ANGIOGRAPHIC PREDICTORS OF RECURRENCE OF RESTENOSIS AFTER WIKTOR STENT IMPLANTATION IN NATIVE CORONARY-ARTERIES

Intracoronary stenting has been proposed as an adjunct to balloon angi oplasty to improve the immediate and long-term results. However, late luminal narrowing has been reported following the implantation of a va riety of stents. One of the studies conducted with the Wiktor stent is a prospective registry designed to evaluate the feasibility, safety a nd efficacy of elective stent implantation in patients with documented restenosis of a native coronary artery. To identify angiographic vari ables predicting recurrence of restenosis, the angiograms of the first 91 patients with successful stent implantation and without dinical ev idence of (sub)acute thrombotic stent occlusion were analyzed with the Computer Assisted Angiographic Analysis System using automated edge d etection. The incidence of restenosis was 44% by patient and 45% by st ent according to the 0.72 mm criterion, and 30% by patient and 29% by stent according to the 50% diameter stenosis criterion. The risk for r estenosis for several angiographic variables was determined using an u nivariate analysis and is expressed as odds ratio with corresponding c onfidence interval. The only statistically significant predictor of re stenosis was the relative gain when it exceeded 0.48 using the 0.72 mm criterion (odds ratio 2.7, 95% confidence interval 1.1-6.4). Furtherm ore, the relation between the relative gain (increase in minimal lumin al diameter normalized to vessel size) as angiographic index of vessel wall injury and relative loss (decrease in minimal luminal diameter n ormalized to vessel size) as index of neointimal thickening was analyz ed using a linear regression analysis. A Pearson product-moment correl ation coefficient of 0.38 (p <0.001) was found. When using the categor ical approach to address restenosis, there is an approach risk for rec urrent restenosis when the relative gain exceeds 0.48, The continuous approach underscores this concept by indicating a weak but positive re lation between the relative gain and relative loss.