The risk of definitive stent thrombosis is increased after “off-label” stent implantation irrespective of drug-eluting stent or bare-metal stent use

Abstract

A limitation of drug-eluting stent (DES) use to FDA-approved indications has been suggested to reduce the risk of stent thrombosis. This study evaluated predictors of stent thrombosis in clinical practice after the use of drug-eluting as well as bare-metal stents (BMS), including adherence to the FDA indications for DES. Between July 2002 and October 2006 percutaneous coronary intervention (PCI) was performed on 5,945 patients using BMS (68%) or DES (32%). Patients had 1-year follow-up for definitive stent thrombosis (ARC criteria). 76 patients (1.27%) developed definitive stent thrombosis. Clinical, procedural, and angiographic parameters were related to those of 786 patients without stent thrombosis to define predictors of stent thrombosis. Off-label or on-label implantation of stents according to the FDA-approved indications for DES was included as parameter in the analysis. In 434 patients, stent implantation was performed within FDA-approved indications and in 428 patients outside of FDA-approved indications for DES. Predictors of stent thrombosis were PCI in acute myocardial infarction (OR = 4.51, P < 0.001), treatment of bifurcation lesions (OR = 4.43, P < 0.001), stent length per mm (OR = 1.07, P < 0.001), implantation of multiple stents (OR = 3.67, P < 0.001), and stent implantation outside of FDA indications (OR = 6.13, P < 0.001). The risk was increased for DES as well as BMS. In a multivariate analysis, PCI in acute myocardial infarction (OR = 2.56, P = 0.014), LV-EF < 30% (OR = 3.60, P < 0.001), treatment of bifurcation lesion (OR = 3.65, P = 0.004), stent length in mm (OR = 1.04, P = 0.015), and implantation of multiple stents (OR = 2.64, P = 0.002) remained predictors of stent thrombosis. Off-label stent implantation was no independent additional predictor as it is a combined parameter of the above-mentioned predictors. Implantation of coronary stents outside of the FDA-approved indications for DES is associated with an increased risk of stent thrombosis using DES and BMS.