Radiation therapy to inhibit restenosis: early clinical results.
BACKGROUND
Although several early trials indicate that 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 restenosis of stented coronary arteries with catheter-based iridium-192 (192Ir).


METHODS
A double-blind, randomized trial compared 192Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to 192Ir and 29 to placebo.


RESULTS
At 3-year follow-up, target-lesion revascularization was significantly lower in the 192Ir group (15.4% vs. 48.3%; p < 0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in 192Ir patients (33% vs. 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 mm to 2.12 +/- 0.73 mm in 192Ir patients, but was unchanged in placebo patients.


CONCLUSIONS
The early clinical benefits observed after treatment of coronary restenosis with 192Ir appear durable at late follow-up. Angiographic restenosis continues to be significantly reduced in 192Ir-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 192Ir 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.
Teirstein
P S
PS
Division of Cardiovascular Diseases, SW206, Scripps Clinic, 10666 North Torrey Pines Road, La Jolla, CA 92037, USA.
Massullo
V
V
Jani
S
S
Tripuraneni
P
P
D017023:Coronary Angiography; D003327:Coronary Disease / Q000532:radiotherapy*; D003331:Coronary Vessels / Q000473:pathology / Q000528:radiation effects*; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D009204:Myocardial Revascularization; D010919:Placebos; D055502:Secondary Prevention
D007496:Iridium Radioisotopes; D010919:Placebos