Prospective randomized comparison of early and late results of 4 different stent designs

Late results of interventional procedures using coronary stents are largely determined by the rate of restenosis. So far, few data are available addressing the effect of stent design on this crucial variable and on early and late adverse events after stent implantation.

From 1996 through 1998, a total of 965 lesions in 925 patients with coronary artery disease were randomized to treatment with 1 of 4 different stent designs (Micro stent II [M] AVE, Düsseldorf, Germany; Sito [S] Sitomed, Rangendingen, Germany; Pura Vario [PV], Devon, Hamburg, Germany; Inflow [ID] Inflow Dynamics, München, Germany). The primary end point of the study was the degree of diameter stenosis measured by quantitative coronary angiography 6 months after stent implantation.

Diameter stenosis at 6 months follow-up was not different in the 4 study arms (M 40.3 +/- 24.1, S 42.8 +/- 27.0, PV 42.6 +/- 26.9 and ID 42.3 +/- 26.8, P =.7). No significant differences could be detected in net lumen gain and late lumen loss, resulting in comparable restenosis rates (>or=50% diameter stenosis) at follow-up (M 26.0%, S 30.5%, PV 31.3%, and ID 28.7%, P =.7). Early adverse events like stent loss, stent thrombosis, periinterventional acute myocardial infarctions and emergency coronary artery bypass graft also showed no significant differences. Multivariate regression analyses revealed reference vessel diameter <3.0 mm, overall stented length, a history of bypass grafting, localization of the target lesion in the left anterior descending coronary artery, type C lesions, dissection before stent implantation, and diabetes mellitus to be independent predictors for restenosis.

Stent design does not have significant influence on development of restenosis. Adverse event rates were similar with all stent types used in this trial.