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.     

药物涂层支架在复杂冠脉病变中的临床应用

复杂冠脉病变是冠心病介入治疗中的难点及热点,近年来的研究及临床实践表明,药物涂层支架在其中的临床应用取得了令人鼓舞的成绩,但也暴露出了许多问题。现主要针对药物涂层支架在复杂冠脉病变中应用的一些研究结果作一综述。     

Drug-eluting stents versus bypass surgery for multivessel coronary disease

Since the advent of coronary artery bypass graft (CABG) surgery and the development of percutaneous coronary intervention (PCI), there has been debate as to which is the most optimal revascularization strategy for patients with multivessel coronary artery disease. Over the past decade, this controversy has been heightened with the introduction into the PCI armamentarium of drug-eluting stents (DES) and their profound reduction of restenosis and subsequent repeat revascularization. This article reviews the key registries and randomized clinical trials of PCI-DES and CABG in multivessel disease. Focus is placed on the recent data and evidence for long-term outcomes in patients treated with DES or CABG for complex multivessel coronary disease, including unprotected left main disease. The article also discusses risk models and the decision process for appropriate selection of revascularization techniques in patients with multivessel coronary disease.     

Comparison between coronary angioplasty and coronary artery bypass surgery for the treatment of unprotected left main coronary artery stenosis (the Bologna Registry)

Although great interest exists in the relative efficacy of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) for the treatment of unprotected left main coronary artery stenosis, data comparing the 2 strategies are scant. Furthermore, no comparison has ever been performed between CABG and drug-eluting stents in this setting. From January 2002 to June 2005, 154 patients with unprotected left main coronary artery stenosis underwent CABG and 157 underwent PCI. Ninety-four patients received a drug-eluting stent in the left main artery. After a median follow-up of 430 days, the rate of mortality, acute myocardial infarction, and target lesion revascularization was 12.3%, 4.5%, and 2.6%, respectively, in the CABG group and 13.4%, 8.3%, and 25.5%, respectively, in the PCI group (death and myocardial infarction p = NS, target lesion revascularization p = 0.0001). Although patients treated with drug-eluting stents had a 25% relative risk reduction in the rate of death, myocardial infarction, and target lesion revascularization compared with patients treated with bare stents, event-free survival was still better for patients treated with CABG. In the multivariate analysis, age >or=70 years, New York Heart Association classes III and IV, acute coronary syndromes, and peripheral vascular disease were the only independent predictors of mortality. In conclusion, our results have indicated that at long-term follow-up no difference exists in the rate of mortality and myocardial infarction between PCI and CABG for the treatment of unprotected left main coronary artery stenosis. However, the rate of target lesion revascularization was higher in the PCI group.     

Trends in percutaneous versus surgical revascularization of unprotected left main coronary stenosis in the drug-eluting stent era: a report from the American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR).

OBJECTIVES: We sought to determine how practice patterns for unprotected left main stenosis have changed with the advent of drug-eluting stents (DES). BACKGROUND: Percutaneous coronary intervention (PCI) of unprotected left main coronary stenosis has been controversial. METHODS: We analyzed data submitted to the American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR) between January 1, 2002 and December 31, 2004 from 1,276,582 cardiac catheterizations at 417 institutions. Of these, 53,548 (4.2%) had left main stenosis >50% and no prior CABG. After excluding the unrevascularized, the patient sample (N = 32,562) was analyzed for PCI vs. CABG. Data was stratified by year/quarter, bare metal stent vs. DES, elective vs. urgent/emergent situations, LVEF < or > or =40%, and %left main and RCA stenosis. RESULTS: Of unprotected left main revascularizations from 2002 to 2004, PCI increased from 17.0% to 21.9%, while CABG decreased from 83.0% to 78.1% (P < 0.0001). In 2002, bare metal stents were used for all PCIs; in 2004, bare metal stent use was only 25.5%, while DES use was 74.5% (P < 0.0001). Of elective procedures, PCI rose from 19.1% to 27.5% while CABG fell from 80.9% to 72.5% (P < 0.0001). Similar trends, all significant, were seen in every clinical situation. CONCLUSIONS: In the era of DES, the rate of PCI for unprotected left main stenosis has risen, while CABG has declined. These findings are seen across varying clinical situations, including elective procedures. DES have rapidly and largely replaced bare metal stents for PCI of unprotected left mains. However, PCI is still chosen less frequently than CABG for unprotected left main revascularization.     

药物洗脱支架治疗左主干病变的疗效评价

冠脉搭桥术曾经被认为是左主干病变治疗的“金标准”,近年来经皮冠脉介入治疗也在该领域取得一些进展,一系列临床试验证实药物洗脱支架治疗左主干病变安全可行,但在左主干远端分叉病变还存在再狭窄率高的问题。就目前而言,对于有选择的左主干病变,药物洗脱支架是一种充满生机的治疗方法。     

Percutaneous coronary intervention with drug-eluting stent implantation vs. minimally invasive direct coronary artery bypass (MIDCAB) in patients with left anterior descending coronary artery stenosis.

The aim of this study was to assess the effects of percutaneous coronary intervention with drug-eluting stents (DESs) versus minimally invasive direct coronary artery bypass (MIDCAB) surgery in the management of patients with proximal left anterior descending (LAD) coronary artery stenosis. Until recent years, despite the advantages of percutaneous transluminal coronary angioplasty (PTCA) with bare metal stent implantation, such as shorter hospital stays and recovery time, MIDCAB showed better results with regard to the need for repeated intervention in the target vessel than PTCA with proximal LAD lesions. Symptomatic patients (n = 189) were randomly assigned to DES group (n = 119) and MIDCAB group (n = 70). Patients with an isolated high-grade lesion (stenosis of > or = 70% of the luminal diameter) in the proximal LAD coronary artery (from the ostium to the first diagonal branch) were included in this study. During the 6-month follow-up period, 1.7% (n = 2) in the DES group needed repeated revascularization procedures for target lesion revascularization compared with 5.9% (n = 4) in the MIDCAB group (P = 0.196). The rates of death and myocardial infarction were similar in both groups [DES 0.0% (n = 0) vs. MIDCAB 2.9% (n = 2), P = 0.135; DES 1.7% (n = 2) vs. MIDCAB 2.9% (n = 2), P = 0.627; respectively] during 6 months of follow-up. In-hospital length of stay was significantly shorter in the DES group compared with the MIDCAB group (5.8 +/- 2.1 days vs. 8.9 +/- 2.6 days; P = 0.001). DES implantation and MIDCAB surgery showed similar rates of myocardial infarction, the need for repeated revascularization, and death during 6 months of follow-up. However, DES implantation resulted in lower average number of hospital stays and similar postoperative complications.     

Revascularization of left main coronary artery disease

Coronary artery disease with left main stenosis is associated with the highest mortality of any coronary lesion. Studies in the 1970s and 1980s comparing coronary artery bypass grafting (CABG) and medical therapy showed a significant survival benefit with revascularization. In the angioplasty era, initial experience with percutaneous intervention was associated with poor clinical outcomes. As a result, percutaneous coronary intervention (PCI) was restricted to patients who were considered inoperable, or those with prior CABG with a functional graft to the left anterior descending or circumflex artery ("protected left main disease"). With the introduction of drug-eluting stents, there are new studies demonstrating comparable survival in patients who were revascularized using PCI and CABG, although percutaneous revascularization is associated with a higher rate of repeat revascularization. In the SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) trial, the combined incidence of death, myocardial infarction, and stroke was similar between the CABG and PCI groups; however, the stroke rate was higher in the CABG group. The degree and extent of disease as defined by the SYNTAX scoring system has allowed for stratification of risk and improved assignment of patients with left main stenosis to either PCI or CABG.     

Safety and Effectiveness of Firebird Sirolimus-Eluting Stent in Patients With Multi-Vessel Coronary Artery Disease

Objective:This study sought to evaluate the long-term safety and efficacy of the Firebird sirolimus-eluting stent in patients with multi-vessel coronary artery disease.The main limitation of percutaneous coronary intervention(PCI)with bare metal stents(BMS)was the increased incidence of instent restenosis.Recently,DES are frequently implanted in patients with off-label indications such as multi-vessel coronary artery disease.However,the long-term safety and effectiveness of DES among patients with multi-vessel coronary artery disease are not well understood.Methods:From January to December 2006,a total of 392 patients with multi-vessel coronary artery disease,exclusively treated with Firedird stents at 12 centers from China,were enrolled in this prospective,multicenter registry.They were followed up clinically at 6,12,18 and 24 months after the procedure.Results:A core laboratory analyzed quantitative coronary angiography data immediately after stenting and at 6-month follow-up.Acute angiographic success was 100%.Angiographic restenosis rate was 2.80% at the sixth month.The percentage of acute major adverse cardiac events(MACE)was 4.86%,4.37% and 6.91%,and the percentage of secondary cardiac events was 5.62%,5.88% and 6.39% at 12,18 and 24 months,respectively.The incidence of death,myocardial infarction,or stent thrombosis during 24 month was 3.84%(15 of 392),1.02%(4 of 392)or 2.05%(8 of 392).Conclusion:This study indicates that Firebird sirolimus-eluting stent is safe and effective for patients with multi-vessel coronary artery disease.     

Long-term effect of stenting in unprotected left main coronary artery disease in the elderly

Objective To evaluate the feasibility, safety and efficacy of percutaneous stent implantation for treating left main coronary artery (LMCA) stenosis. Methods Consecutive patients with unprotected left main coronary artery disease treated by stent-based percutaneous intervention (PCI) at 6 medical centers in China were enrolled. Procedural data and clinical outcomes were obtained from all patients. Results From January 2001 to December 2004, 138 patients (79 males and 59 females; mean age: 69.7±5.8 years) underwent PCI for LMCA stenosis. Bare metal stents (BMS) were implanted in 51 patients with non-bifurcational lesions and in 5 patients with bifurcational lesions from January of 2001 to June of 2003 (BMS group);. drug eluting stents (DES) were used unselectively to cover both bifurcational and non-bifurcational lesions in 86 patients from July of 2003 to December of 2004 (DES group). Procedural success rate of the 138 cases was 98% (135/138). One patient (0.7%) with bifurcation lesion who was treated with DES died from severe heart failure 2 weeks after the procedure. During a mean follow up period of 21.3±5.6 months, one patient died from renal failure, one from sudden cardiac death, 4 underwent target lesion revascularization (TLR) in the BMS group, which all occurred in patients with bifurcational lesions; whereas in the DES group no deaths occurred and only one patient with bifurcational lesion had TLR. Conclusions (1) PCI is feasible and relatively safe to treat unprotected left main coronary artery disease in elderly patients at medical centers with experienced professionals. (2) BMS and DES have similar immediate and long-term efficacy in the treatment of ostium and shaft lesions of the LMCA. (3) DES are strongly suggested in the therapy of distal bifurcation lesion of unprotected LMCA.     

Percutaneous stent implantation into coronary arteries in infants

Objectives: To investigate the feasibility, procedural techniques, safety, and overall potential of percutaneous coronary angioplasty and stent implantation in infants with coronary artery disease and acute coronary syndrome. Background: Despite extensive experience in adult patients, percutaneous coronary intervention remains uncommon in children and extremely rare in infants. Methods: Retrospective review including all children who underwent percutaneous coronary angioplasty in Rady Children's Hospital—San Diego during a period of 4 years. Results: Seven children including four children less than 15 months of age underwent percutaneous coronary intervention with coronary stent implantation in the proximal portion of the left or right coronary arteries. Successful stent placement with excellent revascularization was achieved in all cases. Mean coronary artery diameter was 0.65 mm prior to stent placement. Balloon angioplasty resulted in suboptimal resolution of coronary stenosis, thus bare metal stents were implanted in all cases, dilated to a mean of 2.5‐mm internal diameter. Average intervention‐free period was 434 days after stent implantation. In‐stent re‐stenosis and stent thrombosis did not occur if the implanted stent diameter was greater than 2.5 mm and the patient received dual anti‐platelet therapy. Conclusions: Our experience suggests that coronary artery stent implantation is a feasible and relatively safe palliative option in infants and toddlers with coronary stenosis. It is a viable strategy for bridging patients with acute ischemia or poor ventricular function to elective surgical revascularization or transplantation. © 2011 Wiley Periodicals, Inc.     

Coronary artery bypass grafting following in-stent restenosis of drug-eluting stents deployed in the left main coronary artery.

Two cases of drug-eluting stent restenosis after percutaneous coronary intervention in the left main coronary artery and its bifurcation are presented. An off-pump coronary artery bypass grafting following in-stent restenosis was performed. Drug-eluting stents have shown a reduced frequency of in-stent restenosis and a good safety profile compared with bare metal stents. However, intervention with drug-eluting stents for left main coronary artery disease should be undertaken with care. It is also important to note that preoperative anti-platelet drug administration can increase the risk of major bleeding during and after emergent surgery.     

Percutaneous coronary intervention for unprotected left main disease in very high risk patients: safety of drug-eluting stents

Percutaneous treatment of unprotected left main coronary artery (ULMCA) stenosis using drug-eluting stents (DES) has been suggested as the best approach for patients who are poor surgical candidates. Some concerns have recently been raised regarding the risk of stent thrombosis following DES implantation. This study was performed in order to evaluate the safety of DES, as compared to bare metal stents (BMS), for ULMCA stenosis treatment in very high risk patients with a high likelihood of stent thrombosis. Forty-two consecutive patients were treated with either BMS (20) or DES (22) for ULMCA critical stenosis. Inclusion criteria were: ST elevation myocardial infarction, non-ST elevation myocardial infarction, cardiogenic shock, or logistic European System for Cardiac Operative Risk Evaluation ≥ 13%. At 1 year, one case of late thrombosis and three cases of restenosis were reported in the BMS group and none in the DES group, leading to a significantly inferior rate of target lesion revascularization (20.0 vs. 0%, p = 0.048) and major adverse cardiac events (65.0 vs. 19%, p = 0.004). DES placement for ULMCA stenosis also appears to be a safe therapeutic choice in very high-risk patients, as it provides the benefit of a reduction in restenosis without increasing the risk of early or late stent thrombosis.     

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.     

Treatment of unprotected left main disease with drug-eluting stents in patients at high risk for coronary artery bypass grafting.

BACKGROUND: Percutaneous coronary intervention (PCI) for high-grade stenosis of the left main coronary artery with bare-metal stents has been limited by restenosis, and most patients are managed with coronary artery bypass grafting (CABG). Recently, drug-eluting stents (DES) have reduced instent restenosis after PCI, but their role in the treatment of left main disease remains unclear. AIMS: The aim of this study was to determine the outcomes after utilizing DES to treat left main disease. METHODS: Twenty consecutive symptomatic patients with >50% angiographic stenosis of the left main coronary artery with no prior history of CABG ["unprotected left main" (ULM)] underwent PCI with DES. Patients were divided into two groups based on the presence (Group A, n=5) or absence (Group B, n=15) of preprocedural cardiogenic shock. At follow up (median, 14 months), cumulative major adverse cardiac events (MACE-death, myocardial infarction, or target vessel revascularization) were determined. RESULTS: Sixteen (80%) of 20 patients were at high risk for CABG because of comorbidity, advanced age, or cardiogenic shock. Procedural success was 100% (20/20). Three of five patients in Group A (60%) died in hospital and the two surviving patients experienced no MACE at follow up. In Group B (n=15), there was no in-hospital MACE, but one patient died suddenly 8 weeks postprocedure [cumulative MACE of 7% (1/15)]. CONCLUSIONS: Our study demonstrates the feasibility of ULM treatment with DES with acceptable medium-term outcomes. While CABG remains the best form of revascularization for the majority of patients with ULM, DES should be considered in those who are at high risk.     

Benefits of drug eluting stents versus bare metal stents in ST-elevation myocardial infarction: a contemporary review

The efficacy of drug-eluting stents (DES) in reducing the rates of in-stent restenosis after percutaneous coronary intervention (PCI) compared to bare metal stents (BMS) in stable coronary artery disease has been well demonstrated. Thus, the Food and Drug Administration has approved the utilization of DES for stable coronary disease. However, there is still much debate surrounding the implantation of DES for patients with ST-segment elevation myocardial infarction (STEMI) given safety concerns about the possibility of increased rates of stent thrombosis with DES. The review of the current body of evidence comparing DES with BMS is consistent with results from previous trials in stable coronary disease and reveals lower rates of revascularization with DES in STEMI patients. The ultimate decision regarding the appropriate stent during PCI needs to be individualized as patients' compliance with dual antiplatelet therapy is critical. The data suggest that PCI with DES in STEMI patients who adhere to long-term dual antiplatelet therapy is safe and effective. Randomized trials with longer-term follow-up are necessary to better elucidate the safety and efficacy of DES versus BMS in patients with STEMI.     

How to treat diabetic patients with multivesseal disease in the DES era

Patients with type 2 diabetes mellitus represent the 25% of those requiring myocardial revascularization. Choice of treatment in diabetic patients is much more controversial than in non-diabetics: this because coronary artery disease is more often complex and diffuse, left ventricular function is depressed, and concomitant multiple risk factors are present. These subset of patients experience worse outcomes than non diabetic patients undergoing either coronary artery bypass grafting (CABG) or percutaneous coronary interventions (PCI). Large randomized trials performed both in the early era of PCI and in the stent era suggest that CABG is superior to bare metal stent implantation in the treatment of diabetic patients with multivessel coronary artery disease. These findings are reflected in current guidelines, which favor CABG over PCI in most diabetics who require revascularization. However, substantial variability exists in practice patterns among individual hospital, suggesting a lack of clinical consensus. The major advantage of CABG over bare metal stent implantation in diabetic patients is the lower risk of repeat revascularization procedures through the follow-up. Better angiographic results have been demonstrated in the new era of drug-eluting stents (DES). Data from both the sirolimus and paclitaxel-eluting stents trials support the potential advantage of DES implantation both in diabetic and non-diabetic patients. Preliminary data from studies comparing DES versus CABG in diabetic patients with multivessel coronary artery disease suggests that 1) no significant difference exists in the 12-month rate of death, myocardial infarction and cerebrovascular events in patients treated with DES as compared to off-pump bypass surgery, 2) a difference of 7.1% in the rate of repeat revascularization at 12-month exists in favor of bypass surgery and 3) diabetic retinopathy identifies a subgroup with poor outcome after both percutaneous and surgical myocardial revascularization.     

Drug-eluting stents for interventional revascularization of coronary multivessel disease

The treatment of coronary artery disease has changed over the past 35 years since the introduction of coronary artery bypass surgery in 1968. Percutaneous coronary intervention, introduced in 1977 with balloon angioplasty, was accelerated by the establishment of elective stent placement in 1994, together with the development of suitable antiplatelet regimes. In 2002, DES were made commercially available, following the results of clinical trials in single lesions. A meta-analysis of four randomized clinical trials comparing bare stents to bypass surgery for multivessel disease conducted in the 1990s demonstrate no mortality difference at 1 year. Similar 5-year outcomes have been reported by the ARTS trial. These trials, however, showed that repeat revascularization was much higher in the stent arm, due to restenosis. Various single center (RESEARCH, T-SEARCH) and multicenter (ARTS II) registries have consistently showed a low need for repeat intervention in patients with multivessel disease with the use of DES. Three major trials comparing DES against bypass surgery are ongoing or about to start and will determine the optimum revascularization therapy in multivessel disease. The recently commenced SYNTAX randomized trial will enroll only three-vessel or left main disease, while the upcoming FREEDOM and ongoing CARDia trial will specifically enroll diabetic patients only with multivessel disease. Results for these trials are expected in 2006-2007 at the earliest.     

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.     

Unprotected left main coronary artery stenting: immediate and medium-term outcomes of 24 procedures

OBJECTIVES: We have examined the immediate and long-term patient outcomes following angioplasty of unprotected left main coronary artery stenoses. BACKGROUND: Coronary disease of the unprotected left main artery is considered as an absolute contraindication for percutaneous intervention. Recently, several studies have reported good results with unprotected left main coronary artery stenting when surgical revascularization was contraindicated. METHODS: From October 2004 to June 2006, 24 patients with a contraindication to surgery and with unprotected left main coronary artery stenoses received stents. Patients were surveyed at one, six and 12 months with telephone interviews. RESULTS: The procedure's success rate was 100%. The percentage of stenosis and minimum lumen diameter (MLD) were respectively 63.4% (+/-15.4) and 1.1mm (+/-0.5) before procedure; 13.8% (+/-10.2) and 3.2mm (+/-0.5) after angioplasty. The size of stents averaged 3.79mm (+/-0.46) with an average 1.04 stents per patient. During follow up, two deaths occurred (8.3%). No intrastent restenosis was found. CONCLUSIONS: Stenting of unprotected left main coronary artery stenoses may be a safe and effective alternative to coronary artery bypass especially when surgical revascularization is contraindicated. However, further studies with larger patient populations are needed to assess the late outcome and to clarify the relevance of percutaneous intervention compared to surgery.