Drug-eluting stents and glycoprotein IIb/IIIa inhibitors in vessels at low anatomic risk: A retrospective analysis of previously published data from the Basel Stent Kosten Effektivitäts Trial

Abstract

Background: Drug-eluting stents (DESs) are associated with late stent thromboses, but the exact mechanism of action is unknown. Objective: The goal of this article was to assess the clinical interaction of glycoprotein IIb/IIIa inhibitors (GPIs) with different stent and vessel types in unselected patients undergoing percutaneous coronary intervention (PCI). Methods: This was a predefined retrospective analysis of the randomized controlled Basel Stent Kosten Effektivitats Trial (BASKET), which compared DES with bare-metal stents (BMSs) in patients undergoing PCI. Patients were compared for major adverse clinical events in relation to GPI use (abciximab and tirofiban) after 18 months. In a subgroup analysis prespecified in the study protocol, specific regard was given to angiographic groups at different risk levels for late events (high-risk vessels [ie, small vessels with a diameter <3.0 mm and saphenous vein grafts], and low-risk vessels [ie, large native vessels ≥3.0 mm]). Baseline differences between patients with or without GPI use were identified and incorporated into a multivariable Cox proportional hazards regression analysis if different at a <0.05 level. Results: A total of 826 patients (650 males, 176 females) were enrolled in BASKET; 301 (36%) received GPI therapy. Of these 301 patients, 255 (85%) received abciximab and 46 (15%) received tirofiban. After 18 months, the rate of cardiac death and nonfatal myocardial infarction was higher in patients with GPI use than in those without GPI use (35/301 [12%] vs 32/525 [6%]; P = 0.005). In patients undergoing PCI in anatomically low-risk vessels and receiving GPI therapy, there was a higher rate of cardiac death and nonfatal myocardial infarction at 18 months with a DES versus a BMS (22/151 [15%] vs 3/66 [5%]; P = 0.033). In patients undergoing PCI in anatomically low-risk vessels and without GPI therapy, there was no significant difference for cardiac death and nonfatal myocardial infarction (DES vs BMS, 11/207 [5%] vs 6/134 [4%]). In the multivariable analysis, GPI use (hazard ratio = 2.93; 95% CI, 1.53-5.63; P = 0.001) and age (hazard ratio = 1.034 per year increase; 95% CI, 1.008-1.062; P = 0.012) remained the only significant independent predictors of outcome. Interaction of stent type and GPI use was significant ( P = 0.006). Conclusions: This retrospective analysis of the BASKET data found that GPIs and DESs used in patients with large native vessels may have an adverse interaction in terms of late stent thromboses. However, large prospective studies are needed to confirm these findings.