Elective stenting of unprotected left main coronary artery stenosis: effect of debulking before stenting and intravascular ultrasound guidance

Left Main Coronary Artery Disease-Current Management and Future Perspectives

Due to its anatomical features, patients with an obstruction of the left main coronary artery (LMCA) have an increased risk of death. For years, coronary artery bypass grafting (CABG) has been considered as a gold standard for revascularization. However, notable advancements in the field of percutaneous coronary intervention (PCI) led to its acknowledgement as an important treatment alternative, especially in patients with low and intermediate anatomical complexity. Although recent years brought several random clinical trials that investigated the safety and efficacy of the percutaneous approach in LMCA, there are still uncertainties regarding optimal revascularization strategies. In this paper, we provide a comprehensive review of state-of-the-art diagnostic and treatment methods of LMCA disease, focusing on percutaneous methods.

Expansion Capacity of Drug-Eluting Stents in Patients with Left Main Coronary Artery Disease: An Intravascular Ultrasound Guided Study

Aims: The aim of this study was to assess the expansion capacity ofcurrent commercially available Drug Eluting Stents (DES) with nominaldiameters of 3.5-4.0mm in patients with Left Main disease.Materials and Methods: This study was conducted on 50Patients who underwent percutaneous coronary intervention(PCI)for Left Main disease at Benha university hospitals and NationalHeart Institute. PCI was done with Drug Eluting Stents(DES) with large diameters of 3.5-4mm and post dilatation wasdone with non-compliant (NC) balloons with diameters of 4.5-5mm. Intravascular ultrasound (IVUS) was used to measuremaximal stent diameter and area.Results: Three commercially available DESs were used in ourstudy; XIENCE Xpeditionᵀᴹ, Ultimasterᵀᴹ and Onyxᵀᴹ. Maximal stentdiameter was 4.5±0.3mm and diameter expansion index was0.96±0.05. Maximal stent area was 14.67±2.06mm² and area expansionindex was 0.86±0.07mm². On IVUS images, significantlymore calcification< 90 ̊ was detected in the group with expansionindex ˂ 0.85 (68.4 percent versus 25.8%, P=0.003) comparedto the group with expansion index >0.85. We found that DESswith diameters of 3.5-4.0mm can be expanded up to diameter of5.3mm after post-dilation. No complications were reported in thestudied patients, including perforation or stent fracture.Conclusion: Current DESs with nominal diameters of 3.5-4.0mmcan be safely and effectively over-expanded to reach the predicteddiameters in the left main, but the presence of calcification>90 may affect the achievement of the predicted area.

Association of quantitative flow ratio-derived microcirculatory indices with anatomical-functional discordance in intermediate coronary lesions

Discrepancy between coronary lesion severity and functional significance has always been a relevant issue in the management of patients undergoing coronary angiography and/or revascularization. We sought to investigate the relationship between quantitative flow ratio (QFR)-derived microcirculatory indices and anatomical-functional mismatch/reverse mismatch in intermediate coronary lesions. Intravascular ultrasound (IVUS) imaging and QFR were analyzed in 117 de novo intermediate coronary lesions. Lesions with QFR ≤ 0.8 were considered hemodynamically significant. Anatomical significance of the lesions was defined according to the best cutoff value of combined IVUS parameters for predicting QFR ≤ 0.8. QFR-derived microcirculatory indices including contrast-flow QFR minus fixed-flow QFR (cQFR-fQFR), hyperemic flow velocity and angiography-derived index of microcirculatory resistance (IMR_angio) were calculated. The best cutoff values of IVUS parameters for predicting QFR ≤ 0.8 were minimum lumen area (MLA) 3.1mm² and plaque burden (PB) 70%, with area under the curve of 0.635 and 0.703, respectively. The total discordance rate of lesion functional significance between IVUS and QFR assessments was 26.5%, with 21 lesions (17.9%) being classified as mismatch (MLA ≤ 3.1mm² and PB ≥ 70% and QFR > 0.8) and 10 lesions (8.5%) as reverse-mismatch (MLA > 3.1 mm² or PB < 70% and QFR ≤ 0.8). At multivariate analysis, IMR_angio was identified as an independent predictor of mismatch (OR1.675, 95%CI:1.176-2.386, P = 0.004), whereas hyperemic flow velocity was identified as an independent predictor of reverse-mismatch (OR 1.233, 95%CI:1.073-1.416, P = 0.003). In intermediate coronary lesions, although MLA 3.1mm² and PB 70% determined by IVUS are predictive of QFR-defined functional significance, the discordance rate remains substantial. QFR-derived microcirculatory indices are independently associated with anatomical-functional discordance between IVUS and QFR assessments.

Coronary artery double stenting techniques and their results in complex left main bifurcation disease

Aim: Complex left main (LM) bifurcation disease seems to be better approached by a planned double stent technique. Materials & methods: Medline search for articles including randomized trials, prospective series, large registries and retrospective studies >50 patients has been performed. Results: Double kissing crush demonstrated its superiority over culotte stenting and cross over, while other techniques such as the T-stenting and T-stent and Protrusion have not been extensively reported in LM setting. The nano inverted-T-stenting has provided evidences that the use of ultrathin strut stents and very minimal crush is beneficial for both the physiological and rheological properties. Conclusion: The double stenting techniques used in LM should be evaluated in terms of procedural differences and technical simplicity.

Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting for the Treatment of Left Main Coronary Artery Disease

Severe stenosis of the left main coronary artery (LMCA) generally occurs as a result of atherosclerosis and compromises the blood supply to a wide area of myocardium, thereby increasing the risk of serious adverse cardiac events. Current revascularization strategies for patients with significant LMCA disease include coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), both of which have a range of advantages and disadvantages. In general, PCI is associated with a lower rate of periprocedural adverse events and provides more rapid recovery, while CABG provides more durable revascularization. Most clinical trials comparing PCI and CABG for the treatment of LMCA disease have shown PCI to be non-inferior to CABG with respect to mortality and the serious composite outcome of death, myocardial infarction, or stroke in patients with low-to-intermediate anatomical complexities. Remarkable advancements in PCI standards, including safer and more effective stents, adjunctive intravascular imaging or physiologic evaluation, and antithrombotic treatment, may have contributed to these favorable results. This review provides an update on the current management of LMCA disease with an emphasis on clinical data and academic and clinical knowledge that supports the use of PCI in an increasing proportion of patients with LMCA disease.

Percutaneous Left Main Coronary Intervention: A Review of Plaque Modification in Left Main Percutaneous Coronary Intervention

Left main coronary artery (LMCA) stenosis has long been recognized as a marker of increased morbidity and mortality. Current treatment algorithms for LMCA stenosis consider both percutaneous coronary intervention (PCI) with drug eluting stents (DES) and coronary bypass surgery, each with advantages based on individual patient characteristics. Since the LMCA is the largest artery in the coronary tree, plaque volume and calcification is greater than other coronary segments and often extends to the distal bifurcation segment. In LMCA bifurcation lesions, larger minimal stent area is strongly associated with better outcome in the DES era. Plaque modification strategies such as rotational, orbital, or laser atherectomy are effective mechanisms to reduce plaque volume and alter compliance, facilitating stent delivery and stent expansion. We present a case of a calcified, medina class 1,1,1 LMCA lesion where intravascular ultrasound (IVUS) and orbital atherectomy were employed for optimal results. In this context, we review the evidence of plaque modification devices and the rationale for their use in unprotected left main PCI.

Percutaneous coronary intervention in left main disease: SYNTAX, PRECOMBAT, EXCEL and NOBLE-combined cardiology and cardiac surgery perspective

Although coronary-artery bypass grafting (CABG) is the standard choice of revascularization for significant left main coronary artery (LMCA) disease, percutaneous coronary intervention (PCI) for LMCA disease has been widely expanded with adoption of drug-eluting stents (DES). Several small- and moderate-sized trials of CABG and first-generation DES showed that PCI might be a good alternative for selected patients with LMCA disease. However, these early trials were relatively underpowered and comparative results of contemporary DES and CABG were clearly required. Subsequently, two large-sized trials comparing CABG and contemporary DES (EXCEL and NOBLE) were conducted, but these trials showed conflicting results with regards to the effects of PCI and CABG on clinical outcomes, which raises further uncertainty on the optimal revascularization for LMCA disease. This article serves to summarize the key findings of landmark clinical trials, to share our knowledge and experience and to express personal opinions on current controversies in the treatment of LMCA disease.

Meta-analysis and systematic review of intravascular ultrasound versus angiography-guided drug eluting stent implantation in left main coronary disease in 4592 patients

Background

Although several meta-analyses have demonstrated the utility of intravascular ultrasound (IVUS) in guiding drug-eluting stent (DES) implantation compared to angiography-guidance, there has been a dearth of evidence in the left main coronary artery (LMCA) lesion subset.

Methods

We performed a meta-analysis to compare clinical outcomes of IVUS versus conventional angiography guidance during implantation of DES for patients with LMCA disease. Pubmed, Cochrane Library, Embase were searched.

Results

A total of 1002 publications were reviewed; and finally, seven clinical studies - one prospective randomized controlled trial and six observational studies with 4592 patients (1907 IVUS-guided and 2685 angiography-guided) - were included in the meta-analysis. IVUS guidance was associated with a significant reduction in major adverse cardiac events (relative ratio [RR] 95% CI 0.61; 95% confidence interval [CI] 0.53 to 0.70; P < 0.001), all-cause death (RR 0.55; 95% CI 0.42 to 0.71; P < 0.001), cardiac death (RR 0.45; 95% CI 0.32 to 0.62; P < 0.001), myocardial infarction (RR 0.66; 95% CI 0.55 to 0.80; P < 0.001), and stent thrombosis (RR 0.48; 95% CI 0.27 to 0.84; P = 0.01) compared with angiographic guidance. However, there was no significant difference regarding target lesion revascularization (RR 0.60; 95% CI 0.31 to 1.18; P = 0.099) and target vessel revascularization (RR 0.64; 95% CI 0.26 to 1.56; P = 0. 322).

Conclusions

Compared to angiographic guidance, IVUS-guided DES implantation was associated with better clinical outcomes for patients with LMCA lesions, especially hard endpoints of death, myocardial infarction, and stent thrombosis.

Meta-analysis study comparing percutaneous coronary intervention/drug eluting stent versus coronary artery bypass surgery of unprotected left main coronary artery disease: Clinical outcomes during short-term versus long-term (> 1 year) follow-up

BACKGROUND

Results on the safety and long-term efficacy of drug-eluting stent placement in unprotected left main coronary artery disease (ULMCAD) compared with those of coronary artery bypass surgery (CABG) remain inconsistent across randomized clinical trials and recent meta-analysis studies. We aimed to compare the clinical outcomes and safety over short- and long-term follow-ups by conducting a meta-analysis of large pooled data from randomized controlled trials and up-to-date observational studies.

METHODS

A systematic review of PubMed, Google Scholar, Medline, and reference lists of related articles was performed for studies conducted in the drug-eluting stent era, to compare percutaneous coronary intervention (PCI) with CABG in ULMCAD. The primary outcome was major adverse cardiovascular and cerebrovascular events (MACCE), myocardial infarction (MI), stroke, all-cause mortality, and revascularization after at least 1-year follow-up. In-hospital and 30-day clinical outcomes were considered secondary outcomes. Furthermore, a subgroup analysis of studies with ≥5 years follow-up was performed to test the sustainability of clinical outcomes.

RESULTS

A total of 29 studies were extracted with 21,832 patients (10,424 in PCI vs 11,408 in CABG). Pooled analysis demonstrated remarkable differences in long-term follow-up (≥1 year) MACCE (odds ratio [OR] 1.42, 95% CI 1.27-1.59), P < .00001), repeat revascularization (OR 3.00, 95% CI 2.41-3.73, P < .00001), and MI (OR 1.32, 95% CI 1.14-1.53, P = .0002), favoring CABG over PCI. However, stroke risk was significantly lower in the PCI group. Subgroup analysis of studies with ≥5 years follow-up showed similar outcomes except for the noninferiority outcome of MACCE in the PCI arm. However, the PCI group proved good safety profile after a minimum of 30-day follow-up with lower MACCE outcome.

CONCLUSION

PCI for ULMCAD can be applied with attentiveness in carefully selected patients. MI and the need for revascularization remain drawbacks and areas of concern among previous studies. Nonetheless, it has been proven safe during short-term follow-up.

Meta-Analysis Comparing Coronary Artery Bypass Grafting to Drug-Eluting Stents and to Medical Therapy Alone for Left Main Coronary Artery Disease

Historically, coronary artery bypass graft (CABG) surgery has been the standard revascularization method for unprotected left main coronary artery (LMCA) disease. Over the last decade, several randomized controlled trials (RCTs) have shown favorable results for percutaneous coronary intervention (PCI) with drug-eluting stent (DES) compared with CABG; however, no RCT has been conducted directly comparing DESs with medical therapy alone (MTA). Furthermore, the 2 most recently reported larger RCTs, using new-generation DESs reached somewhat conflicting conclusions comparing the 2 revascularization strategies. Therefore, we performed a traditional pairwise meta-analysis and Bayesian network meta-analysis to compare the efficacies of the 3 currently available treatment strategies (MTA, CABG, and DES) for unprotected LMCA disease. Scientific databases and websites were searched to find RCTs. Data from 8 trials including 4,850 patients were analyzed. Overall PCI increased the risk of major adverse cardiac and cerebrovascular events (MACCEs) driven by increased rate of revascularization compared with CABG, but no differences in all-cause mortality, cardiac mortality, and recurrent myocardial infarction were found. However, early (i.e., within 30 days) PCI decreased the risk of MACCEs and stroke compared with CABG. In the mixed-treatment comparison models, both CABG and DESs were associated with better survival compared with MTA, but no difference was found between them. In conclusion, in patients with unprotected LMCA disease, PCI with DESs yields similar all-cause and cardiac mortalities compared with CABG. Furthermore, CABG increases early (i.e., within 30 days) MACCE rates, driven by an increased risk of stroke. Over longer durations, PCI increases MACCE rates because of increased recurrent revascularization.

Percutaneous coronary intervention in left main coronary artery disease with or without intravascular ultrasound: A meta-analysis

This meta-analysis compared IVUS-guided with angiography-guided PCI to determine the effect of IVUS on the mortality in patients with LM CAD. Current guidelines recommend intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with left main coronary artery disease (LM CAD; Class IIa, level of evidence B). A systematic search of the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases was conducted to identify randomized or non-randomized studies comparing IVUS-guided PCI with angiography-guided PCI in LM CAD. Ten studies (9 non-randomized and 1 randomized) with 6,480 patients were included. The primary outcome was mortality including all-cause death and cardiac death. Compared with angiography-guide PCI, IVUS-guided PCI was associated with significantly lower risks of all-cause death (risk ratio [RR] 0.60, 95% confidence interval [CI] 0.47-0.75, p<0.001), cardiac death (RR 0.47, 95% CI 0.33-0.66, p<0.001), target lesion revascularization (RR 0.43, 95% CI 0.25-0.73, p = 0.002), and in-stent thrombosis (RR 0.28, 95% CI 0.12-0.67, p = 0.004). Subgroup analyses indicated the beneficial effect of IVUS-guide PCI was consistent across different types of studies (unadjusted non-randomized studies, propensity score-matched non-randomized studies, or randomized trial), study populations (Asian versus non-Asian), and lengths of follow-up (<3 years versus ≥3 years). IVUS-guided PCI in LM CAD significantly reduced the risks of all-cause death by ~40% compared with conventional angiography-guided PCI. PROSPERO registration number: CRD 42017055134.

Over-expansion of drug-eluting stents in patients with left main coronary artery disease: An in vivo study

Objective

We aimed to determine the capacity of drug-eluting stent (DES) over-expansion in left main coronary artery disease.

Methods

Left main interventions with the largest available DES platforms (4.0 mm) and post-dilation performed with large non-compliant balloons (≥ 4.5 mm) were included. Maximal stent diameter (mm) and area (mm²) were measured using post-intervention intravascular ultrasound (IVUS). Stent diameter and area were calculated with the balloon diameter and inflation pressure. The diameter and area expansion indices were defined as follows: maximal/calculated stent diameter and maximal/calculated stent area, respectively.

Results

Twenty-three consecutive patients were included. The maximal stent diameter was 4.40 mm (4.30–4.80 mm), and 22 of 23 patients showed a diameter expansion index greater than 0.90. The area expansion index was 0.862. The expansion index < 0.85 group had a significantly higher percentage of calcification ≥ 90° on IVUS than did the expansion index ≥ 0.85 group (72.7% versus 16.7%, P = 0.007). One stent fracture occurred during over-expansion and one ischemic event occurred during follow-up.

Conclusions

DESs with a nominal diameter of 4.0 mm can be effectively over-expanded in left main coronary artery disease. Achievement of predicted stent area can be affected by calcification.

Percutaneous Coronary Intervention of Left Main Disease

For nearly half a century, coronary artery bypass grafting has been the standard treatment for patients with obstructive left main coronary artery (LMCA) disease. However, there has been considerable evolution in the field of percutaneous coronary intervention, and especially, percutaneous coronary intervention for LMCA disease has been rapidly expanded with adoption of drug-eluting stents. Some, but not all randomized trials, have shown that percutaneous coronary intervention with drug-eluting stents might be a suitable alternative for selected patients with LMCA disease instead of bypass surgery. However, none of previous trials involving early-generation drug-eluting stents was sufficiently powered and comparative trials using contemporary drug-eluting stents were limited. Recently, primary results of 2 new trials of EXCEL (Evaluation of XIENCE Everolimus Eluting Stent Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) and NOBLE (Nordic-Baltic-British Left Main Revascularization Study) were reported. However, these trials showed conflicting results, which might pose uncertainty on the optimal revascularization strategy for LMCA disease. In this article, with the incorporation of a key review on evolution of LMCA treatment, we summarize the similarity or disparity of the EXCEL and NOBLE trials, focus on how they relate to previous trials in the field, and finally speculate on how the treatment strategy may be changed or recommended for LMCA treatment.

Comparison of the efficacy of drug-eluting stents versus bare-metal stents for the treatment of left main coronary artery disease

Background:

Recent studies reported that percutaneous coronary intervention with stent implantation was safe and feasible for the treatment of left main coronary artery (LMCA) disease in select patients. However, it is unclear whether drug-eluting stents (DESs) have better outcomes in patients with LMCA disease compared with bare-metal stent (BMS) during long-term follow-up in Chinese populations.

Methods:

From a perspective multicenter registry, 1136 consecutive patients, who underwent BMS or DES implantation for unprotected LMCA stenosis, were divided into two groups: 1007 underwent DES implantation, and 129 underwent BMS implantation. The primary outcome was the rate of major adverse cardiac events (MACEs), including cardiovascular (CV) death, myocardial infarction (MI), and target lesion revascularization (TLR) at 5 years postimplantation.

Results:

Patients in the DES group were older and more likely to have hyperlipidemia and bifurcation lesions. They had smaller vessels and longer lesions than patients in the BMS group. In the adjusted cohort of patients, the DES group had significantly lower 5 years rates of MACE (19.4% vs. 31.8%, P = 0.022), CV death (7.0% vs. 14.7%, P = 0.045), and MI (5.4% vs. 12.4%, P = 0.049) than the BMS group. There were no significant differences in the rate of TLR (10.9% vs. 17.8%, P = 0.110) and stent thrombosis (4.7% vs. 3.9%, P = 0.758). The rates of MACE (80.6% vs. 68.2%, P = 0.023), CV death (93.0% vs. 85.3%, P = 0.045), TLR (84.5% vs. 72.1%, P = 0.014), and MI (89.9% vs. 80.6%, P = 0.029) free survival were significantly higher in the DES group than in the BMS group. When the propensity score was included as a covariate in the Cox model, the adjusted hazard ratios for the risk of CV death and MI were 0.41 (95% confidence interval [CI]: 0.21–0.63, P = 0.029) and 0.29 (95% CI: 0.08–0.92, P = 0.037), respectively.

Conclusions:

DES implantation was associated with more favorable clinical outcomes than BMS implantation for the treatment of LMCA disease even though there was no significant difference in the rate of TLR between the two groups.

Long-term outcome of unprotected left main stenting: a Canadian tertiary care experience

BACKGROUND

Coronary stenting is increasingly used to treat unprotected left main disease in selected patients. However, there is a paucity of data on the long-term outcome of these patients in a Canadian context outside of clinical trials.

METHODS

We retrospectively reviewed all provincially-insured patients undergoing left main coronary stenting at a large tertiary referral centre from 2000-2011. Pre-procedural angiograms were reviewed to identify the location of left main disease, and extent of concomitant coronary disease quantified by calculating Synergy Between Percutaneous Coronary Intervention With TAXUS Drug-Eluting Stent and Cardiac Surgery (SYNTAX) scores for each patient. In-hospital death and major adverse cardiac event (MACE) rates were evaluated as were long-term death and MACE rates obtained via linkage of our institutional registry with the Ontario health claims database.

RESULTS

Two hundred twenty-one patients underwent unprotected left main stenting with 29 (13.1%) in-hospital death and 34 (15.4%) a MACE. At an average follow-up of 3.1 ± 2.8 years, 109 patients (49.3%) died and 151 (68.3%) experienced a MACE. Higher SYNTAX tertile and use of bare metal rather than drug-eluting stents was associated with increased rates of in-hospital and long-term death.

CONCLUSIONS

This study reports, to our knowledge, the largest Canadian cohort of unprotected left main stenting over more than a decade. Coronary stenting was associated with acceptable in-hospital event rates, but poor long-term outcomes, reflecting the higher-risk population traditionally selected for this procedure.

Role of intravascular ultrasound in unprotected left main percutaneous coronary intervention

Percutaneous coronary intervention (PCI) to the unprotected left main stem offers an attractive alternative to bypass grafting, but is associated with a significant clinical risk and therefore demands special consideration. Successful left main PCI is dependent upon the morphology of the lesion and the technical quality of the procedure. For these reasons, intravascular ultrasound (IVUS) has been the most popular adjunct to coronary angiography during left main PCI. However, trials of IVUS in left main PCI have produced inconclusive results, and most data predate the use of drug-eluting stents. Despite this, IVUS offers practical benefits in both case selection, and in guiding angioplasty and stenting. Here, we review the arguments for the present and future role of IVUS in left main PCI.

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.

Outcomes of primary percutaneous intervention of the unprotected left main coronary artery stenosis in myocardial infarction

OBJECTIVE

The aim of our study was to examine the 30-day and 1-year survival rate for patients undergoing percutaneous coronary artery intervention (PCI) of unprotected left main (ULM) stenosis by the presence (acute myocardial infarction [AMI] group) or absence (non-AMI group) of AMI at the time of hospital admission.

METHODS

We retrospectively reviewed 64 patients undergoing PCI of ULM stenosis at our regional heart institute between 2000 and 2008. Patients had no history of coronary artery bypass grafting.

RESULTS

Thirty-six men and 28 women underwent PCI for ULM stenosis. Overall Kaplan-Meier survival at 30 days and 1 year was 71.5% and 57.8%, respectively. Thirty-three patients (51.6%) presented with AMI. Those with AMI had lower survival at both 30 days (59.2 vs 83.9%; P = 0.04) and 1 year (45.2 vs 70.2%; P = 0.04) compared with those without AMI. Compared with a lesion involving only the ostial/mid LM, diffuse disease (N = 11) was associated with an increased mortality at 1 year (hazard ratio 0.27; 95% confidence interval 0.09-0.79). A stent size >3 mm was associated with lower mortality at 1 year (hazard ratio 0.42; 95% confidence interval 0.19-0.93).

CONCLUSIONS

We found that AMI at presentation was significantly associated with higher mortality in patients undergoing ULM stenting. LM lesion location and stent size were both significantly associated with mortality. ULM stenting is an option in patients who are unable to undergo coronary artery bypass grafting, but patients should understand the overall high risk of mortality, particularly if they present with AMI.

Real World Application of Stenting of Unprotected Left Main Coronary Stenosis: A Single-Center Experience

BACKGROUND

The aim of this study was to summarize our single-center real-world experience with percutaneous coronary intervention (PCI) stenting of unprotected left main coronary artery (ULMCA). PCI-stenting of the ULMCA, while controversial, is emerging as an alternative to coronary artery bypass graft (CABG) surgery in select patients and clinical situations.

METHODS

Between January 2005 and December 2008, PCI-stenting was performed on 125 patients with ULMCA lesions at our institution. Clinical and procedural data were recorded at the time of procedure, and patients were followed prospectively (mean 1.7 years; range 1 day-4.1 years) for outcomes, including death, myocardial infarction (MI), and target vessel revascularization (TVR).

RESULTS

The majority of cases were urgent or emergent (82.5%), 50.4% of patients were non-surgical candidates, and 63.2% had 3 vessel disease. Many emergent patients presented in shock (62.1%), were not surgical candidates (89.7%), and had high mortality (20.7% in-hospital, 44.8% long-term). Mortality in the elective group was 6.3%. Cumulative death and TVR rates were 28.8% and 13.6%, respectively. Independent predictors of mortality were ejection fraction (EF) ≤ 35% (HR 2.4, CI 1.1 - 5.4) and left main bifurcation (HR 2.7, CI 1.2 - 5.7).

CONCLUSIONS

PCI-stenting is a viable option in patients with LMCA disease and extends options to patients who are poor candidates for CABG. Elective PCI in low-risk CABG patients results in good long-term survival. Cumulative TVR is 13.6%. EF ≤ 35% and left main bifurcation are independently associated with increased mortality.

Comparison of bypass surgery with drug-eluting stents in diabetic patients with left main coronary stenosis

PURPOSE

Several studies have compared the effects of coronary stenting and coronary- artery bypass grafting (CABG) on left main coronary artery (LMCA) disease. However, there are limited data on the long-term outcomes of these two interventions in diabetic patients.

MATERIALS AND METHODS

We evaluated 56 patients with LMCA stenosis who underwent drug-eluting stent (DES) implantation and 116 patients who underwent CABG in a single hospital in China between January 2004 and December 2006. We compared long-term major adverse cardiac events (death; a "serious outcome" composite of death, myocardial infarction, or stroke; and target-vessel revascularization).

RESULTS

In-hospital (30-day) mortality was 0% for the DES group and 3.4% for the CABG group (p=0.31). There was no difference between the two groups in terms of risk of death [hazard ratio for stenting group, 0.49; 95% confidence interval (CI), 0.13-1.63; p=0.55] or risk of serious outcome (hazard ratio for DES group, 1.11; 95% CI, 0.39-1.45; p=0.47). The target-vessel revascularization rate was higher in the DES group than in the CABG group (hazard ratio, 3.67; 95% CI, 1.24-11.06; p=0.018).

CONCLUSION

In this cohort of diabetic patients with LMCA stenosis, there was no difference in composite endpoints between patients receiving DESs and those undergoing CABG. However, stenting was associated with higher rates of target-vessel revascularization than CABG. DES implantation in diabetic patients with LMCA disease was found to be at least as safe as CABG.

Stenting of complex lesions: an overview

Contemporary management of coronary artery disease relies increasingly on percutaneous techniques combined with medical therapy. Although percutaneous coronary intervention (PCI) can be performed successfully in most lesions, several difficult lesion subsets continue to present unique technical challenges. These complex lesions may be classified according to anatomic criteria, including extensive calcification, thrombus, and chronic occlusions, or by location, such as bifurcations, saphenous vein grafts and unprotected left main. PCI of these lesions often requires novel devices, such as drug-eluting stents, hydrophilic guidewires, distal protection balloons or filters, thrombectomy catheters, rotational atherectomy, and cutting balloons. An integrated approach that combines these devices with specialized techniques and adjunctive pharmacologic agents has greatly improved PCI success rates for these complex lesions.

Long-term clinical outcomes following elective stent implantation for unprotected left main coronary artery disease

BACKGROUND/PURPOSE

Percutaneous coronary intervention (PCI) has been increasingly adopted for unprotected left main coronary artery (LMCA) disease. The aim of this study was to evaluate the predictors of long-term clinical outcomes in patients after elective stent implantation for unprotected LMCA disease.

METHODS

A total of 122 patients with medically refractory angina who received coronary stenting for unprotected LMCA disease between August 1997 and December 2008 were included.

RESULTS

During the follow-up period of 45 ± 35 months (range: 1-137 months), the incidence of repeated PCI and/or coronary artery bypass grafting (CABG), and cardiovascular and total mortality were 28% (34 patients), 20% (24 patients), and 25% (31 patients), respectively. Multivariate analysis revealed that young age [p = 0.02; hazard ratio (HR): 2.19, 95% confidence interval (CI): 1.11-4.30] and bare-metal stent (BMS) use (p = 0.02; HR: 5.35, 95% CI: 1.27-22.57) were the independent predictors of repeated PCI and/or CABG. Only lower left ventricular ejection fraction (LVEF) could predict both cardiovascular mortality (p = 0.003; HR: 4.25, 95% CI: 1.63-11.08) and total mortality (p = 0.002; HR: 3.95, 95% CI: 1.65-9.45). Lower LVEF (p = 0.001; HR: 0.31, 95% CI: 0.16-0.61) and small stent size (p = 0.01; HR: 5.95, 95% CI: 1.43-24.80) could predict the composite endpoint, including target vessel revascularization and total mortality.

CONCLUSION

We showed that young age and BMS implantation could predict repeated PCI and/or CABG after stent implantation for unprotected LMCA disease. Only lower LVEF could predict both cardiovascular and total mortality. Lower LVEF and small stent size but not BMS implantation could predict composite target vessel revascularization/total mortality.

Effect of intravascular ultrasound findings on long-term repeat revascularization in patients undergoing drug-eluting stent implantation for severe unprotected left main bifurcation narrowing

We studied the effect of the preprocedural intravascular ultrasound findings on stent expansion and the pre- and postprocedural findings on the long-term clinical outcomes in patients undergoing drug-eluting stent implantation for unprotected left main (LM) bifurcation disease. Using a left anterior descending (LAD) pullback, we evaluated the ostial LAD artery (3 mm distal to the carina), the polygon of confluence (POC; the confluent zone of the LAD artery and left circumflex artery), and the distal LM artery (3 mm just proximal to the POC). The measurements included the minimum lumen area (MLA) and minimum stent area within each segment. In 168 LM bifurcations, the preprocedural MLA and post-stenting minimum stent area within the LM artery were located within the POC in 41% and 70%, respectively. Independent predictors for the post-stent minimum stent area within the distal portion of LM artery above the LAD carina were the preprocedural lumen area of the LAD carina (β = 0.253, 95% confidence interval [CI] 0.10 to 0.36, p = 0.001) and preprocedural MLA within the POC (β = 0.205, 95% CI 0.04 to 0.23, p = 0.008). During the 41.8 ± 18.0-month follow-up period, 26 patients experienced cardiac events. In the multivariate Cox model, female gender (adjusted hazard ratio 2.56, 95% CI 1.173 to 5.594, p = 0.018) and preprocedural MLA within the POC (adjusted hazard ratio 0.829, 95% CI 0.708 to 0.971, p = 0.020) were independent predictors for the occurrence of events at 3 years of follow-up. In conclusion, as assessed by the LAD pullback, the preprocedural MLA within the POC was a surrogate reflecting the overall severity of LM bifurcation disease, contributed to the post-stent minimum stent area within the distal segment of LM bifurcation, and was a predictor of clinical events during follow-up.

Bare metal stent implantation in large-sized unprotected left main coronary artery stenosis in the drug-eluting stent era

Recently, drug-eluting stent (DES) has been recommended as the first choice in those patients who need stent implantation in unprotected left main coronary artery (ULMCA) stenosis. However, the long-term safety and efficacy of this procedure is still controversial. The objective of this study was to evaluate the safety and efficacy of bare metal stent (BMS) implantation in ULMCA stenting in the DES era. We implanted BMS (mainly 4 mm-diameter) in large-sized ULMCA after December 2004 when DES became available. The results of BMS implantation (n = 19) were compared with those of DES implantation (n = 39). There was no significant difference between the 2 groups regarding age, gender and coronary risk factors. Emergency procedures were more frequently performed in the BMS group than in the DES group (53% vs. 26%, p = 0.08). The initial mortality was 10.5% (n = 2) in the BMS group and 2.6% (n = 1) in the DES group (p = 0.25). There was no stent thrombosis, Q-wave myocardial infarction or emergent bypass surgery in either group during their hospital stay. The restenosis rate was 0% (n = 45) in both groups, and the target vessel revascularization rate was 5.9% in the BMS group (1/17) and 2.6% (1/38) in the DES group (p = 0.53). Therefore, there were no statistically significant differences in outcomes between the two study groups. These results indicate that BMS implantation in a large-sized ULMCA may be a safe and effective treatment even in the DES era.

Long-term follow-up after nonurgent percutaneous coronary intervention in unprotected left main coronary arteries

OBJECTIVES

To evaluate the long-term outcomes of the selected patients by the local Heart Team to undergo percutaneous coronary intervention (PCI) of unprotected left main coronary artery (ULMCA) stenosis and to compare patients considered at low surgical risk versus at high surgical risk for coronary artery bypass grafting (CABG).

BACKGROUND

CABG is recommended in patients with ULMCA stenosis according to the AHA/ACC and ESC guidelines, and there are limited data on the long-term outcomes in patients selected by the local Heart Team to undergo PCI.

METHODS

Between 1996 and 2007, 227 patients underwent PCI for ULMCA stenosis based on decision of the local Heart Team and patient's and/or physician's preference. All patients were contacted at 1 year and in November 2008.

RESULTS

Long-term follow-up was up to 8 years with a mean of 3.9 +/- 2.6 years. Overall, the Kaplan-Meier estimate of the composite of cardiac death, myocardial infarction (MI), or target lesion revascularization (TLR) was 14.8% at 1 year, 18.3% at 3 years, and 20.9% at 5 years with no events occurring thereafter. Patients considered at low surgical risk for CABG had a significantly lower incidence of cardiac death or MI compared to patients considered at high surgical risk at 8 years (1.4 vs. 16.8%; 1.4 vs. 14.8%, respectively); however, no significant difference was observed for cardiac death, MI, or TLR (18.6 vs. 24.4%).

CONCLUSIONS

PCI of ULMCA stenosis in patients selected by the Heart Team resulted in good long-term clinical outcomes with most events occurring within the 1st year. Patients considered at low surgical risk for CABG have a significantly better long-term survival than patients at high risk for surgery.

Percutaneous coronary intervention with stent implantation versus coronary artery bypass surgery for treatment of left main coronary artery disease: is it time to change guidelines?

On the basis of clinical trials comparing coronary-artery bypass grafting (CABG) with medical therapy, current guideline recommend CABG as the treatment of choice for patients with asymptomatic ischemia, stable angina, or unstable angina/non-ST elevation myocardial infarction who have left main coronary artery disease. Percutaneous coronary intervention can be selectively performed in patients who are candidates for revascularization but who are ineligible for CABG. However, because of advances in periprocedural and postprocedural medical care in patients undergoing either CABG or percutaneous coronary intervention with stenting, new evaluation, and a review of current indications, may be required to determine the standard of care for patients with left main coronary artery disease. Current evidences indicate that stenting results in mortality and morbidity rates that compared favorably with those seen after CABG, suggesting that a current guideline (the Class III recommendation of percutaneous coronary intervention for unprotected left main coronary artery disease) may no longer be justified. Data from several extensive registries and a large clinical trial may have prompted many interventional cardiologists to select percutaneous coronary intervention with stenting as an alternative revascularization strategy for such patients. In addition, these data may inform future guidelines and support the need for well-designed, adequately powered, prospective, randomized trials comparing the 2 revascularization strategies. The cumulative evidence from ongoing and future clinical trials will change the current clinical practice of revascularization for unprotected left main coronary artery disease, which was introduced several decades ago and which has continued to date without major revision.

Stenting versus bypass surgery for the treatment of left main coronary artery disease

Based on data comparing coronary-artery bypass grafting (CABG) with medical therapy, the current guidelines recommend CABG as the treatment of choice for patients with left main coronary artery (LMCA) disease. Percutaneous coronary intervention (PCI) can be selectively performed in patients who are candidates for revascularization but who are ineligible for CABG. Current evidence indicates that stenting results in mortality and morbidity rates compared favorably with those seen after CABG. Data from several extensive registries and a large clinical trial may have prompted many interventional cardiologists to choose PCI with stenting as an alternative treatment option for such patients. In addition, these data may inform future guidelines and support the need for well-designed, adequately powered, prospective, randomized trials comparing the two revascularization strategies.

Long-term clinical outcomes of sirolimus- versus paclitaxel-eluting stents for patients with unprotected left main coronary artery disease: analysis of the MAIN-COMPARE (revascularization for unprotected left main coronary artery stenosis: comparison of percutaneous coronary angioplasty versus surgical revascularization) registry

OBJECTIVES

The aim of this study was to evaluate long-term clinical outcomes after implantation of sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES) among patients with unprotected left main coronary artery (LMCA) disease.

BACKGROUND

There have been few comparisons of long-term outcomes among currently available drug-eluting stents (DES) for the treatment of LMCA disease.

METHODS

A total of 858 consecutive patients with unprotected LMCA stenosis were treated with SES (n = 669) or PES (n = 189) between May 2003 and June 2006. Primary outcome was the composite of death, myocardial infarction (MI), or target vessel revascularization (TVR).

RESULTS

Baseline clinical and angiographic characteristics were similar in the 2 groups. During 3 years of follow-up, the adjusted risk of primary composite outcome was similar among the groups (SES vs. PES: 25.8% vs. 25.7%, hazard ratio [HR]: 0.95, 95% confidence interval [CI]: 0.64 to 1.41, p = 0.79). The 2 groups also showed a comparable adjusted rate of each component of outcome: death (9.1% vs. 11.0%, HR: 0.92, 95% CI: 0.47 to 1.80, p = 0.82), MI (8.1% vs. 8.0%, HR: 0.80, 95% CI: 0.43 to 1.48, p = 0.47), and TVR (12.1% vs. 10.6%, HR: 1.10, 95% CI: 0.53 to 2.29, p = 0.81). The 3-year rates of definite or probable stent thrombosis were 0.6% in the SES group and 1.6% in the PES group (adjusted p = 0.18).

CONCLUSIONS

In consecutive patients with unprotected LMCA disease undergoing DES implantation, SES and PES showed similar long-term clinical outcomes in terms of death, MI, repeat revascularization, and stent thrombosis.