Stenting of unprotected left main coronary artery stenosis

Unprotected left main stenosis greater than 50% has traditionally been managed with coronary artery bypass surgery. There is now emerging evidence to support a percutaneous strategy adopting drug-eluting stents, especially in patients at high risk for surgery. This paper will review recent outcomes of both bare-metal and drug-eluting stent use for unprotected left main stenosis and summarise results of an Australian registry. Results of studies comparing the percutaneous approach to surgery will also be reviewed together with ESC and AHA/ACC current guidelines. Although percutaneous intervention of unprotected left main has been shown to be a safe and feasible procedure, unanswered questions remain. Large multi-centre randomised trials underway comparing percutaneous to surgical intervention will help clarify these ongoing issues.     

Percutaneous coronary intervention for unprotected left main coronary artery stenosis

Hemodynamically significant left main coronary artery stenosis (LMCA) is found in around 4% of diagnostic coronary angiograms and is known as unprotected LMCA stenosis if the left coronary artery and left circumflex artery has no previous patent grafts. Previous randomized studies have demonstrated a significant reduction in mortality when revascularization by coronary artery bypass graft (CABG) surgery was undertaken compared with medical treatment. Therefore, current practice guidelines do not recommend percutaneous coronary intervention (PCI) for such a lesion because of the proven benefit of surgery and high rates of restenosis with the use of bare metal stents. However, with the advent of drug-eluting stents (DES), the long term outcomes of PCI with DES to treat unprotected LMCA stenoses have been acceptable. Therefore, apart from the current guidelines, PCI for treatment of unprotected LMCA stenosis is often undertaken in individuals who are at a very high risk of CABG or refuse to undergo a sternotomy. Future randomized studies comparing CABG vs PCI using DES for treatment of unprotected LMCA stenosis would be a great advance in clinical knowledge for the adoption of appropriate treatment.     

Treatment of unprotected left main coronary artery stenosis in the drug-eluting stent era

Coronary angiography is often inadequate for estimating the severity of ambiguous left main coronary artery (LMCA) stenoses. Our assessment of these lesions can be improved by the techniques of intravascular ultrasound and fractional flow reserve which provide indices of stenosis severity to enable the prediction of future events and planning of treatment. For patients requiring LMCA revascularization, coronary artery bypass graft (CABG) surgery has been gold standard for decades. However, this technique continues to be limited by factors such as periprocedural mortality, prolonged hospital stay and rehabilitation, and long-term graft patency. LMCA stenosis remains one of the few serious challenges for the interventional cardiologists and, in the bare metal stent era, the long-term results were not sufficient to replace CABG surgery, mainly because of the high restenosis rate. Drug-eluting stents (DES) have dramatically reduced the restenosis rate and early results in small series (approximately 300 patients in total) treated with DES in LMCA have been encouraging, especially for lesions at the ostium and in the left main shaft. Before changes are made in the guidelines for treatment, we must wait for a refinement in the technique and stent design used for bifurcational left main lesion and the results of randomized, specific multicenter studies (SYNTAX trial). It is likely that, for selected patients, LMCA stenosis will be regarded as an indication for PCI.     

Sirolimus- versus paclitaxel-eluting stent implantation for unprotected left main coronary artery stenosis

We performed this study in order to compare the immediate and mid-term outcomes of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in lesions of the unprotected left main coronary artery (LMCA). We assessed 54 patients from 5 centers who had undergone unprotected LMCA stenting (35 SES and 19 PES). The procedural success rates were 100 and 95%, respectively, in the SES and PES patients (p = 0.19). At the 6-month clinical follow-up, the event-free probability was 100% in the SES group, and 88% in the PES group (p = 0.07). At the 6-month angiographic follow-up (n = 24), the SES group exhibited a slightly lower late loss than did the PES group (0.24 +/- 0.44 vs. 0.65 +/- 0.60 mm, p = 0.09), and the restenosis rates were 8 and 9% (p = 0.94) in the SES and PES patients, respectively. In conclusion, both groups exhibited excellent in-hospital and 6-month outcomes with no significant differences between them.     

Revascularization for unprotected left main stem coronary artery stenosis stenting or surgery

For coronary artery disease with unprotected left main stem (LMS) stenosis, coronary artery bypass grafting (CABG) is traditionally regarded as the "standard of care" because of its well-documented and durable survival advantage. There is now an increasing trend to use drug-eluting stents for LMS stenosis rather than CABG despite very little high-quality data to inform clinical practice. We herein: 1) evaluate the current evidence in support of the use of percutaneous revascularization for unprotected LMS; 2) assess the underlying justification for randomized controlled trials of stenting versus surgery for unprotected LMS; and 3) examine the optimum approach to informed consent. We conclude that CABG should indeed remain the preferred revascularization treatment in good surgical candidates with unprotected LMS stenosis.     

Angiographic recognition of ostial left main coronary artery stenosis: case report

Ostial left main coronary stenosis has a poor prognosis and increased mortality rate with coronary arteriography. Due to its anatomic location, visualization of the stenosis may be difficult. A high index of suspicion based upon only a few signs should prompt the physician to perform certain maneuvers to obtain the correct diagnosis. Four illustrative cases are presented and discussed.     

Effectiveness of drug-eluting stent implantation for patients with unprotected left main coronary artery stenosis

This study was aimed to evaluate outcomes of patients with unprotected left main coronary artery (LMCA) stenosis who were treated with drug-eluting stents. Sixty-three consecutive patients with unprotected LMCA stenosis were treated with sirolimus-eluting stents in 52 (83%) patients and paclitaxel-eluting stents in 11 (17%) patients, in whom percutaneous intervention was considered the sole alternative because of high surgical risk and/or patient preference. Urgent percutaneous coronary intervention within 24 hours after angiography was performed in 6 (10%) patients. The patients were predominantly at high surgical risk with 35 (56%) having EuroSCORE >6 and 39 (62%) having Parsonnet score >15. Involvement of the distal LMCA was observed in 46 (73%) patients. Procedural success was achieved in all patients. Intravascular ultrasound was used in 51 (81%) patients. Single-stenting strategy was adopted in 36 (78%) patients with bifurcation stenosis. There were no death, Q-wave myocardial infarction, stent thrombosis, or urgent repeat revascularization events during hospitalization. Over a mean follow-up of 11.7 +/- 7.7 months, 18 (29%) patients experienced major adverse cardiac events, including 3 (5%) deaths, 7 (11%) myocardial infarctions, and 10 (16%) target lesion revascularizations. Stent thrombosis developed in 1 (0.6%) patient at 35 days after the procedure. Bifurcation involvement was an independent predictor of major adverse cardiac events by multivariate analysis (hazard ratio 12.90, 95% confidence interval 1.36 to 122.45, p = 0.0259). In conclusion, drug-eluting stent placement for unprotected LMCA stenosis may be a feasible therapeutic alternative in patients at high surgical risk. However, bifurcation stenosis remains a significant predictor of unfavorable clinical outcome.     

Angioplasty of unprotected two coronary artery ostia using cardiopulmonary bypass as a single emergency procedure - case report

Mortality in patients with a significant left main and right coronary artery ostia stenosis is high, reaching 50% during a five-year follow-up period. To date, this type of lesion has been rarely treated with percutaneous coronary interventions (PCI). We present a case of a 50-year-old man who had had coronary artery bypass surgery because of left main stenosis in the past and was currently admitted to the hospital because of unstable angina. Coronary angiography showed tight left main and right coronary ostia stenosis and total occlusion of the left anterior descending artery. Vein grafts were occluded. The PCI procedure combined with the cardiopulmonary bypass was performed. The lesions were dilated and stents were successfully implanted. The patient tolerated the procedure well. He was discharged five days after PCI and the course of a 12-month follow-up was uneventful.     

Outcome in high risk patients with unprotected left main coronary artery stenosis treated with percutaneous coronary intervention

Objective : We examined mortality, risk of myocardial infarction (MI), and target lesion revascularization (TLR) in high‐risk patients with unprotected left main (LM) percutaneous coronary intervention (PCI) in Western Denmark. Background : PCI of left main coronary artery lesions may be an alternative to coronary artery bypass grafting in high‐risk surgical patients. Methods : From January 2005 to May 2007, all patients who had unprotected LM PCI with stent implantation were identified in the Western Denmark Heart Registry. The indications for PCI were: (1) ST segment elevation MI (STEMI), (2) non‐STEMI (NSTEMI) or unstable angina, and (3) stable angina. All patients were followed up for 18 months. Results : A total of 344 patients were treated with LM PCI (STEMI: 71, NSTEMI/unstable angina: 157, and stable angina: 116). In STEMI patients, the median logistic EuroSCORE was 22.5 (interquartile range 12.5–39.5), in non‐STEMI (NSTEMI)/unstable angina patients 13.8 (4.8–23.9), and in stable angina patients 4.8 (2.2–10.4). Mortality after 18 months 38.0, 18.5, and 11.2% (P < 0.001) in patients with STEMI, NSTEMI/unstable angina, and stable angina, respectively. MI after 18 months was 9.9, 6.4, and 6.0% (P = ns), respectively. Four subacute and one late definite stent thrombosis were seen. TLR occurred in 5.6, 4.5, and 6.9% (P = ns) of patients, respectively. Conclusion : After PCI, patients with STEMI and LM culprit lesion have a high‐mortality risk, whereas long‐term outcome for patients with NSTEMI and stable angina pectoris is comparable with other high surgical risk patients with unprotected left main lesion. Further, TLR rates and risk of stent thrombosis were low. © 2009 Wiley‐Liss, Inc.     

Percutaneous intervention of unprotected left main coronary artery

Successful percutaneous intervention of unprotected left main coronary artery (LMCA) in lieu of surgical revascularization represents the next wave of challenges that the field of interventional cardiology will try to overcome. Significant LMCA stenosis, commonly secondary to atherosclerosis, is seen in about 4-10% of cases presenting to the cardiac catheterization laboratory. Currently, the vast majority of these patients undergo surgical revascularization unless there are prohibitive reasons for surgical revascularization. Several challenges of percutaneous revascularization have been overcome with stents, intravascular brachytherapy, and other technical improvements. Yet, several remaining limitations of percutaneous intervention, such as in-stent restenosis, have to be improved further before randomized clinical trials of surgical and percutaneous revascularization of unprotected LMCA disease can be contemplated to establish a new standard of care.     

Percutaneous coronary intervention of unprotected left main coronary artery disease

Data have emerged demonstrating the safety and efficacy of percutaneous coronary intervention (PCI) of the unprotected left main (ULM) artery. The 2009 American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions focused guidelines for PCI no longer state that ULM PCI is contraindicated in patients with anatomic conditions that are associated with a low risk of procedural complications and clinical conditions that predict an increased risk of adverse surgical outcomes. ULM PCI should be performed by operators with experience in the management of the anatomic complexities of left main and multivessel disease, specifically in issues relating to bifurcation disease, calcification, and hemodynamic support. Patients with ostial or shaft disease have lower risk of restenosis compared with distal bifurcation disease. Drug‐eluting stents (DES) should be used whenever possible as they reduce clinical restenosis. Intravascular ultrasound is an integral component of the procedure as it provides accurate assessment of lesion severity and can confirm optimal stent expansion and apposition. Compliance with dual antiplatelet therapy for at least 12 months is essential if DES are used. A collaborative, multidisciplinary approach with a “Heart Team” represented by a cardiac surgeon, interventional cardiologist, and non‐invasive cardiologist may optimize patient education and objective decision making when obtaining informed consent. Application of clinical and angiographic variables into risk models facilitates appropriate patient selection. Randomized clinical trials will address unanswered issues and help build consensus between cardiology and surgical societies to inform clinical decision making and optimize the outcomes for patients with ULM coronary artery disease. © 2011 Wiley Periodicals, Inc.     

Iatrogenic left main coronary artery stenosis

Iatrogenic left main coronary artery stenosis is a potentially life-threatening complication of cardiac valve replacement surgery due to injury by perfusion cannulas. This requires prompt clinical recognition and diagnosis by repeat coronary angiography, and treatment by early coronary artery bypass grafting. We present 3 patients who had normal coronary arteries prior to valve replacement surgery, and who developed severe left main coronary artery stenosis after surgery. Accelerating angina and refractory ventricular arrhythmia were presenting clinical manifestations. Coronary artery bypass grafting was successfully performed in all 3 patients.     

无保护左主干病变冠状动脉搭桥术与雷帕霉素洗脱支架治疗的对比研究

目的:回顾性分析无保护左主干病变患者使用雷帕霉素洗脱支架(DES)的经皮冠状动脉介入治疗(PCI)与冠状动脉旁路移植手术(CABG)治疗的中、远期疗效,并探讨应用SYNTAX SCORE来评估病变风险与临床事件的相关性。方法:本研究回顾性收集了176例无保护左主干病变患者,其中CABG组80例,PCI-DES组96例。收集患者的基本情况、左主干病变特点及SYNTAX评分、CABG和PCI手术情况,随访患者术后3年的主要不良心脑血管事件(MACCE)的发生率。结果:术后3年随访,PCI-DES组与CABG组的MACCE发生率及无MACCE生存率比较差异无统计学意义,但PCI组靶血管再次血运重建率(TVR)明显高于CABG组(P<0.05)。用SYNTAX SCORE把PCI-DES和CABG两组患者分为高积分组(≥30.0)和低积分组(<30.0):高积分组,术后3年PCI-DES亚组MACCE事件发生率高于CABG亚组(23.53%∶18.05%,P<0.05),无MACCE事件生存率低于CABG亚组(51.47%∶70.83%,P<0.05)。低积分组,术后3年MACCE事件发生率CABG亚组高于PCI-DES亚组(12.50%∶7.14%,P>0.05),而无MACCE事件生存率低于PCI-DES亚组(75.00%∶82.14%,P<0.05)。结论:PCI-DES与CABG治疗无保护左主干病变患者总体疗效相似。用SYNTAX SCORE指导无保护左主干病变血管重建方式的选择有重要价值,但在不同的患者人群中,仍应结合临床特征和冠状动脉病变特点选择恰当的血运重建术。     

选择性左冠状动脉主干病变的介入治疗

目的冠状动脉旁路移植术(CABG)是多支血管病变血运重建的最佳方法,是无保护性左冠状动脉主干(LMCA)病变的标准治疗.本研究探讨无保护性LMCA病变介入治疗的疗效和可行性.方法总结分析1996年10月～2000年8月间20例住院的冠心病左主干病变患者接受直接支架术治疗.入选患者例行左室造影(LVEF>45%),冠状动脉血管成形术及其疗效评判采用常规标准,合并右冠脉严重弥漫狭窄病变或前降支(LAD)与回旋支(LCX)同时严重狭窄者不行该术.结果 20例中男17例、女3例,年龄42～71(平均64±12)岁,临床呈心绞痛Ⅱ-Ⅲ级,其中合并高血压9例、糖尿病(2型)1例.冠脉造影显示,左冠脉主干病变呈单纯狭窄者8例,其中近中段狭窄(50%～80%)者6例、开口狭窄(50%～60%)者2例,左主干夹层分离者2例,动脉瘤者1例,合并LAD或LCX病变(狭均>70%)者9例(狭窄50%～70%).全部患者左主干病变均进行直接支架术,其中6例伴LAD或LCX病变者先行PTCA或支架术后再进行左主干病变的支架置入术.置入左主干内的支架均为管状宽径短支架,16例为4.0 mm×9 mm(直径×长度)支架,3例为3.5 mm×9 mm支架,1例冠状动脉瘤者应用4.5 mm×9mm支架.左主干支架术成功率为100%,无残余狭窄或残余狭窄<10%,无任何并发症如支架血栓形成、急性心肌梗死、紧急CABG及死亡等.9例合并LAD(6例)或LCX(3例)狭窄者,先行LAD或LCX的PTCA术,其中3例PTCA术后残余狭窄<20%,5例残余狭窄30%～40%者中2例置入3.0×16mm支架、1例3.5×20mm支架、1例3.0×14 mm支架,1例LCX开口后狭窄(75%)者因PTCA后发生夹层放置3.5×12 mm支架,造影示夹层消失,无残余狭窄.冠状动脉瘤行带膜支架术者造影示瘤体消失,左主干管壁平整.随访1～4年,14例心绞痛发作消失、6例心绞痛复发但显著减轻(心绞痛Ⅰ级),后者有4例于术后半年～1年内复查冠脉造影提示早期再狭窄,其中2例单纯LMCA再狭窄者再次行冠脉血管成形术、2例LMCA合并LAD再狭窄者行CABG手术,无急性心肌梗塞或死亡等严重心脏事件发生,患者均能维持正常生活.结论本研究结果表明,选择性无保护性左冠状动脉主干病变支架术在临床上切实可行、疗效显著,可以是继CABG的另一治疗选择.