第二代药物洗脱支架

自2002年药物洗脱支架被引入以来,该类支架已经在冠状动脉介入治疗中获广泛应用。药物洗脱支架就是在金属裸支架的表面涂以包含抗增殖剂的聚合物。这种聚合物能在支架置入后的数周至数月内持续释放并持续抑制血管内膜增生。第一代药物洗脱支架主要是西罗莫司和紫杉醇支架,相对于金属裸支架和单纯球囊扩张,它在减少支架内再狭窄和再次介入方面显示了优势。     

Future Directions of Drug-Eluting Stents

Coronary artery stents have changed the face of interventional cardiology since their introduction in 1986. The commercial release of drug-eluting stents in 2002 promised to abolish in-stent restenosis as the predominant clinical limitation following stent implantation. Concerns raised about increased risks of adverse events with drug-eluting stents now appear unfounded but have heralded a new era of research, where only hard clinical end-points in sufficiently large numbers of patients are considered adequate. In this review, we highlight some of the potential future directions of drug-eluting stents including specialized stent platforms (including dedicated bifurcation stents), fully degradable stents, and the potential use of stents to prevent cardiac events.     

Drug-Eluting Stents in the Elderly

The introduction of drug-eluting stents (DES) in 2003 has had a great impact on the management of coronary artery disease in the United States. The application of DES to older adults, the population with the highest prevalence of and worst prognosis for coronary artery disease, remains relatively more controversial. Dual-antiplatelet therapy, which is recommended for at least 12 months after DES placement, is particularly problematic for older patients because of greater age-related bleeding risks. Unfortunately, few current data are available to gauge the balance of risk and benefit in elderly community-dwelling DES patients. Although trial data show a benefit for DES among elderly patients, many older adults typically are excluded from randomized trials because of comorbidities, making generalizability of DES safety based on trial data less certain. New, more potent thienopyridines may place the elderly at a particularly elevated bleeding risk. There is a fine balance between efficacy and safety for older DES patients that still needs to be clarified. As the population ages, these issues become more pervasive and of widespread concern. This review summarizes the current literature on DES therapy in the elderly, with a focus on effectiveness and safety profiles of DES versus bare metal stents.     

药物洗脱支架与金属裸支架内血栓发生率比较

目的:了解置入药物洗脱支架(DES)患者在经皮冠状动脉(冠脉)介入治疗(PCI)术后各期支架血栓(ST)的发生情况,并与置入金属裸支架(BMS)患者进行比较,探讨影响支架血栓发生的危险因素.方法:连续入选2001-07至2002-06和2003-07至2005-06期间接受PCI并置入支架的所有患者,共入选3 893例.随访至少2年.根据所使用支架分为DES组(n=2 930,至少置入1枚DES)和BMS组(n=963,单纯置入BMS).记录所有患者住院期和随访期内临床资料,并根据美国和欧洲学者组成的学术研究联盟(ARC)正式发表的支架血栓定义判定支架血栓事件.结果:与BMS组相比,DES组患者的平均年龄较大,而白细胞数、甘油三脂水平和空腹血糖水平较低,既往有冠脉血运重建病史者较多,但吸烟、糖尿病和ST段抬高型心肌梗死(STEMI)发生率较低;在DES组患者的冠脉病变中,多支病变、开口病变、前降支(LAD)近段病变和左主干(LM)病变发生率较高,但慢性完全闭塞性(CTO)病变所占的发生率较低,造影成功率及完全血运重建率均较高,差异均有统计学意义(P均＜0.05～0.001).两组患者PCI术后无论在住院期还是之后的随访期内,所有的不良心脑血管事件发生率均无显著差异,而支架血栓发生率在急性期、亚急性期、晚期和晚晚期均无差异(P均＞0.05).Cox回归分析结果提示,DES组患者发生支架血栓的危险因素为:氯吡格雷疗程短和冠脉多支病变(P均＜0.001);而BMS组患者发生支架血栓的危险因素为:血清肌酐值升高和合并高血压(P均＜0.05).结论:尽管DES时代患者的病变更为复杂,所置入的DES数更多,但支架血栓的发生率并不比BMS时代更高.但术后双联抗血小板治疗的疗程过短和冠脉多支病变是支架血栓发生的危险因素,应引起重视.     

Drug-Eluting Stents, Restenosis and Revascularization

Several meta-analyses have demonstrated the superiority of drug-eluting stents (DES) in reducing the incidence of restenosis, target vessel revascularization and target lesion revascularization compared to their predecessor, the bare-metal stent. In comparing Cypher and Taxus stents, the two most recent meta-analyses have given the edge to the Cypher. However, it must be stressed that the superiority of one DES over another remains debatable due to ever changing "real-world data" compared to those attained from randomized trials. The newer sirolimus analogs and selective inhibitors are challenging the old guard in their quest to further limit restenosis. So too are the newer "high-tech" polymers and additionally by using more biodegradable material in the stent's design. Stents aimed at targeting lesions are a new armament in the battle against restenosis and together with combination therapies are exciting key areas to watch. The ideal way to treat a DES in-stent restenosis is still a challenge and hence the impetus is to avoid it from happening in the first place.     

Long-Term Clinical Outcomes of Biodegradable-Polymer Drug-Eluting Stents Versus Second-Generation Durable-Polymer Drug-Eluting Stents for ST-Segment Elevation Myocardial Infarction

BackgroundBiodegradable polymer drug eluting stents (BP-DES) may offer the advantage of vascular healing in ST-segment elevation myocardial infarction (STEMI). Long-term outcome data comparing BP-DES and second-generation durable polymer drug eluting stents (DP-DES) in STEMI is lacking. This study aims to compare the long-term clinical outcomes of BP-DES versus second-generation DP-DES in STEMI.MethodsThis is an observational study of consecutive patients with STEMI who received either BP-DES (n = 854) or DP-DES (n = 708) during primary percutaneous coronary intervention (PCI) from 1st February 2007 to 31st December 2016. The primary outcome was target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction (MI), and target lesion revascularization with follow up till 30th November 2019.ResultsThe baseline demographics, lesion and procedural characteristic were similar between the two groups except for more prior MI and chronic obstructive pulmonary disease in the BP-DES group. At a median follow up of 4.2 years (interquartile range: 2.6–6.2 years), the incidence of TLF was similar between BP-DES and DP-DES (adjusted hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.70–1.26). Likewise, incidence of major adverse cardiovascular events (MACE: all-cause death, any MI or target vessel revascularization) and definite stent thrombosis were similar in both groups (MACE: adjusted HR 1.04, 95% CI 0.82–1.32; definite stent thrombosis: adjusted HR 1.06, 95% CI 0.31–3.64).ConclusionAmong patients with STEMI who underwent primary PCI, BP-DES and DP-DES implantation was associated with similar long-term clinical outcomes.     

Comprehensive Meta-Analysis on Drug-Eluting Stents versus Bare-Metal Stents during Extended Follow-up

Background

Several observational reports have documented both increased and decreased cardiac mortality or Q-wave myocardial infarction with drug-eluting stents compared with bare-metal stents.

Methods

We sought to evaluate the safety and efficacy of drug-eluting stents compared with bare-metal stents early after intervention (<1 year) and late (>1 year) among a broad population of patients, using a meta-analysis of randomized clinical trials.

Results

We identified 28 trials with a total of 10,727 patients and a mean follow-up of 29.6 months. For early outcomes (<1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 2.1% versus 2.4% (risk ratio [RR] 0.91, [95% confidence interval (CI), 0.70-1.18]; P = .47), non-Q-wave myocardial infarction was 3.3% versus 4.4% (RR 0.78 [95% CI, 0.61-1.00]; P = .055), target lesion revascularization was 5.8% versus 18.4% (RR 0.28 [95% CI, 0.21-0.38]; P <.001), and stent thrombosis was 1.1% versus 1.3% (RR 0.87 [95% CI, 0.60-1.26]; P = .47). For late outcomes (>1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 5.9% versus 5.7% (RR 1.03 [95% CI, 0.83-1.28]; P = .79), target lesion revascularization was 4.0% versus 3.3% (RR 1.22 [95% CI, 0.92-1.60]; P = .16), non-Q-wave myocardial infarction was 1.6% versus 1.2% (RR 1.36 [95% CI, 0.74-2.53]; P = .32) and stent thrombosis was 0.7% versus 0.1% (RR 4.57 [95% CI, 1.54-13.57]; P = .006).

Conclusions

There was no excess mortality with drug-eluting stents. Within 1 year, drug-eluting stents appear to be safe and efficacious with possibly decreased non-Q-wave myocardial infarction compared with bare-metal stents. After 1 year, drug-eluting stents still have similar mortality, despite increased stent thrombosis. The reduction in target lesion revascularization with drug-eluting stents mainly happens within 1 year, but is sustained thereafter.     

Drug-Eluting Stents Versus Bare-Metal Stents in Patients With End-Stage Renal Disease

Background

The clinical outcomes of drug-eluting stents versus bare-metal stents in end-stage renal disease patients remains controversial.

Biodegradable Polymer Drug-Eluting Stents Versus Second-Generation Drug-Eluting Stents for Patients With Coronary Artery Disease: An Update Meta-Analysis

Objective

Permanent polymer drug-eluting stents (DES) are associated with a higher risk of late and very late stent thrombosis (ST); biodegradable polymer drug-eluting stents (BP-DES) were designed to reduce these risks. However, their benefits are not completely clear.

Method

We undertook a meta-analysis of randomized studies identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database. Eligible studies were those that compared BP-DES with second-generation permanent polymer DES in patients undergoing percutaneous coronary intervention.

Results

Five studies (8,740 patients) with a mean follow-up of 19.2 months were included. Overall, BP-DES were associated with a broadly equivalent risk of definite and probable ST (odds ratio [OR], 1.07; 95 % confidence interval [CI], 0.67 to 1.71; P?=?0.76; I ²?=?5.0 %), target vessel revascularization (OR, 1.04; 95 % CI, 0.87 to 1.24; P?=?0.68; I ²?=?38.0 %), all-cause mortality (OR, 1.10; 95 % CI, 0.87 to 1.41; P?=?0.42; I ²?=?0.0 %), and major adverse cardiac events (OR, 1.03; 95 % CI, 0.88 to 1.20; P?=?0.74; I ²?=?0.0 %) when compared with second-generation DES. However, BP-DES significantly decreased in-stent late luminal loss (standard mean difference [SMD], ?0.01; 95 % CI, ?0.12 to 0.11; P?=?0.93; I ²?=?0.0 %) and in-segment late luminal loss (SMD, ?0.06; 95 % CI, ?0.17 to 0.05; P?=?0.27; I ²?=?0.0 %) compared with second-generation DES.

Conclusions

Compared with second-generation permanent polymer DES, biodegradable stents appear to have equivalent short- to medium-term clinical benefits, and it remains unclear whether they reduce the incidence of very late ST.