The risks and benefits of drug-eluting stents in the setting of STEMI

Primary percutaneous coronary intervention (PCI) represents the treatment of choice in patients with ST-segment elevation myocardial infarction (STEMI). In randomized trials excluding STEMI patients, using drug-eluting stents (DES) significantly reduced angiographic restenosis and target vessel revascularization compared with bare metal stents (BMS); however, concerns exist regarding an increased follow-up incidence of stent thrombosis after DES implantation. This complication, which is associated with higher mortality and morbidity rates, may be more frequent among STEMI patients receiving DES versus BMS. Various registries, randomized trials, and two recent meta-analyses on patients undergoing primary PCI have shown that using DES is safe and is associated with significantly reduced rates of restenosis and repeat intervention without an increased risk of myocardial infarction or stent thrombosis at intermediate-term follow-up. However, large trials with hard clinical end points and longer follow-up are needed before routine DES use can be recommended in patients undergoing primary PCI.     

Drug-eluting stents in the treatment of intermediate lesions: pooled analysis from four randomized trials.

OBJECTIVES: To address the safety and efficacy of drug-eluting stents (DES) in the treatment of intermediate lesions, we performed a pooled analysis of four randomized DES versus bare-metal stent (BMS) trials and assessed outcomes among patients with intermediate lesions. BACKGROUND: Before the introduction of DES, intermediate coronary lesions were commonly managed based on physiologic or anatomic assessment of lesion severity. The DES may challenge this paradigm. METHODS: The study population involved 167 of 2,478 randomized patients (6.7%) with intermediate lesions (diameter stenosis <50% [mean 44%] by quantitative coronary angiography) from the Sirolimus-coated Bx Velocity Balloon Expandable Stent in the Treatment of Patients with De Novo Coronary Artery Lesions (SIRIUS), TAXUS-IV, and the First and Second First Use to Underscore Restenosis Reduction with Everolimus (FUTURE-I and -II) trials. End points examined included early (in-hospital and 30-day) and late (1-year) major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis, and follow-up angiographic restenosis. RESULTS: Patients with intermediate lesions randomized to DES versus BMS had low rates of 30-day MACE (1.1% vs. 4.0% respectively; p = 0.22). At one-year follow-up, patients treated with DES versus BMS had similar rates of cardiac death (0% vs. 2.7%, respectively; p = 0.11) and MI (3.4% vs. 5.4%; p = 0.49) but markedly lower rates of TVR (3.4% vs. 20.3%; p = 0.0004), MACE (5.6% vs. 25.4%; p = 0.0003), and binary angiographic restenosis (1.8% vs. 34.0%; p < 0.0001). No patient in either group developed stent thrombosis. CONCLUSIONS: Compared with BMS, treatment of intermediate lesions with DES appears safe and results in a marked reduction in clinical and angiographic restenosis. The efficacy of DES may require a reevaluation of current treatment paradigms for intermediate lesions.     

Long-term Outcomes of Drug-eluting versus Bare-metal stent for ST-elevation Myocardial Infarction

Background

Long-term outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) remain uncertain.

Objective

To investigate long-term outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI).

Methods

We performed search of MEDLINE, EMBASE, the Cochrane library, and ISI Web of Science (until February 2013) for randomized trials comparing more than 12-month efficacy or safety of DES with BMS in patients with STEMI. Pooled estimate was presented with risk ratio (RR) and its 95% confidence interval (CI) using random-effects model.

Results

Ten trials with 7,592 participants with STEMI were included. The overall results showed that there was no significant difference in the incidence of all-cause death and definite/probable stent thrombosis between DES and BMS at long-term follow-up. Patients receiving DES implantation appeared to have a lower 1-year incidence of recurrent myocardial infarction than those receiving BMS (RR = 0.75, 95% CI 0.56 to 1.00, p= 0.05). Moreover, the risk of target vessel revascularization (TVR) after receiving DES was consistently lowered during long-term observation (all p< 0.01). In subgroup analysis, the use of everolimus-eluting stents (EES) was associated with reduced risk of stent thrombosis in STEMI patients (RR = 0.37, p=0.02).

Conclusions

DES did not increase the risk of stent thrombosis in patients with STEMI compared with BMS. Moreover, the use of DES did lower long-term risk of repeat revascularization and might decrease the occurrence of reinfarction.     

Drug-eluting stent thrombosis: results from a pooled analysis including 10 randomized studies

OBJECTIVES: We compared the risk of stent thrombosis (ST) after drug-eluting stents (DES) versus bare-metal stents (BMS), and tested the hypothesis that the risk of DES thrombosis is related to stent length. BACKGROUND: Whether DES increase the risk of ST remains unclear. Given the very low restenosis rate after drug-eluting stenting, longer stents are frequently implanted for the same lesion length in comparison to BMS. METHODS: We included in a meta-analysis 10 randomized studies comparing DES and BMS. Overall, 5,030 patients were included (2,602 were allocated to DES and 2,428 to BMS). The risk of thrombosis after DES versus BMS was compared, and the relationship between the rate of DES thrombosis and stent length was evaluated. RESULTS: Incidence of ST was not increased in patients receiving DES (0.58% vs. 0.54% for BMS; odds ratio: 1.05; 95% confidence interval [CI]: 0.51 to 2.15; p = 1.000). The overall rate of ST did not differ significantly between patients receiving sirolimus- or paclitaxel-eluting stents (0.57% vs. 0.58%; p = 1.000). We found a significant relation between the rate of ST and the stented length (Y = -1.455 + 0.121 X; 95% CI for beta: 0.014 to 0.227; R = 0.716; p = 0.031). In patients with DES, mean stented length was longer in those suffering ST (23.4 +/- 8.1 mm vs. 21.3 +/- 4.1 mm, p = 0.025). CONCLUSIONS: Drug-eluting stents do not increase the risk of ST, at least under appropriate anti-platelet therapy. The risk of ST after DES implantation is related to stent length.     

Long-term follow-up of drug-eluting stents when inserted for on- and off-label indications

This study reports long-term follow-up of the on- and off-label implantation of drug-eluting stents (DESs) in a retrospective study of 1,044 patients. Off-label implantation of DESs was performed for left main coronary artery lesions, bifurcation lesions, bare metal stent restenosis, ostial disease, chronic total occlusions, saphenous vein graft lesions, internal mammary artery graft lesions, left ventricular ejection fraction <30%, and acute myocardial infarction. End points examined were procedural complications, in-hospital myocardial infarction, and acute stent thrombosis; end points examined at follow-up were subacute stent thrombosis, late stent thrombosis, target vessel revascularization, myocardial infarction, death, and major adverse clinical events (MACEs; a composite of death, myocardial infarction, and target vessel revascularization). The study included 364 patients who received a DES on an on-label basis and 680 patients who received a DES on an off-label basis. Patient characteristics were not significantly different between the 2 groups, and there was no difference in procedural complications or acute stent thrombosis (on-label, 0%; off-label, 0.3%; p=0.55). There were no significant differences in subacute stent thrombosis (0% vs 0.6%, p=0.3), late stent thrombosis (1.4% vs 1.2%, p=0.78), death at follow-up (4.9% vs 4.1%, p=0.53), or myocardial infarction (1.9% vs 2.4%, p=0.83). Off-label DES implantation was associated with higher rates of target vessel revascularization (13.2% vs 24.1%, p=0.0001) and MACEs (17.6% vs 28.2%, p=0.0001). Multivariate analysis showed associations between target vessel revascularization and MACEs (respective p values) with bare metal stent restenosis (p=0.001 and p=0.001), diabetes mellitus (p=0.002 and p=0.001), and previous coronary artery bypass grafting (p=0.04 and p=0.01), but not off-label DES implantation (p=1.36 and p=1.16). In conclusion, DES use in the off-label situations studied was safe and was not associated with increased stent thrombosis, myocardial infarction, or death. Multivariate analysis showed that off-label DES implantation was not a risk factor for target vessel revascularization or MACEs.     

Randomized trial of Sirolimus-Eluting Stent Versus Bare-Metal Stent in Acute Myocardial Infarction (SESAMI).

OBJECTIVES: To confirm whether sirolimus-eluting stents (SES) safely reduce the incidence of restenosis in patients with ST-segment elevation acute myocardial infarction compared with bare-metal stents (BMS). BACKGROUND: In the setting of primary angioplasty, stent restenosis occurs in up to 27% of patients. The introduction of drug-eluting stents has drastically reduced the incidence of restenosis in clinically stable patients. METHODS: We conducted a randomized trial of 320 patients with acute ST-segment elevation myocardial infarction assigned to receive SES or BMS. The primary end point was binary restenosis at 1-year angiographic follow-up. RESULTS: At 1 year, the incidence of binary restenosis was lower in the SES group than in the BMS group (9.3% vs. 21.3%, respectively; p = 0.032), as were the rates of target lesion revascularization (4.3% vs. 11.2%; p = 0.02), target vessel revascularization (5% vs. 13.1; p = 0.015), major adverse cardiac events (6.8% vs. 16.8%; p = 0.005), and target vessel failure (8.7% vs. 18.7%; p = 0.007). The incidence of angiographically documented stent thrombosis was 1.2% (n = 2) in the SES group and 0.6% (n = 1) in the BMS group. CONCLUSIONS: In patients with acute myocardial infarction, SES are superior to BMS, reducing the incidence of binary restenosis by 56%, target lesion revascularization by 61%, target vessel revascularization by 62%, adverse cardiac events by 59%, and target vessel failure by 53% at 1 year. (Sirolimus Eluting Stenting in Acute Myocardial Infarction; http://www.clinicaltrials.gov/ct/show/NCT00288210; NCT00288210).     

Stent thrombosis is a major concern in clinical practice: A single Saudi center experience

BackgroundDrug-eluting stents (DES) are used in the majority of patients who undergo percutaneous coronary intervention (PCI), and have reduced the rate of in-stent restenosis and repeated revascularization in comparison to bare metal stents. However, stent thrombosis (ST) is an uncommon but serious complication of coronary artery stents that is mostly fatal or presents as a large non-fatal myocardial infarction (MI), usually with ST elevation.ObjectiveTo study the incidence of stent thrombosis in Middle Eastern Saudi patients who underwent PCI using both drug-eluting stents (DES) and bare metal stents (BMS). ST can occur acutely (within 24 h), sub acutely (within 30 days), or as late as one year (late) or even more than one year (very late).MethodsIn an observational, single center study in catheterization (cath) lab a total of 1386 patients underwent PCI between January 2008 and September 2010. The study included all patients in that period who had acute coronary syndrome and stable coronary artery disease (CAD).ResultsA total of 1386 patients had PCI and stent deployments; 19 (1.3%) patients had stent thrombosis, four patients (21%) received BMS and 15 patients (79%) received DES. Four patients had acute ST; five had subacute ST; eight patients had late ST; while two patients had very late ST. Nine patients (47%) had DM and eight patients (42%) had hypertension.ConclusionThe incidence of ST in Saudi patients who received DES at our center is similar to internationally reported numbers. Almost half of ST patients are diabetics and there is increasing concern that the risk for late stent thrombosis is slightly higher with DES than BMS.     

Long-term outcomes following coronary drug-eluting- and bare-metal-stent implantation

Background

Although drug-eluting stents (DES) reduce restenosis rates relative to bare-metal stents (BMS), recent reports have indicated that the use of DES may be associated with an increased risk of stent thrombosis. Our study focused on the effect of stent type on clinical outcomes in a “real world” setting.

Methods

889 patients undergoing percutaneous coronary intervention (PCI) with either DES (Cypher or Taxus; n = 490) or BMS (n = 399) were enrolled in a prospective single center registry. The outcome analysis covered a period of up to 3.2 years (mean 2.7 years ± 0.5 years) and was based on 65 deaths, 27 myocardial infarctions, 76 clinically driven target lesion revascularizations (TLR), and 15 angiographically confirmed cases of definite stent thrombosis and was adjusted for differences in baseline characteristics.

Results

In total 1277 stents (613 BMS and 664 DES) were implanted in 1215 lesions. Despite a significantly different unadjusted death rate (10.1% and 5.1% in BMS and DES patients, respectively; p < 0.05), the patient groups did not differ significantly in the risk of myocardial infarction during 2.7 years of follow-up. After adjustment for differences in baseline characteristics between groups, the difference in the cumulative incidence of death did not remain statistically significant (p = 0.22). Target lesion revascularizations occurred significantly less frequently in patients with DES compared to individuals after BMS implantation (5.9% and 11.8% in patients with DES and BMS, respectively; p < 0.05). The rate of angiographically confirmed stent thrombosis was 2.1% in patients with DES and 1.1% in BMS patients (p = 0.31).There was a significantly lower unadjusted event rate (including deaths, myocardial infarction, target lesion revascularization, and stent thrombosis) in patients with drug-eluting stents than in those with bare-metal stents (16.4% and 25.8%, respectively), with 9.4 fewer such events per 100 patients (unadjusted hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.46 to 0.87). After adjustment, the relative risk for all outcome events in patients with drug-eluting stents was 0.79 (95% CI, 0.67 to 0.95). However, the adjusted relative risk for death and myocardial infarction did not differ significantly between groups (adjusted relative risk in patients with drug-eluting stents 0.94 (95% CI, 0.77 to 1.37)).

Conclusions

In this real-world population, the beneficial effect of first generation DES in reducing the need for new revascularization compared with BMS extends to more than 2.5 years without evidence of a worse safety profile. The minor risk of stent thrombosis and myocardial infarction within this period after implantation of DES seems unlikely to outweigh the benefit of these stents.     

Comparison of drug-eluting stents with bare metal stents in unselected patients with acute myocardial infarction.

OBJECTIVES: The aim of this study was to compare the procedural characteristics and outcomes of patients with acute myocardial infarction treated with drug-eluting stents (DES) vs. bare metal stents (BMS). BACKGROUND: DES have been shown to reduce the incidence of restenosis and target vessel revascularization (TVR) in clinical randomized studies when compared with BMS in patients undergoing elective percutaneous intervention. Limited data are available with the use of DES in patients with acute ST-segment elevation myocardial infarction. METHODS: Two hundred and sixty-one consecutive patients who presented with myocardial infarction between 7/2001 and 8/2005 were studied. The procedural characteristics, 30-day and 12-month outcomes of 131 patients treated with DES were compared with 130 patients treated with BMS. RESULTS: At 12-months follow-up DES therapy was associated with a substantial decrease in major adverse cardiovascular events (MACE) (HR 0.33; P =0.002), TVR (HR 0.19; P =0.002), and recurrent myocardial infarction (HR 0.23; P =0.051) vs. BMS therapy. Coronary interventions utilizing DES were characterized by a marked increase in the number of stent per target vessel (DES: 1.9 +/- 0.9 vs. BMS: 1.38 +/- 0.6, P < 0.0001), treatment of bifurcation (DES: 21% vs. BMS: 5%, P =0.0004), and multivessel intervention (DES: 22% vs. BMS: 8%, P =0.003). CONCLUSION: The routine use of DES in acute myocardial infarction is associated with reduced rates of MACE at 12 months vs BMS, despite a higher rate of complex procedures in the DES treated patients. In addition to its anti-restenosis effect, the improved outcome of patients treated with DES may be linked to a more complete revascularization in association with prolonged clopidogrel therapy.     

Recurrent coronary stent thromboses and myocardial infarctions

Although stent thrombosis is a recognized complication of coronary intervention, recurrent stent thrombosis is rarely reported. We present a patient who suffered 3 ST-segment elevation myocardial infarctions associated with repeated stent thromboses within a month and a half. Although a potentially mechanical cause of thrombosis was identified in the only baremetal stent implanted in this case, no predisposing factors were seen for the 2 drug-eluting stents (DES). While recent worrisome data have suggested a slight increase in the incidence of late angiographic stent thrombosis (defined as occurring beyond 30 days) with drug-eluting stents (DES), their risk of subacute thrombosis (from 1 to 30 days) is reported to be equivalent to that of BMS. Therefore, this rare occurrence serves as a sobering reminder of the risks of subacute thrombosis with both BMS and DES. Marked neointimal inhibition, allergic reactions, as well as thienopyridine resistance, may all contribute to the pathophysiology of DES thrombosis. The Food and Drug Administration advisory panel has concluded that when these devices are used for "on-label" indications, the counterbalance of dramatic target lesion revascularization reduction versus rare incidence of late angiographic stent thrombosis results in no overall increase in DES myocardial infarction or mortality risk. Furthermore, a minimum of 1 year of dual antiplatelet therapy is recommended for all recipients of DES at low risk of bleeding.     

Drug-eluting stents: towards new endpoints

Drug-eluting stents (DES) have significantly reduced the rates of in-stent restenosis (ISR). As previously observed with bare-metal stents (BMS), either patient's clinical characteristics and lesion morphology may influence the risk of recurrence even with DES. In this review we will focus on the most recent available data on clinical settings where DES efficacy on long-term outcomes are largely unknown. In particular, we report on very complex lesions (bifurcations, small vessels, chronic total occlusions, in-stent restenosis) myocardial infarction, multivessel disease, treatment of bypass graft and of unprotected left main disease. Several issues are still open on DES routinary use for these indications, mainly as far as stent thrombosis is concerned. Recent pathological studies show that DES are characterized by chronic inflammatory infiltrates and delayed endothelialization. Therefore, this effect could translate in a 'vulnerable period' for thromboses longer than with BMS. Even though large meta-analysis have excluded higher rates of stent thrombosis with DES rather than with BMS, few cases of unusual very late stent thrombosis have been described, pointing out that this problem seems to be still unsolved. Although DES provide better angiographic outcomes in each clinical setting, further randomized studies are running to assess their safety and efficacy on currently off-label indications.     

Frequency of and risk factors for stent thrombosis after drug-eluting stent implantation during long-term follow-up

Despite concerns regarding the long-term safety of drug-eluting stent (DES) implantation because of late-onset stent thrombosis, the actual incidence of stent thrombosis after 1 year is unknown. We investigated the incidence, risk factors, and association of antiplatelet therapy interruption for the development of stent thrombosis after DES implantation during long-term follow-up. A total of 1,911 consecutive patients with DES implantation were enrolled (sirolimus-eluting stents in 1,545 patients, 2,045 lesions; paclitaxel-eluting stents in 366 patients, 563 lesions). During long-term follow-up (median 19.4 months, interquartile range 15.3 to 24.3), 15 patients (0.8%, 95% confidence interval 0.5% to 1.3%) developed stent thrombosis within 6 hours to 20.4 months. Eleven patients (0.6%, 95% confidence interval 0.3% to 1.0%) had late thrombosis (median 6.1 months). The incidence of stent thrombosis was 3.3% (4 of 121 patients) in patients with complete interruption of antiplatelet therapy (vs 0.6% in those without, p = 0.004) and 7.8% (5 of 64 patients) with premature interruption of aspirin or clopidogrel, or both (vs 0.5% in those without, p < 0.001). Independent predictors of stent thrombosis were premature antiplatelet therapy interruption, primary stenting in acute myocardial infarction, and total stent length. Stent thrombosis also developed while patients were on dual antiplatelet therapy (all patients with acute/subacute stent thrombosis and 36% of those with late stent thrombosis; 47% of total with stent thrombosis). In conclusion, stent thrombosis occurred in 0.8% after DES implantation during long-term follow-up. The incidence of late stent thrombosis was 0.6%, similar to that for bare metal stents. The predictors of stent thrombosis were premature antiplatelet therapy interruption, primary stenting in acute myocardial infarction, and total stent length.     

Patency of paclitaxel-eluting versus bare metal stents long term after implantation in acute ST-segment elevation myocardial infarction

Drug-eluting stents effectively inhibit neointimal hyperplasia within the first year, thereby reducing the need for repeat revascularization. However, a delayed pattern of restenosis might be more prominent in drug-eluting stents compared to bare metal stents (BMSs). The extent of restenosis of paclitaxel-eluting stents (PESs) long term after implantation in acute ST-segment elevation myocardial infarction is currently unknown. The present study was designed to evaluate very late luminal loss (VLLL) of PESs used in ST-segment elevation myocardial infarction compared to BMSs. A total of 116 patients (61 with PESs and 55 with BMSs) initially included in the Paclitaxel Eluting Stent Versus Conventional Stent in ST-segment Elevation Myocardial Infarction (PASSION) trial and who were free from previous lesion failure underwent angiographic follow-up. Off-line quantitative coronary analysis of the angiogram immediately after stent implantation and at follow-up was performed. The primary end point was VLLL within the stent. The presence of binary restenosis was defined as diameter stenosis >50% as a secondary end point. The mean interval between stent implantation and follow-up was 4.1 ± 0.5 years in both stent groups. In-stent VLLL was 0.12 mm (interquartile range -0.03 to 0.42) in the PES group versus 0.30 mm (interquartile range 0.08 to 0.69) in the BMS group (p = 0.011). In-segment binary restenosis was found in 4 patients (6.6%) with a PES and 6 patients (10.9%) with a BMS (p = 0.40). In conclusion, angiographic follow-up 4 years after implantation in ST-segment elevation myocardial infarction showed that in patients prospectively randomized to PESs or BMSs, VLLL was low in both stent groups. PESs were associated with lower VLLL than BMSs, and the observed rate of binary restenosis was not significantly different between the 2 stent groups.     

药物支架和裸支架治疗急性ST段抬高心肌梗死患者的随访研究

目的 评价药物支架和裸支架治疗急性ST段抬高心肌梗死患者疗效和预后方法217例接受了急诊经皮冠状动脉介入治疗急性ST段抬高心肌梗死患者纳入本研究,药物支架组92例、裸支架组125例,收集基线资料并随访6～38个月.结果 裸支架组的平均年龄(64.6±11.9)岁、Killip分级(2、3、4级)为25.9%和支架平均直径为(3.07±0.38)mm,均高于药物支架组(61.2±11.8)岁、12.2%和(2.91±0.40),差异有统计学意义(t=2.09,P=0.037;χ2=5.53,P=0.019;t=2.78,P=0.006),裸支架组平均左心室射血分数(55.4±11.9)%低于药物支架组(60.3±12.8)%,差异有统计学意义(t=-2.57,P=0.011).支架长度[(32.8±16.2)mm、(26.2±11.2)mm]、支架后扩张(45.7%、21.6%)、糖尿病(28.2%、16.0%)药物支架组高于裸支架组(t=-3.54,P=0.001;χ2=13.85,P=0.0002;χ2=4.77,P=0.030).随访期间,主要不良心脏事件(MACE)发生36例,药物支架组6例(6.5%),裸支架组30例(24.0%)(χ2=11.70,P＜0.01).结论 急性ST段抬高心肌梗死急诊介入治疗是安全有效的,同裸支架相比药物支架明显降低随访期MACE发生率而改善预后.     

Safety and efficacy with drug-eluting stent in ST-segment elevation and non-ST-segment elevation myocardial infarction

BACKGROUND: Drug-eluting stents (DES) have been shown to reduce the need for repeat revascularization compared with bare metal stents (BMS). However, there is little information regarding the safety and long-term efficacy of DES in patients with acute myocardial infarction (AMI). HYPOTHESIS: The aim of this study was to evaluate the safety and efficacy of DES in patients with AMI. METHODS: Data from 211 consecutive patients with AMI treated with DES were compared with those from 228 consecutive patients with AMI treated with BMS. All patients were treated within 7 days of symptom onset. The incidence of major adverse cardiovascular events ([MACE]: death, reinfarction, and target vessel revascularization) was evaluated at 30 days and 1 year. RESULTS: Baseline clinical and angiographic characteristics were similar for both stent groups. However, patients who received DES had longer lesion lengths (23.0 +/- 12.7 vs. 18.8 +/- 10.6 mm, respectively; p < 0.001) and smaller reference diameters (2.97 +/- 0.52 vs. 3.19 +/- 0.63 mm, respectively, p < 0.001). At 30 days, the incidence rates of MACE (DES vs. BMS: 2.2 vs. 1.9%, p = 1.000) and stent thrombosis (BMS vs. DES: 0.9 vs. 1.7%; p = 0.434) did not differ significantly between the groups. At 1 year, patients with DES had a lower rate of MACE (BMS vs. DES: 14.0 vs. 6.6%; p = 0.011) primarily due to a lower target vessel revascularization rate (BMS vs. DES: 9.6 vs. 4.8%; p = 0.028). CONCLUSIONS: The DES appear to be superior to the BMS in reducing the risk of MACE in patients with AMI.     

药物洗脱支架在老年急性心肌梗死患者治疗中疗效观察

目的评价药物洗脱支架治疗老年ST段抬高型急性心肌梗死（AMI）患者的安全性和有效性。方法连续性收集2005年1月-12月行直接介入治疗的105例60岁及以上的老年ST段抬高型AMI患者，其中，49例接受药物洗脱支架植入，56例接受金属裸支架植入，对两组患者术后30d和240d的主要心血管不良事件（包括死亡、非致死性再梗死和靶血管血运重建）进行随访、分析。结果药物洗脱支架组和金属裸支架组的手术成功率差异无统计学意义（96％与95％，P〉0．05）。术后30d内，药物洗脱支架组和金属裸支架组的心脏不良事件发生率差异无统计学意义（8、2％与12．5％，P〉0.05），两组由冠状动脉造影证实的早期支架内血栓发生率差异无统计学意义（2．0％与1．8％，P〉0.05）。术后240d随访，与金属裸支架植入比较，药物洗脱支架植入能明显减少心脏不良事件发生率[12．2％与30、0％，相对危险比为0、38，95％可信限（CI）：0、12～0、96，P〈0.053，靶血管血运重建率显著降低[2.0％与25．0％，相对危险比为0．08（95％CI：0．01～0.63），P〈0．01]。术后30～240d，两组未发生晚期支架内血栓。结论与金属裸支架比较，药物洗脱支架应用于老年ST段抬高型AMI患者可能并不增加支架内血栓的中期发生率，同时可以降低患者8个月靶血管再次血运重建率。     

Pathology of drug-eluting stents in humans: delayed healing and late thrombotic risk.

OBJECTIVES: This study examined human drug-eluting stents (DES) to determine the long-term effects of these stents on coronary arterial healing and identified mechanisms underlying late stent thrombosis (LST). BACKGROUND: Although DES reduce the need for repeat revascularization compared with bare-metal stents (BMS), data suggest the window of thrombotic risk for Cypher (Cordis Corp., Miami Lakes, Florida) and Taxus (Boston Scientific Corp., Natick, Massachusetts) DES extends far beyond that for BMS. METHODS: From a registry of 40 autopsies of DES (68 stents), 23 DES cases of >30 days duration were compared with 25 matched autopsies of BMS implantation. Late stent thrombosis was defined as an acute thrombus within a stent >30 days old. RESULTS: Of 23 patients with DES >30 days old, 14 had evidence of LST. Cypher and Taxus DES showed greater delayed healing characterized by persistent fibrin deposition (fibrin score 2.3 +/- 1.1 vs. 0.9 +/- 0.8, p = 0.0001) and poorer endothelialization (55.8 +/- 26.5%) compared with BMS (89.8 +/- 20.9, p = 0.0001). Moreover, DES with LST showed more delayed healing compared with patent DES. In 5 of 14 patients suffering LST, antiplatelet therapy had been withdrawn. Additional procedural and pathologic risk factors for LST were: 1) local hypersensitivity reaction; 2) ostial and/or bifurcation stenting; 3) malapposition/incomplete apposition; 4) restenosis; and 5) strut penetration into a necrotic core. CONCLUSIONS: The Cypher and Taxus DES result in delayed arterial healing when compared with BMS of similar implant duration. The cause of DES LST is multifactorial with delayed healing in combination with other clinical and procedural risk factors playing a role.     

Sirolimus-eluting stent implantation for unprotected left main coronary artery stenosis: comparison with bare metal stent implantation

OBJECTIVES: This study was designed to compare the clinical and angiographic outcomes of sirolimus-eluting stent (SES) and bare metal stent (BMS) implantation for unprotected left main coronary artery (LMCA) stenosis. BACKGROUND: The safety and effectiveness of SES implantation for unprotected LMCA stenosis have not been ascertained. METHODS: Elective SES implantation for de novo unprotected LMCA stenosis was performed in 102 consecutive patients with preserved left ventricular function from March 2003 to March 2004. Data from this group were compared to those from 121 patients treated with BMS during the preceding two years. RESULTS: Compared to the BMS group, the SES group received more direct stenting, had fewer debulking atherectomies, had a greater number of stents, had more segments stented, and underwent more bifurcation stenting. The procedural success rate was 100% for both groups. There were no incidents of death, stent thrombosis, Q-wave myocardial infarction (MI), or emergent bypass surgery during hospitalization in either group. Despite less acute gain (2.06 +/- 0.56 mm vs. 2.73 +/- 0.73 mm, p < 0.001) in the SES group, SES patients showed a lower late lumen loss (0.05 +/- 0.57 mm vs. 1.27 +/- 0.90 mm, p < 0.001) and a lower six-month angiographic restenosis rate (7.0% vs. 30.3%, p < 0.001) versus the BMS group. At 12 months, the rate of freedom from death, MI, and target lesion revascularization was 98.0 +/- 1.4% in the SES group and 81.4 +/- 3.7% in the BMS group (p = 0.0003). CONCLUSIONS: Sirolimus-eluting stent implantation for unprotected LMCA stenosis appears safe with regard to acute and midterm complications and is more effective in preventing restenosis compared to BMS implantation.     

Late and very late thrombosis of drug-eluting stents: evolving concepts and perspectives.

Coronary stents are the mainstay of percutaneous coronary revascularization procedures and have significantly decreased the rates of acute vessel closure and restenosis. Stent thrombosis (ST) after percutaneous coronary intervention is an uncommon and potentially catastrophic event that might manifest as myocardial infarction and sudden death. Optimization of stent implantation and dual antiplatelet therapy have markedly reduced the occurrence of this complication. Bare-metal stent (BMS) thrombosis occurs in <1% of the cases, usually within the first month after implantation. The advent of drug-eluting stents (DES) has raised concerns regarding later occurrence of ST, beyond the traditional 1-month timeframe, especially in complex lesion subsets that were excluded from randomized trials that compared BMS to DES. There is widespread controversy regarding the actual incremental risk associated with DES. Recent studies suggest a 0.5% increased long-term thrombosis risk with DES; however, the clinical significance of these events remains under debate. The degree of protection achieved by dual antiplatelet therapy and optimal duration of treatment are under investigation. Novel stent designs might potentially decrease the incidence of this event. In this review, we will describe the current knowledge of the pathophysiology of late DES thrombosis, although many aspects remain incompletely understood.     

Late and very late thrombosis of drug-eluting stents: evolving concepts and perspectives

Coronary stents are the mainstay of percutaneous coronary revascularization procedures and have significantly decreased the rates of acute vessel closure and restenosis. Stent thrombosis (ST) after percutaneous coronary intervention is an uncommon and potentially catastrophic event that might manifest as myocardial infarction and sudden death. Optimization of stent implantation and dual antiplatelet therapy have markedly reduced the occurrence of this complication. Bare-metal stent (BMS) thrombosis occurs in <1% of the cases, usually within the first month after implantation. The advent of drug-eluting stents (DES) has raised concerns regarding later occurrence of ST, beyond the traditional 1-month timeframe, especially in complex lesion subsets that were excluded from randomized trials that compared BMS to DES. There is widespread controversy regarding the actual incremental risk associated with DES. Recent studies suggest a 0.5% increased long-term thrombosis risk with DES; however, the clinical significance of these events remains under debate. The degree of protection achieved by dual antiplatelet therapy and optimal duration of treatment are under investigation. Novel stent designs might potentially decrease the incidence of this event. In this review, we will describe the current knowledge of the pathophysiology of late DES thrombosis, although many aspects remain incompletely understood.