新一代药物洗脱支架的安全性明显更优

Percutaneous coronary intervention with new-generation drug-eluting stents is associated with significantly lower risk of restenosis, stent thrombosis, and death compared with both older generation drug-eluting stents and bare metal stents, according to findings from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR).

The findings bolster the current recommendations regarding use of drug-eluting stents (DES), and are the first to show a mortality benefit with new- vs. older-generation DES. Compared with older bare-metal stents (BMS), the risk of death was reduced with older DES at 2 years, by 28%, and lower still with new DES, by 45%.

The 1- and 2-year restenosis rates among 10,551 implantations with a new-generation DES in SCAAR were 2.8% and 3.9%, respectively, compared with 4.0% and 5.8% in 19,202 implantations with an older-generation DES (cumulative adjusted hazard ratio, 0.62), and 6.3% and 7.4% in 64,631 implantations with a BMS (cumulative adjusted HR, 0.29), wrote Dr. Giovanna Sarno of Uppsala (Sweden) University and colleagues. The results are online in the Jan. 9 issue of the European Heart Journal.

The 1- and 2-year definite stent thrombosis rates among the new-generation DES implantations were 0.5% and 0.6%, respectively, compared with 0.9% and 1.3% in the older-generation DES implantations, for a risk reduction of 43%, and 1.2% and 1.4% in the bare-metal stent implantations, showing a 62% reduction in risk.

The overall mortality rate among the 61,351 patients who underwent the 94,384 stent implantations was 5.6%. Mortality was 1.9% in the new-generation DES recipients, compared with 3.4% in the older-generation DES recipients (adjusted hazard ratio, 0.77), and 6.8% in the bare-metal stent recipients (adjusted HR 0.55), the investigators said (Eur. Heart J. 2011 Jan. 9 [doi:10.1093/eurheartj/ehr479]).

“A main finding of this study is that new-generation DES are associated with a 38% lower risk of clinically relevant restenosis and a 43% lower risk of definite stent thrombosis up to 2 years, compared with older-generation DES in a large real world population,” the investigators said.

Furthermore, the findings indicate that mortality with new-generation and older-generation DES is 45% and 28% lower, respectively, than with bare-metal stents, and 23% lower with new-generation DES than with older-generation DES, they said.

New-generation DES were developed with an improved design, including thinner struts and more biocompatible polymers, thought to have potential for overcoming limitations – namely those relating to long-term safety, and particularly risk of late stent thrombosis – of older generation DES. Although randomized studies demonstrated low late loss and thrombotic risk with restricted use of the new generation DES, only a few trials and reports from single-center experiences evaluating only one type of the new generation DES have looked at unrestricted use.

“Our study evaluated the performance up to 2 years of different types of new-generation DES in an unselected large real-world population – including patients with myocardial infarction, three-vessel and/or left main disease, bifurcation lesions, graft disease, restenotic lesions, and chronic total occlusions,” the investigators said.

Participants in the observational cohort study included all patients in Sweden who received coronary stents from November 2006 to October 2010. In their analysis, the investigators adjusted for potential confounders, including age, sex, diabetes, hypertension, dyslipidemia, smoking status, clinical indication of the procedure, medications used at the index procedure, treated vessel and lesion type, and previous MI and revascularization.

In a press statement, study author Dr. Stefan James, also of Uppsala University, described the findings as “intriguing” and noted that, “the low rates of restenosis and stent thrombosis correspond with the results of several recent randomized trials, and this may well translate into mortality reduction in a sufficiently large study population.”

However, despite the large sample size, the findings of this study should be considered within the context of the intrinsic limitations of registry data. Although the findings may be useful for the management of patients at risk for stent thrombosis and restenosis – and although they support the current strong recommendations for the use of drug-eluting stents in appropriate patients, they require confirmation by large-scale randomized studies, the investigators concluded.

New-generation DES used in this study included Endeavor Resolute (Medtronic Inc.), XienceV, Xience Prime (Abbott Laboratories), and Promus and Promus Element (Boston Scientific Corp.). Older generation DES included Cypher and Cypher Select (Cordis Corp., Miami, USA), Taxus Express and Taxus Liberté (Boston Scientific Corp.), and Endeavor (Medtronic Inc.) Bare-metal stents include Multilink, Multilink MiniVision, and Flexmaster (Abbott Laboratories), Driver and Micro Driver coronary (Medtronic Inc.), Liberté (Boston Scientific Corp.), Braun Coroflex Blue (B.Braun Melsungen AG, Germany), and Chrono stent (CID, Saluggia, Italy).

SCAAR is sponsored by the Swedish Health Authorities. Financial support for analyses was provided by the Swedish Heart and Lung Foundation. One study author, Dr. James, disclosed that he received institutional research grants from Terumo, Medtronic, and Vascular Solutions.

Copyright (c) 2010 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

《欧洲心脏杂志》(European Heart Journal)1月9日在线发表的来自瑞典冠状动脉造影和血管成形术登记库(SCAAR)的结果显示，与老一代的药物洗脱支架(DES)和裸金属支架(BMS)相比，新一代DES经皮冠状动脉介入治疗的再狭窄、支架内血栓形成和死亡风险明显较低(Eur. Heart J. 2011 Jan. 9 [doi:10.1093/eurheartj/ehr479])。

瑞典乌普萨拉大学的Giovanna Sarno博士及其同事在未经选择的大规模真实世界人群中对不同类型的新型DES的性能进行了长达2年的评价。该观察性队列研究的人群是2006年11月~2010年10月间植入冠状动脉支架的所有瑞典患者，这些患者患有心肌梗死、三支和(或)左主干病变、分叉病变、移植物病变、再狭窄病变和慢性完全闭塞。该研究所用的新一代DES包括Endeavor Resolute (美敦力)、XienceV、Xience Prime (雅培实验室)以及Promus和Promus Element (波士顿科学)。老一代DES包括Cypher和Cypher Select (Cordis Corp., Miami, USA)、Taxus Express和Taxus Liberté (波士顿科学)以及Endeavor (美敦力)。裸金属支架包括Multilink、Multilink MiniVision和Flexmaster (雅培实验室)、Driver和Micro Driver冠脉支架(美敦力)、Liberté (波士顿科学)、Braun Coroflex Blue (德国贝朗医疗)以及Chrono支架(意大利索林集团前身)。

研究者校正包括年龄、性别、糖尿病、高血压、血脂异常、吸烟状态、手术临床指征、索引手术时所用的药物、治疗过的血管和病变类型以及既往MI和血运重建等潜在混杂因素后分析首次发现，新一代DES在降低死亡率方面优于老一代DES。与老一代BMS植入者相比，老一代DES和新一代DES植入者术后2年的死亡风险分别降低28%和45%。在10,551例植入新一代DES的患者中，术后1年和2年的再狭窄率分别为2.8%和3.9%，而在19,202例植入老一代DES的患者中分别为4.0%和5.8% [校正后的累计危险比(HR)=0.62]，在64,631例植入BMS的患者中分别为6.3%和7.4%(校正后的累计HR=0.29)。在新一代DES植入者中，术后1年和2年的明确支架内血栓形成率分别为0.5%和0.6%，而在老一代DES植入者中分别为0.9%和1.3%，在BMS植入者中分别为1.2%和1.4%。与老一代DES和BMS植入者相比，新一代DES植入者的支架内血栓形成风险分别降低43%和62%。在进行94,384次支架植入术的61,351例患者中，总死亡率为5.6%：新一代DES植入者的死亡率为1.9%，而老一代DES植入者为3.4%(校正后的HR=0.77)，BMS植入者为6.8%(校正后的HR=0.55)。

该研究的主要发现是，与老一代DES植入者相比，新一代DES植入者术后2年具有临床意义的再狭窄风险和明确支架内血栓形成风险分别降低了38%和43%。此外，上述研究结果显示，新一代和老一代DES植入者的死亡率分别比BMS植入者低45%和28%，并且新一代DES植入者的死亡率比老一代DES植入者低23%。

该研究结果可能有助于管理具有支架内血栓形成和再狭窄风险的患者，并且支持目前对适当患者应用DES的强烈建议。尽管该研究的样本量较大，但考虑到登记库数据的固有局限性，应审慎解读该研究结果，并且该研究结果尚需通过大型随机研究加以验证。

SCAAR由瑞典卫生部门支持。上述分析的资金由瑞典心肺基金会提供。1位研究者声明从泰尔茂、美敦力和Vascular Solutions公司获得研究资金。

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