Sirolimus-eluting stent fractures associated with aneurysm and very late stent thrombosis in the right coronary artery

Although the occurrence of coronary stent fracture is rare,recent reports showed that stent fracture after sirolimus-eluting stent(SES)implantation may be associated with neointimal hyperplasia and restenosis.We report two cases of stent fracture that occurred late after elective SES implantation into the right coronary artery(RCA)that were related to the aneurysm,restenosis,thrombosis,and vessel occlusion.……

Comparison of the incidence of late stent thrombosis after implantation of different drug-eluting stents in the real world coronary heart disease patients： three-year follow-up results

Background Late stent thrombosis （LST） is still concerned by interventions cardiologists in daily clinical practice. This study aimed to compare the incidence of LST after implantation of different drug-eluting stents （DES） in coronary heart disease （CHD） patients in the real world.Methods From December 2001 to February 2009, a total of 11 875 consecutive CHD patients undergone DES implantation were enrolled in this single-center registery study. Patients with acute ST-segment elevation myocardial infarction, mixed DES implantation, restenosis lesions, and patients who could not take dual antiplatlet medication and those who were contraindicated for coronary interventional treatment were excluded. All patients were treated with completed dual antiplatelet medications for at least 9 months after DES deployment. The follow-up was completed by outpatient visits, letter correspondence, phone calls and coronary angiography. Definite LST was diagnosed auording to the Academic Research Consortium （ARC） definition.Results Cypher or Cypher Select stents were implanted in 4104 cases, Taxus or Taxus Liberty stents in 2271 cases and Firebird stents （Chinese rapamycin-eluting stents） in 5500 cases. One-year follow-up was completed in 9693 patients, including 3346 cases with Cypher or Cypher Select stents, 1529 cases with Taxus or Taxus Liberty stents and 4818 cases with Firebird stents. Two- and three-year follow-up results were obtained in 7133 and 4353 patients, respectively, including 2410 and 1760 cases with Cypher or Cypher Select stents, 1285 and 900 cases with Taxus or Taxus Liberty stents as well as 3438 and 1693 cases with Firebird stents. One-year follow-up results showed that the incidence of LST was 1.08% in patients with Cypher or Cypher Select stents, 1.24% in those with Taxus or Taxus Liberty stents and 0.71% in those with Firebird stents; there was no significant difference between those with Cypher or Cypher Select and Firebird stents, but there was significant difference between those with Taxus or Taxus Liberty and Firebird stents （P=0.044）. The incidence of LST at the 2- and 3-year follow-up was 1.33% and 1.70% in those with Cypher or Cypher Select stents, 1.40% and 1.70% in those with Taxus or Taxus Liberty stents, and 0.83% and 0.95% in those with Firebird stents, respectively. There were no significant differences among the three groups.Conclusions This study indicates that first-generation DES are acceptable to treat complex coronary lesions, and there is no significant difference of LST for three different DES.

Coronary aneurysm and very late stent thrombosis formation associated with sirolimus-eluting stent implantation

Since drug-eluting stents （DES） can significantly reduce the risk of instant restenosis compared with bare-metal stents, they have been widely used in interventional therapy for coronary heart disease. With bare-metal stents being rapidly replaced by DES there is a great concern about the safety of DES due to stent thrombosis.Very late stent thrombosis （VLST） has been categorized as occurring beyond 1 year.3 Coronary aneurysm formation induced stent malapposition is a rare but potentially fatal cause of VLST. We report a case of coronary aneurysm with VLST formation 35 months after sirolimus-eluting stent （SES） implantation.

Late stent thrombosis:a not negligible issue after drug-eluting stent implantation

Drug-eluting stent （DES） has markedly reduced restenosis and the need for target lesion revascularization （TLR）. The safety profile of DES does not seem to differ from that of bare metal stent in the acute and subacute phases following coronary intervention. However, at World Congress of Cardiology 2006 a meta-analysis of randomized trials suggested that there was a small but significant increase in risk of death or Q-wave myocardial infarction throughout a period of 3 years after implantation of a Cypher stent possible due to late stent thrombosis） The study received wide attention and since then the long-term safety of DES has been questioned by the physicians, patients and societies.

Recent advances in cardiovascular stent for treatment of in-stent restenosis:Mechanisms and strategies

Treatments of atherogenesis,one of the most common cardiovascular diseases(CVD),are continuously being made thanks to innovation and an increasingly in-depth knowledge of percutaneous transluminal coronary angioplasty(PTCA),the most revolutionary medical procedure used for vascular restoration.Combined with an expanding balloon,vascular stents used at stricture sites enable the long-time restoration of vascular permeability.However,complication after stenting,in-stent restenosis(ISR),hinders the advancement of vascular stents and are associated with high medical costs for patients for decades years.Thus,the development of a high biocompatibility stent with improved safety and efficiency is urgently needed.This review provides an overview of current advances and potential technologies for the modification of stents for better treatment and prevention of ISR.In particular,the mechanisms of in-stent restenosis are investigated and summarized with the aim to comprehensively understanding the pathogenesis of stent complications.Then,according to different therapeutic functions,the current stent modification strategies are reviewed,including polymeric drug eluting stents,biological friendly stents,prohealing stents,and gene stents.Finally,the review provides an outlook of the challenges in the design of stents with optimal properties.Therefore,this review is a valuable and practical guideline for the development of cardiovascular stents.

Intravascular ultrasound assessment of very late bare-metal stent thrombosis： a case report

Very late stent thrombosis （VLST） is increasingly being regarded as a complication of drug-eluting stents （DES）, and delayed endothelization, local hypersensitivity reactions, and late stent malapposition due to excessive positive remodeling have been postulated as mechanisms. Considering that stent endothelialization seems to be completed within 4 weeks following bare-metal stent （BMS） placement and that BMS do not possess antiproliferative coating, the mechanism of VLST may differ between patients with DES and those with BMS. We report a case of VLST 9 years after BMS implantation, in which thrombus from the ruptured neointima was confirmed by intravascular ultrasound. This finding suggests that de novo plaque rupture at the neointimal layer within the stent may be one of the explanations for VLST.

Morphologic characteristics of late stent malapposition after drug-eluting stents implantation by optical coherence tomography follow-up

Background Late stent malapposition was frequently observed after DES implantation, which has been associated with the occurrence of late stent thrombosis due to poor neointimal coverage. This study was designed to evaluate the frequency of late stent malapposition at least 1 year after different DESs implantation by optical coherence tomography （OCT）. Methods Angiographic and OCT examinations were given to 68 patients who had received total 126 various DESs implantation for at least 1 year to detect late stent malapposition. Malapposed strut distance （MSD）, malapposed strut area （MSA）, reference lumen area （RLA） and reference stent area （RSA） were checked with off-line OCT analysis. Results Totally 26 Cypher Select stents, 15 Taxus Liberte stents, 51 Partner stents and 34 Firebird I stents were examined. Among 68 patients who underwent DES implantation, 7 patients （10.3%） had late malapposition. Average RSA, MSA and MSD were （7.9=6？..8） mm2,（2.0＋1.6） mm2 and （590_＋_270） pm respectively. According to the MSA/RSA ratio 4 patients had slight malapposition, 2 patients had moderate malapposition and 1 patient had severe malapposition. Conclusions Late stent malapposition is detected frequently after implantation of DES, but if this predisposes to late stent thrombosis and requires any specific therapy needs to be further elucidated.