Three-Year Clinical and Angiographic Follow-Up After Intracoronary Radiation

Abstract

Background —Although several early trials indicate treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The objective of this report is to document angiographic and clinical outcome 3 years after treatment of restenotic stented coronary arteries with catheter-based 192 Ir. Methods and Results —A double-blind, randomized trial compared 192 Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to 192 Ir and 29 to placebo. At 3-year follow-up, target-lesion revascularization was significantly lower in the 192 Ir group (15.4% versus 48.3%; P <0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in 192 Ir patients (33% versus 64%; P <0.05). In a subgroup of patients with 3-year angiographic follow-up not subjected to target-lesion revascularization by the 6-month angiogram, the mean minimal luminal diameter between 6 months and 3 years decreased from 2.49±0.81 to 2.12±0.73 mm in 192 Ir patients but was unchanged in placebo patients. Conclusions —The early clinical benefits observed after treatment of coronary restenosis with 192 Ir appear durable at late follow-up. Angiographic restenosis continues to be significantly reduced in 192 Ir-treated patients, but a small amount of late loss was observed between the 6-month and 3-year follow-up time points. No events occurred in the 192 Ir group to suggest major untoward effects of vascular radiotherapy. At 3-year follow-up, vascular radiotherapy continues to be a promising new treatment for restenosis.

Long-Term Outcome of Patients Treated With Repeat Percutaneous Coronary Intervention After Failure of γ-Brachytherapy for the Treatment of In-Stent Restenosis

“…This rate is also acceptable when compared with the rate of first TLR after ␥-brachytherapy (23% to 24%) or that in patients treated with percutaneous intervention without brachytherapy for in-stent restenosis (41% to 63%). 11,12 Major adverse cardiac events (excluding TLR) in the irradiated group were also comparable to those seen in both brachytherapy/restenosis series and de novo PTCA/ stenting trials, 6,[21][22][23][24] especially when the long follow-up period of the present patient population is taken into account.…”

Paclitaxel Stent Coating Inhibits Neointimal Hyperplasia at 4 Weeks in a Porcine Model of Coronary Restenosis

“…This combined approach has been used successfully in intracoronary brachytherapy. 4,5 Late thrombosis and edge stenosis (the "candy wrapper effect") are potential complications that may limit the effectiveness of this approach. 5,6 Pharmacological inhibitors of neointimal hyperplasia, like paclitaxel, represent an alternative to radiation therapy.…”

“…The dip-coating technique also allows paclitaxel to have immediate contact with the vessel wall, favoring its rapid accumulation by arterial tissue. This strategy for local drug delivery resembles short-term irradiation 4 by optimizing the conditions for blocking the earliest cellular events triggered by injury. 13,14 …”

Evolução da Intervenção Percutânea para o Tratamento da Doença Coronária Multiarterial

“…O estudo SCRIPPS (Catheter-Based Radiotherapy to Inhibit Restenosis After Coronary Stenting) comparou o uso da radiação gama com o placebo em lesões reestenóti-cas, mostrando uma taxa de reestenose de 17% versus 54% em seis meses (p=0,01) e de 33% versus 64% em três anos (p<0,05) 43,44 . Portanto, apesar da radiação gama ocasionar uma redução de 69% na taxa de reestenose em seis meses e esta diminuir para 48% em três anos, ainda assim a redução da taxa de reestenose em três anos permaneceu significativa, o que demonstra os efeitos benéficos da braquiterapia a longo prazo.…”