Clinical and angiographic outcomes of patients treated with everolimus-eluting stents or first-generation Paclitaxel-eluting stents for unprotected left main disease

A large, prospective, multicentre study of left main PCI using a latest-generation zotarolimus-eluting stent: the ROLEX study

BACKGROUND

Data on left main (LM) percutaneous coronary interventions (PCI) have mostly been obtained in studies using drug-eluting stent (DES) platforms without dedicated large-vessel devices and with limited expansion capability.

AIMS

Our study aimed to investigate the safety and efficacy of LM PCI with the latest-generation Resolute Onyx DES.

METHODS

ROLEX (Revascularization Of LEft main with resolute onyX) is a prospective, multicentre study (ClinicalTrials.gov: NCT03316833) enrolling patients with unprotected LM coronary artery disease and a SYNTAX score <33 undergoing PCI with the Resolute Onyx zotarolimus-eluting coronary stent, that includes dedicated extra-large vessel platforms. The primary endpoint (EP) was target lesion failure (TLF): a composite of cardiac death, target vessel myocardial infarction (TVMI) and ischaemia-driven target lesion revascularisation (ID-TLR), at 1 year. All events were adjudicated by an independent clinical event committee. An independent core lab analysed all procedural angiograms.

RESULTS

A total of 450 patients (mean age 71.8 years, SYNTAX score 24.5±7.2, acute coronary syndrome in 53%) were enrolled in 26 centres. Of these, 77% of subjects underwent PCI with a single-stent and 23% with a 2-stent technique (8% double kissing [DK] crush, 6% culotte, 9% T/T and small protrusion [TAP] stenting). Intravascular imaging guidance was used in 45% (42% intravascular ultrasound [IVUS], 3% optical coherence tomography [OCT]). At 1 year, the primary EP incidence was 5.1% (cardiac death 2.7%, TVMI 2.7%, ID-TLR 2.0%). The definite/probable stent thrombosis rate was 1.1%. In a prespecified adjusted subanalysis, the primary EP incidence was significantly lower in patients undergoing IVUS/OCT-guided versus angio-guided PCI (2.0 vs 7.6%; hazard ratio [HR] 0.28, 95% confidence interval [CI]: 0.13-0.58; p<0.001).

CONCLUSIONS

In this large, multicentre, prospective registry, LM PCI with the Resolute Onyx DES showed good safety and efficacy at 1 year, particularly when guided by intracoronary imaging.

Outcomes of Left Main Revascularization after Percutaneous Intervention or Bypass Surgery

Background

This study is aimed at comparing the clinical outcomes of unprotected left main coronary artery disease (ULMCAD) treatment with contemporary percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in a "real-world" population.

Methods and Results

Overall, 558 consecutive patients with ULMCAD (mean age 71 ± 9 years, male gender 81%) undergoing PCI or CABG were compared. The primary endpoint was the composite of death, nonfatal myocardial infarction, or stroke. Diabetes was present in 29% and acute coronary syndrome in 56%; mean EuroSCORE was 11 ± 8. High coronary complexity (SYNTAX score >32) was present in 50% of patients. The primary composite endpoint was similar after PCI and CABG up to 4 years (15.5 ± 3.1% vs. 17.1 ± 2.6%; p=0.585). The primary end point was also comparable in a two propensity score matched cohorts. Ischemia-driven revascularization was more frequently needed in PCI than in CABG (5.5% vs. 1.5%; p=0.010). By multivariate analysis, diabetes mellitus (HR 2.00; p=0.003) and EuroSCORE (HR 3.71; p < 0.001) were the only independent predictors associated with long-term outcome.

Conclusions

In a "real-world" population with ULMCAD, a contemporary revascularization strategy by PCI or CABG showed similar long-term clinical outcome regardless of the coronary complexity.

Percutaneous Coronary Intervention for Left Main Coronary Artery Disease: Present Status and Future Perspectives

For several decades, coronary artery bypass grafting has been regarded as the standard choice of revascularization for significant left main coronary artery (LMCA) disease. However, in conjunction with remarkable advancement of device technology and adjunctive pharmacology, percutaneous coronary intervention (PCI) offers a more expeditious approach with rapid recovery and is a safe and effective alternative in appropriately selected patients with LMCA disease. Several landmark randomized clinical trials showed that PCI with drug-eluting stents for LMCA disease is a safe option with similar long-term survival rates to coronary artery bypass grafting surgery, especially in those with low and intermediate anatomic risk. Although it is expected that the updated evidence from recent randomized clinical trials will determine the next guidelines for the foreseeable future, there are still unresolved and unmet issues of LMCA revascularization and PCI strategy. This paper provides a comprehensive review on the evolution and an update on the management of LMCA disease.

Five-year outcomes comparing percutaneous coronary intervention with drug-eluting stents versus coronary artery bypass grafting in patients with left main coronary artery disease: A systematic review and meta-analysis

BACKGROUND AND AIMS

In patients with left main coronary artery disease (LMCAD), long-term outcomes after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) compared with coronary artery bypass grafting (CABG) remain controversial. We conducted a meta-analysis to compare the efficacy and safety of PCI with DES and CABG in LMCAD patients.

METHODS

We comprehensively searched in Web of Science, EMBASE, PubMed, and Cochrane databases for eligible randomised controlled trials (RCTs) comparing the 5-year clinical outcomes between PCI with DES and CABG in LMCAD patients. Random-effect models were applied to analyse risk ratios (RRs) and hazard ratios (HRs) across studies, and I² to assess heterogeneity.

RESULTS

We screened 4 RCTs including 4394 patients distributed randomly into PCI (n = 2197) and CABG (n = 2197) groups. In comparison to CABG, PCI showed non-inferiority concerning a composite of death, myocardial infarction, and stroke (HR 1.22, 95% confident interval [CI] 0.84-1.75), death (HR 1.06, 95% CI 0.81-1.40) and stroke (HR 0.80, 95% CI 0.42-1.53). Regarding major adverse cardiac or cerebrovascular events (MACCE) rate, both strategies show clinical equipoise in patients with a low-to-intermediate Synergy Between PCI with TAXUS and Cardiac Surgery (SYNTAX) score (HR 1.20, 95% CI 0.85-1.70), while CABG had an advantage over PCI in those with a high SYNTAX score (HR 1.64, 95% CI 1.20-2.24).

CONCLUSIONS

CABG showed advantage over PCI with DES for LMCAD patients in MACCE. PCI and CABG showed equivalent 5-year clinical risk of a composite of all-cause mortality, myocardial infarction, and stroke, but the former had higher risk of repeat revascularization.

Long-term outcome in patients treated with first- versus second-generation drug-eluting stents for the treatment of unprotected left main coronary artery stenosis

OBJECTIVE AND BACKGROUND

The study aim is to provide long-term clinical outcome after percutaneous coronary intervention (PCI) for unprotected left main coronary arteries (ULMCA) stenosis with the first-generation (1^st -gen) drug-eluting stents (DES) in comparison to 2^nd -gen DES, since this is largely unknown.

METHODS

Between May 2002, and December 2014, a consecutive series of 656 all-comer patients underwent a PCI for ULMCA stenosis at the Erasmus Medical Center. A total of 235 patients were treated with 1^st -gen DES, while a total of 421 patients were treated with 2^nd -gen DES.

RESULTS

Overall, the population consisted of 73% males and 58% presented with an acute coronary syndrome. Median follow-up time was 1,361 days (range from 0 to 5,031). At 5 years, the cumulative incidence of major adverse clinical events (the primary composite endpoint of all-cause death, any myocardial infarction or target lesion revascularization; MACE) did not differ between 1^st - and 2^nd -gen DES (36.8 vs. 38.6%, respectively, Log Rank p = .79, adjusted hazard ratio [HR] = 1.28 [95% confidence interval (CI) 0.94-1.74]). No difference was found in the individual endpoints of all-cause mortality (29.5 vs. 29% respectively, p = .88, adjusted HR = 1.19 [95% CI, 0.84-1.68]), target vessel myocardial infarction (5.0 vs. 8.4%, p = 0.17, adjusted HR = 1.75 [95% CI, 0.78-3.96]) and target lesion revascularization (8.1 vs. 9.8%, p = .94, adjusted HR = 1.16 [95% CI, 0.59-2.29]) between the 1^st - and 2^nd -gen DES cohorts, respectively.

CONCLUSIONS

In this large cohort of consecutive patients treated for ULMCA stenosis, no significant differences were found in the safety and efficacy of 1^st versus 2^nd -gen DES at 5 years follow-up.

Full-metal jacket technique using second-generation drug-eluting stent: clinical and angiographic follow-up in 2 years

The aims of this study are to evaluate the efficacy of percutaneous coronary intervention (PCI) using full-metal jacket (FMJ) with second-generation drug-eluting stents (DES). A single-center, non-randomized, retrospective study was performed from May 2005 to February 2014 at Miyazaki Medical Association Hospital, Japan. PCI using FMJ with DES was performed to treat 240 very long lesions (> 60 mm) in 240 patients. Subjects were divided into a first-generation or second-generation DES group. The primary endpoint was the incidence of major adverse cardiac events (MACE) at 2 years. MACE included all-cause death, myocardial infarction (MI), cerebrovascular event, and target vessel revascularization. The secondary endpoint was binary restenosis (> 50% stenosis) assessed by angiography at 1 year of follow-up. Second-generation DES were implanted to treat 121 lesions, and the first-generation DES were implanted to treat 119 lesions. Since 35 patients were lost to follow-up, the final analysis included 102 patients with second-generation DES and 103 with first-generation DES. At the 2-year follow-up, the incidence of MACE was significantly less in the second-generation DES group (9.8% vs. 20.4%, p = 0.03). The incidence of binary restenosis at 1 year was also significantly lower in the second-generation DES group (6.7% vs 29.1%, p < 0.01). When PCI was performed using FMJ with DES to treat very long lesion, the angiographic and clinical outcomes were better with second-generation than first-generation DES.

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.

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.

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 Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting for Unprotected Left Main Coronary Artery Disease

Coronary artery bypass grafting (CABG) decreases mortality in patients with significant left main (LM) coronary artery disease and for years remained the therapy of choice for patients with this ominous lesion. Advances in percutaneous coronary intervention (PCI) have enabled it to become an alternative to CABG. The results of observational registries and randomized comparisons have shown the safety and efficacy of PCI in appropriately selected patients with low or intermediate angiographic risk scores. Furthermore, the use of physiological measures of flow limitation and the use of intracoronary imaging techniques has added benefit and improved outcomes. The use of fractional flow reserve to more accurately evaluate the significance of intermediate lesions and guide the extent of revascularization has been an important refinement. Intravascular ultrasound and optical coherence tomography assessment of optimal stent deployment has led to reductions in restenosis. Newer generation stents, combined with improvements in specific techniques, especially at the LM bifurcation have extended PCI to more complex anatomic scenarios. The availability of left ventricular support devices in patients with complex coronary anatomy and severely depressed left ventricular function has added a margin of safety to LM and multivessel intervention. Randomized comparisons of CABG with PCI in carefully selected patients, using contemporaneous surgical and interventional techniques and optimal medical therapy, will further aid heart teams in the decision-making process. In conclusion, this review will give a concise overview of the management of unprotected LM disease.

Second vs. First generation drug eluting stents in multiple vessel disease and left main stenosis: Two-year follow-up of the observational, prospective, controlled, and multicenter ERACI IV registry

OBJECTIVE

To compare second generation drug eluting stents (2DES) with first generation (1DES) for the treatment of patients (pts) with multiple coronary vessel disease (MVD).

BACKGROUND

Although 2DES improved safety and efficacy compared to 1DES, MVD remains a challenge for percutaneous coronary interventions.

METHODS

ERACI IV was a prospective, observational, and controlled study in pts with MVD including left main and treated with 2DES (Firebird 2, Microport). We included 225 pts in 15 sites from Argentina. Primary endpoint was the incidence of major adverse cardiovascular events (MACCE) defined as death, myocardial infarction (MI), cerebrovascular accident (CVA) and unplanned revascularization; and to compare with 225 pts from ERACI III study (1DES). PCI strategy was planned to treat lesions ≥70% in vessels ≥ 2.00 mm, introducing a modified Syntax score (SS) where severe lesions in vessels < 2.0 mm and intermediate lesions were not scored.

RESULTS

Baseline characteristics showed that compared to ERACI III, ERACI IV pts had higher number of diabetics (P = 0.02), previous revascularization (P = 0.007), unstable angina IIb/IIIc (P < 0.001) and three vessels/left main disease (P = 0.003). Modified SS was 22.2 ± 11. At 2 years of follow-up ERACI IV group had significantly lower incidence of death+ MI + CVA, (P = 0.01) and MACCE (P = 0.001). MACCE rate was similar in diabetics, (5.8%) and nondiabetics (7.0%). After performing a matched propensity score, MACCE remain significantly lower in ERACI IV (P = 0.005).

CONCLUSION

This registry showed that 2DES in MVD has a remarkable low incidence of MACCE in unadjusted and adjusted analysis. © 2016 Wiley Periodicals, Inc.

Computational simulation of platelet interactions in the initiation of stent thrombosis due to stent malapposition

Coronary stenting is one of the most commonly used approaches to open coronary arteries blocked due to atherosclerosis. Stent malapposition can induce thrombosis but the microscopic process is poorly understood. The objective of this study was to determine the platelet-level process by which different extents of stent malapposition affect the initiation of stent thrombosis. We utilized a discrete element model to computationally simulate the transport, adhesion, and activation of thousands of individual platelets and red blood cells during thrombus initiation in stented coronary arteries. Simulated arteries contained a malapposed stent with a specified gap distance (0, 10, 25, 50, or 200 μm) between the struts and endothelium. Platelet-level details of thrombus formation near the proximal-most strut were measured during the simulations. The relationship between gap distance and amount of thrombus in the artery varied depending on different conditions (e.g., amount of dysfunctional endothelium, shear-induced activation of platelets, and thrombogenicity of the strut). Without considering shear-induced platelet activation, the largest gap distance (200 μm) produced no recirculation and less thrombus than the smallest two gap distances (0 and 10 μm) that created recirculation downstream of the strut. However, with the occurrence of shear-induced platelet activation, the largest gap distance produced more thrombus than the two smallest gap distances, but less thrombus than an intermediate gap distance (25 μm). A large gap distance was not necessarily the most thrombogenic, in contrast to implications of some computational fluid dynamics studies. The severity of stent malapposition affected initial stent thrombosis differently depending on various factors related to fluid recirculation, platelet trajectories, shear stress, and endothelial condition.

Update on percutaneous intervention for left main coronary artery stenosis

Percutaneous coronary intervention (PCI) using drug-eluting stents (DES) is currently considered as a viable alternative to coronary artery bypass graft surgery (CABG) for selected patients with left main coronary artery disease. The updated results of the landmark randomized trials comparing CABG versus PCI demonstrated comparable 5-year outcomes and are in line with the current guidelines that designate PCI as a reasonable treatment in this disease subset. Given that the completed randomized trials did not include contemporary DESs, the upcoming results of the ongoing trials evaluating the performance of new-generation DES compared with CABG (such as the EXCEL trial), may further help to clarify the current role and future recommendations of PCI for left main coronary artery disease. Apart from the recent stent technology, further improvements in outcomes after PCI may be possible when it is used with an integrated approach that combines functional concepts for decision-making, adjunctive imaging support and optimal pharmacotherapies.

Simulation of the microscopic process during initiation of stent thrombosis

OBJECTIVE

Coronary stenting is one of the most commonly used approaches to open coronary arteries blocked due to atherosclerosis. However, stent struts can induce stent thrombosis due to altered hemodynamics and endothelial dysfunction, and the microscopic process is poorly understood. The objective of this study was to determine the microscale processes during the initiation of stent thrombosis.

METHODS

We utilized a discrete element computational model to simulate the transport, collision, adhesion, and activation of thousands of individual platelets and red blood cells in thrombus formation around struts and dysfunctional endothelium.

RESULTS

As strut height increased, the area of endothelium activated by low shear stress increased, which increased the number of platelets in mural thrombi. These thrombi were generally outside regions of recirculation for shorter struts. For the tallest strut, wall shear stress was sufficiently low to activate the entire endothelium. With the entire endothelium activated by injury or denudation, the number of platelets in mural thrombi was largest for the shortest strut. The type of platelet activation (by high shear stress or contact with activated endothelium) did not greatly affect results.

CONCLUSIONS

During the initiation of stent thrombosis, platelets do not necessarily enter recirculation regions or deposit on endothelium near struts, as suggested by previous computational fluid dynamics simulations. Rather, platelets are more likely to deposit on activated endothelium outside recirculation regions and deposit directly on struts. Our study elucidated the effects of different mechanical factors on the roles of platelets and endothelium in stent thrombosis.

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.

Randomized trials of PCIs versus CABG surgery: why coronary stenting should remain the first choice of revascularization in non-diabetic patients and why the controversy is still present in diabetics

Knowing the best revascularization option for diabetic patients with multiple vessel disease is a challenge without a definitive answer. There have been several randomized clinical trials and subsequent meta-analyses comparing current available technology trying to reach an exhaustive conclusion; comparisons between coronary artery bypass grafts and bare-metal stents, coronary artery bypass grafts and first generation drug-eluting stents and, most recently, first generation versus latest generation drug-eluting stents generated some interesting results. Information provided by pooled data from some of the most important randomized clinical cardiology trials from the last two decades have produced surprising results. The authors analyze these data to discuss the best therapeutic procedures for each patient.

Comparison of the degree of platelet aggregation inhibition with prasugrel versus clopidogrel and clinical outcomes in patients with unprotected left main disease treated with everolimus-eluting stents

The everolimus-eluting stent (EES) performs better than the first generation drug-eluting stent. Prasugrel compared with clopidogrel in acute coronary syndromes treated invasively is associated with improved clinical outcome and decreased risk of stent thrombosis. The aim of the study was to compare the clinical outcome and degree of platelet aggregation inhibition of patients treated with EES for unprotected left main disease (ULMD) and receiving clopidogrel or prasugrel. Patients receiving an EES for ULMD and with low residual platelet reactivity on clopidogrel or prasugrel treatment were included in the analysis. The primary end point of the study was the composite of cardiac mortality and myocardial infarction at 1 year. The secondary end point was the degree of platelet aggregation inhibition as assessed by light transmittance aggregometry. From January 2009 to December 2011, 252 patients with low residual platelet reactivity on thienopyridine treatment were treated with EES for ULMD. Of these, 104 patients received clopidogrel and 148 received prasugrel. The primary end point rate was lower in the prasugrel group compared with clopidogrel group: 1.3% and 9.6%, respectively (p = 0.002). Residual platelet reactivity was less in the prasugrel group compared with clopidogrel group (adenosine diphosphate 10 μmol/L 37 ± 17% and 45 ± 15%, respectively, p <0.001). At multivariate analysis, prasugrel treatment was related to the primary end point (hazard ratio 0.17; 95% confidence interval 0.04 to 0.77, p = 0.022). In conclusion, in patients treated with EES for ULMD, prasugrel compared with clopidogrel is associated with increased platelet aggregation inhibition and a better clinical outcome.

Pathology of second-generation everolimus-eluting stents versus first-generation sirolimus- and paclitaxel-eluting stents in humans

BACKGROUND

Clinical trials have demonstrated that the second-generation cobalt-chromium everolimus-eluting stent (CoCr-EES) is superior to the first-generation paclitaxel-eluting stent (PES) and is noninferior or superior to the sirolimus-eluting stent (SES) in terms of safety and efficacy. It remains unclear whether vascular responses to CoCr-EES are different from those to SES and PES because the pathology of CoCr-EES has not been described in humans.

METHODS AND RESULTS

A total of 204 lesions (SES=73; PES=85; CoCr-EES=46) from 149 autopsy cases with duration of implantation >30 days and ≤3 years were pathologically analyzed, and comparison of vascular responses was corrected for duration of implantation. The observed frequency of late and very late stent thrombosis was less in CoCr-EES (4%) versus SES (21%; P=0.029) and PES (26%; P=0.008). Neointimal thickness was comparable among the groups, whereas the percentage of uncovered struts was strikingly lower in CoCr-EES (median=2.6%) versus SES (18.0%; P<0.0005) and PES (18.7%; P<0.0005). CoCr-EES showed a lower inflammation score (with no hypersensitivity) and less fibrin deposition versus SES and PES. The observed frequency of neoatherosclerosis, however, did not differ significantly among the groups (CoCr-EES=29%; SES=35%; PES=19%). CoCr-EES had the least frequency of stent fracture (CoCr-EES=13%; SES=40%; PES=19%; P=0.007 for CoCr-EES versus SES), whereas fracture-related restenosis or thrombosis was comparable among the groups (CoCr-EES=6.5%; SES=5.5%; PES=1.2%).

CONCLUSIONS

CoCr-EES demonstrated greater strut coverage with less inflammation, less fibrin deposition, and less late and very late stent thrombosis compared with SES and PES in human autopsy analysis. Nevertheless, the observed frequencies of neoatherosclerosis and fracture-related adverse pathological events were comparable in these devices, indicating that careful long-term follow-up remains important even after CoCr-EES placement.