Scripps Coronary Radiation to Inhibit Proliferation Post Stenting IV - SCRIPPS IV

Description:

The goal of the SCRIPPS IV trial was to compare two doses of gamma radiation (14 Gy vs. 17 Gy) for the treatment of in-stent restenosis with brachytherapy.

Hypothesis:

An increase in the dose of gamma radiation brachytherapy for treatment of in-stent restenosis will be associated with a reduction in major adverse cardiac events (MACE), restenosis, and target vessel revascularization (TVR).

Study Design

Study Design:

Patients Enrolled: 358
Mean Follow Up: 1 year; 8-month angiographic follow-up
Mean Patient Age: mean age 62 years

Patient Populations:

In-stent restenotic lesion >60% in native coronary or vein graft; reference vessel diameter 2.75-4.0 mm; target lesion length <81 mm; and vessel diameter 1 cm distal to target is >2.5 mm

Primary Endpoints:

MACE at one year

Secondary Endpoints:

In-stent late loss at eight-month angiographic follow-up

Drug/Procedures Used:

Patients (n=352) from two clinical centers were randomized to a gamma radiation dose of either 14 Gy or 17 Gy for brachytherapy treatment of in-stent restenosis.

Concomitant Medications:

Aspirin and clopidogrel for six months if no new stent was placed and for 12 months if a new stent was placed during the procedure

Principal Findings:

Mean number of prior interventions was 1.7 in the 17 Gy arm and 1.8 in the 14 Gy arm. Baseline lesion length did not differ between treatment arms (21.8 mm in the 17 Gy arm and 23.3 mm in the 14 Gy arm). In-stent restenosis was lower in the 17 Gy arm compared with the 14 Gy arm (26.6% vs. 41.8%, p=0.01), as was late loss (0.35 mm vs. 0.50 mm).

Both target lesion revascularization (TLR) (15.2% vs. 27.2%, p<0.01) and TVR (21.3% vs. 33.1%, p=0.06) were lower in the 17 Gy arm. MACE was also lower in the 17 Gy arm (17.3% vs. 29.0%). There was no difference in late thrombosis (1.2% vs. 1.2%, p=NS), but total occlusions occurred less frequently in the 17 Gy arm (2.4% vs. 9.7%, p=0.02). Similar benefits were observed in the diabetic subgroup and in patients with long lesions.

Interpretation:

Among patients undergoing gamma radiation brachytherapy for treatment of in-stent restenosis, use of a 17 Gy dose of radiation was associated with a reduction in MACE, TLR, and restenosis compared with the lower 14 Gy dose of radiation. Despite the benefit observed with the higher dose of gamma radiation without an increase in early or late thrombosis, gamma radiation brachytherapy is not a widely used procedure. Given the low in-stent restenosis rates associated with use of drug-eluting stents, it is unlikely there will be a growing need for gamma radiation brachytherapy for treatment of in-stent restenosis.

References:

Presented at the 2003 Transcatheter Cardiovascular Therapeutics conference, by Paul S. Teirstein, MD

Keywords: Thrombosis, Drug-Eluting Stents, Coronary Disease, Brachytherapy, Diabetes Mellitus, Gamma Rays, Stents


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