Quantitative angiographic analysis of stent restenosis in the Scripps Coronary Radiation to Inhibit Initial Proliferation Post Stenting (SCRIPPS) trial

To identify luminal dimension changes occurring within the stent alone and within the stent + margin segment, we reviewed the quantitative angiographi c results obtained from the Scripps Coronary Radiation to inhibit Prolifera tion Post Stenting (SCRIPPS) trial, a prospective randomized trial assessin g the effect of iridium-192 (Ir-192) on the prevention of stent restenosis. Fifty-five patients were randomly assigned to receive Ir-192 or placebo so urces after successful intervention. Procedural and 6-month follow-up cinea ngiograms were quantitatively reviewed in 52 patients to identify changes w ithin the stent and the stent + margin segment. The percent diameter stenos is was lower within the stent than within the stent + margin segment after the procedure (6% +/- 22% vs 21 +/- 15%, p < 0.0001) and at follow-up(28% /- 29% vs 42 +/- 21%, p < 0.0001). As a result, a lower restenosis rate was found within the stent than within the stent + margin (25% vs 37%, p < 0.0 001); isolated stent margin restenosis occurred in 11.5% of lesions. Treatm ent with Ir-192 reduced restenosis within the stent (8% vs 39%; p = 0.010) and within the stent + margin segment (17% vs 54%; p = 0.010); the reductio n in restenosis at the margin only (8.3% vs 14.3%, p 0.503) was not signifi cant. The lowest relative risk for restenosis resulting from Ir-192 occurre d within the stent (0.21; 95% confidecne interval [CI] 0.05 to 0.86) compar ed with the stent + margin segment (0.31; 95% CI 0.12 to 0.81) or the stent margin (0.58; 95% CI 0.12 to 2.91). In the SCRIPPS trial, 32% of restenosi s occurred at the stent margins. Treatment with Ir-192 reduced restenosis p rimarily within the stent rather than the margin. Whether extending the tre atment length to fully include the stent margins will further reduce resten osis requires further study. (C) 1999 by Excerpta Medica, Inc.