Prevalence of unfavorable angiographic characteristics for percutaneous intervention in patients with unprotected left main coronary artery disease

Left Main Percutaneous Coronary Intervention

Significant unprotected left main stem (ULMS) disease is in approximately 5% to 7% of patients undergoing coronary angiography. Historically, coronary artery bypass grafting has been the gold standard treatment of these patients. With recent advances in stent technology, adjunctive pharmacotherapy, and operator experience, percutaneous coronary intervention (PCI) is increasingly regarded as a viable alternative treatment option, especially in patients with favorable coronary anatomy (low and intermediate SYNTAX (Synergy Between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery) scores). This article aims to discuss the evidence supporting PCI for ULMS disease, current guidelines, and technical aspects.

The EXCEL and NOBLE trials: similarities, contrasts and future perspectives for left main revascularisation

Unprotected left main coronary artery (ULMCA) stenosis has relatively high prevalence and exposes patients to a high risk for adverse cardiovascular events. The optimal revascularisation strategy (coronary artery bypass surgery [CABG] or percutaneous coronary intervention [PCI]) for patients with complex coronary artery disease is a topic of continuing debate. The introduction of the newer-generation drug-eluting stents (DES) -with documented improvements in both safety and efficacy- has prompted the interventional community to design two new dedicated randomised trials comparing CABG and PCI: the NOBLE (Coronary Artery Bypass Grafting Vs Drug Eluting Stent Percutaneous Coronary Angioplasty in the Treatment of Unprotected Left Main Stenosis) and EXCEL (Evaluation of XIENCE Everolimus Eluting Stent Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trials. The aims of the present review are to describe the similarities and contrasts between these two trials as well to explore their future implications in ULMCA treatment.

Unprotected Left Main Disease: Indications and Optimal Strategies for Percutaneous Intervention

OPINION STATEMENT

Although the incidence of left main (LM) coronary artery disease is relatively low in patients undergoing routine angiography, it is a common presentation in patients with acute coronary syndromes. With the current interventional tools and techniques, percutaneous intervention for LM disease has become a viable alternative to the traditional coronary artery bypass grafting. Factors that contribute to the success and appropriateness of percutaneous intervention for LM disease include coronary anatomy and patient-specific factors such as left ventricular function. Multiple considerations should be taken into account prior to intervention, including hemodynamic support if necessary, intravascular imaging to guide therapy, and stent technique. This review provides an overview of the current body of literature to support the use of percutaneous intervention in LM disease and serves as guideline for the interventionalist approaching LM revascularization.

Left main coronary artery disease: importance, diagnosis, assessment, and management

Left main coronary disease is seen in 4%-6% of patients undergoing coronary angiography for an ischemic evaluation and is a potentially fatal condition if not promptly identified and treated. Recent studies have increased our understanding of the complexity of left main coronary artery disease. This lesion subset offers numerous challenges in diagnosis and management. Fractional flow reserve and intravascular ultrasound are important adjuncts to angiography to determine the significance of ambiguous lesions of the left main coronary artery. Surgery is associated with much better outcomes than medical therapy and is considered by many to be the standard of care in patients who are surgical candidates. Recent studies comparing surgery with percutaneous coronary intervention (PCI) have defined subgroups with lesser extent of disease burden that may do just as well with PCI. Challenges remain in the management of bifurcation disease, and the interventional community anxiously awaits the results of the large-scale randomized trials comparing PCI with surgery.

Drug-eluting stents in unprotected left main coronary artery disease

Though coronary bypass graft surgery (CABG) has traditionally been the cornerstone of therapy in patients with unprotected left main coronary artery (ULMCA) disease, recent evidence supports the use of percutaneous coronary intervention in appropriate patients. Indeed in patients with ULMCA disease, drug-eluting stents (DES) have shown similar incidence of hard end points, fewer periprocedural complications and lower stroke rates compared with CABG, though at the cost of increased revascularization with time. Furthermore, the availability of newer efficacious and safer DES as well as improvements in diagnostic tools, percutaneous techniques and, importantly, a better patient selection, allowed percutaneous coronary intervention a viable alternative to CABG of left main-patients with low disease complexity; however, even in this interventional era characterized by efficacious DES, patients with ULMCA disease remain a challenging high-risk population where outcomes strongly depend on clinical characteristics, anatomical disease complexity and extension and operator's experience. This review summarizes the role of DES in ULMCA disease patients.

Safety and technical success of percutaneous left main coronary artery stenting

OBJECTIVE

Critical stenosis of left main coronary artery (LMCA) has always remained a challenge for interventional cardiologists. Conventionally Coronary Artery Bypass Grafting (CABG) is done for these patients but recently Percutaneous Coronary Intervention (PCI) is also being tried more frequently, but data of PCI is scarce in this regard. Our objective was to determine the safety and technical success rate of percutaneous left main coronary artery stenting.

METHODS

This was 12 month follow up study conducted at Pakistan Institute of Medical Sciences (PIMS), Islamabad from 11(th) Jan 2012 to 11(th) Jan 2013. All symptomatic patients who underwent coronary angiogram at PIMS and were found to have either isolated LMCA disease or coexisting osteal Left Anterior Descending (LAD) artery disease were potentially eligible for the study. Patients who had previous surgical treatment for coronary artery disease and those with renal dysfunction requiring dialysis were excluded. Patients were counselled in detail regarding the pros and cons of PCI versus CABG.Those who opted for PCI were included in the study. All these patients were treated with percutaneous left main coronary artery stenting with or without osteal LAD stenting.

RESULTS

Seventy two patients had LMCA disease during angiogram. Fifteen patients opted for CABG. Four patients did not meet the inclusion criteria, whereas 53 patients were finally enrolled. Mean age of patients were 55.45±10.275 years. Twenty nine patients were with acute coronary syndrome and 22 presented with unstable angina.PCI with stenting was technically successful in all patients. One patient died three months after PCI, there was no other mortality.

CONCLUSION

Our study showed that Percutaneous Coronary Intervention (PCI) to LMS has good technical success rate; the safety of the procedure is also acceptable.

Prevalence, location, and extent of significant coronary artery disease in patients with normal myocardial perfusion imaging

BACKGROUND

False-negative myocardial perfusion imaging (MPI) can by due to left main (LM) or three-vessel disease causing "balanced ischemia". However, so far prevalence of LM or three-vessel-disease in patients with normal MPI is unclear. We assessed prevalence, location, and extent of significant coronary artery disease (CAD) in patients with normal MPI.

METHODS

Between 2006 and 2010, 256 patients with normal MPI who had invasive angiography because of persisting or worsening of the same initial symptoms were studied. Significant CAD was defined as stenosis > 70% or LM > 50%.

RESULTS

A total of 93 patients (36%) had significant CAD. Significant CAD was observed more frequently in males, higher age and those with typical angina complaints. Significant LM disease was present in 7%, three-vessel disease in 10%, two-vessel disease in 22%, and single vessel disease (not left main) in 61%. In those with single vessel disease, the location was the LAD in 40%, the RCA in 30%, and the LCX in 30%.

CONCLUSIONS

In selected patients with normal MPI, one-third had significant CAD. The majority of these patients had single vessel disease (not left main). LM or three vessel disease, causing "balanced ischemia", is a less common cause of false-negative MPI.

Evaluation of Percutaneous Coronary Intervention and stenting of Left Main Coronary Artery Stenosis in Tehran's Rajaie and Lavasani Hospitals from 2010 to 2011

BACKGROUND

Data of the results from treatment of unprotected and protected LMCA diseases with PCI and stent implantations in our country were limited. Surgical therapy is considered as an standard care for patients with unprotected LMCA stenosis. This notion is based on some randomized and observational studies performed three decades ago which convincingly showed superiority of CABGs over medical therapy. Moreover, preliminary studies have shown that the use of DES for the treatment of unprotected LMCA diseases is associated with very favorable mid-term outcome, which is highly competitive with that of surgery, especially for ostial lesions.

OBJECTIVES

This study sought to evaluate one year safety and effectiveness of PCI and stenting in LMCA disease.

PATIENTS AND METHODS

We performed a one year clinical follow-up of any patients with LMCA disease "Protected and Unprotected" who underwent PCI and stenting (n = 40) with BMS (n = 17) or DES (n = 23) in Tehran's Rajaje and Lavasani hospitals from September 2010 to September 2011. The primary end points were all-cause mortality, and MACCE which consisted of the composite of death, MI, stroke, and target vessel revascularization, and the duration of hospitalization change the severity of angina pain and the function class of physical activity.

RESULTS

In the one year follow-up, the adjusted risk of death was 5% and the composite of death, MI, stroke and target vessel revascularization (MACCE) was 22%. In 94.7% the number of patients, the severity of angina pain were decreased, and in 92.5% of patients, the function class of physical activity has been improved. The duration of hospitalization was 4.38 ± 1.63 days which was less than that of CABGs.

CONCLUSIONS

For the treatment of protected and unprotected LMCA diseases, PCI with stent implantation is effective, and leads to decreasing the mortality and the death rate, MI, stroke, the severity of angina pain, and improving the function class of physical activity and tolerance.

Long-term clinical outcomes after unprotected left main coronary artery stenting in an all-comers patient population

BACKGROUND

The goal of treating patients with coronary artery disease is to improve survival and relieve symptoms. Several studies have compared the safety and efficacy of left main coronary artery (LMCA) stenting and coronary-artery bypass grafting in case control and randomized trials.

OBJECTIVE

In this study we present the long term outcome of stenting unprotected LMCA stenosis in day to day practice in unselected patients.

METHODS

One hundred and fifty eight patients were prospectively recruited with symptomatic unprotected LMCA stenosis undergoing percutaneous coronary intervention (PCI). Using the euroSCORE, each patient's surgical mortality risk was estimated. Study end-points were any major adverse cardiac event (MACE) defined as cardiac death, nonfatal myocardial infarction, or target lesion revascularization at follow-up with either CABG or repeat PCI.

RESULTS

The mean follow-up was 54 ± 25 months. The mean euroSCORE was 10.6 ± 13.4 (0.9-71) and the mean SYNTAX score was 39.6 ± 10.7 (10-65). The MACE rate was 11.4% at a mean follow up of 54 months. Six (3.8%) patients suffered postprocedure myocardial infarction. There were 24 (15%) deaths of which 12 were cardiac (mean euroSCORE 21.6 ± 5.5 P < 0.001). Repeat angiography was performed in 88 (55.7%) patients. Seven (4.4%) patients had in-stent restenosis; three occurred in BMS (P = 0.06). Two patients underwent revascularization with CABG and five had successful repeat PCI.

CONCLUSION

In this on-going registry of high risk patients with LMCA stenosis, stenting was found to be safe and clinically effective in maintaining event-free survival.

Racial disparities in left main stenting: insights from a real world inner city population

BACKGROUND

Left main coronary artery (LMCA) disease is associated with significant cardiovascular mortality. The data on patient characteristics' predicting outcomes after LMCA revascularization is sparse.

METHODS

A retrospective study of 227 patients with LMCA disease documented on coronary angiography from March 2000 to December 2008. Data included demographic variables, co-morbidities, cardiac function, and medications. Race was self-identified. The study outcome was a composite end-point including myocardial infarction (MI) and all-cause mortality. Cox proportional hazard analysis was performed to study the effect of various patient attributes including race and gender on the composite end-point.

RESULTS

Baseline characteristics were specifically compared between individuals who had the study outcome versus those who did not. Mean age was higher in the group with study outcomes when compared to the group without any outcomes (64.3 ± 11.8 years versus 59.2 ± 13.6 years; p = 0.013). After the final multivariate regression analysis, only African American (AA) race and age were found to be independent predictors of adverse cardiac outcome at the end of the first year (race-hazard ratio (HR) 3.82, 95% confidence interval (CI) 1.38-10.62, p = 0.010; age-HR 1.08, 95% CI 1.04-1.13, p < 0.001) and at the end of the study (race-HR 2.71, 95% CI 1.44-5.10, p = 0.002; age-HR 1.03, 95% CI 1.01-1.08, p = 0.017).

CONCLUSION

In our study of patients with unprotected LMCA disease, AA race, and age were significantly predictive of poor prognosis following revascularization, while gender had no predictive value in prognosticating cardiovascular mortality.

Meta-analysis of three randomized trials and nine observational studies comparing drug-eluting stents versus coronary artery bypass grafting for unprotected left main coronary artery disease

Clinical outcomes for unprotected left main coronary artery (ULMCA) disease between coronary artery bypass grafting (CABG) and drug-eluting stents (DESs) remain controversial. We aimed to compare the safety and efficacy of percutaneous coronary intervention (PCI) using DESs with CABG in patients with ULMCA disease. Databases were searched for clinical studies that reported outcomes after PCI with DESs and CABG for treatment of ULMCA disease. End points of this meta-analysis were mortality; composite of death, myocardial infarction (MI), or stroke; and target vessel revascularization at 1-year follow-up. Pooled effects were calculated using fixed-effects model (Mantel-Haenszel method) or random-effects models (Dersimonian-Laird method). Twelve clinical studies (3 randomized trials and 9 observational studies) with 5,079 patients were involved in this study. At 1-year follow-up, there were trends toward lower risk of death (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.45 to 1.02) and the composite end point of death, MI, or stroke (OR 0.70, 95% CI 0.49 to 1.00) in the DES group compared to the CABG group. However, target vessel revascularization was significantly higher in the DES group compared to the CABG group (OR 3.52, 95% CI 2.72 to 4.56). In conclusion, PCI with DESs is associated with favorable outcomes for mortality; composite end point of death, MI, or stroke; and a higher risk of target vessel revascularization compared to CABG in patients with ULMCA disease.

Unprotected left main coronary artery disease in patients with low predictive risk of mortality

BACKGROUND

There has been an increasing use of percutaneous coronary intervention with drug-eluting stent (DES) in patients with unprotected left main coronary artery disease. We assessed whether coronary artery bypass grafting (CABG) would be superior to percutaneous coronary intervention with first-generation DES in patients with unprotected left main coronary artery disease.

METHODS

Between January 2003 and December 2007, a total of 295 patients with unprotected left main coronary artery disease were treated with Kurashiki Central Hospital, Okayama, Japan. Among these patients, 169 and 126 underwent CABG and percutaneous coronary intervention with DES, respectively. The average Society of Thoracic Surgeons' predictive risk of mortality score was 2.3±3.8%. We defined higher-risk and lower-risk patients as those with Society of Thoracic Surgeons' predictive risk of mortality scores higher than 2.3% (CABG, n=48; percutaneous coronary intervention, n=28) and lower than 2.3% (CABG, n=121; percutaneous coronary intervention, n=98), respectively. Survival, major adverse cardiac-related events, and target lesion revascularization were analyzed by the Kaplan-Meier method.

RESULTS

Between-group differences in favor of CABG were seen with respect to the rate of major adverse cardiac-related events and target lesion revascularization in both strata. In patients with lower scores according to the Society of Thoracic Surgeons' predictive risk of mortality, the cardiac death-free survival rate was significantly higher in CABG.

CONCLUSIONS

In this 5-year single-center experience, CABG is recommended for unprotected left main coronary artery disease, especially in patients with low scores in the Society of Thoracic Surgeons' predictive risk of mortality.

Revascularization for left main and multivessel coronary artery disease in the drug-eluting stent era: integration of recent drug-eluting stent trials

As older patients comprise a greater proportion of the population, the incidence of multivessel and left main coronary artery disease is increasing. Given the improvements in percutaneous coronary intervention, more patients are suitable for this revascularization strategy. However, the optimal revascularization strategy remains a moving target. Numerous trials, extending from the bypass surgery versus medical therapy era to the most current drug-eluting stent versus bypass surgery era, provide information to select the most appropriate revascularization strategy. The objective of this review is to summarize these data.

Drug-eluting stents versus coronary artery bypass graft surgery in left main coronary artery disease: a meta-analysis of early outcomes from randomized and nonrandomized studies

OBJECTIVE

The present meta-analysis aimed to compare the short-term safety and efficacy of drug-eluting stents and coronary artery bypass graft surgery for patients with left main coronary artery disease.

METHODS

Fourteen relevant studies were identified from 5 electronic databases. End points included mortality, stroke, myocardial infarction, repeat revascularization, and major adverse cardiac and cerebrovascular events.

RESULTS

Results indicate that all-cause mortality was similar between drug-eluting stents and coronary artery bypass grafting at 30 days and at follow-up beyond 1 year. Likewise, the incidence of myocardial infarction was similar between drug-eluting stents and coronary artery bypass grafting at 12 months and at follow-up beyond 1 year. However, drug-eluting stents were associated with a lower incidence of all-cause mortality at 12 months and a higher incidence of myocardial infarction at 30 days compared with coronary artery bypass grafting. Drug-eluting stents were consistently associated with a higher incidence of repeat revascularization, whereas coronary artery bypass grafting had a higher incidence of stroke. The incidence of major adverse cardiac and cerebrovascular events was similar between the 2 groups at 30 days but higher for drug-eluting stents at 12 months and beyond.

CONCLUSIONS

Patients treated by drug-eluting stents in randomized controlled trials and observational studies in the current literature are often a preselected subgroup with less complex lesions compared with the overall target population. Results drawn from these studies should be viewed with caution. Coronary artery bypass grafting is associated with a lower incidence of major adverse cardiac and cerebrovascular events at 1 year and beyond, and thus should be regarded as the standard of treatment. However, drug-eluting stents may have a role for selected patients with percutaneously amenable left main disease who are poor surgical candidates.

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.

Long-term (4-year) outcomes and predictors of adverse cardiac events after sirolimus-eluting stent implantation in unprotected left main coronary artery

The long-term safety and efficiency of sirolimus-eluting stent (SES) treatment in unprotected left main coronary artery (ULMCA) have not yet been ascertained.From 2003 to 2006, 126 consecutive patients with de novo lesions in ULMCA who underwent SES were retrospectively analyzed in a single center in China. During 4-year follow-up, major adverse cardiovascular event (MACE)-free survival was 74.6%. Cardiac death occurred in 5 (4.0%), and target lesion revascularization (TLR) and target vessel revascularization (TVR) occurred in 15 (11.9%) and 24 (19.0%) patients, respectively. One (0.8%) experienced probable stent thrombosis while 1 (0.8%) presented possible stent thrombosis. Impaired LVEF (< 40%) and high surgical risk (Euro score > 6) were the independent predictors of MACEs.PCI with SES for de novo lesions in ULMCA is feasible with a low procedural risk. However, SES was associated with a relatively higher rate of TLR and TVR. Impaired LVEF and high surgical risk were important predictors of MACEs.

Two-year outcomes of the sirolimus-eluting stent according to unprotected left main lesion

BACKGROUND

The data of long-term outcomes of sirolimus-eluting stent (SES) according to lesion location of unprotected left main coronary artery (LMCA) is scarce.

HYPOTHESIS

The purpose of this study was to evaluate the long-term outcomes after implantation of the SES in LMCA.

METHODS

A total of 84 patients (51 males) who had undergone SES implantation for the treatment of native LMCA stenosis were enrolled. The patients were divided into 2 groups based on angiographic lesion location: those with significant stenosis in the ostium and/or body (group 1; n = 39) and those involving bifurcation (group 2; n = 45).

RESULTS

All of the group 1 patients were treated with simple lesion coverage while different stenting techniques were used in group 2 (cross-over: 44.8%, T: 6.7%, kissing: 37.8%, and crush techniques: 11.1%). The 8-month quantitative angiographic findings and in-hospital and 2 year rates of major adverse cardiac events (MACE) were compared between the 2 groups. Although angiographic success and in-hospital MACE rates were similar in both groups with 1 cardiac death due to acute stent thrombosis in group 2, at 2-year follow-up, the MACE rate was significantly higher in group 2 than in group 1 at 2 years (22.2% vs 2.6%, respectively, P = 0.008). Coronary angiography revealed a significantly higher binary restenosis rate in group 2 compared with group 1 (20% vs 0%, respectively, P = 0.003).

CONCLUSIONS

Interventional treatment using SES in left main lesions showed favorable short-term and long-term outcomes in selected patients with lesion location being an important determinant of clinical and angiographic outcomes.

Left main coronary artery stenosis: state-of-the-art

Patients with stenosis of the left main coronary artery present difficult challenges. The risks associated with this lesion have been known since the early days of angiography when patients were found to have increased mortality during follow-up. This information led to the general guidelines that surgical revascularization should be considered the treatment of choice in patients with significant left main coronary artery stenosis. Current advances in invasive cardiology have brought important information to the field. Intravascular ultrasound is now used routinely to evaluate angiographically indeterminate lesions with criteria now set forward as to what constitutes an indication for revascularization. Stents have even further dramatically changed the landscape. There are substantial issues, however, that need to addressed. These include the following: (1) the effect of specific lesion location on outcome - it is known that patients with distal bifurcation left main disease have worse outcome; (2) the potential for subacute thrombosis of the left main coronary artery; (3) the impact of left ventricular function and patient comorbidities irrespective of the degree and location of left main coronary artery stenosis; and (4) the risk-benefit ratio of stenting versus coronary artery bypass graft surgery. These issues are currently being addressed in two seminally important trials including the SYNTAX trial, which randomizes patients with left main and/or three-vessel disease to either coronary artery bypass graft surgery or a TAXUS drug-eluting stent. This trial is in the final stages of patient recruitment and will have important implications for the field. The other trial is the COMBAT trial, which is focused exclusively on left main coronary artery stenosis and randomizes patients with left main coronary artery disease either to a Sirolimus-eluting stent (Cypher, Johnson and Johnson Cordis, USA) or to coronary artery bypass graft surgery. The field of left main coronary artery disease continues to expand in terms of the evidence available for optimal patient evaluation and selection of treatment modalities.

[Interventional cardiology 2006]

The range of applications of percutaneous coronary intervention (PCI) continues to expand and a growing number of patients are being treated, including those with extensive cardiovascular disease, more serious comorbid conditions, and more complex lesions. Even so, the success rate is high, serious complications are rare in stable patients, and the restenosis rate has been dramatically reduced by drug-eluting stents. Nevertheless, percutaneous techniques still have major limitations restricting their use in some type of lesions, such as bifurcations and total occlusions, and their role in relation to surgical revascularization has not yet been well defined in the treatment of the left main coronary artery or multivessel disease. The development of novel types of coated stent with better mechanical characteristics and a lower risk of occlusion will further expand the ambit of PCI. The role of PCI in the management of acute coronary syndromes is already well defined, and has increased the preference for an invasive rather than a conservative approach in high-risk patients without ST elevation and the preference for primary angioplasty rather than thrombolysis in those with ST elevation. The development and implementation of integrated coronary syndrome treatment networks will enable human and material resources to be used efficiently, and will guarantee rapid access to high-quality PCI for those who need it. The potential usefulness of combining cellular therapy with interventional procedures in the treatment of acute myocardial infarction has still to be determined. At present, there is extensive research into noncoronary interventions, which, in the not too distant future, could provide percutaneous treatment for the many elderly patients with severe aortic stenosis who are not currently eligible for surgery.