Very Late Pathological Responses to Cobalt-Chromium Everolimus-Eluting, Stainless Steel Sirolimus-Eluting, and Cobalt-Chromium Bare Metal Stents in Humans

Stenting of native right ventricular outflow tract obstructions in symptomatic infants: histological work-up of explanted specimen

BACKGROUND

Stenting of stenotic right ventricular outflow tract is a palliative measure for severely impaired small babies with Tetralogy of Fallot or similar pathologies. Little is known about the histopathological fate of the stents in the right ventricular outflow tract.

METHODS

Eight samples of surgically removed right ventricular outflow tract stents were histologically analysed according to a predefined protocol.

RESULTS

The most frequent diagnosis was Tetralogy of Fallot in four patients, pulmonary atresia with ventricular septal defect in two patients, double outlet right ventricle with pulmonary obstruction in one patient, and muscular obstruction of the right ventricular outflow tract in one patient with a syndromic disease with hypertrophic cardiomyopathy. Stents mean implantation duration was 444 days ranging from 105 to 1117 days (median 305.5 days). Histology revealed a variable degree of pseudointima formation consisting of fibromuscular cells surrounded by extracellular matrix. Four of the specimen contained adjacent myocardial tissue fragments, which showed regressive changes. Neither myocardium nor pseudointima tissue or tissue parts locally related to stent struts were infiltrated by inflammatory cells.

CONCLUSIONS

Histological analysis after explantation of early-in-life implanted right ventricular outflow tract stents revealed predominantly pronounced neo-intimal proliferation with a visible endothelial layer, no signs of inflammation, and no prolapse of muscular tissue through the stent struts. Thus, implantation of stents in early life seems to interfere little with the hosts' immune system and might help to open up the right ventricular outflow tract by mechanical forces and regressive changes in adjacent muscular tissue.

Targeted therapy with a localised abluminal groove, low-dose sirolimus-eluting, biodegradable-polymer coronary stent - five-year results of the TARGET All Comers randomised clinical trial

BACKGROUND

In the prospective, multicentre, randomised TARGET All Comers study, percutaneous coronary intervention (PCI) with the FIREHAWK biodegradable-polymer sirolimus-eluting stent (BP-SES) was non-inferior to the durable-polymer everolimus-eluting stent (DP-EES) for the primary endpoint of target lesion failure (TLF) at 12 months.

AIMS

We aimed to report the final study outcomes at 5 years.

METHODS

Patients referred for PCI were randomised to receive either a BP-SES or DP-EES in a 1:1 ratio in 10 European countries. Randomisation was stratified by centre and ST-elevation myocardial infarction (STEMI) presentation, and clinical follow-up extended to 5 years. The primary endpoint was TLF (composite of cardiac death, target vessel myocardial infarction [MI], or ischaemia-driven target lesion revascularisation). Secondary endpoints included patient-oriented composite events (POCE; composite of all-cause death, all MI, or any revascularisation and its components).

RESULTS

From December 2015 to October 2016, 1,653 patients were randomly assigned to the BP-SES or DP-EES groups, of which 93.8% completed 5-year clinical follow-up or were deceased. At 5 years, TLF occurred in 17.1% of the BP-SES group and in 16.3% of the DP-EES group (p=0.68). POCE occurred in 34.0% of the BP-SES group and 32.7% of the DP-EES group (p=0.58). Revascularisation was the most common POCE, occurring in 19.3% of patients receiving BP-SES and 19.2% receiving DP-EES, of which less than one-third was ischaemia-driven target lesion-related. In the landmark analysis, there were no differences in the rates of TLF and POCE between groups from 1 to 5 years, and these results were consistent across all subgroups.

CONCLUSIONS

In an all-comers population requiring stent implantation for myocardial ischaemia, the BP-SES was non-inferior to the DP-EES for the primary endpoint of TLF at 12 months, and results were sustained at 5 years, confirming the long-term safety and efficacy of the FIREHAWK BP-SES.

The relation of polymer structure of stent used in patients with acute coronary syndrome revascularized by stent implantation with long-term cardiovascular events

INTRODUCTION

Drug-eluting stents (DES) have revolutionized percutaneous coronary intervention (PCI) by improving event-free survival compared to older stent designs. However, early-generation DES with polymer matrixes have raised concerns regarding late stent thrombosis due to delayed vascular healing. To address these issues, biologically bioabsorbable polymer drug-eluting stents (BP-DES) and polymer-free drug-eluting stents (PF-DES) have been developed.

AIM

The aim of the present study is to evaluate and compare the long-term effects of different stent platforms in patients with acute coronary syndrome (ACS) undergoing PCI.

MATERIAL AND METHODS

We conducted a retrospective, observational study involving 1192 ACS patients who underwent urgent PCI. Patients were treated with thin- strut DP-DES, ultra-thin strut BP-DES, or thin-strut PF-DES. The primary endpoint was a composite of cardiac death, target vessel myocardial infarction (TVMI), and clinically driven target lesion revascularization (CITLR) at 12 months and 4 years.

RESULTS

The baseline demographics and clinical characteristics of patients in the three stent subgroups were similar. No significant differences were observed in target lesion failure (TLF), cardiac mortality, TVMI, and stent thrombosis (ST) rates among the three subgroups at both 12 months and 4 years. However, beyond the first year, the rate of CITLR was significantly lower in the ultra-thin strut BP-DES subgroup compared to thin-strut DP-DES, suggesting potential long-term advantages of ultra-thin strut BP-DES. Additionally, both ultra-thin strut BP-DES and thin-strut PF-DES demonstrated lower ST rates after the first year compared to thin-strut DP-DES.

CONCLUSION

Our study highlights the potential advantages of ultra-thin strut BP-DES in reducing CITLR rates in the long term, and both ultra-thin strut BP-DES and thin-strut PF-DES demonstrate lower rates of ST beyond the first year compared to thin-strut DP-DES. However, no significant differences were observed in overall TLF, cardiac mortality and TVMI rates among the three stent subgroups at both 12 months and 4 years.

The ISCHEMIA trial revisited: setting the record straight on the benefits of coronary bypass surgery and the misinterpretation of a landmark trial

OBJECTIVES

The ISCHEMIA trial is a landmark study that has been the subject of heated debate within the cardiovascular community. In this analysis of the ISCHEMIA trial, we aim to set the record straight on the benefits of coronary artery bypass grafting (CABG) and the misinterpretation of this landmark trial. We sought to clarify and reorient this misinterpretation.

METHODS

We herein analyse the ISCHEMIA trial in detail and describe how its misinterpretation has led to an erroneous guideline recommendation downgrading for prognosis-altering surgical therapy in these at-risk patients.

RESULTS

The interim ISCHEMIA trial findings align with previous evidence where CABG reduces the long-term risks of myocardial infarction and mortality in advanced coronary artery disease. The trial outcomes of a significantly lower rate of cardiovascular mortality and a higher rate of non-cardiovascular mortality with the invasive strategy are explained according to landmark evidence.

CONCLUSIONS

The ISCHEMIA trial findings are aligned with previous evidence and should not be used to downgrade recommendations in recent guidelines for the indisputable benefits of CABG.

Heterogeneous vascular response after implantation of bare nitinol self-expanding stents in the swine femoropopliteal artery

BACKGROUND

Mechanism of femoropopliteal in-stent restenosis has been underappreciated.

AIM

The aim of this animal study was to elucidate vascular response after femoropopliteal bare nitinol self-expanding stents (SESs) implantation.

METHODS

Misago, Smart Flex, or Innova stent was randomly implanted in 36 swine femoropopliteal arteries. At week 4, quantitative vessel analysis (QVA) was performed on 36 legs, of which 18 underwent histological evaluation after angiography. The remaining 18 legs underwent QVA and histological evaluation at week 13.

RESULTS

Fibrin deposition was excessive at week 4. Internal elastic lamina (IEL) progressively enlarged over time, and vessel injury developed from mild level at week 4 to moderate level at week 13. Vessel inflammatory reaction was mild to moderate at week 4, and was moderate to severe at week 13. Increased fibrin deposition was an early-acting, IEL enlargement and increased vessel inflammation were long-acting, and increased vessel injury and giant cells infiltration were late-acting contributors to neointimal hyperplasia (NIH). Stent type altered time-dependent process of vessel injury, vessel inflammation, eosinophils and giant cells infiltration. Misago had less fibrin deposition and vessel enlargement, and less progressive vessel injury, vessel inflammation, and eosinophils and giant cells infiltration. Net lumen as assessed by percent diameter stenosis or minimum lumen diameter was preserved with Misago, but was not preserved with the other stents.

CONCLUSIONS

In the context of bare nitinol SES platform with less progressive mechanical stress and inflammatory reaction, the advantage of less NIH outweighed the disadvantage of less vessel enlargement, leading to net lumen preservation.

Neointimal characteristic changes following drug-coated balloons in lesions with repeated revascularization

BACKGROUND

Since their emergence, drug-coated balloons (DCBs) have been used widely to treat in-stent lesions with coronary artery disease (CAD). However, despite their superior efficacy to balloon angioplasty, how DCBs affect neointimal characteristics is poorly understood.

OBJECTIVES

We aimed to assess the neointimal characteristic changes following DCB treatment.

METHODS

Using optical frequency domain imaging (OFDI), we serially observed the in-stent lesion site just after and 1 year after DCB angioplasty in 12 lesions of 11 patients with repeated revascularization. Neoatherosclerosis was defined as lipid-laden neointima with or without calcification in the stented lesion. Progression or regression of neoatherosclerosis, newly formed neointimal calcification, newly formed uncovered strut and newly formed evagination were assessed. Tiny tissue protrusion was also recorded as mushroom-like protrusion.

RESULTS

Underlying stents were first-generation (n = 5) or newer (n = 7) drug-eluting stents (DESs) with implantation durations ranging from 1 to 15 years (median 8 years). Surprisingly, two-thirds of the lesions (67%, 8 of 12) showed progression of neoatherosclerosis, while a quarter of lesions (25%, 3 of 12) showed regression of neoatherosclerosis. The maximal lipid arc increased from 122° to 174°. Newly formed neointimal calcification was observed in 2 of 12 lesions (16%). Newly formed uncovered struts (33%; 4 of 12) and newly formed evaginations (33%; 4 of 12) were not rare. Mushroom-like protrusion was found in a quarter of lesions (25%; 3 of 12).

CONCLUSION

Our study demonstrated that a considerable number of lesions showed varied neointimal characteristic changes in a small number of patients. Further studies in a larger population are needed to understand the clinical impact of these findings.

Prevalence and Impact of Neoatherosclerosis on Clinical Outcomes After Percutaneous Treatment of Second-Generation Drug-Eluting Stent Restenosis

BACKGROUND

Clinical and morphological factors associated with lipidic versus calcified neoatherosclerosis within second-generation drug-eluting stents and the impact of lipidic versus calcified neoatherosclerosis on long-term outcomes after repeat intervention have not been well studied.

METHODS

A total of 512 patients undergoing optical coherence tomography before percutaneous coronary intervention for second-generation drug-eluting stents in-stent restenosis were included. Neoatherosclerosis was defined as lipidic or calcified neointimal hyperplasia in ≥3 consecutive frames or ruptured lipidic neointimal hyperplasia. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, or clinically driven target lesion revascularization).

RESULTS

The overall prevalence of neoatherosclerosis was 28.5% (146/512): 56.8% lipidic, 30.8% calcified, and 12.3% both lipidic and calcific. The prevalence increased as a function of time from stent implantation: 20% at 1 to 3 years, 30% at 3 to 7 years, and 75% >7 years. Renal insufficiency, poor lipid profile, and time from stent implantation were associated with lipidic neoatherosclerosis, whereas severe renal insufficiency, female sex, and time from stent implantation were associated with calcified neoatherosclerosis. Multivariable Cox regression revealed that female sex and lipidic neoatherosclerosis were associated with more target lesion failure, whereas stent age and final minimum lumen diameter after reintervention were related to lower target lesion failure. Calcified neoatherosclerosis was not related to adverse events after reintervention for in-stent restenosis given a large enough minimum lumen diameter was achieved.

CONCLUSIONS

Lipidic but not calcified neoatherosclerosis was associated with poor subsequent outcomes after repeat revascularization if optimal stent expansion was achieved in lesions with calcified neoatherosclerosis.

Applying Principles of Regenerative Medicine to Vascular Stent Development

Stents are a widely-used device to treat a variety of cardiovascular diseases. The purpose of this review is to explore the application of regenerative medicine principles into current and future stent designs. This review will cover regeneration-relevant approaches emerging in the current research landscape of stent technology. Regenerative stent technologies include surface engineering of stents with cell secretomes, cell-capture coatings, mimics of endothelial products, surface topography, endothelial growth factors or cell-adhesive peptides, as well as design of bioresorable materials for temporary stent support. These technologies are comparatively analyzed in terms of their regenerative effects, therapeutic effects and challenges faced; their benefits and risks are weighed up for suggestions about future stent developments. This review highlights two unique regenerative features of stent technologies: selective regeneration, which is to selectively grow endothelial cells on a stent but inhibit the proliferation and migration of smooth muscle cells, and stent-assisted regeneration of ischemic tissue injury.

Sirolimus-eluting cobalt-chrome alloy stent suppresses stent-induced tissue hyperplasia in a porcine Eustachian tube model

Various preclinical studies with developed Eustachian tube (ET) stents are in progress but have not yet been clinically applied. ET stent is limited by stent-induced tissue hyperplasia in preclinical studies. The effectiveness of sirolimus-eluting cobalt–chrome alloy stent (SES) in suppressing stent-induced tissue hyperplasia after stent placement in the porcine ET model was investigated. Six pigs were divided into two groups (i.e., the control and the SES groups) with three pigs for each group. The control group received an uncoated cobalt–chrome alloy stent (n = 6), and the SES group received a sirolimus-eluting cobalt–chrome alloy stent (n = 6). All groups were sacrificed 4 weeks after stent placement. Stent placement was successful in all ETs without procedure-related complications. None of the stents was able to keep its round shape as original, and mucus accumulation was observed inside and around the stent in both groups. On histologic analysis, the tissue hyperplasia area and the thickness of submucosal fibrosis were significantly lower in the SES group than in the control group. SES seems to be effective in suppressing stent-induced tissue hyperplasia in porcine ET. However, further investigation was required to verify the optimal stent materials and antiproliferative drugs.

COBRA PzF™ coronary stent in clinical and preclinical studies: setting the stage for new antithrombotic strategies?

Major advances have been made in coronary artery stent technology over the last decades. Drug-eluting stents reduced in-stent restenosis and have shown better outcomes compared with bare metal stents, yet some limitations still exist to their use. Because they delay healing of the vessel wall, longer dual antiplatelet therapy is mandatory to mitigate against stent thrombosis and this limitation is most concerning in subjects at high risk for bleeding. The COBRA PzF nanocoated coronary stent has been associated with accelerated endothelialization relative to drug-eluting stents, reduced inflammation and thromboresistance in preclinical studies, suggesting more flexible dual antiplatelet therapy requirement with potential benefits especially in those at high bleeding risk. Here, we discuss the significance of COBRA PzF in light of recent experimental and clinical studies.

Comparison of 6-month vascular healing response after bioresorbable polymer versus durable polymer drug-eluting stent implantation in patients with acute coronary syndromes: A randomized serial optical coherence tomography study

Objectives

This study was conducted to use optical coherence tomography (OCT) to compare vascular healing between bioresorbable polymer (BP) and durable polymer (DP) everolimus‐eluting stents (EES) in patients with acute coronary syndromes (ACS).

Background

Whether BP‐EES induce better vascular healing compared to contemporary DP‐EES remains controversial, especially for ACS.

Methods

In this prospective, randomized, non‐inferiority trial, we used OCT to compare 6‐month vascular healing in patients with ACS randomized to BP versus DP‐EES: percent strut coverage (primary endpoint, non‐inferiority margin of 2.0%) and neointimal thickness and percent neointimal hyperplasia (NIH) volume. As an exploratory analysis, morphological factors related to the endpoints and the effect of underlying lipidic plaque on stent healing were evaluated.

Results

A total of 104 patients with ACS were randomly assigned to BP‐EES (n = 52) versus DP‐EES (n = 52). Of these, 86 patients (40 BP‐EES and 46 DP‐EES) were included in the final OCT analyses. Six‐month percent strut coverage of BP‐EES (83.6 ± 11.4%) was not non‐inferior compared to those of DP‐EES (81.6 ± 13.9%), difference 2.0% (lower 95% confidence interval‐2.6%), p_{non‐inferiority} = 0.07. There were no differences in neointimal thickness 70.0 ± 33.9 μm versus 67.2 ± 33.9 μm, p = 0.71; and percent NIH volume 7.5 ± 4.7% versus 7.3 ± 5.3%, p = 0.85. By multivariable linear regression analysis, stent type was not associated with percent strut coverage or percent NIH volume; however, percent baseline embedded struts or stent expansion was positively associated with percent NIH volume. Greater NIH volume was observed in lipidic compared with non‐lipidic segments (8.7 ± 5.6% vs. 6.1 ± 5.2%, p = 0.005).

Conclusions

Six‐month strut coverage of BP‐EES was not non‐inferior compared to those of DP‐EES in ACS patients. Good stent apposition and expansion were independently associated with better vascular healing.

Endothelial Recovery in Bare Metal Stents and Drug-Eluting Stents on a Single-Cell Level

[Figure: see text].

Vascular responses to coronary calcification following implantation of newer-generation drug-eluting stents in humans: impact on healing

AIMS

Vascular calcification is routinely encountered in percutaneous coronary intervention (PCI) and severe coronary calcification is a known predictor of in-stent restenosis and stent thrombosis. However, the histopathologic mechanisms behind such events have not been systematically described.

METHODS AND RESULTS

From our registry of 1211 stents, a total of 134 newer-generation drug-eluting stents (DES) (Xience, Resolute-Integrity, PROMUS-Element, and Synergy) with duration of implant ≥30 days were histologically analysed. The extent of calcification of the stented lesions was evaluated radiographically and divided into severe (SC, n = 46) and non-severely calcified lesions (NC, n = 88). The percent-uncovered struts per section {SC vs. NC; median 2.4 [interquartile range (IQR) 0.0-19.0] % vs. 0.0 (IQR 0.0-4.6) %, P = 0.02} and the presence of severe medial tears (MTs) (59% vs. 44%, respectively, P = 0.03) were greater in SC than NC. In addition, SC had a higher prevalence of ≥3 consecutive struts lying directly in contact with surface calcified area (3SC) (52% vs. 8%, respectively, P < 0.0001). Multivariate analysis demonstrated that sections with duration of implantation ≤6 months [odds ratio (OR): 7.7, P < 0.0001], 3SC (OR: 6.5, P < 0.0001), strut malapposition (OR: 5.0, P < 0.0001), and lack of MTs (OR: 2.5, P = 0.0005) were independent predictors of uncovered struts. Prevalence of neoatherosclerosis was significantly lower in SC than that of NC (24% vs. 44%, P = 0.02).

CONCLUSION

Severe calcification, especially surface calcified area is an independent predictor of uncovered struts and delayed healing after newer-generation DES implantation. These data expand of knowledge of the vascular responses of stenting of calcified arteries and suggests further understand of how best to deal with calcification in patients undergoing PCI.

Novel Supreme Drug-Eluting Stents With Early Synchronized Antiproliferative Drug Delivery to Inhibit Smooth Muscle Cell Proliferation After Drug-Eluting Stents Implantation in Coronary Artery Disease: Results of the PIONEER III Randomized Clinical Trial

BACKGROUND

Accelerated endothelial healing after targeted antiproliferative drug delivery may limit the long-term inflammatory response of drug-eluting stents (DESs). The novel Supreme DES is designed to synchronize early drug delivery within 4 to 6 weeks of implantation, leaving behind a prohealing permanent base layer. Whether the Supreme DES is safe and effective in the short term and can improve long-term clinical outcomes is not known.

METHODS

In an international, 2:1 randomized, single-blind trial, we compared treatment with Supreme DES to durable polymer everolimus-eluting stents (DP-EES) in patients with acute and chronic coronary syndromes. The primary end point was target lesion failure-a composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. The trial was designed to demonstrate noninferiority (margin of 3.58%) of the Supreme DES at 12 months compared with DP-EES (URL: https://www.clinicaltrials.gov; Unique identifier: NCT03168776).

RESULTS

From October 2017 to July 2019, a total of 1629 patients were randomly assigned (2:1) to the Supreme DES (N=1086) or DP-EES (N=543). At 12 months, target lesion failure occurred in 57 of 1057 patients (5.4%) in the Supreme DES group and in 27 of 532 patients (5.1%) in the DP-EES group (absolute risk difference, 0.32% [95% CI, -1.87 to 2.5]; P_{noninferiority}=0.002]. There were no significant differences in rates of device success, clinically driven target lesion revascularization, or stent thrombosis at 12 months, and the safety composite of cardiovascular death and target vessel myocardial infarction was 3.5% versus 4.6% (hazard ratio, 0.76 [95% CI, 0.46-1.25]) with Supreme DES compared with DP-EES, although rates of combined clinically and non-clinically driven target lesion revascularization at 12 months were higher with Supreme DES.

CONCLUSIONS

Among patients with acute and chronic coronary syndromes undergoing percutaneous coronary intervention, the Supreme DES proved to be noninferior to the standard DP-EES. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03168776.

Vascular Responses to First-Generation Sirolimus-Eluting Stents and Bare-Metal Stents Beyond 10 Years

Background: There are limited data regarding differences in vascular responses between first-generation sirolimus-eluting stents (1G-SES) and bare-metal stents (BMS) >10 years after implantation.

Methods and Results: We retrospectively investigated 223 stents (105 1G-SES, 118 BMS) from 131 patients examined by optical coherence tomography (OCT) >10 years after implantation. OCT analysis included determining the presence or absence of a lipid-laden neointima, calcified neointima, macrophage accumulation, malapposition, and strut coverage. Neoatherosclerosis was defined as having lipid-laden neointima. OCT findings were compared between the 1G-SES and BMS groups, and the predictors of neoatherosclerosis were determined. The median stent age at the time of OCT examinations was 12.3 years (interquartile range 11.0–13.2 years). There were no significant differences in patient characteristics between the 1G-SES and BMS groups. On OCT analysis, there was no difference in the prevalence of neoatherosclerosis and calcification between 1G-SES and BMS. Multivariable logistic regression analysis revealed that stent size, stent length, and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use were significant predictors of neoatherosclerosis. In addition, uncovered and malapposed struts were more prevalent with 1G-SES than BMS.

Conclusions: After >10 years since implantation, the prevalence of neoatherosclerosis was no different between 1G-SES and BMS, whereas uncovered struts and malapposition were significantly more frequent with 1G-SESs.

Five-Year Comparative Efficacy of Everolimus-Eluting vs. Resolute Zotarolimus-Eluting Stents in Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Among drug-eluting stents (DESs), the durable polymer everolimus-eluting stent (EES) and resolute zotarolimus-eluting stent (R-ZES) are widely used in clinical practice and have contributed to improve the outcomes of patients undergoing percutaneous coronary intervention (PCI). Few studies addressed their long-term comparative performance in patients with acute coronary syndrome (ACS). We aimed to investigate the 5 year comparative efficacy of EES and R-ZES in ACS. We queried ACTION-ACS, a large-scale database of ACS patients undergoing PCI. The treatment groups were analyzed using propensity score matching. The primary endpoint was a composite of mortality, myocardial infarction (MI), stroke, repeat PCI, and definite or probable stent thrombosis, which was addressed at the five-year follow-up. A total of 3497 matched patients were analyzed. Compared with R-ZES, a significant reduction in the primary endpoint at 5 years was observed in patients treated with EES (hazard ratio (HR) [95%CI] = 0.62 [0.54-0.71], p < 0.001). By landmark analysis, differences between the two devices emerged after the first year and were maintained thereafter. The individual endpoints of mortality (HR [95%CI] = 0.70 [0.58-0.84], p < 0.01), MI (HR [95%CI] = 0.55 [0.42-0.74], p < 0.001), and repeat PCI (HR [95%CI] = 0.65 [0.53-0.73], p < 0.001) were all significantly lower in the EES-treated patients. Stroke risk did not differ between EES and R-ZES. In ACS, a greater long-term clinical efficacy with EES vs. R-ZES was observed. This difference became significant after the first year of the ACS episode and persisted thereafter.

Procedural safety and outcome of ultrathin strut stents (<60 μm) in the management of very long coronary artery stenosis (>30 mm) - A retrospective real world study

BACKGROUND

The ultrathin strut stents (<60 μm) are new in the current stents technology. This technology has assured to have less stent thrombosis, restenosis and better deliverability. Still there is lacking data of using long ultrathin strut stents in very long segment coronary artery disease (>30 mm).

AIM

The aim of this retrospective study was to assess the procedural safety and outcome of using ultrathin strut stents in very long segment coronary artery lesion.

METHODS

In this retrospective analysis, we have enrolled those patients who had an implant of more than 30 mm length of ultrathin strut stents (Evermine 50^TM and Tetrilimus stents) in real world patients as per physician discretion. Here, we enrolled 156 patients which included both acute coronary syndrome (ACS) and stable ischemic heart disease (SIHD). The endpoint of this study was to evaluate the immediate procedural success and short to intermediate term follow-up of all-cause mortality and clinically driven target lesion revascularization.

RESULTS

Out of these 156 patients (mean age- 61.2 +/- 10.4 years; male: 114), in 12 patients, these long stents couldn't be delivered. In rest 144 patients, 147 ultrathin strut stents were implanted. In about 56% patients were hypertensive and 48% patients were diabetic. About 63% patients had ACS and rest 37% patients had SIHD. The mean duration of follow up was 8.4 +/- 13.9 months. Average stent length and diameter were 39.5 +/- 5.9 mm and 3.03 +/- 0.4 mm, respectively. There was no acute or sub-acute stent thrombosis and no procedural complication. Five patients died during follow-up (all-cause mortality) and rest are all symptoms free. There were no statistical significant differences seen among the stent types.

CONCLUSION

Ultrathin strut stents can be considered for stenting in long segment coronary artery stenosis with reasonably good procedural success rate and have good clinical outcome, but needs further large randomized trial before using in this particular clinical condition. Both the stent designs have similar clinical outcome and procedural success.

Long-Term Outcomes After Revascularization for Stable Ischemic Heart Disease

Background:

Whether revascularization improves prognosis in stable ischemic heart disease is controversial.

Methods:

Individual patient-level data from 19 prospective, randomized stent trials were pooled. Rates of 5-year major adverse cardiovascular events (MACE; a composite of cardiac death, myocardial infarction, or ischemia-driven target lesion revascularization) were assessed and compared after percutaneous coronary intervention with bare-metal stents (BMS) and first-generation and second-generation drug-eluting stents (DES1 and DES2, respectively). Poisson multivariable regression analysis was performed to identify predictors of adverse events.

Results:

Among 10 987 patients treated with percutaneous coronary intervention for stable ischemic heart disease, 1550, 2776, and 6661 received BMS, DES1, and DES2, respectively. The 5-year rates of MACE progressively declined with evolution in stent technology (BMS: 24.1% versus DES1: 17.9% versus DES2: 13.4%, P <0.0001). However, MACE rates between 1 and 5 years increased from BMS to DES1, then declined with DES2 (BMS: 7.4% versus DES1: 10.2%, DES2: 8.5%, P =0.02).

Conclusions:

Patients with stable ischemic heart disease remain at substantial risk for long-term MACE after revascularization with percutaneous coronary intervention, even with contemporary DES. New approaches to reduce the ongoing risk of MACE beyond 1 year after stent implantation are necessary.

Are we curing one evil with another? A translational approach targeting the role of neoatherosclerosis in late stent failure

Neoatherosclerosis is defined as foamy macrophage infiltration into the peri-strut or neointimal area after stent implantation, potentially leading to late stent failure through progressive atherosclerotic changes including calcification, fibroatheroma, thin-cap fibroatheroma, and rupture with stent thrombosis (ST) in advanced stages. Human autopsy as well as intravascular imaging studies have led to the understanding of neoatherosclerosis formation as a similar but significantly accelerated pathophysiology as compared to native atherosclerosis. This acceleration is mainly based on disrupted endothelial integrity with insufficient barrier function and augmented transmigration of lipids following vascular injury after coronary intervention and especially after implantation of drug-eluting stents. In this review, we summarize translational insights into disease pathophysiology and discuss therapeutic approaches to tackle this novel disease entity. We introduce a novel animal model of neoatherosclerosis alongside accompanying in vitro experiments, which show impaired endothelial integrity causing increased permeability for low-density lipoprotein cholesterol resulting in foam cell transformation of human monocytes. In addition, we discuss novel intravascular imaging surrogates to improve reliable diagnosis of early stage neoatherosclerosis. Finally, a therapeutic approach to prevent in-stent neoatherosclerosis with magnesium-based bioresorbable scaffolds and systemic statin treatment demonstrated the potential to improve arterial healing and re-endothelialization, leading to significantly mitigated neoatherosclerosis formation in an animal model of neoatherosclerosis.

Twelve-month comparative analysis of clinical outcomes using biodegradable polymer-coated everolimus-eluting stents versus durable polymer-coated everolimus-eluting stents in all-comer patients

Aim

The purpose of the present study was to examine whether clinical differences exist between the biodegradable polymer (BDP)–coated Tetrilimus everolimus-eluting stent (EES) and the durable polymer (DP)–coated Xience EES by comparing the major adverse cardiac event (MACE) rate at 12 months in all-comer patients.

Methods

This study was designed as a multicentre, observational, retrospective, investigator-initiated study between January 2016 and October 2016. Two hundred thirteen patients who underwent percutaneous coronary intervention (PCI) with the BDP-EES were compared with 204 patients who underwent PCI with the DP-EES, irrespective of lesion complexity, comorbidities and acute presentation. The primary end point was MACE defined as a composite of cardiac death, myocardial infarction and target lesion revascularization.

Results

Baseline clinical and lesion characteristics of both the groups were similar, although the BDP-EES group had a significantly higher number of patients with diabetes mellitus (39.9% vs. 30.4%; p = 0.042) and type C lesion (67.4% vs. 48.1%; p < 0.001) than the DP-EES group. The 12-month MACE rate was 4.2% for the BDP-EES group versus 4.9% for the DP-EES group (p = 0.740). Mortality was lower in the BDP-EES group than in the DP-EES group (0.9% vs. 2.0%; p = 0.441).

Conclusion

The present comparative analysis shows that the BDP-coated Tetrilimus EES was as safe and effective as the DP-coated Xience EES during the 12-month follow-up period despite complex lesion characteristics.

Clinical Outcomes of World's Thinnest (50 μmr) Strut Biodegradable Polymer Coated Everolimus-Eluting Coronary Stent System in Real-World Patients

Background

The thinnest strut platform is revolutionary improvement into the field of percutaneous coronary intervention. The aim of this study was to assess the safety and performance of world’s thinnest (50 µm) strut biodegradable polymer coated Evermine 50™ everolimus-eluting coronary stent system (EES) in real-world patients with coronary artery disease.

Methods

This was a prospective, single-arm, single-center, post-marketing study in real-world patients. A total of 251 patients with de novo coronary artery lesion (lengths < 44 mm) and/or in-stent restenosis were enrolled and implanted with at least one Evermine 50 EES. The safety endpoint was major adverse cardiac events (MACE), composite of cardiac death, myocardial infarction (MI) attributed to the target vessel and clinically-driven target lesion revascularization (CD-TLR), at 6-month follow-up.

Results

Out of 251 patients enrolled (mean age: 58.20 ± 9.92 years and 193 males), 48.6% and 45.4% patients were diabetic and hypertensive, respectively. A total of 343 lesions were intervened successfully with Evermine 50 out of 474 identified lesions (1.89 lesions per patients). Average stent length and diameter were 23.50 ± 12.21 mm and 2.83 ± 0.23 mm, respectively. At 6-month follow-up, the incidence of MACE was two (0.8%) in the form of one (0.4%) cardiac death and one (0.4%) CD-TLR. In addition, there was no definite or probable stent thrombosis reported up to 6-month follow-up.

Conclusions

In the present study, lower rate of MACE was demonstrated, which reaffirms favourable clinical safety and performance of world’s thinnest (50 µm) strut Evermine 50 EES in real-world patients with coronary artery disease.

Targeted therapy with a localised abluminal groove, low-dose sirolimus-eluting, biodegradable polymer coronary stent (TARGET All Comers): a multicentre, open-label, randomised non-inferiority trial

BACKGROUND

The FIREHAWK is a drug-eluting stent with a fully biodegradable sirolimus-containing polymer coating localised to recessed abluminal grooves on the stent surface. We investigated clinical outcomes with this targeted, low-dose, biodegradable polymer, sirolimus-eluting stent compared with XIENCE durable polymer, everolimus-eluting stents in an all-comers population.

METHODS

The TARGET All Comers study was a prospective, multicentre, open-label randomised non-inferiority trial done at 21 centres in ten European countries. Patients with symptomatic or asymptomatic coronary artery disease and objective evidence of myocardial ischaemia who qualified for percutaneous coronary intervention were randomised 1:1 to undergo implantation of a FIREHAWK or XIENCE. Randomisation was web-based, with random block allocation and stratification by centre and ST elevation myocardial infarction. Outcome assessors were masked to treatment allocation, but treating physicians and patients were not. The primary endpoint was target lesion failure at 12 months, a composite of cardiac death, target vessel myocardial infarction, or ischaemia-driven target lesion revascularisation. The control event rate for XIENCE was assumed to be 7%, the non-inferiority margin was 3.5%, and the primary analysis was in the intention-to-treat population, censoring patients who did not have either an event before 365 days or contact beyond 365 days. Late lumen loss was the primary endpoint of an angiographic substudy designed to investigate the non-inferiority of the FIREHAWK compared with the XIENCE stent. This trial is registered with ClinicalTrials.gov, number NCT02520180.

FINDINGS

From Dec 17, 2015, to Oct 14, 2016, 1653 patients were randomly assigned to implantation of the FIREHAWK (n=823) or XIENCE (n=830). 65 patients in the FIREHAWK group and 66 in the XIENCE group had insufficient follow-up data and were excluded from the analyses. At 12 months, target lesion failure occurred in 46 (6·1%) of 758 patients in the FIREHAWK group and in 45 (5·9%) of 764 patients in the XIENCE group (difference 0·2%, 90% CI -1·9 to 2·2, p_{non-inferiority}=0·004, 95% CI -2·2 to 2·6, p_superiority=0·88). There were no differences in ischaemia-driven revascularisation or stent thrombosis rates at 12 months. 176 patients were included in the angiographic substudy, in which in-stent late lumen loss was 0·17 mm (SD 0·48) in the FIREHAWK group and 0·11 mm (0·52) in the XIENCE group (p=0·48), with an absolute difference of 0·05 mm (95% CI -0·09 to 0·18, p_{non-inferiority}=0·024).

INTERPRETATION

In a broad all-comers population of patients requiring stent implantation for myocardial ischaemia, the FIREHAWK was non-inferior to the XIENCE as assessed with the primary endpoint of target lesion failure at 12 months and in-stent late lumen loss at 13 months. The FIREHAWK is a safe and effective alternative stent to treat patients with ischaemic coronary artery disease in clinical practice.

FUNDING

Shanghai Microport Medical.

Favorable early vessel healing after everolimus-eluting stent implantation: 3-, 6-, and 12-month follow-up of optical coherence tomography

BACKGROUND

Although a prospective randomized control study revealed that 3-month dual anti-platelet therapy (DAPT) is safe and does not compromise the efficacy of everolimus-eluting stent (EES) in selected patients, detailed vessel healing at early phase after EES implantation has yet to be investigated in Japanese patients.

METHODS AND RESULTS

A total of 27 lesions in 19 patients treated with EES were serially evaluated by using optical coherence tomography (OCT) at 3, 6, and 12 months after stent implantation. In addition to standard quantitative OCT parameters, the percentage of stents with peri-strut low-intensity area (PLIA, a region around stent struts homogenously showing lesser intensity than the surrounding tissue, suggesting fibrin deposition or impaired neointima maturation) and that with in-stent thrombi were evaluated. There was a significant, but small increase in neointimal thickness (63±17μm; 83±30μm; and 111±44μm, respectively; p=0.006) and small decrease in average lumen area (6.80±2.57mm², 6.62±2.58mm², 6.33±2.58mm², p=0.038) from the 3- to the 12-month follow-up. The incidences of uncovered and malapposed struts were low at 3 months and did not significantly change at 6 months and 12 months (3.01±4.43; 2.45±3.75; and 1.47±3.16, p=0.143, and 0.75±0.65; 0.63±0.73; and 0.58±1.42, p=0.162, respectively). Also, frequency of struts with PLIA was already low at three months and significantly decreased during the follow-up (6.4±6.5; 4.6±5.4; and 2.3±3.3, respectively; p=0.001).

CONCLUSION

Favorable vessel healing was achieved at 3 months after EES implantation without neointimal hyperplasia which was persistently suppressed up to 12 months.

A new category stent with novel polyphosphazene surface modification

The COBRA-PzF™ (CeloNova BioSciences, Inc., TX, USA) is a new type of coronary stent composed of a cobalt chromium metallic backbone surrounded by a nanothin layer of Polyzene-F (PzF) without any added drug. Evidence from basic studies supports antithrombotic and anti-inflammatory properties for the PzF surface coating. Preclinical studies support the thromboresistance of PzF-coated surfaces and clinical studies have shown good outcomes for patients receiving this device with very low rates of stent thrombosis. COBRA-PzF may be especially useful in patients at high risk for bleeding. Ongoing clinical trials will determine whether shortening the duration of dual antiplatelet therapy to less than 1 month is feasible and these data may represent a new paradigm with regards to patients at high risk for bleeding.