Washington Radiation for In-Stent Restenosis Trial - WRIST


This trial examines the clinical and angiographic efficacy of gamma radiation in patients with in stent restenosis.


To determine the effects of intracoronary γ-radiation on clinical and angiographic outcomes in patients with in-stent restenosis.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 130

Patient Populations:

In-stent restenosis in native or SVG lesions; reference diameter 3.0-5.0mm; lesion length < 47mm; LVEF > 30%

Primary Endpoints:

MACE at 6 months; binary restenosis at 6 months.

Drug/Procedures Used:

Patients randomized to receive a nylon ribbon containing either placebo or seed trains of 192Ir at the lesion site.

Principal Findings:

Primary clinical endpoint was cumulative composite of death, MI, repeat target lesion revascularization at 6 months. At 6 months angiographic endpoints were restenosis (diameter stenosis greater than or equal to 50%), magnitude of late loss, and late loss index. Rate of restenosis (binary angiographic) was 19% in the irradiated group vs 58% in the placebo group (p=0.001). The main angiographic pattern of restenosis in the radiation group occurred at the edges of the stent. Late luminal loss was lower in the radiated vs placebo patients. Late loss index was 0.16 +/- 0.73mm in the radiated patients vs 0.70 +/- 0.46 in placebo patients (p=0.0001). At 6 months 29.2% of radiated patients had a major cardiac event (death, Q wave MI, and target vessel revascularization) vs 67.6% in the placebo group (p<0.001). There was no difference in death at 6 months between radiated (4.6%) or nonradiated groups (6.2%) and no patients had Q wave infarcts. Hence the major clinical difference was a reduction in target vessel revascularization in the radiation group (26.1%) vs the placebo group (67.6%;p<0.001). Target lesion revascularization also was lower in the radiation group (13.8%) vs the placebo group (63.1%) and the same pattern was observed at 12 months.


Gamma radiation as adjunct therapy for patients with in-stent restenosis reduced angiographic evidence of restenosis and reduced the need for target lesion and target vessel revascularization.


Circulation 2000;101:2165-71.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Nylons, Constriction, Pathologic, Gamma Rays, Stents

< Back to Listings