Are drug-eluting stents superior to bare-metal stents in patients with unprotected non-bifurcational left main disease? Insights from a multicentre registry

Management of failed stenting of the unprotected left main coronary artery

Percutaneous coronary intervention (PCI) is increasingly accepted as treatment for unprotected left main coronary artery (ULMCA) disease especially in those patients who are unsuitable for cardiac surgery. Treatment of any stent failure is associated with increased complexity and worse clinical outcomes when compared with de novo lesion revascularization. Intracoronary imaging has provided new insight into mechanisms of stent failure and treatment options have developed considerably over the last decade. There is paucity of evidence on the management strategy for stent failure in the specific setting of ULMCA. Treating any left main with PCI requires careful consideration and consequently treatment of failed stents in ULMCA is complex and provides unique challenges. Consequently, we provide an overview of ULMCA stent failure, proposing a tailored algorithm to guide best management and decision in daily clinical practice, with a special focus on intracoronary imaging characterization of causal mechanisms and specific technical and procedural considerations.

A Case Summary of the Application of a Drug-Eluting Stent Combined with a Drug-Coated Balloon in Left Main Coronary Artery Disease

Objective: To evaluate the clinical efficacy of a drug-eluting stent (DES) combined with a drug-coated balloon (DCB)in the treatment of left main coronary artery bifurcation lesions.Methods: A retrospective analysis was conducted on the clinical data of eight patients with left main coronary arterybifurcation lesions treated with a DES combined with a DCB who were admitted to our hospital from July 2016 to July2017. These eight patients all underwent DES treatment for their left main coronary artery and left anterior descendingcoronary artery lesions, and DCB treatment at the ostium of the left circumflex artery; six of the patients underwentsurgical procedures under the guidance of intravascular ultrasonography. Immediate postoperative angiography wasused to evaluate the patency of the diseased vessels, and the restenosis rate at the 6-month follow-up after the operationand the incidence of serious clinical events within 6 months were assessed as well.Results: The use of a DES combined with a DCB in the treatment of left main coronary artery bifurcation lesions hada low restenosis rate (left main coronary artery (8.4 ± 5.3)%, left anterior descending coronary artery (18.2 ± 5.0)%,left circumflex artery (30.5 ± 16.5)%). No serious clinical events occurred in any patients.Conclusion: A DES combined with a DCB is a safe and effective interventional treatment for left main artery coronarybifurcation lesions.

[Angioplasty of the unprotected left main trunk: short and medium term outcomes]

Introduction

Notre but était de déterminer le devenir des patients traités par angioplastie du tronc commun non protégé de l'artère coronaire gauche.

Méthodes

Une étude rétrospective a porté sur tous les patients traités par angioplastie du tronc commun non protégé de la coronaire gauche entre janvier 2004 et juin 2009. Les données cliniques et angiographiques ont été recueillies sur les dossiers médicaux, complétées par un entretien téléphonique avec le patient ou ses médecins.

Résultats

Quarante-huit patients d'âge moyen de 68,50±14,06 ans ont été inclus. Les syndromes coronariens aigus étaient le principal motif d'admission (75%). Les lésions du tronc étaient distales (77,1%) et pluritronculaires (64,6%). Un stent nu a été implanté chez 73% des patients. Après un suivi moyen de 22 mois, le taux d'événements cardiovasculaires majeurs a été de 31,3% dont 20,8% de resténose et 14,6% de revascularisation. Le taux de décès hospitalier a été de 4,2%. Les facteurs prédictifs d'événements cardiovasculaires majeurs ont été un EuroSCORE ≥ 10 et les antécédents cardiovasculaires.

Conclusion

L'angioplastie du tronc commun est une alternative dans les situations d'urgence ou en cas de contre-indication de la chirurgie. Le risque évolutif des patients est lié à leur risque global avant angioplastie.

The DELTA 2 Registry: A Multicenter Registry Evaluating Percutaneous Coronary Intervention With New-Generation Drug-Eluting Stents in Patients With Obstructive Left Main Coronary Artery Disease

OBJECTIVES

The aim of this study was to evaluate clinical outcomes of unprotected left main coronary artery percutaneous coronary intervention (PCI) with new-generation drug-eluting stents in a "real world" population.

BACKGROUND

PCI of the unprotected left main coronary artery is currently recommended as an alternative to coronary artery bypass grafting (CABG) in selected patients.

METHODS

All consecutive patients with unprotected left main coronary artery stenosis treated by PCI with second-generation drug-eluting stents were analyzed in this international, all-comers, multicenter registry. The results were compared with those from the historical DELTA 1 (Drug Eluting Stent for Left Main Coronary Artery) CABG cohort using propensity score stratification. The primary endpoint was the composite of death, myocardial infarction (MI), or stroke at the median time of follow-up.

RESULTS

A total of 3,986 patients were included. The mean age was 69.6 ± 10.9 years, diabetes was present in 30.8%, and 21% of the patients presented with acute MI. The distal left main coronary artery was involved in 84.6% of the lesions. At a median of 501 days (≈17 months) of follow-up, the occurrence of the primary endpoint of death, MI, or cerebrovascular accident was lower in the PCI DELTA 2 group compared with the historical DELTA 1 CABG cohort (10.3% vs. 11.6%; adjusted hazard ratio: 0.73; 95% confidence interval: 0.55 to 0.98; p = 0.03). Of note, an advantage of PCI was observed with respect to cerebrovascular accident (0.8% vs. 2.0%; adjusted hazard ratio: 0.37; 95% confidence interval: 0.16 to 0.86; p = 0.02), while an advantage of CABG was observed with respect to target vessel revascularization (14.2% vs. 2.9%; adjusted hazard ratio: 3.32; 95% confidence interval: 2.12 to 5.18; p < 0.0001).

CONCLUSIONS

After a median follow-up period of 17 months, PCI with new-generation drug-eluting stents was associated with an overall low rate of the composite endpoint of death, MI, or cerebrovascular accident.

Propensity Score-Based Methods in Comparative Effectiveness Research on Coronary Artery Disease

This review examines the conduct and reporting of observational studies using propensity score-based methods to compare coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or medical therapy for patients with coronary artery disease. A systematic selection process identified 48 studies: 20 addressing CABG versus PCI; 21 addressing bare-metal stents versus drug-eluting stents; 5 addressing CABG versus medical therapy; 1 addressing PCI versus medical therapy; and 1 addressing drug-eluting stents versus balloon angioplasty. Of 32 studies reporting information on variable selection, 7 relied exclusively on statistical criteria for the association of covariates with treatment, and 5 used such criteria to determine whether product or nonlinear terms should be included in the propensity score model. Twenty-five (52%) studies reported assessing covariate balance using the estimated propensity score, but only 1 described modifications to the propensity score model based on this assessment. The over 400 variables used in the 48 propensity score models were classified into 12 categories and 60 subcategories; only 17 subcategories were represented in at least half of the propensity score models. Overall, reporting of propensity score-based methods in observational studies comparing CABG, PCI, and medical therapy was incomplete; when adequately described, the methods used were often inconsistent with current methodological standards.

Comparison of Bare-Metal Stent and Drug-Eluting Stent for the Treatment of Patients Undergoing Percutaneous Coronary Intervention for Unprotected Left Main Coronary Artery Disease - Long-Term Result from a Single Center Experience

BACKGROUND

Percutaneous coronary intervention (PCI) has become an alternative treatment for left main (LM) coronary artery disease. The aim of our study was to compare long-term clinical outcomes of patients undergoing unprotected LM PCI with bare-metal stent (BMS) or drug-eluting stent (DES) in a high-risk population.

METHODS AND RESULTS

We enrolled 223 consecutive patients with unprotected LM coronary artery disease undergoing PCI (mean age: 71.1 ± 11.2 years, 187 male), including 94 patients receiving BMS and 129 patients receiving DES. The patients receiving DES had a significantly higher SYNTAX score (p = 0.05). During the mean follow-up period of 2.5 years, there were 31 cardiovascular deaths (BMS: 21 cases, DES: 10 cases, p = 0.04 by log-rank test), 56 major adverse cardiovascular events (MACE, including cardiovascular death, non-fatal myocardial infarction (MI) and clinical-driven target lesion revascularization; BMS: 33 cases, DES: 23 cases, p = 0.03 by log-rank test) and 6 cases with definite/probable stent thrombosis (BMS: 5 cases, DES: 1 cases, p = 0.09). In multivariate Cox analysis, the use of DES was identified as an independent protective factor against cardiovascular death [hazard ratio (HR) = 0.34, 95% confidence interval (Cl) = 0.15-0.79, p = 0.01] and MACE (HR = 0.50, 95% CI = 0.28-0.88, p = 0.02). The clinical outcome analyses in propensity-score matched the cohort (87 matched pair of patients receiving BMS and DES) and yielded similar results.

CONCLUSIONS

In the general practice among a high-risk population undergoing unprotected LM PCI, the use of DES appeared to be beneficial in reducing the risk of long-term cardiovascular death and MACE.

KEY WORDS

Bare-mental stent; Drug-eluting stent; Left main coronary artery disease; Percutaneous coronary intervention.

Stenting of left main coronary artery stenosis: A to Z

For several decades, coronary artery bypass grafting (CABG) has been considered as the gold standard treatment of unprotected left main coronary artery (LMCA) disease. The marked improvement in technique and technology makes percutaneous coronary interventions (PCIs) feasible for patients with unprotected LMCA stenosis. The recent introduction of drug-eluting stents (DESs), together with advances in periprocedural and postprocedural adjunctive pharmacotherapies, has improved outcomes of PCIs of these lesions. Recent studies comparing efficacy and safety of PCIs using drug-eluting stents and CABG revealed comparable results in terms of safety and a lower need for repeat revascularisation for CABG. Patient selection for both the techniques directly impacts clinical outcome. Despite improvement in stent technology and operator experience, management can be challenging especially in LMCA bifurcation lesions and, therefore, an integrated approach combining advanced devices, tailored techniques, adjunctive support of physiological evaluation, and adjunctive pharmacological agents should be reinforced to improve clinical outcome.

Percutaneous revascularization of left main: role of imaging, techniques, and adjunct pharmacology

Refinement of interventional techniques, adjunctive pharmacological therapy, and the introduction of drug-eluting stents have fostered new interest for the percutaneous treatment of unprotected left main coronary artery (ULMCA) stenosis. Several observational registries, some randomized trials and several meta-analyses have consistently shown no difference in mortality and myocardial infarction between percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery in patients with ULMCA stenosis, but a higher rate of target vessel revascularization in patients treated with PCI. As a consequence, PCI of ULMCA stenosis has been upgraded to class IIa or IIb indication in the current European or American practice guidelines. However, several critical issues should be properly addressed when pursuing a percutaneous strategy for the treatment of ULMCA stenosis, such as the use of IVUS for procedural guidance, assessment of disease location, optimal technique for distal ULMCA stenosis, risk of stent thrombosis, optimal duration of dual antiplatelet therapy, and the most appropriate strategy for post-procedure follow up. Multidisciplinary team approach remains essential to provide a balanced information to the patient and to offer the beast treatment option.

[Left main intervention: options and limitations in interventional cardiology]

Revascularisation is indicated in patients with left main stenosis (LMS) because of its known positive effect on long-term survival. Coronary artery bypass graft (CABG) surgery has been the traditional procedure of choice for LMS patients, with percutaneous coronary intervention (PCI) being reserved for high-risk surgical patients or for those who have one or more functioning distal bypass grafts (i.e. "protected" left main PCI). Recent studies have re-examined the role of PCI in LMS, however, leading to a recent Class II recommendation for its use in selected patients. The SYNTAX Trial demonstrated that PCI can be performed with good results in the following patient subgroups: patients with isolated LMS, particularly if confined to the ostium; patients with concomitant LMS and isolated single vessel disease; patients with a SYNTAX score of <33; and patients who are at high risk for conventional CABG surgery. Patients with complex coronary anatomy (SYNTAX score >33) or those with concomitant double- or triple-vessel disease are more suited to CABG surgery. Patients who undergo PCI for LMS should be treated in specialized centers with surgical back-up, preferably with patient management decisions being made by a "heart team" consisting of at least one cardiologist and one cardiac surgeon. Ongoing studies are being performed using the hard clinical endpoints of death, myocardial infarction, and stroke in order to further compare the results of PCI vs CABG in LMS patients.

Validating the EXCEL hypothesis: a propensity score matched 3-year comparison of percutaneous coronary intervention versus coronary artery bypass graft in left main patients with SYNTAX score ≤32

OBJECTIVES

The aim of this study is to verify the study hypothesis of the EXCEL trial by comparing percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) in an EXCEL-like population of patients.

BACKGROUND

The upcoming EXCEL trial will test the hypothesis that left main patients with SYNTAX score ≤ 32 experience similar rates of 3-year death, myocardial infarction (MI), or cerebrovascular accidents (CVA) following revascularization by PCI or CABG.

METHODS

We compared the 3-year rates of death/MI/CVA and death/MI/CVA/target vessel revascularization (MACCE) in 556 patients with left main disease and SYNTAX score ≤ 32 undergoing PCI (n = 285) or CABG (n = 271). To account for confounders, outcome parameters underwent extensive statistical adjustment.

RESULTS

The unadjusted incidence of death/MI/CVA was similar between PCI and CABG (12.7% vs. 8.4%, P = 0.892), while MACCE were higher in the PCI group compared to the CABG group (27.0% vs. 11.8%, P < 0.001). After propensity score matching, PCI was not associated with a significant increase in the rate of death/MI/CVA (11.8% vs. 10.7%, P = 0.948), while MACCE were more frequently noted among patients treated with PCI (28.8% vs. 14.1%, P = 0.002). Adjustment by means of SYNTAX score and EUROSCORE, covariates with and without propensity score, and propensity score alone did not change significantly these findings.

CONCLUSIONS

In an EXCEL-like cohort of patients with left main disease, there seems to be a clinical equipoise between PCI and CABG in terms of death/MI/CVA. However, even in patients with SYNTAX score ≤ 32, CABG is superior to PCI when target vessel revascularization is included in the combined endpoint.

An overview of the objectives of and the approaches to propensity score analyses

The assessment of treatment effects from observational studies may be biased with patients not randomly allocated to the experimental or control group. One way to overcome this conceptual shortcoming in the design of such studies is the use of propensity scores to adjust for differences of the characteristics between patients treated with experimental and control interventions. The propensity score is defined as the probability that a patient received the experimental intervention conditional on pre-treatment characteristics at baseline. Here, we review how propensity scores are estimated and how they can help in adjusting the treatment effect for baseline imbalances. We further discuss how to evaluate adequate overlap of baseline characteristics between patient groups, provide guidelines for variable selection and model building in modelling the propensity score, and review different methods of propensity score adjustments. We conclude that propensity analyses may help in evaluating the comparability of patients in observational studies, and may account for more potential confounding factors than conventional covariate adjustment approaches. However, bias due to unmeasured confounding cannot be corrected for.

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.

Drug-eluting versus bare-metal stents in unprotected left main coronary artery stenosis a meta-analysis

OBJECTIVES

We undertook a meta-analysis to assess outcomes for drug-eluting stents (DES) and bare-metal stents (BMS) in percutaneous coronary intervention for unprotected left main coronary artery (ULMCA) stenosis.

BACKGROUND

Uncertainty exists regarding the relative performance of DES versus BMS in percutaneous coronary intervention for unprotected left main coronary stenosis.

METHODS

Of a total of 838 studies, 44 met inclusion criteria (n = 10,342). The co-primary end points were mortality, myocardial infarction (MI), target vessel/lesion revascularization (TVR/TLR), and major adverse cardiac events (MACE: mortality, MI, TVR/TLR).

RESULTS

Event rates for DES and BMS were calculated at 6 to 12 months, at 2 years, and at 3 years. Crude event rates at 3 years were mortality (8.8% and 12.7%), MI (4.0% and 3.4%), TVR/TLR (8.0% and 16.4%), and MACE (21.4% and 31.6%). Nine studies were included in a comparative analysis (n = 5,081). At 6 to 12 months the adjusted odds ratio (OR) for DES versus BMS were: mortality 0.94 (95% confidence interval [CI]: 0.06 to 15.48; p = 0.97), MI 0.64 (95% CI: 0.19 to 2.17; p = 0.47), TVR/TLR 0.10 (95% CI: 0.01 to 0.84; p = 0.01), and MACE 0.34 (95% CI: 0.15 to 0.78; p = 0.01). At 2 years, the OR for DES versus BMS were: mortality 0.42 (95% CI: 0.28 to 0.62; p < 0.01), MI 0.16 (95% CI: 0.01 to 3.53; p = 0.13), and MACE 0.31 (95% CI: 0.15 to 0.66; p < 0.01). At 3 years, the OR for DES versus BMS were: mortality 0.70 (95% CI: 0.53 to 0.92; p = 0.01), MI 0.49 (95% CI: 0.26 to 0.92; p = 0.03), TVR/TLR 0.46 (95% CI: 0.30 to 0.69; p < 0.01), and MACE 0.78 (95% CI: 0.57 to 1.07; p = 0.12).

CONCLUSIONS

Our meta-analysis suggests that DES is associated with favorable outcomes for mortality, MI, TVR/TLR, and MACE as compared to BMS in percutaneous coronary intervention for unprotected left main coronary artery stenosis.

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.

Meta-analysis of clinical studies comparing coronary artery bypass grafting with percutaneous coronary intervention and drug-eluting stents in patients with unprotected left main coronary artery narrowings

The aim of this study was to compare the safety and efficacy of coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) using drug-eluting stents (DES) in patients with unprotected left main coronary artery (ULMCA) disease. The current American College of Cardiology and American Heart Association guidelines recommend CABG for the treatment of patients with ULMCA disease on the basis of clinical trials demonstrating a survival benefit with CABG compared to medical therapy. DES reduce the rate of target vessel revascularization compared with bare-metal stents in ULMCA PCI and may be a safe alternative to CABG. A meta-analysis was conducted of clinical studies comparing CABG and PCI with DES for ULMCA disease with respect to death; the composite of death, myocardial infarction, or stroke; and target vessel revascularization at 1 year follow-up. The analysis included 2,905 patients from 8 clinical studies (2 randomized trials and 6 nonrandomized studies). At 1-year follow-up, there was no significant difference between the CABG and DES groups in the risk for death (odds ratio [OR] 1.12, 95% confidence interval [CI] 0.80 to 1.56) or the composite end point of death, myocardial infarction, or stroke (OR 1.25, 95% CI 0.86 to 1.82). The risk for target vessel revascularization was significantly lower in the CABG group compared to the PCI group (OR 0.44, 95% CI 0.32 to 0.59). In conclusion, PCI with DES is safe and could represent a good alternative to CABG for selected cases in patients with ULMCA disease.

C-peptide fragments stimulate glucose utilization in diabetic rats

Studies of C-peptide cellular effects show that not only the full-length native peptide but also specific C-terminal fragments are biologically active in in vitro systems. In the present study, the effect of five C-peptide fragments and the native peptide on whole-body glucose turnover was studied in streptozotocin diabetic rats using the insulin clamp technique. Insulin was infused intravenously at 18 pmol kg(-1) min(-1) for 90 min and blood glucose concentration was clamped at 8 and 4 mM in diabetic and non-diabetic animals. A steady state was reached during the last 30 min of the study period. Rat C-peptide II and fragments comprising residues 27-31 and 28-31 were effective in augmenting glucose turnover in diabetic rats (+100% to 150%), while no significant effects were seen for segments 1-26, 11-19 and 11-15. The metabolic clearance rate for glucose during infusion of C-peptide or fragments 27-31 and 28-31 in diabetic rats was similar to that seen in non-diabetic animals. We conclude that C-terminal tetra- and pentapeptides, but not fragments from the middle segment of C-peptide, are as effective as the full-length peptide in stimulating whole-body glucose turnover in diabetic rats.