Randomized Clinical Comparison of the Dual-Therapy CD34 Antibody-Covered Sirolimus-Eluting Combo Stent With the Sirolimus-Eluting Orsiro Stent in Patients Treated With Percutaneous Coronary Intervention: The SORT OUT X Trial

Comparison of Outcome After Percutaneous Coronary Intervention for De Novo and In-Stent Restenosis Indications

In-stent restenosis (ISR) still occurs after percutaneous coronary intervention (PCI). Few studies have compared the outcomes of PCI for de novo stenosis with those of PCI for ISR, and the results are conflicting. The present study aimed to conduct this comparison. Using patient-level data from the randomized all-comer SORT OUT studies III to X, we included all patients with previous PCI and either an ISR or a de novo lesion as the study target lesion. Outcomes of interest were major adverse cardiac events (MACE) and target lesion revascularization (TLR) after 5 years. Of the 2,928 patients with a previous PCI included in the SORT OUT studies, 491 (17%) were treated for ISR and 2,437 (83%) for a de novo stenosis. Baseline characteristics did not differ significantly. At 5 years, MACE occurred in 148 patients (32%) in the ISR group and 654 patients (28%) in the de novo stenosis group (crude and adjusted hazard ratio 1.16 [95% confidence interval (CI) 0.97 to 1.38] and 1.16 [95% CI 0.97 to 1.38]). The risk of TLR was higher in the ISR group compared with the de novo stenosis group (crude and adjusted hazard ratio 1.64 [95% CI 1.24 to 2.17] and 1.71 [95% CI 1.27 to 2.30]). In conclusion, the risk of MACE was similar between PCI for ISR and PCI for de novo lesions after 5 years. However, the risk of TLR was higher in the ISR group compared with the de novo stenosis group.

Stent strategies: Endothelial progenitor cell coated stents vs sirolimus eluting stents in a pairwise meta-analysis

BACKGROUND

Endothelial progenitor cells (EPCs) capturing stents were developed to enhance endothelial repair and reduce the risk of stent thrombosis, addressing limitations of Sirolimus-Eluting Stents (SES). This study aims to compare the safety and efficacy of EPC stents versus SES in patients undergoing percutaneous coronary intervention (PCI).

METHODS

We performed a meta-analysis following PRISMA guidelines in patients undergoing PCI treated with Sirolimus eluting stent (SES) vs the use of EPC stents and recognized 8 clinical trials with patients undergoing PCI and reporting outcomes such as Target Lesion Failure (TLF), stent thrombosis, and revascularisation. Relative risks were calculated using a random effects model and heterogeneity was assessed with I^2 statistics.

RESULTS

The EPC group showed higher incidence of TLF (RR ​= ​1.28), MI(RR ​= ​1.10), and cardiac death (RR ​= ​1.19) compared to SES, though these differences were not statistically significant. Revascularisation rates were significantly higher in EPC group with TVR (RR ​= ​1.60) and TLR(RR ​= ​2.20) while stent thrombosis was lower (RR ​= ​0.93).

CONCLUSION

The results of this EPC study reveals that while EPC stents show promise in revascularisation and lowering stent thrombosis, they are also associated with higher incidence of adverse events. The utility of EPC, especially vast reendothelialization, may have niche applications but their full potential can be realized with more rigorous trials as a clear advantage over SES remains lacking.

Mobilization of endothelial progenitor cells after implantation of CD34 antibody-covered sirolimus-eluting COMBO® stent: assessment with EPC colony-forming assay

The COMBO® stent is a unique stent on which the CD34 antibody is mounted to capture CD34 + endothelial progenitor cells (EPCs) and from which sirolimus is eluted to suppress neointimal hyperplasia. The COMBO® stent aims to induce early re-endothelialization and vascular healing and to prevent restenosis. In the clinical setting, however, the effects of the COMBO® stent have not been validated in terms of EPC biology. In this study, we assessed the kinetics of circulating EPCs, not only quantitatively by flow cytometric analysis but also qualitatively by an EPC colony-forming assay, in 25 patients undergoing COMBO® stent implantation. Among all patients, flow cytometric analysis indicated that the number of circulating CD34 + /KDR + EPCs did not change after COMBO® stent implantation compared with baseline (before stent implantation). The EPC colony-forming assay demonstrated that the number of small-type EPC colonies increased on day 2 (3 [2, 9] to 6 [4, 9]/dish, P = 0.026) and that of large-type EPC colonies more prominently increased on day 2 (1 [0, 4] to 5 [1, 10]/dish, P < 0.001) and day 7 (to 2 [1, 7], P = 0.006) after COMBO® stent implantation. Based on the results of optical coherence tomography at 3 months after stent implantation, the patients were divided into two groups: well (uncovered strut ratio < 10%, n = 14) and poor (uncovered strut ratio ≥ 10%, n = 10) stent coverage. Compared with baseline values, the number of large-type EPC colonies increased on day 2 (2.9 ± 0.8 to 7.3 ± 2.0, P = 0.026) and tended to increase on day 7 (6.8 ± 2.0/dish, P = 0.062) after COMBO® stent implantation in the well coverage group, while it did not change in the poor coverage group. Thus, the COMBO® stent might induce mature EPCs in the circulation, which might be associated with subsequent healing processes in vessel sites with stent-induced injury.

Use cases of registry-based randomized controlled trials-A review of the registries' contributions and constraints

Registry-based randomized controlled trials (RRCTs) can combine the advantages of registries with those of randomization. This review aimed to expand the current knowledge on RRCT utilization and implementation by providing a comprehensive overview of RRCT use cases. A targeted literature search was conducted through July 2023 to identify articles on RRCTs. Information regarding the RRCT characteristics, their utilization, and the registries' contributions and the constraints faced was extracted. Descriptive statistics were used. We identified 102 RRCTs in 110 publications. RRCTs were mostly performed for the assessment of medical devices or surgical/clinical procedures (n = 45), followed by drugs (n = 30). More than half of the RRCTs were conducted in the Nordic countries (n = 58) and the most used registry types were health service registries/administrative health data (n = 63), followed by disease registries (n = 46). Approximately half of the RRCTs (n = 53) utilized additional data sources aside from registry data. The contribution of a registry to the RRCT was mostly for data collection and study follow-up (n = 90-92), followed by patient recruitment (n = 56-61), and randomization (n = 28-38), with varying levels of transparency in reporting. We collated author-reported constraints related to the used registries into four overarching themes, that is, data availability and completeness, data quality, representativeness, and registry infrastructure and accessibility. This review shows that RRCTs are already used in different domains and geographic regions. Guidelines on structured and transparent reporting of RRCT methods and the optimal use are, however, needed to inform decision-making by health authorities and to reach their full potential.

In-Stent Re-Endothelialization Strategies: Cells, Extracellular Matrix, and Extracellular Vesicles

Arterial stenosis caused by atherosclerosis often requires stent implantation to increase the patency of target artery. However, such external devices often lead to in-stent restenosis due to inadequate re-endothelialization and subsequent inflammatory responses. Therefore, re-endothelialization strategies after stent implantation have been developed to enhance endothelial cell recruitment or to capture circulating endothelial progenitor cells. Notably, recent research indicates that coating stent surfaces with biogenic materials enhances the long-term safety of implantation, markedly diminishing the risk of in-stent restenosis. In this review, we begin by describing the pathophysiology of coronary artery disease and in-stent restenosis. Then, we review the characteristics and materials of existing stents used in clinical practice. Lastly, we explore biogenic materials aimed at accelerating re-endothelialization, including extracellular matrix, cells, and extracellular vesicles. This review helps overcome the limitations of current stents for cardiovascular disease and outlines the next phase of research and development.

Randomized comparison of TAVI valves: The Compare-TAVI trial

INTRODUCTION

Based on technical advancements and clinical evidence, transcatheter aortic valve implantation (TAVI) has been widely adopted. New generation TAVI valve platforms are continually being developed. Ideally, new valves should be superior or at least non-inferior regarding efficacy and safety, when compared to best-in-practice contemporary TAVI valves.

METHODS AND ANALYSIS

The Compare-TAVI trial (ClinicalTrials.gov NCT04443023) was launched in 2020, to perform a 1:1 randomized comparison of new vs contemporary TAVI valves, preferably in all comers. Consecutive cohorts will be launched with sample sizes depending on the choice of interim analyses, expected event rates, and chosen superiority or non-inferiority margins. Enrollment has just been finalized in cohort B, comparing the Sapien 3/Sapien 3 Ultra Transcatheter Heart Valve (THV) series (Edwards Lifesciences, Irvine, California, USA) and the Myval/Myval Octacor THV series (Meril Life Sciences Pvt. Ltd., Vapi, Gujarat, India) balloon expandable valves. This non-inferiority study was aimed to include 1062 patients. The 1-year composite safety and efficacy endpoint comprises death, stroke, moderate-severe aortic regurgitation, and moderate-severe valve deterioration. Patients will be followed until withdrawal of consent, death, or completion of 10-year follow-up, whichever comes first. Secondary endpoints will be monitored at 30 days, 1, 3, 5, and 10 years.

SUMMARY

The Compare-TAVI organization will launch consecutive cohorts wherein patients scheduled for TAVI are randomized to one of two valves. The aim is to ensure that the short- and long-term performance and safety of new valves being introduced is benchmarked against what achieved by best-in-practice contemporary valves.

Vascular stent with immobilized anti-inflammatory chemerin 15 peptides mitigates neointimal hyperplasia and accelerates vascular healing

Endovascular stenting is a safer alternative to open surgery for use in treating cerebral arterial stenosis and significantly reduces the recurrence of ischemic stroke, but the widely used bare-metal stents (BMSs) often result in in-stent restenosis (ISR). Although evidence suggests that drug-eluting stents are superior to BMSs in the short term, their long-term performances remain unknown. Herein, we propose a potential vascular stent modified by immobilizing clickable chemerin 15 (C15) peptides on the stent surface to suppress coagulation and restenosis. Various characterization techniques and an animal model were used to evaluate the surface properties of the modified stents and their effects on endothelial injury, platelet adhesion, and inflammation. The C15-immobilized stent could prevent restenosis by minimizing endothelial injury, promoting physiological healing, restraining the platelet-leukocyte-related inflammatory response, and inhibiting vascular smooth muscle cell proliferation and migration. Furthermore, in vivo studies demonstrated that the C15-immobilized stent mitigated inflammation, suppressed neointimal hyperplasia, and accelerated endothelial restoration. The use of surface-modified, anti-inflammatory, endothelium-friendly stents may be of benefit to patients with arterial stenosis. STATEMENT OF SIGNIFICANCE: Endovascular stenting is increasingly used for cerebral arterial stenosis treatment, aiming to prevent and treat ischemic stroke. But an important accompanying complication is in-stent restenosis (ISR). Persistent inflammation has been established as a hallmark of ISR and anti-inflammation strategies in stent modification proved effective. Chemerin 15, an inflammatory resolution mediator with 15-aa peptide, was active at picomolar through cell surface receptor, no need to permeate cell membrane and involved in resolution of inflammation by inhibiting inflammatory cells adhesion, modulating macrophage polarization into protective phenotype, and reducing inflammatory factors release. The implications of this study are that C15 immobilized stent favors inflammation resolution and rapid re-endothelialization, and exhibits an inhibitory role of restenosis. As such, it helps the decreased incidence of ISR.

Dual-therapy CD34 antibody-covered sirolimus-eluting COMBO stents versus sirolimus-eluting Orsiro stents in patients treated with percutaneous coronary intervention: the three-year outcomes of the SORT OUT X randomised clinical trial

BACKGROUND

Target lesion failure (TLF) remains an issue with contemporary drug-eluting stents. The dual-therapy sirolimus-eluting and CD34 antibody-coated COMBO stent (DTS) was designed to improve early healing.

AIMS

We aimed to compare the 3-year outcomes of the DTS and the sirolimus-eluting Orsiro stent (SES) in all-comer patients treated with percutaneous coronary intervention.

METHODS

The SORT OUT X trial is a prospective multicentre randomised clinical trial with a registry-based follow-up comparing DTS and SES. The primary endpoint, TLF, is a composite of cardiac death, myocardial infarction or target lesion revascularisation (TLR).

RESULTS

A total of 3,146 patients were randomised to treatment with the DTS (1,578 patients) or the SES (1,568 patients). At 3 years, an intention-to-treat analysis showed that 155 patients (9.8%) who were assigned the DTS and 118 patients (7.5%) who were assigned the SES met the primary endpoint (incidence rate ratio for TLF=1.33, 95% confidence interval: 1.04-1.70; p=0.02). This difference was caused by a significantly higher TLF rate in the DTS group compared to the SES group within the first year, which was mainly explained by a higher incidence of TLR in the DTS group compared to the SES group. Of note, the TLF rates were almost identical from 1 year to 3 years in both stent groups.

CONCLUSIONS

At 3 years, the SES was superior to the DTS, mainly because the DTS was associated with an increased risk of TLF within the first year but not from 1 to 3 years.

CLINICALTRIALS

gov: NCT03216733.

Very short-term tissue coverage of the CD34 antibody-covered sirolimus-eluting stent: an optical coherence tomography study

It is well known that patients with acute myocardial infarction (AMI) have delayed vessel healing despite accelerated endothelial progenitor cells (EPC) mobilization. The COMBO stent is a unique biodegradable-polymer sirolimus-eluting stent with an anti-CD34 antibody coating which captures EPC and potentially promotes vessel healing. However, there are limited data about strut tissue coverage at the very short-term period after COMBO stent implantation. This was a prospective study to investigate strut tissue coverage within 1 month after COMBO stent implantation using optical coherence tomography (OCT). Struts fully covered with tissue were defined as covered, and struts with distance from lumen surface longer than strut plus polymer thickness were defined as malapposed. Mean tissue thickness was measured only in apposed struts. A total of 8173 struts of 33 lesions in 32 patients were analyzed at an average of 19.8 ± 4.6 days after COMBO stent implantation. In lesion-level analysis, the rate of covered struts was 89.6 ± 7.2%, the rate of malapposed struts was 0.9 ± 2.0% and mean tissue thickness was 46.8 ± 14.3 µm. In comparison between AMI (n = 12) and non-AMI (n = 21) patients, there were no significant differences in the rate of covered struts (88.4 ± 8.4% vs. 90.2 ± 6.6%, p = 0.48) and mean tissue thickness (46.8 ± 13.7 µm vs. 46.9 ± 15.0 µm, p = 0.98). Multivariable analysis demonstrated that time from implantation to OCT imaging was significantly associated with mean tissue thickness. The COMBO stent had substantial tissue coverage at the very short-term period after implantation even in AMI patients, and follow-up time had an impact on vessel healing.

Ultrathin bioresorbable polymer sirolimus-eluting stents in US patients undergoing coronary revascularization: 1-Year outcomes from the BIOFLOW VII trial

BACKGROUND

Ultrathin strut coronary drug-eluting stents (DES) have demonstrated improved safety and efficacy in large contemporary trials. The evaluation of an ultrathin strut DES in a post-market United States (US) patient population was undertaken.

OBJECTIVE

The purpose of this post-approval study is to confirm that the clinical performance of an ultrathin strut bioresorbable polymer sirolimus-eluting stent (BP SES) in clinical practice is similar to that observed with BP SES in the BIOFLOW V pivotal trial.

METHODS

BIOFLOW VII is a prospective, multicenter, single-arm US post-market approval study to confirm the clinical performance of BP SES in a real-world setting. The primary endpoint of 1-year target lesion failure (TLF) was compared with a performance goal of 6.9% based on an adapted BIOFLOW V trial BP SES TLF rate and TLF rates from other US market-released DES utilizing the Society for Cardiovascular Angiography and Interventions definition for peri-procedural myocardial infarction (MI). Subjects undergoing percutaneous coronary intervention with BP SES were consented within 24 h post-index procedure with planned follow-up through 5 years.

RESULTS

Among 556 enrolled patients, clinical demographics included: 34.7% female, 35.6% with diabetes mellitus, and 56.8% with acute coronary syndromes. The average stent length (mean ± standard deviation) was 20.2 ± 11.8 mm, and the mean number of stents per patient was 1.3 ± 0.6. Procedure success was 99.1% (551/556), and device success was 99.9% (689/690). Among 531 subjects included in the primary endpoint analysis, the 1-year rate of TLF rate was 1.7% (9/531), and the primary endpoint was met compared with the performance goal (p < 0.0001, 95% confidence interval: 0.69%, 3.43%). Rates of target vessel MI and clinically driven target lesion revascularization were 1.3% (7/531) and 0.9% (5/531), with no occurrence of cardiac death. Definite stent thrombosis was observed for two cases (0.4%; 2/556) with one acute (≤24 h) and one late (>30 days and ≤1 year) event.

CONCLUSION

In a post-approval study, 1-year clinical outcomes with BP SES were consistent with prior trials supporting the safety and effectiveness of ultrathin BP SES.

In-stent restenosis after percutaneous coronary intervention: emerging knowledge on biological pathways

Percutaneous coronary intervention (PCI) has evolved significantly over the past four decades. Since its inception, in-stent restenosis (ISR)-the progressive reduction in vessel lumen diameter after PCI-has emerged as the main complication of the procedure. Although the incidence of ISR has reduced from 30% at 6 months with bare-metal stents to 7% at 4 years with drug-eluting stents (DESs), its occurrence is relevant in absolute terms because of the dimensions of the population treated with PCI. The aim of this review is to summarize the emerging understanding of the biological pathways that underlie ISR. In-stent restenosis is associated with several factors, including patient-related, genetic, anatomic, stent, lesion, and procedural characteristics. Regardless of associated factors, there are common pathophysiological pathways involving molecular phenomena triggered by the mechanical trauma caused by PCI. Such biological pathways are responses to the denudation of the intima during balloon angioplasty and involve inflammation, hypersensitivity reactions, and stem cell mobilization particularly of endothelial progenitor cells (EPCs). The results of these processes are either vessel wall healing or neointimal hyperplasia and/or neo-atherosclerosis. Unravelling the key molecular and signal pathways involved in ISR is crucial to identify appropriate therapeutic strategies aimed at abolishing the 'Achille's heel' of PCI. In this regard, we discuss novel approaches to prevent DES restenosis. Indeed, available evidence suggests that EPC-capturing stents promote rapid stent re-endothelization, which, in turn, has the potential to decrease the risk of stent thrombosis and allow the use of a shorter-duration dual antiplatelet therapy.

Paper II: thematic framework analysis of registry-based randomized controlled trials provided insights for designing trial ready registries

OBJECTIVES

Registry-based randomized controlled trials (RRCTs) are increasingly used, promising to address challenges associated with traditional randomized controlled trials. We identified strengths and limitations reported in planned and completed RRCTs to inform future RRCTs.

STUDY DESIGN AND SETTING

We conducted an environmental scan of literature discussing conceptual or methodological strengths and limitations of using registries for trial design and conduct (n = 12), followed by an analysis of RRCT protocols (n = 13) and reports (n = 77) identified from a scoping review. Using framework analysis, we developed and refined a conceptual framework of RRCT-specific strengths and limitations. We mapped and interpreted strengths and limitations discussed by authors of RRCT articles using framework codes and quantified the frequencies at which these were mentioned.

RESULTS

Our conceptual framework identified six main RRCT strengths and four main RRCT limitations. Considering implications for RRCT conduct and design, we formulated ten recommendations for registry designers, administrators, and trialists planning future RRCTs.

CONCLUSION

Consideration and application of empirically underpinned recommendations for future registry design and trial conduct may help trialists utilize registries and RRCTs to their full potential.

A novel glycyrrhizin acid-coated stent reduces neointimal formation in a rabbit iliac artery model

Introduction: Most drug-eluting stents (DESs) inhibit intimal hyperplasia but impair re-endothelialization. This study aimed to evaluate in vivo strut coverage and neointimal growth in a new glycyrrhizin acid (GA)-eluting stent. Methods: New Zealand White rabbits (n = 20) with atherosclerotic plaques were randomly divided into three groups based on implanted iliac artery stents: bare-metal stents (BMSs), rapamycin-eluting stents, and GA-eluting stents. After the in vivo intravascular ultrasound (IVUS) assessment at 28 days, the vessels were harvested for scanning electron microscopy (SEM) and histology. After 4 weeks of follow-up, the stent and external elastic lamina (EEL) areas were compared among the groups. Results: The rapamycin- or GA-eluting stents significantly reduced the neointimal area compared with BMSs, though GA-eluting stents had the lowest reduction. There were more uncovered struts for rapamycin-eluting stents than those for GA-eluting stents and bare-metal stents. The endothelial nitric oxide synthase (eNOS) expression in GA-eluting stents was much higher than that in BMSs and rapamycin-eluting stents, even though the endothelial coverage between struts was equivalent between BMSs and GA-eluting stents. Moreover, GA-eluting stents markedly promoted re-endothelialization and improved arterial healing compared to rapamycin-eluting stents in a rabbit atherosclerotic model. Conclusion: In conclusion, the novel GA-coated stent used in this study inhibited intimal hyperplasia and promoted re-endothelialization.

Drug loaded implantable devices to treat cardiovascular disease

INTRODUCTION

It is widely acknowledged that cardiovascular diseases (CVDs) continue to be the leading cause of death globally. Furthermore, CVDs are the leading cause of diminished quality of life for patients, frequently as a result of their progressive deterioration. Medical implants that release drugs into the body are active implants that do more than just provide mechanical support; they also have a therapeutic role. Primarily, this is achieved through the controlled release of active pharmaceutical ingredients (API) at the implementation site.

AREAS COVERED

In this review, the authors discuss drug-eluting stents, drug-eluting vascular grafts, and drug-eluting cardiac patches with the aim of providing a broad overview of the three most common types of cardiac implant.

EXPERT OPINION

Drug eluting implants are an ideal alternative to traditional drug delivery because they allow for accurate drug release, local drug delivery to the target tissue, and minimise the adverse side effects associated with systemic administration. Despite the fact that there are still challenges that need to be addressed, the ever-evolving new technologies are making the fabrication of drug eluting implants a rewarding therapeutic endeavour with the possibility for even greater advances.

Impact of acute coronary syndrome on clinical outcomes after revascularization with the dual-therapy CD34 antibody-covered sirolimus-eluting Combo stent and the sirolimus-eluting Orsiro stent

OBJECTIVES

To compare the efficacy and safety of the dual-therapy CD34 antibody-covered sirolimus-eluting Combo stent (DTS) and the sirolimus-eluting Orsiro stent (O-SES) in patients with and without acute coronary syndrome (ACS) included in the SORT OUT X study.

BACKGROUND

The incidence of target lesion failure (TLF) after treatment with modern drug-eluting stents has been reported to be significantly higher in patients with ACS when compared to patients without ACS. Whether the results from the SORT OUT X study apply to patients with and without ACS remains unknown.

METHODS

In total, 3146 patients were randomized to stent implantation with DTS (n = 1578; ACS: n = 856) or O-SES (n = 1568; ACS: n = 854). The primary end point, TLF, was a composite of cardiac death, target-lesion myocardial infarction (MI), or target lesion revascularization (TLR) within 1 year.

RESULTS

At 1 year, the rate of TLF was higher in the DTS group compared to the O-SES group, both among patients with ACS (6.7% vs. 4.1%; incidence rate ratio: 1.65 [95% confidence interval, CI: 1.08-2.52]) and without ACS (6.0% vs. 3.2%; incidence rate ratio: 1.88 [95% CI: 1.13-3.14]). The differences were mainly explained by higher rates of TLR, whereas rates of cardiac death and target lesion MI did not differ significantly between the two stent groups in patients with or without ACS CONCLUSION: Compared to the O-SES, the DTS was associated with a higher risk of TLF at 12 months in patients with and without ACS. The differences were mainly explained by higher rates of TLR.

The mega COMBO collaboration: An individual patient data pooled analysis of patients undergoing PCI with COMBO stent

BACKGROUND

COMBO (OrbusNeich Medical, Hong Kong) is a dual-therapy coronary stent featuring sirolimus as antiproliferative drug and an anti-CD34+ antibody coating to attract endothelial progenitor cells favoring rapid stent re-endothelization. The Mega COMBO collaboration aimed to evaluate the performance of the COMBO stent in a large contemporary cohort of patients undergoing percutaneous coronary intervention (PCI).

METHODS

Patient-level data of subjects undergoing PCI with the COMBO stent from the REMEDEE-Trial, REMEDEE-OCT, HARMONEE, REDUCE, SORT OUT X, REMEDEE-Registry and MASCOT studies were pooled together. The primary endpoint was 1-year target lesion failure (TLF), a composite of cardiovascular death, target vessel myocardial infarction (TV-MI) or clinically driven target lesion revascularization (CD-TLR). Secondary outcomes were the individual components of the primary endpoint and stent thrombosis (ST). Endpoints were evaluated against performance goals based on the EAPCI (the European Association of Percutaneous Coronary Intervention) recommendations for new drug-eluting stents.

RESULTS

A total of 6753 patients (mean age 63.7 ± 11.4 years, 23% women) were included. At 1-year follow-up, TLF occurred in 303 (4.6%) patients. The rates of cardiovascular death, TV-MI, and CD-TLR were 1.3%, 1.8%, and 2.5%, respectively. The rate of definite/probable ST was 0.73%, early ST (<1 month) was 0.48%, while late ST (1-12 months) was 0.26%. The performance goals were met for all of the evaluated endpoints.

CONCLUSIONS

This large patient-level pooled analysis provides a comprehensive outline of the performance of the dual-therapy COMBO stent. The low rates of primary and secondary endpoints suggest that this stent technology may be a good alternative to other contemporary drug eluting coronary stent platforms.

Biofunctionalization of cardiovascular stents to induce endothelialization: Implications for in- stent thrombosis in diabetes

Stent thrombosis remains one of the main causes that lead to vascular stent failure in patients undergoing percutaneous coronary intervention (PCI). Type 2 diabetes mellitus is accompanied by endothelial dysfunction and platelet hyperactivity and is associated with suboptimal outcomes following PCI, and an increase in the incidence of late stent thrombosis. Evidence suggests that late stent thrombosis is caused by the delayed and impaired endothelialization of the lumen of the stent. The endothelium has a key role in modulating inflammation and thrombosis and maintaining homeostasis, thus restoring a functional endothelial cell layer is an important target for the prevention of stent thrombosis. Modifications using specific molecules to induce endothelial cell adhesion, proliferation and function can improve stents endothelialization and prevent thrombosis. Blood endothelial progenitor cells (EPCs) represent a potential cell source for the in situ-endothelialization of vascular conduits and stents. We aim in this review to summarize the main biofunctionalization strategies to induce the in-situ endothelialization of coronary artery stents using circulating endothelial stem cells.

Ultrathin Bioresorbable Polymer Sirolimus-Eluting Stents Versus Durable Polymer Everolimus-Eluting Stents: BIOFLOW V Final 5-Year Outcomes

BACKGROUND

Randomized trials have demonstrated the superiority of ultrathin strut drug-eluting stents compared with alternative stent designs. Whether these differences persist over late-term follow-up is uncertain.

OBJECTIVES

This study sought to compare late-term (5-year) clinical outcomes among patients treated with ultrathin strut (60 µm) bioresorbable polymer sirolimus-eluting stents (BP SES) and thin strut (81 µm) durable polymer everolimus-eluting stents (DP EES).

METHODS

BIOFLOW V (Biotronik Prospective Randomized Multicenter Study to Assess the Safety and Effectiveness of the Orsiro Sirolimus Eluting Coronary Stent System in the Treatment of Subjects with Up to Three De Novo or Restenotic Coronary Artery Lesions V) was an international, 2:1 randomized trial comparing percutaneous coronary intervention with ultrathin strut BP SES versus thin strut DP EES regarding the primary endpoint of 12-month target lesion failure (TLF). Prespecified outcomes through 5 years were assessed.

RESULTS

Among 1,334 patients randomized to treatment with BP SES (n = 884) or DP EES (n = 450), the 5-year rates of TLF were 12.3% for BP SES and 15.3% for DP EES (P = 0.108). Revascularization with BP SES was associated with a significantly lower target vessel-related myocardial infarction (6.6% vs 10.3%, P = 0.015) and late/very late definite/probable stent thrombosis (0.3% vs 1.6%, P = 0.021). Ischemia-driven target lesion revascularization was numerically but not significantly lower with BP SES (5.9% vs 7.7%, P = 0.202). Cardiac death rates were 2.6% versus 1.9% (P = 0.495) for BP SES and DP EES, respectively.

CONCLUSIONS

In a large, randomized trial, TLF and the individual outcomes of cardiac death and target lesion revascularization at 5 years were similar among patients treated with BP SES versus DP EES. Both target vessel-related myocardial infarction and late/very late definite/probable stent thrombosis were significantly lower with BP SES. These results confirm the durability of safety and the effectiveness of percutaneous coronary intervention with ultrathin BP SES.

Coronary Artery Restenosis in Women by History of Preeclampsia

Background A history of preeclampsia is associated with increased risk of coronary artery disease and experimental evidence suggests that a history of preeclampsia also increases the risk of restenosis. However, the extent to which a history of preeclampsia is associated with risk of restenosis after percutaneous coronary intervention in women is unknown. Methods and Results We included 6065 parous women aged ≤65 years with first percutaneous coronary intervention on 9452 segments 2006 to 2017, linking nationwide data on percutaneous coronary intervention and delivery history in Sweden. Main outcomes were clinical restenosis and target lesion revascularization within 2 years. We accounted for segment-, procedure-, and patient-related potential predictors of restenosis in proportional hazards regression models. Restenosis occurred in 345 segments (3.7%) and target lesion revascularization was performed on 383 patients (6.3%). A history of preeclampsia was neither significantly associated with risk of restenosis (predictor-accounted hazard ratio [HR], 0.71 [95% CI, 0.41-1.23]) nor target lesion revascularization (0.74 [95% CI, 0.51-1.07]) compared with a normotensive pregnancy history. When term and preterm preeclampsia were investigated separately, segments in women with a history of term preeclampsia had a lower risk of restenosis (predictor-accounted HR, 0.45 [95% CI, 0.21-0.94]). A history of preeclampsia was not significantly associated with death by any cause within 2 years of the index procedure (predictor-accounted HR 1.06, [95% CI, 0.62-1.80]). Conclusions A history of preeclampsia was not associated with increased risk of restenosis but instead some evidence pointed to a decreased risk. To facilitate future studies and allow for replication, concomitant collection of data on pregnancy complication history and percutaneous coronary intervention outcomes in women is warranted.

Restenosis after Coronary Stent Implantation: Cellular Mechanisms and Potential of Endothelial Progenitor Cells (A Short Guide for the Interventional Cardiologist)

Coronary stents are among the most common therapies worldwide. Despite significant improvements in the biocompatibility of these devices throughout the last decades, they are prone, in as many as 10–20% of cases, to short- or long-term failure. In-stent restenosis is a multifactorial process with a complex and incompletely understood pathophysiology in which inflammatory reactions are of central importance. This review provides a short overview for the clinician on the cellular types responsible for restenosis with a focus on the role of endothelial progenitor cells. The mechanisms of restenosis are described, along with the cell-based attempts made to prevent it. While the focus of this review is principally clinical, experimental evidence provides some insight into the potential implications for prevention and therapy of coronary stent restenosis.

Endothelial Progenitor Cells in Coronary Artery Disease: From Bench to Bedside

Endothelial progenitor cells (EPCs) are a heterogeneous group of cells present in peripheral blood at various stages of endothelial differentiation. EPCs have been extensively investigated in patients with coronary artery disease (CAD), with controversial findings both on their role in atherosclerosis progression and in the process of neointimal growth after a percutaneous coronary intervention (PCI). Despite nearly 2 decades of experimental and clinical investigations, however, the significance of EPCs in clinical practice remains unclear and poorly understood. This review provides an update on the role of EPCs in the most common clinical scenarios that are experienced by cardiologists managing patients with CAD. We here summarize the main findings on the association of EPCs with cardiovascular risk factors, coronary atherosclerosis, and myocardial ischemia. We then discuss the potential effects of EPCs in post-PCI in-stent restenosis, as well as most recent findings with EPC-coated stents. Based on the mounting evidence of the relationship between levels of EPCs and several different adverse cardiovascular events, EPCs are emerging as novel predictive biomarkers of long-term outcomes in patients with CAD.

Impact of diabetes on clinical outcomes after revascularization with the dual therapy CD34 antibody-covered sirolimus-eluting Combo stent and the sirolimus-eluting Orsiro stent

OBJECTIVES

To compare the efficacy and safety of the dual therapy CD34 antibody-covered sirolimus-eluting Combo stent (DTS) and the sirolimus-eluting Orsiro stent (SES) in patients with and without diabetes mellitus (DM) included in the Scandinavian Organization for Randomized Trials with Clinical Outcome (SORT OUT) X study.

BACKGROUND

The incidence of target lesion failure (TLF) after treatment with modern drug-eluting stents has been reported to be significantly higher in patients with DM when compared to patients without DM. Thus, whether the results from the SORT OUT X study apply to patients with and without DM remains unknown.

METHODS

In total 3146 patients were randomized to stent implantation with DTS (n = 1578; DM: n = 279) or SES (n = 1568; DM: n = 271). The primary end point, TLF, was a composite of cardiac death, target-lesion myocardial infarction (MI), or target lesion revascularization (TLR) within 1 year.

RESULTS

At 1 year, the rate of TLF was increased in the DTS group compared to the SES group, both among patients with DM (9.3% vs. 4.8%; risk difference: 4.5%; incidence rate ratio: 1.99, 95% confidence interval [CI]: 1.02-3.90) and without DM (5.7% vs. 3.5%; incidence rate ratio: 1.67, 95% CI: 1.15-2.42). The differences were mainly explained by higher rates of TLR.

CONCLUSION

Compared to the SES, the DTS was associated with an increased risk of TLF at 12 months in patients with and without DM. The differences were mainly explained by higher rates of TLR, whereas rates of cardiac death and target lesion MI did not differ significantly between the two stent groups in patients with or without DM.

Consequences of Inaccurate Assumptions in Coronary Stent Noninferiority Trials: A Systematic Review and Meta-analysis

IMPORTANCE

The outcome and interpretation of noninferiority trials depend on the magnitude of the noninferiority margin and whether a relative or absolute noninferiority margin is used and may be affected by imprecision in event rate estimation.

OBJECTIVE

To assess the consequence of imprecise event rate estimations on interpretation of peer-reviewed randomized clinical trials.

DATA SOURCES

PubMed/MEDLINE was searched for articles published between January 1, 2015, and April 30, 2021.

STUDY SELECTION

Noninferiority randomized clinical trials of coronary stents published in selected journals with clinical events as the primary end point.

DATA EXTRACTION AND SYNTHESIS

Two reviewers (M.S. and F.V.) independently extracted data on trial characteristics, noninferiority assumptions, primary end point clinical outcomes, and study conclusions. Overestimation or underestimation of the control event rate was evaluated by dividing the assumed control event rate by the observed control event rate. For noninferiority end points with absolute margins, the assumed corresponding relative margin was defined as the ratio of the absolute margin and the assumed event rate, and the observed corresponding relative margin as the ratio between the absolute margin and the observed event rate in the control arm. Noninferiority comparisons with absolute margins were reanalyzed using the assumed corresponding relative margin and the Farrington-Manning score test for relative risk.

MAIN OUTCOMES AND MEASURES

Overestimation or underestimation, assumed and observed corresponding relative margins, and relative reanalysis of the primary end points of trials with absolute margins.

RESULTS

A total of 106 989 patients from 58 trials were included. The event rate in the control arms was overestimated by a median (IQR) of 28% (2%-74%). Most noninferiority trials used absolute rather than relative margins (55 of 58 trials [94.8%]). Owing to overestimation, absolute noninferiority margins became more permissive than originally assumed (median [IQR] of observed relative noninferiority margin, 1.62 [1.50-1.80] vs assumed relative noninferiority margin, 1.47 [1.39-1.55]; P < .001). Among trial comparisons that met noninferiority with an absolute noninferiority margin, 17 of 50 trials (34.0%) would not have met noninferiority with a corresponding assumed relative noninferiority margin.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, assumed event rates were often overestimated in noninferiority coronary stent trials. Because most of these trials use absolute margins to define noninferiority, such overestimation results in excessively permissive relative noninferiority margins.

A Narrative Review of Ultrathin-strut Drug-eluting Stents: The Thinner the Better?

Second-generation drug-eluting stents (DES) are considered standard of care for revascularization of patients undergoing percutaneous coronary intervention. Besides the polymer and antiproliferative drug used, the metallic backbone of DES is an attractive target for further development. Ultrathin-strut DES (≤70 μm strut thickness) are more flexible, have an improved trackability and crossability compared to conventional second-generation DES. Importantly, ultrathin-strut DES reduce the risk of in-stent restenosis, thereby decreasing the risk of angiographic and clinical restenosis. In this narrative review, we will discuss the clinical outcomes of the commercially available ultrathin-strut DES.

Endothelial repair by stem and progenitor cells

The integrity of the endothelial barrier is required to maintain vascular homeostasis and fluid balance between the circulatory system and surrounding tissues and to prevent the development of vascular disease. However, the origin of the newly developed endothelial cells is still controversial. Stem and progenitor cells have the potential to differentiate into endothelial cell lines and stimulate vascular regeneration in a paracrine/autocrine fashion. The one source of new endothelial cells was believed to come from the bone marrow, which was challenged by the recent findings. By administration of new techniques, including genetic cell lineage tracing and single cell RNA sequencing, more solid data were obtained that support the concept of stem/progenitor cells for regenerating damaged endothelium. Specifically, it was found that tissue resident endothelial progenitors located in the vessel wall were crucial for endothelial repair. In this review, we summarized the latest advances in stem and progenitor cell research in endothelial regeneration through findings from animal models and discussed clinical data to indicate the future direction of stem cell therapy.

Nonbone Marrow CD34+ Cells Are Crucial for Endothelial Repair of Injured Artery

[Figure: see text].