Risk of stent thrombosis after sirolimus or paclitaxel eluting coronary stent implantation

Abstract

Both sirolimus (SES) and paclitaxel eluting stents (PES) have been shown to reduce significantly both the incidence of binary angiographic restenosis and the need for new revascularization procedures [1]. We read with great interest the paper by Sidhu et al., in which the better angiographic behaviour of SES in comparison with PES was not translated into significant differences in terms of clinical events [2]. As paclitaxel is cytotoxic, whereas sirolimus is cytostatic, the risk of stent thrombosis between the two types of drug-eluting stents could be different. In fact, in a recent work, a trend to an increased risk of stent thrombosis after PES implantation was found, whereas the risk of stent thrombosis was similar with SES and bare-metal stents [3].Stent thrombosis is an infrequent complication. Because of that, data from single trials are not sufficient to compare the incidence of stent thrombosis between two different types of stent. For the evaluation of such an infrequent entity, meta-analysis may increase increase power and precision and provides an overall estimate and range of effect. In order to help to clarify whether the risk of stent thrombosis is different between SES and PES, we have performed a meta-analysis from nine randomized trials that have compared SES and PES, including 5024 patients (2514 allocated to SES, 2510 allocated to PES). The trials included in the metaanalysis were: TAXI (n = 202), REALITY (n = 1353), SIRTAX (n = 1012), ISAR-DIABETES (n = 250), ISAR-DESIRE (n = 200), CORPAL (n = 652), ISAR-SMART-3 (n = 360), BASKET (n = 545) and ISAR-TEST (n = 450) [4][5][6][7][8][9][10][11][12]. Follow-up ranged from 6 to 12 months. In most trials, the Cypher stent (Cordis Corp., Miami Lakes, FL, USA) and the Taxus stent (Boston Sci., Natick, MA, USA), with polymeric-release of sirolimus and paclitaxel, respectively, were randomly compared in patients with native de novo lesions. In the ISAR-DESIRE study, only patients with in-stent restenosis after bare-metal stent implantation were included. In the ISAR-TEST, the Yukon stent, with nonpolymeric release of sirolimus, was compared with the Taxus stent.The risk ratio for stent thrombosis and its 95% confidence interval (CI) was calculated comparing SES with PES rates using raw data for each study and for the pooled population. The Q-test for heterogeneity and the fixed-effect model were used.There was no heterogeneity among the trials [Q-test for heterogeneity: c 2 = 5.41, d.f. = 6 (P = 0.49); I 2 = 0%]. The overall risk of stent thrombosis in the overall population was 0.92% (n = 46 patients): 0.83% (21/ 2514) and 1.00% (25/2510) in patients allocated to SES and PES, respectively (risk ratio 1.17, 95% CI 0.67, 2.35; P = 0.57) (Figure 1).Sirolimus and paclitaxel have different mechanisms of action (sirolimus is cytostatic, whereas paclitaxel is cytotoxic). Moreover, both stent platform and polymer are different in Taxus and Cypher stents, and whereas Taxus releases paclitaxel from a polymer, the Yukon stent has a nonpolymeric release of sirol...

Surface Modification of Bare-Metal Stents for Preventing Restenosis (Part 1)

“…Сиролимус и паклитоксел оказывают мощный антипролифе-ративный эффект как в отношении ГМК, так и всех видов эндотелиальных клеток (эндотели-альные прогениторные, эндотелиоциты разной степени зрелости), препараты действуют как цитостатики и вызывают апоптоз клеток [11,12]. Подавление пролиферации эндотелия при-водит к замедлению эндотелизации внутренней поверхности стента и способствует повторным тромбозам в поздние (6-12 мес.)…”

Histopathological evaluation of a retinoic acid eluting stent in a rabbit iliac artery model

“…The devices release an antiproliferative drug locally, thereby acting against the proliferation of smooth muscle cells, directly in the endothelium preventing restenosis. Currently used drugs on DES include paclitaxel, a cytotoxic drug and rapamycin (sirolimus) and its derivatives such as everolimus, a group of cytostatic drugs 2 . Although the wide use of DES significantly reduced restenosis compared with bare metal stents (BMS), restenosis still is a major complication 3 .…”

eG Coated Stents Exhibit Enhanced Endothelial Wound Healing Characteristics

“…after the drug release is complete. One possible explanation is that sirolimus is a cytostatic drug which inhibits the proliferation of ECs more effectively than SMCs 22 ; thus, the sooner the drug disappears, the sooner ECs are able to proliferate and migrate and to thus promote strut coverage. This, however, would also hold true for SMCs and may account for the slightly higher late lumen loss observed with BuMA SupremeÒ in comparison to Xience V, even though restenosis rates remain low.…”