Intraprocedural stent thrombosis during implantation of sirolimus-eluting stents

Background - Intraprocedural stent thrombosis (IPST) is a rare event (<0.01% in our experience with bare metal stents), with the exception of specific settings such as acute myocardial infarction, thrombus-containing lesions, and dissections. We report the occurrence of this event during elective implantation of sirolimus- eluting stents. Methods and Results - Between April 2002 and August 2003, 670 patients with 1362 lesions were treated with Cypher ( Cordis, Johnson and Johnson Co) sirolimus- eluting stent implantation in San Raffaele Hospital and EMO Centro Cuore Columbus. Diabetes mellitus was present in 142 patients (21%), and 164 (24.5%) had unstable angina. Pretreatment with glycoprotein IIb/IIIa ( GP IIb/IIIa) inhibitors was carried out in 235 patients (35%). Total stent length per vessel was 42.9 +/- 28.3 mm. IPST occurred in 5 patients (0.7%). None of the patients with IPST were pretreated with GP IIb/IIIa inhibitors. Using univariate exact logistic regression, only total stent length per vessel, in millimeters ( exact OR, 1.03; 95% CI, 1.011 to 1.046; P = 0.0028), was associated with the occurrence of IPST. Conclusions - Stent length was associated with the occurrence of IPST. Particular attention will need to be directed to this potential complication when long sirolimus- eluting stents are being used.