Percutaneous treatment of coronary bifurcation lesions in the era of drug-eluting stents

The current report provides an overview of the evolving techniques for percutaneous treatment of bifurcation lesions, including the approaches most commonly used in the current era of DES, and reviews the angiographic and clinical outcomes from clinical series published to date.     

Update in management of coronary bifurcation lesions in the drug-eluting stent era

Despite advances in percutaneous coronary interventions, treatment of coronary lesions remains a challenge for the interventional cardiologists. It has been relatively more successful to manage the bifurcation lesions, which entail higher procedural success rates, lower costs, shorter hospitalization and lower clinical and angiographic restenosis rates in comparison with non-bifurcation lesions. After introduction of drug-eluting stents, there has been substantial reduction in event rate and main vessel restenosis, although the side branch ostial residual stenosis and long-term restenosis continue to pose a problem. This article reviews the various techniques being currently employed with varying degrees of success.     

Rates of stent thrombosis in bare-metal versus drug-eluting stents (from a large Australian multicenter registry)

Recent reports suggest that drug-eluting stents (DESs) may increase the risk of stent thrombosis (ST) relative to bare-metal stents (BMSs). Therefore, the aim of this study was to compare DES and BMS outcomes with a specific focus on ST. We analyzed 30-day and 1-year outcomes of 2,919 patients who underwent percutaneous coronary intervention with stent implantation from the Melbourne Interventional Group registry. Academic Research Consortium definitions of ST were used: (1) definite ST (confirmed using angiography in patients with an acute coronary syndrome), (2) probable ST (unexplained death <30 days or target-vessel myocardial infarction without angiographic confirmation), and (3) possible ST (unexplained death >30 days). Multivariate analysis was performed to identify predictors of ST. The incidence of ST (early or late) was similar between BMSs and DESs (1.6% vs 1.4%; p=0.66), and DES use was not predictive of ST. Independent predictors of ST included the absence of clopidogrel therapy at 30 days (odds ratio [OR] 2.58, 95% confidence interval [CI] 1.29 to 5.29, p<0.01), renal failure (OR 3.30, 95% CI 1.43 to 7.59, p<0.01), index procedure presentation with an acute coronary syndrome (OR 2.59, 95% CI 1.14 to 5.87, p=0.02), diabetes mellitus (OR 2.25, 95% CI 1.19 to 4.23, p=0.01), and total stent length >or=20 mm (OR 1.85, 95% CI 1.00 to 3.42, p=0.04). In conclusion, DESs were not associated with increased risk of ST compared with BMSs at 12 months in this large Australian registry that selectively used DESs for patients at high risk of restenosis.     

A prospective registry to evaluate sirolimus-eluting stents implanted at coronary bifurcation lesions using the "crush technique"

The "crush technique" has been proposed as an alternative approach to treat bifurcation lesions because of its predictability and high procedural success rate. However, few data are available regarding its safety and long-term efficacy. We report the long-term clinical outcomes of patients with coronary bifurcation lesions treated with sirolimus-eluting stents using the crush technique. From April 2003 to May 2004, 120 patients with coronary bifurcation lesions were treated with sirolimus-eluting stents using the crush technique. Six months of clinical follow-up was completed in 95.8% of patients. Mean patient age was 64 years; 36% had diabetes mellitus, and the left anterior descending artery/diagonal was the most frequent bifurcation location (69%). Final kissing balloon inflation was performed in 87.5% of patients. Compared with the main vessel, side branch lesions were shorter, with a smaller reference diameter and final in-stent minimum lumen diameter. Procedural success was achieved in 97.5%. At 30 days of follow-up, 1 patient had died of noncardiac causes and 2 patients (1.7%) had subacute stent thrombosis. At 6 months of follow-up, target lesion revascularization was required in 13 patients (11.3%), all of whom had focal restenosis predominantly at the side branch ostium. In conclusion, the crush technique with final kissing balloon inflation can be safely used by experienced operators to treat highly complex bifurcation lesions with sirolimus-eluting stents. The safety profile of this technique is similar to that of other bifurcation stenting techniques reported thus far. Nonetheless, despite the excellent patency rates of the main vessel, the need for revascularization at the ostium of the side branch was not fully eliminated.     

双支架与单支架治疗分叉病变疗效的比较

目的：观察比较双支架与单支架在分又病变患者中的疗效。方法：64例急性心肌梗塞患者被随机分成两组,一组给予双支架治疗（36例）;另一组仅在母血管植入支架而对分支血管进行球囊扩张术（28例）,术后行造影检查。结果：两组术后造影成功率方面（95．4％：82．1％）,6个月再狭窄率（33．3％：46．4％）,需再血管化治疗（19．4％：21．4％）均无显著差别（P〉0．05）。结论：对于冠脉分叉病变双支架与单支架治疗的疗效没有明显差别。     

应用双药物洗脱支架治疗分叉病变的近期临床疗效

目的探讨应用双药物洗脱支架（DES）治疗分叉病变的临床近期疗效。方法自2003年10月至2005年2月入选应用双DES治疗分叉病变患者71例,72处病变。分叉病变的类型为前降支／对角支45例（62．5％）,左冠状动脉主干分叉病变20例（27．8％）,回旋支／钝缘支6例,右冠状动脉远端分又病变1例。72处分叉病变中采用Crush技术42处,包括标准Crush技术16处和改良Crush26处;“T”型支架置入19处;改良“Y”型支架置入5处;“V”型支架置入3处和Culotte技术3处。结果入选71例患者中男性59例（83．1％）,女性12例,平均年龄57岁。72处分叉病变中（144处病变）使用Cypher或Cypher Select DES 59个,TAXUS DES48个,Firebird DES 25个和金属裸支架24个。72处分叉病变置入双支架后60处（83．3％）完成了对吻球囊扩张技术。手术成功率为100％。住院期间1例发生亚急性血栓致急性心肌梗死（AMI）,再次经皮冠状动脉介入治疗成功。住院期间主要心脏不良事件（MACE,包括死亡、AMI、再次血管重建）发生率为1．4％（1／71）。71例中16例完成了6个月的临床随访,无死亡和AMI发生,1例6个月时冠状动脉造影显示对角支口部完全闭塞,随访期间MACE发生率为6．3％（1／16）。结论本研究结果显示对于分支口径〉2．5mm且口部有严重狭窄性病变的分叉病变,采用双DES治疗是安全的,近期临床疗效十分满意,远期临床疗效初步显示也是满意的,但仍有待进一步证实。     

冠状动脉分叉病变单支架术及双支架术临床疗效对比

目的探讨分叉病变单支架术和双支架术的临床疗效。方法分析冠状动脉分叉病变102例的临床资料,其中52例行单支架术（单支架植入组）、50例行双支架术（双支架植入组）。单支架植入组仅主支植人支架,边支不植入支架;双支架植入组运用mini-crushing技术行双支架植入术。观察两组分叉病变的手术即刻及术后6个月临床疗效及主要心血管事件的发生情况。结果术后即刻冠状动脉造影结果显示两组主支血管心肌梗死溶栓试验（thrombolysisinmyocardialinfarction．TIMI）血流3级、分支血管TIMI血流3级、主支血管残余狭窄〉30％、分支血管残余狭窄〉50％四个指标比较,均差异无统计学意义（P〉0．05）。随访6个月后对两组进行冠状动脉造影后发现,分支血管残余狭窄〉50％在单支架植入组发生率高于双支架植入组,差异有统计学意义[25．0％（13／52）vs．12．0％（6／50）,P〈0．05];其余几项两组比较,差异无统计学意义（P〉0．05）。住院期间单支架植入组1例（1．92％）发生主要心血管事件,双支架植入组2例（4．00％）发生主要心血管事件。6个月后．单支架植入组8例（15．38％）发生主要心血管事件,双支架植入组7例（14．00％）发生主要心血管事件。结论单支架术与双支架术治疗分叉病变短期观察临床疗效基本无差异,其长期疗效还需进一步研究。     

Efficacy of drug-eluting stents for treating in-stent restenosis of drug-eluting stents (from the Korean DES ISR multicenter registry study [KISS])

There is currently no established standard treatment for in-stent restenosis (ISR) after the implantation of a drug-eluting stent (DES). The aim of this study was to investigate the efficacy of DES versus balloon angioplasty (BA) for the treatment of DES ISR in a multicenter registry cohort. After matching propensity scores of 805 patients with DES ISR treated with either DES (n = 422) or BA (n = 383), 268 matched pairs were selected and analyzed for major adverse cardiac events, a composite of death, myocardial infarction, and target-vessel revascularization, as the primary end point. Baseline clinical and lesion characteristics of the matched pairs were similar. Survival free of major adverse cardiac events at 2 years was higher with DES compared to BA (88.9% vs 78.7%, p <0.001), mainly because of higher TVR-free survival (92.4% vs 81.0%, p <0.001). Among various baseline variables, BA (hazard ratio 2.546, 95% confidence interval 1.412 to 4.593, p = 0.002) was the most important independent risk factor for recurrent target vessel revascularization, followed by acute coronary syndromes as the clinical presentation of DES ISR, and previous implantation of a sirolimus-eluting stent. Survival free of death, myocardial infarction, or stent thrombosis did not differ between the 2 groups. Whereas there was no significant difference in survival free of target vessel revascularization between DES and BA for focal ISR lesions, DES was superior to BA in diffuse ISR lesions (94.3% vs 75.2% at 2 years, p <0.001). In conclusion, compared to BA, the implantation of DES was safe and more effective in the treatment of DES ISR.     

双对吻挤压与经典挤压技术治疗冠状动脉分叉病变的前瞻性、随机、多中心研究

目的 比较双对吻挤压(DK crush)和经典挤压技术治疗冠状动脉分叉病变的临床效果.方法 311例真性分叉病变患者随机分入DK crush组(n=155)和经典挤压组(n=156),随访时间8个月.一级及二级终点分别为主要心脏不良事件(MACE,包括心肌梗死、心原性死亡和靶病变血运重建)和血管直径再狭窄及晚期丢失.结果 DK crush组糖尿病患者较多.经典挤压组及DKcrush组最终对吻扩张(FKBI)成功率分别为76%和100%(P＜0.001).DK crush术式的不足包括造影剂用量大(P=0.04)、球囊数量多(P＜0.01)、手术时间长(P＜0.001),但是对吻扩张不满意率显著减少(27.6%比6.3%,P＜0.01).临床随访率为100%,冠状动脉造影随访率为82%.经典挤压组累计再狭窄率为32.3%,而DK crush组为20.3%(P=0.01),经典挤压组分支血管再狭窄率高(24.4%比12.3%,P=0.01),而两组间主干血管再狭窄率差异无统计学意义.经典挤压组术后8个月时的累计MACE发生率为24.4%(FKBI失败组为35.9%,FKBI成功组为19.7%),显著高于DK crush组(11.4%,P=0.02).经典挤压组血栓栓塞率为3.2%(FKBI失败组为5.1%,FKBI成功组为1.7%),而DK crush组为1.3%(P＞0.05).经典挤压组术后8个月时无靶病变血运重建生存率为75.4%(FKBI失败组为71.2%,FKBI成功组为77.6%),而DK crush组为89.5%(P=0.002).结论 DK crush可能是治疗冠状动脉分叉病变的较佳术式.