results of intracoronary beta (32P) brachytherapy in "real world" patients with high-risk in-stent restenosis lesions.
Methods: Sixty-nine consecutive patients (77 lesions) with high-risk in-stent restenosis (mean lesion length 30.3 +/- 16.1 mm, pattern III-IV 57.2%, diabetes 33.3%) treated with percutaneous dilation procedures and beta-radiation therapy, underwent 7-month clinical and angiographic follow-up.
Results: One patient (1.4%) presented with procedural non-Q wave myocardial infarction. At a mean follow-up of 7 +/- 1.5 months, death was observed in 1 patient (1.4%) and non-Q wave myocardial infarction in 3 (4.3%) (in 2 patients, who prematurely discontinued antiplatelet therapy, caused by late coronary thrombosis). Seven-month binary angiographic restenosis occurred in 20 lesions (25.9%) (in-stent restenosis 11.6%). Target lesion and target vessel revascularization occurred in 20 (28.9%) and 21 (30.4%) patients. At follow-up only 12 (17.3%) patients presented with CCS class III-IV angina. After intracoronary beta brachytherapy angiographic restenosis occurred regardless of the vessel size, lesion length and ostial location. On the contrary a high restenosis rate was documented in obstructive lesions.
Conclusions: As applied in routine clinical practice, radiation therapy is safe and effective in the treatment of high-risk in-stent restenosis. In spite of all that, total occlusion at baseline predicts late angiographic restenosis.