Comparison of sirolimus eluting stent with bioresorbable polymer to everolimus eluting stent with permanent polymer in bifurcation lesions: Results from CENTURY II trial

Bioresorbable polymer and durable polymer metallic stents in coronary artery disease: a meta-analysis

BACKGROUND

Literature on bioresorbable-polymer-stents (BPS) and second-generation durable-polymer-stents (DPS) in percutaneous coronary intervention (PCI) for all comer CAD is conflicting.

METHODS

Randomized controlled studies comparing PCI among BPS and second-generation DPS were identified up until May-2020 from online databases.  Primary outcomes included are all-cause myocardial infarction (MI), cardiac-death, target-vessel-revascularization (TVR), target-vessel MI (TVMI), and stent-thrombosis (ST). Random effect method of risk ratio and confidence interval of 95% was used.

RESULTS

25 prospective randomized controlled trials with 31,822 patients (BPS n = 17,065 and DPS n = 14,757) were included in the study. Follow-up ranged between a minimum of 6 months to more than 5 years. Cardiac death (RR 1.02, 95% CI 0.89-1.45, p = 0.16) was comparable in BPS and second-generation DPS. Risk of all-cause MI was similar between BPS and DPS (RR 0.97, 95% CI 0.84-1.11, p = 0.73). TVMI (RR 0.88, 95% CI 0.69-1.11, p = 0.33) and ST rates were also comparable in BPS and DPS groups (RR 1.06, 95% CI 0.80-1.40, p = 1.00). Overall TVR had comparable outcomes between BPS and DPS (RR 0.95, 95% CI 0.79-1.14, p < 0.001); however, higher TVR was seen among BPS group at follow-up of ≥5 years (RR 1.39, 95% CI 1.12-1.14, p = 0.02). Bias was low and heterogeneity was moderate.

CONCLUSION

Patients undergoing PCI treated with BPS had comparable outcomes in terms of cardiac death, TVR, ST, TVMI, and all-cause MI to patients treated with second-generation DPS; however, BPS had higher rates of TVR for follow-up of ≥5-years.

Influence of Stent Flexibility on Artery Wall Stress and Wall Shear Stress in Bifurcation Lesions

Purpose

Stent flexibility can influence clinical outcome, especially in bifurcation lesions. For instance, an overly rigid stent can impose mechanical stress on the artery at the stent edges and alter both arterial geometry and blood flow dynamics in bifurcations. This study investigated the influence of stent flexibility on vessel geometry, histology, wall stress, and blood flow dynamics in arterial bifurcations.

Materials and Methods

We compared arterial angulation, stenosis, histopathology, simulated wall shear stress (WSS), and simulated blood flow velocity distribution in swine coronary artery bifurcations following placement of the less flexible Multi-link 8 or more flexible Kaname stent (4.1 ± 0.5 vs 1.5 ± 0.1 mN, p < 0.05, t-test). Stents were implanted into six coronary artery bifurcations each using the single-stent crossover technique without side branch strut dilatation. Outcomes were examined after 28 days.

Results

Implantation of both stents significantly increased site angulation (Multi-link 8: 148° ± 8° to 172° ± 2°, p < 0.05, paired t-test; Kaname: 152° ± 5° to 164° ± 4°, p < 0.05, paired t-test), but the change tended to be greater after Multi-link 8 stent implantation (24° ± 15° vs 11° ± 7°, p = 0.1, t-test), suggesting greater straightening of the bifurcation. The Multi-link 8 stent induced greater neointimal thickness than the Kaname stent (0.53 ± 0.3 mm vs 0.26 ± 0.1 mm, p < 0.05, t-test). The distribution of neointimal hyperplasia following stent implantation as revealed by longitudinal histopathology matched the distribution of WSS simulated using computational fluid dynamics (CFD). The endothelium at low WSS areas exhibited aberrant cell morphology and leukocyte adhesion. A CFD model of a curved bifurcation suggested that the region of low WSS is expanded by artery straightening.

Conclusion

In bifurcated lesions, stent flexibility influences not only mechanical stress on the artery but also WSS, which may induce local neointimal hyperplasia.

The Ultimaster coronary stent system: 5-year worldwide experience

Newer generation drug-eluting stents have significantly improved outcomes in patients undergoing percutaneous coronary intervention by reducing the risk of restenosis and stent thrombosis. In comparison with first-generation ones, contemporary drug-eluting stents have thinner struts and more biocompatible polymers, which reduce inflammation, promote endothelialization and decrease neointimal proliferation. The Ultimaster™/Ultimaster™ Tansei™ coronary stent system is a cobalt–chromium, biodegradable polymer, sirolimus-eluting stent (Terumo, Tokyo, Japan) that received the Conformitè Européenne mark approval for clinical use in 2014/2018. This device has been the object of intense clinical evaluation in controlled randomized studies and observational registries. In this article, we analytically reviewed the available clinical data with a focus on the latest real-world evidence that demonstrates excellent performance in all of the clinical subsets.

Histopathologic and physiologic effect of bifurcation stenting: current status and future prospects

Introduction: Coronary bifurcation lesions are involved in up to 20% of all percutaneous coronary interventions (PCI). However, bifurcation lesion intervention is associated with a high complication rate, and optimal treatment of coronary bifurcation is an ongoing debate.Areas covered: Both different stenting techniques and a variety of devices have been suggested for bifurcation treatment, including the use of conventional coronary stents, bioresorbable vascular scaffolds (BVS), drug-eluting balloons (DEB), and stents dedicated to bifurcations. This review will summarize different therapeutic approaches with their advantages and shortcomings, with special emphasis on histopathologic and physiologic effects of each treatment strategy.Expert opinion: Histopathology and clinical data have shown that a more simple treatment strategy is beneficial in bifurcation lesions, achieving superior results. Bifurcation interventions through balloon angioplasty or placement of stents can importantly alter the bifurcation's geometry and accordingly modify local flow conditions. Computational fluid dynamics (CFD) studies have shown that the outcome of bifurcation interventions is governed by local hemodynamic shear conditions. Minimizing detrimental flow conditions as much as possible should be the ultimate strategy to achieve long-term success of bifurcation interventions.

Comparison of long-term clinical outcomes in multivessel coronary artery disease patients treated either with bioresoarbable polymer sirolimus-eluting stent or permanent polymer everolimus-eluting stent: 5-year results of the CENTURY II randomized clinical trial

OBJECTIVES

To assess the long-term safety and efficacy of a sirolimus-eluting stent with bioresorbable polymer (BP-SES; Ultimaster), in comparison to a benchmark everolimus-eluting, permanent polymer stent (PP-EES; Xience), in a prespecified subgroup of patients with multivessel coronary artery disease (MVD) enrolled in the CENTURY II trial.

BACKGROUND

The use of coronary stenting in high-risk subgroups, like MVD patients, is rising. The clinical evidence, including long-term comparative analysis of the efficacy and safety benefits of different new-generation drug eluting stents, however, remains insufficient.

METHODS

Among 1,119 patients (intention-to-treat) enrolled in the CENTURY II prospective, randomized, single-blind, multicenter trial, a prespecified subgroup of 456 MVD patients were allocated by stratified randomization to treatment with BP-SES (n = 225) or PP-EES (n = 231). The previously reported primary endpoint of this study was freedom from target lesion failure (TLF: a composite of cardiac death, target vessel-related myocardial infarction [MI] and clinically-indicated target lesion revascularization) at 9 months.

RESULTS

In this MVD substudy, baseline patient, lesion and procedure characteristics were similar between the treatment arms. At 1 and 5 years, both BP-SES and PP-EES displayed low and comparable rates of TLF (5.3 vs. 7.8%; p = .29 and 10.2 vs. 13.4%; p = .29), and definite or probable stent thrombosis (0.4 vs. 1.3%; p = .33 and 0.9 vs. 1.7%; p = .43), respectively. Composite endpoint of cardiac death and MI, and patient-oriented composite endpoint of any death, MI, and coronary revascularizations were also similar.

CONCLUSIONS

These results confirm good long-term safety and efficacy of the studied bioresorbable polymer stent in this high-risk patient population.

One-year clinical outcome of biodegradable polymer sirolimus-eluting stent in patients needing short dual antiplatelet therapy. Insight from the ULISSE registry (ULtimaster Italian multicenter all comerS Stent rEgistry)

BACKGROUND

This study aimed to evaluate real-world clinical outcome of patients needing short dual antiplatelet therapy (S-DAPT) following PCI with Ultimaster® thin-strut, biodegradable polymer sirolimus-eluting stent (BP-SES), which was supposed to induce faster stent endothelialization and reduce device thrombogenicity.

METHODS

In this sub-group analysis of patients enrolled in the ULISSE registry, two groups were identified: 1) patients discharged with S-DAPT (≤3-month) due to high bleeding risk or need for urgent major non-cardiac surgery and 2) patients discharged with recommended DAPT (R-DAPT) duration (≥6-month). The primary ischemic-safety and bleeding-safety endpoints were TLF (composite of cardiac-death, target vessel MI, and clinically driven target lesion revascularization), and BARC major bleedings (≥type-3a) at 1-year follow-up. To account for events occurring before DAPT discontinuation we performed 3-month landmark analysis.

RESULTS

82 patients (5%) were discharged with ≤3-month DAPT (57 ± 27 days), and 1558 patients (94%) were discharged with ≥6-month DAPT (318 ± 75 days). No significant differences between S-DAPT and R-DAPT group were observed in TLF at 1-year (7.9% vs. 4.6%). The rate of BARC major bleeding resulted significantly higher in S-DAPT group (3.9% vs. 0.3%; p = 0.001), with the majority of bleeding events occurring within 3 months. The landmark analysis showed no significant differences in BARC major bleedings between groups (1.4% vs. 0.3%; p = 0.142).

CONCLUSIONS

As compared to those treated with R-DAPT (≥6-month), patients needing -S-DAPT (≤3-month) after PCI with Ultimaster® BP-SES had similar rates of 1-year TLF and BARC major bleedings following early DAPT discontinuation.

Randomized comparison between 2-link cell design biolimus A9-eluting stent and 3-link cell design everolimus-eluting stent in patients with de novo true coronary bifurcation lesions: the BEGIN trial

The appropriate stent platform for treating coronary bifurcation lesions (CBLs) remains controversial. Previous bench tests have demonstrated the superiority of a 2-link cell design to 3-link cell design for creating inter-strut dilation at the side branch ostium. This randomized multicenter prospective BEGIN trial compared the biodegradable polymer-based biolimus A9-eluting stent (2-link BES) with the durable polymer-based cobalt chromium everolimus-eluting stent (3-link EES) in 226 patients with de novo CBLs. Patients with true bifurcations, defined as > 50% stenosis in the main vessel and side branch (SB) and an SB diameter > 2.25 mm, were enrolled. Guide wire re-crossing to the distal cell (near the carina) in the jailed SB and final kissing inflation were recommended. The SB angiographic endpoint was < 50% stenosis diameter. Left-main CBLs (13.5% vs. 13.0%) and 2-stent technique (30.6% vs. 22.6%) rates were similar. The primary endpoints (minimum lumen diameter at the SB ostium measured at an independent core laboratory at the 8-month follow-up) were comparable (1.64 ± 0.50 mm vs. 1.63 ± 0.51 mm, p = 0.976). There was no significant difference in composite outcomes of cardiac death, myocardial infarction, or target vascular revascularization at 12 months (7.4% vs. 8.0%, p = 0.894). Two-link BES and 3-link EES showed similar 8-month angiographic and 1-year clinical outcomes for true CBLs.

Predictors of clinical outcomes after coronary implantation of bioresorbable polymer sirolimus-eluting Ultimaster stents in all-comers: A report of 1,727 cases

BACKGROUND

Although bioresorbable polymer sirolimus-eluting Ultimaster stents (BP-SESs) are likely useful for percutaneous coronary interventions (PCIs), the clinical data from real-world cases are insufficient. Furthermore, the predictors of adverse clinical outcomes after BP-SES implantation have not been fully investigated.

OBJECTIVES

This study evaluated the 1-year clinical outcomes after BP-SES implantation in real-world PCI cases and identified the predictors of adverse outcomes.

METHODS

In this single-center, all-comers study, we consecutively implanted BP-SESs in all patients who required coronary stents between October 2015 and August 2016. We conducted a clinical follow-up assessment of these patients.

RESULTS

The sample comprised 1,727 patients; 67% were men, the mean age was 72 years, and 37% had diabetes. Of the 2,085 lesions detected, 88% were type B2/C lesions, 4% were chronic total occlusions (CTOs), and 23% were bifurcations. The cumulative incidences of target lesion revascularization (TLR) and target lesion failure (TLF) at 1-year were 2.4% and 5.2%, respectively. A multivariate analysis revealed that hemodialysis (HD) (hazard ratio [HR] 8.40) and CTO (HR 4.21) were independent predictors of TLR. Stent sizes ≤2.5 mm were not associated with either TLR or TLF.

CONCLUSIONS

The current study indicates that patients on HD and those with CTO were more likely to experience adverse clinical outcomes after BP-SES implantation. In contrast, small vessel diameter was not significantly related to adverse outcomes. The 1-year clinical outcomes after BP-SES implantation were found to be favorable among all-comer PCI cases, including patients receiving HD and those with in-stent restenosis.

Angiographic and Midterm Outcomes of Bioresorbable Vascular Scaffold for Coronary Bifurcation Lesions

Data on the angiographic and clinical performance of bioresorbable vascular scaffolds (BVS) for bifurcation lesions treatment are still limited. Data were examined of 107 patients with at least 1 coronary bifurcation lesion involving a side branch ≥2mm. Angiographic and clinical outcomes were collected. Optical coherence tomography analysis was performed in a subgroup of patients. Between July 2009 and December 2015, 423 patients underwent PCI with Absorb BVS. A total of 110 lesions were identified as bifurcations, of which 24.5% were classified as true bifurcation lesions. Lesion complexity B2/C was 68.1%. Ninety-five out of 110 lesions were treated by provisional stenting technique while 2 stenting strategy was the final approach in 15 lesions. Procedural success of main branch was 100% whereas side-branch impairment at the end of the procedure was 4.5%. The mean follow-up was 21 months with one-third of the patients followed up for at least 2 years. The overall target lesion failure and scaffold/stent thrombosis rate at 1 year was 7.8% and 3.9%, respectively. In conclusion the results of the present analysis suggest the BVS implanted in bifurcations lesions are associated with procedural safety and angiographic success as well as acceptable target lesion failure rate at 1 year.

Meta-Analysis of Randomized Clinical Trials Comparing Biodegradable Polymer Drug-Eluting Stent to Second-Generation Durable Polymer Drug-Eluting Stents

OBJECTIVES

The authors sought to perform a meta-analysis of randomized clinical trials (RCTs) comparing the safety and efficacy of biodegradable polymer drug-eluting stents (BP-DES) to second-generation durable polymer drug-eluting stents (DP-DES).

BACKGROUND

Prior meta-analyses have established the superiority of BP-DES over bare-metal stents and first-generation DP-DES; however, their advantage compared with second-generation DP-DES remains controversial.

METHODS

The authors searched PubMed and Scopus databases for RCTs comparing BP-DES to the second-generation DP-DES. Outcomes included target vessel revascularization (TVR) as efficacy outcome and cardiac death, myocardial infarction (MI), and definite or probable stent thrombosis (ST) as safety outcomes. In addition, we performed landmark analysis for endpoints beyond 1 year of follow-up and a subgroup analysis based on the stent characteristics.

RESULTS

The authors included 16 RCTs comprising 19,886 patients in the meta-analysis. At the longest available follow-up (mean duration 26 months), we observed no significant differences in TVR (p = 0.62), cardiac death (p = 0.46), MI (p = 0.98), or ST (risk ratio: 0.83, 95% confidence interval: 0.64 to 1.09; p = 0.19). Our landmark analysis showed that BP-DES were not associated with a reduction in the risk of very late ST (risk ratio: 0.87, 95% confidence interval: 0.49 to 1.53; p = 0.62). Similar outcomes were seen regardless of the eluting drug (biolimus vs. sirolimus), the stent platform (stainless steel vs. alloy), the kinetics of polymer degradation or drug release (<6 months vs. >6 months), the strut thickness of the BP-DES (thin <100 μm vs. thick >100 μm), or the DAPT duration (≥6 months vs. ≥12 months).

CONCLUSIONS

BP-DES have similar safety and efficacy profiles to second-generation DP-DES.

The Ultimaster Biodegradable-Polymer Sirolimus-Eluting Stent: An Updated Review of Clinical Evidence

The Ultimaster coronary stent system (Terumo Corporation, Tokyo, Japan) represents a new iteration in drug-eluting stent (DES) technology that has recently received the Conformité Européenne (CE) mark approval for clinical use. The Ultimaster is a thin-strut, cobalt chromium, biodegradable-polymer, sirolimus-eluting coronary stent. The high elasticity of the biodegradable-polymer (PDLLA-PCL) and the abluminal gradient coating technology are additional novel features of this coronary device. The Ultimaster DES has undergone extensive clinical evaluation in two studies: The CENTURY I and II trials. Results from these two landmark studies suggested an excellent efficacy and safety profile of the Ultimaster DES across several lesion and patient subsets, with similar clinical outcomes to contemporary, new-generation DES. The aim of this review is to summarize the rationale behind this novel DES technology and to provide an update of available evidence about the clinical performance of the Ultimaster DES.