January 20, 2004Open Access
View Full PaperFive-Year Follow-Up After Intracoronary Gamma Radiation Therapy for In-Stent Restenosis
Key Result
Intracoronary radiation therapy using 192-Iridium significantly reduced the 5-year rate of major adverse cardiac events compared to placebo (46.2% vs 69.2%, P=0.008).
Study Design
Type
RCT (n=130)
Blinding
Double-blind
Randomization
Randomized
Structured PICO
Does 192-Iridium intracoronary radiation therapy reduce major adverse cardiac events at 5 years in patients with in-stent restenosis?
P
Population
130 patients with in-stent restenosis (100 native coronary and 30 vein grafts) who underwent percutaneous transluminal coronary angioplasty, laser ablation, rotational atherectomy, or additional stenting (36% of lesions)
I
Intervention
192-Iridium intracoronary radiation therapy (IRT) with a prescribed dose of 15 Gy to a 2-mm radial distance from the center of the source
C
Comparator
Placebo
O
Outcome
Major adverse cardiac event rate at 5 yearscomposite
Intracoronary gamma radiation therapy significantly reduces major adverse cardiac events at 5 years in patients with in-stent restenosis, despite an increase in late target lesion revascularization.
Main Result
Absolute Event Rate: 46.2% vs 69.2%
p-value: p=0.008
Abstract
BACKGROUND: The Washington Radiation for In-Stent Restenosis Trial is a double-blinded randomized study evaluating the effects of intracoronary radiation therapy (IRT) in patients with in-stent restenosis (ISR). METHODS AND RESULTS: One hundred thirty patients with ISR (100 native coronary and 30 vein grafts) underwent percutaneous transluminal coronary angioplasty, laser ablation, rotational atherectomy, or additional stenting (36% of lesions). Patients were randomized to either 192-Iridium IRT or placebo, with a prescribed dose of 15 Gy to a 2-mm radial distance from the center of the source. Angiographic restenosis (27% versus 56%, P=0.002) and target vessel revascularization (26% versus 68%, P<0.001) were reduced at 6 months in patients treated with IRT. Between 6 and 60 months, patients treated with IRT compared with placebo had more target lesion revascularization (IRT, 21.6% versus placebo, 4.7%; P=0.04) and target vessel revascularization (IRT, 21.5% versus placebo, 6.1%; P=0.03). At 5 years, the major adverse cardiac event rate was significantly reduced with IRT (46.2% versus 69.2%, P=0.008). CONCLUSIONS: In the Washington Radiation for In-Stent Restenosis Trial, patients with ISR treated with IRT using 192-Iridium had a reduction in the need for repeat target lesion and vessel revascularization at 6 months and 5 years.