Comparison of a novel biodegradable polymer sirolimus-eluting stent with a durable polymer everolimus-eluting stent: results of the randomized BIOFLOW-II trial

Comparison of the Ultrathin Strut, Biodegradable Polymer Sirolimus-eluting Stent With a Durable Polymer Everolimus-eluting Stent in a Chinese Population: The Randomized BIOFLOW VI Trial

PURPOSE

The BIOFLOW-VI (Biotronik-Safety and Clinical Performance of the Drug Eluting Orsiro Stent in the Treatment of Subjects With De Novo Coronary Artery Lesions-VI) study evaluates the angiographic efficacy, clinical safety, and effectiveness of the ultrathin strut, biodegradable polymer sirolimus-eluting stent (BP-SES) compared with a durable polymer everolimus-eluting stent (DP-EES). This randomized controlled clinical trial was designed to enable approval of new drug-eluting stents in China.

METHODS

A total of 440 eligible patients from 11 sites with up to 2 de novo native coronary artery lesions were randomly assigned to receive either BP-SES (n = 220) or DP-EES (n = 220) from July 2014 to September 2016 in this prospective, multicenter, noninferiority trial.

FINDINGS

The primary end point of 9-month in-stent late lumen loss (LLL) was 0.05 (0.02) mm in the BP-SES group versus 0.07 (0.02) mm in the DP-EES group, with a mean difference of -0.02 mm (95% CI, -0.06 to 0.03; P = 0.44; P_{noninferiority} < 0.0001). At 1 year, the target lesion failure rate (cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization) was similar between the 2 groups (BP-SES 2.3% vs DP-EES 1.4%; P = 0.50). No definite or probable stent thrombosis had occurred in any of the 2 treatment arms.

IMPLICATIONS

The randomized BIOFLOW-VI trial showed that BP-SES was noninferior to DP-EES with regard to the primary end point of 9-month in-stent LLL in a Chinese population. ClinicalTrials.gov Identifier: NCT02870985.

Mechanism of Drug-Eluting Absorbable Metal Scaffold Restenosis

Background:

The pathomechanisms underlying restenosis of the bioabsorbable sirolimus-eluting metallic scaffold (Magmaris) remain unknown. Using serial optical coherence tomography, we investigated causes of restenosis, including the contribution of late scaffold recoil versus neointimal hyperplasia.

Methods:

Patients enrolled in BIOSOLVE-II undergoing serial angiography and optical coherence tomography (post-intervention and follow-up: 6 months and/or 1 year) were analyzed. Patients were divided into 2 groups according to angiographic in-scaffold late lumen loss (LLL) <0.5 or ≥0.5 mm. End points were late absolute scaffold recoil and neointimal hyperplasia area as assessed by optical coherence tomography.

Results:

Serial data were available for analysis from 70 patients (LLL <0.5 mm: n=41; LLL ≥0.5 mm: n=29). Patient and lesion characteristics were comparable, and there was no significant difference in mean and minimal scaffold area between groups at post-intervention. Late absolute scaffold recoil was less among patients with LLL <0.5 mm (0.53±0.68 mm 2 ) compared with those with LLL ≥0.5 mm (1.48±1.20 mm 2 ; P <0.001). Neointimal hyperplasia area was smaller among patients with LLL <0.5 mm at follow-up (1.47±0.33 mm 2 ) compared with patients with LLL ≥0.5 mm (1.68±0.34 mm 2 ; P =0.013). In a matched-frame analysis (post-intervention and follow-up), late absolute scaffold recoil varied according to the underlying plaque type (lipid: 0.63±1.23 mm 2 ; calcified: 0.81±1.44 mm 2 ; and fibrous: 1.20±1.52 mm 2 ; P <0.001), while there was no difference with regards to neointimal hyperplasia area ( P =0.132).

Conclusions:

In addition to neointimal hyperplasia, late scaffold recoil contributed significantly to LLL of sirolimus-eluting absorbable metal scaffolds. The extent of late scaffold recoil was dependent on the underlying plaque morphology and was the highest among fibrotic lesions.

Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01960504.

The Orsiro Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stent: A Review of Current Evidence

Advances in stent design and the development of bioresorbable polymers have allowed the development of novel stent technologies such as the Orsiro bioresorbable-polymer sirolimus eluting stent (BP-SES). Over several noninferiority trials, the BP-SES has demonstrated itself to be a safe and effective therapy for obstructive coronary artery disease. This article reviews the current evidence of the efficacy of the BP-SES and examines its performance in high-risk populations, such as patients presenting with ST-segment myocardial infarction, chronic total occlusions, diabetes, and small vessel disease.

A Review of the Ultrathin Orsiro Biodegradable Polymer Drug-eluting Stent in the Treatment of Coronary Artery Disease

Drug-eluting stents (DES) have revolutionised the treatment of coronary artery disease (CAD) in patients undergoing percutaneous coronary intervention. In recent years, there has been a focus on a new generation of DES, such as biodegradable polymer DES (BP-DES). This novel stent platform was developed with the hope of eliminating the risk of very late stent thrombosis associated with the current gold-standard durable polymer DES (DP-DES). Ultrathin Orsiro BP-DES (Biotronik, Bülach, Switzerland) are based on a cobalt-chromium stent platform that is coated with a bioresorbable polymer coating containing sirolimus. These devices have one of the thinnest struts available in the current market and have the theoretical benefit of reducing a chronic inflammatory response in the vessel wall. In 2019, the United States Food and Drug Administration (FDA) approved the use of Orsiro BP-DES in patients with CAD based on promising results in recent landmark trials, such as BIOFLOW V and BIOSTEMI. The aim of the present review article was to discuss the history of stent technology and the continued opportunities for improvements, focusing on the potential benefits of Orsiro BP-DES.

Comparison of a Novel Biodegradable Polymer Sirolimus-Eluting Stent With a Durable Polymer Everolimus-Eluting Stent: 5-Year Outcomes of the Randomized BIOFLOW-II Trial

OBJECTIVES

The authors aimed to compare long-term data of an ultrathin cobalt-chromium stent with passive silicon carbide coating and an active biodegradable polymer that releases sirolimus (O-SES) (Orsiro, BIOTRONIK, Bülach, Switzerland) with the durable polymer-based Xience Prime everolimus-eluting stent (X-EES) (Abbott Vascular, Santa Clara, California).

BACKGROUND

Biodegradable polymer stents have been developed aiming to overcome long-term detrimental effects of durable polymer stents, ultimately leaving a bare-metal stent in the vessel.

METHODS

This multicenter, assessor-blinded trial randomized 452 patients with 505 lesions to either O-SES or X-EES in a 2:1 fashion. Endpoints at 5 years were target lesion failure (TLF), its components, and stent thrombosis.

RESULTS

TLF occurred in 10.4% (n = 30) of O-SES patients versus 12.7% (n = 19) of X-EES patients (p = 0.473), overall stent thrombosis occurred in 0.7% (n = 2) versus 2.8% (n = 4) (p = 0.088), and definite stent thrombosis in 0% versus 0.7% (n = 1) (p = 0.341). Post hoc analysis was performed in diabetic patients (n = 128) and vessels ≤2.75 mm (n = 259). In diabetic patients, the O-SES group had numerically more target lesion revascularizations (13.5% vs. 4.5%; p = 0.138), but fewer cardiac deaths (1.3% vs. 6.9%; p = 0.089) and stent thrombosis (0% vs. 6.9%; p = 0.039). In small vessels, the O-SES group had a significantly lower 5-year mortality (3.7% vs. 11.3%; p = 0.022).

CONCLUSIONS

At 5 years, the biodegradable polymer O-SES demonstrated low TLF rates comparable to the durable polymer X-EES, confirming its long-term safety and performance. Particularly encouraging is the absence of definite stent thrombosis.

Newer-Generation Ultrathin Strut Drug-Eluting Stents Versus Older Second-Generation Thicker Strut Drug-Eluting Stents for Coronary Artery Disease

BACKGROUND

Contemporary second-generation drug-eluting stents (DES) have superior efficacy and safety in comparison with early-generation stents in patients undergoing percutaneous coronary intervention, in part, related to their thinner struts. Whether newer-generation ultrathin DES further improve clinical outcomes in comparison with older second-generation thicker strut DES is unknown.

METHODS

We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for randomized clinical trials that compared newer-generation ultrathin strut DES (defined as strut thickness <70 µm) versus thicker strut second-generation DES and reported clinical outcomes. The primary outcome was target lesion failure (composite of cardiovascular death, target vessel myocardial infarction or ischemia-driven target lesion revascularization) evaluated at 1-year follow-up. Tests for subgroup effects based on the ultrathin strut DES type and the comparator DES type were performed by using meta-regression analysis.

RESULTS

We identified 10 trials that randomly assigned 11 658 patients and evaluated 3 newer-generation ultrathin strut DES: Orsiro stent (60 μm), MiStent (64 μm), and BioMime (65 µm). In comparison with thicker strut second-generation DES, newer-generation ultrathin strut DES were associated with a 16% reduction in target lesion failure (relative risk, 0.84; 95% CI, 0.72-0.99) driven by less myocardial infarction (relative risk, 0.80; 95% CI, 0.65-0.99). Ultrathin strut DES were also associated with qualitatively lower rates of any stent thrombosis (relative risk, 0.72; 95% CI, 0.51-1.01). Tests for subgroup effects based on the ultrathin strut DES type ( P=0.58) and the comparator DES type ( P=0.98) were not significant, suggesting consistent outcomes across the 3 ultrathin strut DES and with the different DES comparators.

CONCLUSIONS

In patients undergoing percutaneous coronary intervention, newer-generation ultrathin strut DES further improve 1-year clinical outcomes in comparison with contemporary thicker strut second-generation DES.

Outcomes of patients treated with ultrathin-strut biodegradable polymer sirolimus-eluting stents versus fluoropolymer-based everolimus-eluting stents: a meta-analysis of randomised trials

AIMS

The ultrathin-strut biodegradable polymer sirolimus-eluting stent (SES) is a new-generation drug-eluting stent (DES) developed to improve the percutaneous treatment of patients with coronary artery disease. Here, we sought to investigate whether the performance of the ultrathin-strut biodegradable polymer SES is superior to that of the benchmark thin-strut fluoropolymer-based everolimus-eluting stent (EES).

METHODS AND RESULTS

We undertook a study-level meta-analysis of trials in which patients receiving percutaneous coronary intervention (PCI) were randomly assigned to either SES or EES. Primary efficacy and safety outcomes were target lesion revascularisation (TLR) and definite/probable stent thrombosis (ST), respectively. Secondary outcomes were myocardial infarction (MI), death, target lesion failure (TLF) and target vessel failure (TVF). A total of 4,853 patients received a PCI with either SES (n=2,816) or EES (n=2,037) in six trials. After a weighted median follow-up of 12 months, patients treated with SES had a risk of TLR (odds ratio [95% confidence interval]: 1.24 [0.83-1.85], p=0.30), definite/probable ST (0.84 [0.53-1.33], p=0.45) and MI related to the target vessel (0.77 [0.55-1.07], p=0.12) comparable to that of patients treated with EES. We found no significant difference with regard to other secondary outcomes.

CONCLUSIONS

At one-year follow-up, the ultrathin-strut biodegradable polymer sirolimus-eluting stent displays a performance comparable to that of the fluoropolymer-based everolimus-eluting stent.

Magmaris™ resorbable magnesium scaffold: state-of-art review

Bioresorbable scaffolds (BRS) have been advocated as the ‘fourth revolution’ in interventional cardiology because they could provide temporary scaffolding and then ‘disappear’ (resorb) potentially significantly improving coronary artery disease treatment. BRS technology has gradually matured, and there are many devices available worldwide, which are currently undergoing preclinical or clinical testing. Due to the concerns related to polylactide scaffolds, magnesium alloy is now one of the most promising resorbable technologies despite available evidences on its performances in vivo are limited to small observational studies. In this state-of-art review we present Magmaris™ (Biotronik AG, Buelach, Switzerland) magnesium-based BRS from bench to bedside, reviewing to date available clinical trial data and current recommendations for its optimal use in clinical practice.

Comparison between the Outcomes of Using Biodegradable-Polymer Drug-Eluting Stents and Those of Using Durable-Polymer Drug-Eluting Stents in Acute Coronary Syndrome Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND:

Many randomised control studies showed that percutaneous coronary interventions using biodegradable-polymer drug-eluting stents (DES) offer a safe and effective alternative to durable-polymer DES. However, not many studies have discussed its use in the setting of acute coronary syndromes.

AIM:

We aim to compare the biodegradable-polymer DES with durable-polymer DES when it comes to reducing the incidence of non-ST elevation acute coronary syndrome (NSTEACS) associated with adverse events.

METHODS:

We enrolled 205 patients presenting with NSTEACS and a TIMI risk score ≥ 3 in this study and divided them into two groups, group A and group B. Biodegradable-polymer DESs were exclusively used in group A, while durable-polymer DESs were used in group B. Major adverse events were reported in both groups during the hospital stay and patients were followed-up for 1 year.

RESULTS:

In our patients, we intervened on 390 diseased segments in a total of 360 vessels. After intervention, TIMI 0 was achieved in 0.97%, TIMI 1 in 1.46%, TIMI 2 in 2.45%, and TIMI 3 in 95.12% of the treated segments (P-value= 0.677). We implanted 121 biodegradable-polymer DESs and 146 durable-polymer DESs. Clinical success was achieved in 95.12% of our cases. We had 55 patients who needed repeated coronary angiography within 1 year (15 patients treated with biodegradable-polymer DES and 24 patients treated with durable-polymer DES). Eighteen patients experienced angina pains (8 patients treated with biodegradable-polymer DES and 10 patients treated with durable-polymer DES). Only 5 patients needed TLR (2 patients treated with biodegradable-polymer DES and 3 patients treated with durable -polymer DES) (P-value = 0.591), three of them had a myocardial infarction with documented angiographic evidence of significant in-stent restenosis (1 patient treated with biodegradable-polymer DES and 2 patients treated with durable-polymer DESs).

CONCLUSION:

Biodegradable-polymer DES represents a comparable alternative to durable-polymer DES in the setting of acute coronary syndromes.

Clinical and angiographic outcomes of bioabsorbable vs. permanent polymer drug-eluting stents in Sweden: a report from the Swedish Coronary and Angioplasty Registry (SCAAR)

Aims

Randomized clinical trials have consistently demonstrated the non-inferiority of bioabsorbable polymer drug-eluting stents (BP-DES) with respect to DES having permanent polymers (PP-DES). To date, the comparative performance of BP- and PP-DES in the real world has not been extensively investigated.

Methods and results

From October 2011 to June 2016, we analysed the outcomes associated with newer generation DES use in Sweden. After stratification according to the type of DES received at the index procedure, a total of 16 504 and 79 106 stents were included in the BP- and PP-DES groups, respectively. The Kaplan–Meier estimates for restenosis at 2 years were 1.2% and 1.4% in BP- and PP-DES groups, respectively. Definite stent thrombosis (ST) was low in both groups (0.5% and 0.7% in BP- and PP-DES groups, respectively). The adjusted hazard ratio (HR) for either restenosis or definite ST did not differ between BP- and PP-DES [adjusted HR 0.95, 95% confidence interval (CI) 0.74–1.21; P = 0.670 and adjusted HR 0.79, 95% CI 0.57–1.09; P = 0.151, respectively]. Similarly, there were no differences in the adjusted risk of all-cause death and myocardial infarction (MI) between the two groups (adjusted HR for all-cause death 1.01, 95% CI 0.82–1.25; P = 0.918 and adjusted HR for MI 1.05, 95% CI 0.93–1.19; P = 0.404).

Conclusion

In a large, nationwide, and unselected cohort of patients, percutaneous coronary intervention with BP-DES implantation was not associated with an incremental clinical benefit over PP-DES use at 2 years follow-up.

Long-term safety of bioresorbable scaffolds: insights from a network meta-analysis including 91 trials

AIMS

The aim of this study was to investigate the long-term safety and efficacy of biodegradable scaffolds and metallic stents.

METHODS AND RESULTS

We analysed a total of 91 randomised controlled trials with a mean follow-up of 3.7 years in 105,842 patients which compared two or more coronary metallic stents or biodegradable scaffolds and reported the long-term clinical outcomes (≥2 years). Network meta-analysis showed that patients treated with the Absorb bioresorbable vascular scaffold (BVS) had a significantly higher risk of definite or probable scaffold thrombosis (ScT) compared to those treated with metallic DES. The risk of very late ScT was highest with the Absorb BVS among comparators. Pairwise conventional meta-analysis demonstrated that the elevated risk of ScT with Absorb BVS compared to cobalt-chromium everolimus-eluting stents was consistent across the time points of ≤30 days (early), 31 days - 1 year (late) and >1 year (very late) ScT. In addition, target lesion failure rates were significantly higher in the Absorb BVS cohort, driven by both increased risk of target vessel myocardial infarction and ischaemia-driven target lesion revascularisation.

CONCLUSIONS

Absorb BVS implantation was associated with increased risk of long-term and very late ScT compared to current-generation metallic DES. The risk of ScT occurred with a rising trend beyond one year.

Preclinical In-Vivo Evaluation and Screening of Zinc Based Degradable Metals for Endovascular Stents

Zinc alloy development and characterization for vascular stent application has been facilitated by many standardized and inexpensive methods. In contrast, overly simplistic in vitro approaches dominate the preliminary biological testing of materials. In 2012, our group introduced a metal wire implantation model in rats as a cost effective and realistic approach for the biocompatibility evaluation of degradable materials in the vascular environment. Here, we have adapted metrics routinely used for evaluating stents to quantitatively characterize the long-term progression of the neointima that forms around zinc based wire implants. Histological cross-sections were used to measure the length of neointimal protrusion from the wire into the lumen (denoted wire to lumen thickness), the base neointimal length (describing the breadth of neointimal activation), and the neointimal area. These metrics were used to provide in depth characterization details for neointimal responses to Zn-Mg and Zn-Li alloys and may be used to compare different materials.

Serial 3-Dimensional Optical Coherence Tomography Assessment of Jailed Side-Branch by Second-Generation Drug-Eluting Absorbable Metal Scaffold (from the BIOSOLVE-II Trial)

Second-generation drug-eluting absorbable metal scaffold (DREAMS 2G) is used for treating coronary lesions. However, the natural history of the jailed side-branch (SB) after DREAMS 2G implantation remains to be elucidated. The aim of this study is to investigate the effect of scaffold struts on jailed SBs as assessed by 3-dimensional (3D) optical coherence tomography (OCT) after implantation of DREAMS 2G. We enrolled the patients who received a DREAMS 2G implantation and where OCT was performed at postprocedure and 12-month follow-up in the BIOSOLVE-II trial. The area of the ostium of jailed SBs and number of compartments divided by scaffold struts were assessed by cut-plane analysis using 3D OCT. A total of 24 patients with 61 jailed SBs were analyzed in this study. The number of compartments was significantly decreased (postprocedure; 1.98 ± 0.84 vs 12 months; 1.10 ± 0.30, p <0.001) during the 12 months. Since most of the struts disappeared, the ostium area was increased in 62% of jailed SBs at 12 months, however, not significantly different from postprocedure (postprocedure; 0.74 [0.34 to 1.46] mm² vs 12 months; 0.78 [0.41 to 1.68] mm², p = 0.055). The number of compartments created by scaffold struts and branching angle at postprocedure had no effect on the changes of SB ostium area. DREAMS 2G has a favorable absorption process in the jailed SBs up to 12 months and may be considered as an optional therapy for treating lesions that involve SBs.

Newer-generation Metallic Stents: Design, Performance Characteristics, and Outcomes

Several new coronary stents have been, or soon will be, introduced in the United States. These stents incorporate certain characteristics, such as polymer-free drug coatings, ultrathin stent struts, bioresorbable polymers, and composite materials, that address currently unmet clinical needs to enhance acute stent performance, improve longer-term clinical outcomes, and obviate obligatory prolonged dual antiplatelet therapy. This article reviews the key and novel features of these stents.

Impact of procedural characteristics on coronary vessel wall healing following implantation of second-generation drug-eluting absorbable metal scaffold in patients with de novo coronary artery lesions: an optical coherence tomography analysis

Aims 

Second-generation drug-eluting absorbable metal scaffold (DREAMS 2G) is an alternative novel device for treating coronary lesions. However, the relationship between in-scaffold dimensions after implantation of DREAMS 2G and vessel healing and luminal results at follow-up is unknown. The aim of this study is, therefore, to investigate whether the expansion index after implantation of DREAMS 2G as assessed by optical coherence tomography (OCT) impacts late luminal status and healing of the vessel wall.

Methods and results 

This study comprises of a total 65 out of 123 patients who were enrolled in the BIOSOLVE-II trial. We assessed both qualitative and quantitative OCT findings and the expansion index of DREAMS 2G after implantation frame by frame using OCT. Expansion index was defined as minimum scaffold area/mean reference lumen area. The over-expansion group was also defined with expansion index >1.0. The total number of analysed frames at post-procedure and 6-month follow-up was 8243 and 8263 frames, respectively. At 6-month follow-up, in-scaffold healing was documented by the reduction of 82% in dissections, 93% in attached intra-luminal mass (ILM), 65% in non-attached ILM, and 76% in jailed side branch. The over-expansion group had significantly greater in-scaffold luminal volume loss (LVL) compared with the non-over-expansion group [over-expansion: 35.0 (18.5–52.1) mm3 vs. non-over-expansion: 21.0 (11.6–37.9) mm3, P = 0.039].

Conclusion 

Excellent in vivo healing process after implantation of DREAMS 2G was observed at 6 months. We found that higher expansion indices were associated with higher in-scaffold LVL at 6 months assessed by OCT.

Biodegradable polymer versus second-generation durable polymer drug-eluting stents in patients with coronary artery disease: A meta-analysis

AIMS

Biodegradable polymer drug-eluting stents (BP-DES) were developed in hopes of reducing the risk of stent thrombosis. The comparison of this new stent platform with second-generation durable polymer drug-eluting stents (DP-DES) has not been well described. We, therefore, performed a meta-analysis to evaluate the safety and efficacy profiles of BP-DES versus second-generation DP-DES in patients with coronary artery disease.

METHODS AND RESULTS

Electronic database searches were conducted, from their dates of inception to June 2018, to identify randomized controlled trials (RCTs) comparing patients with either BP-DES or second-generation DP-DES. Risk estimates were expressed as risk ratios (RRs) with 95% confidence intervals (CIs). We also performed a landmark analysis beyond 1 year and sensitivity analyses based on different variables. A total of 24,406 patients from 19 RCTs were included in the present meta-analysis. There were no significant differences between BP-DES and second-generation DP-DES for the risks of definite or probable stent thrombosis (RR 0.88; 95% CI, 0.69-1.12; P = 0.29), myocardial infarction (RR 0.97; 95% CI, 0.86-1.09; P = 0.59), cardiac death (RR 1.08; 95% CI, 0.92-1.28; P = 0.34), all-cause death (RR 1.02; 95% CI, 0.91-1.13; P = 0.77), target lesion revascularization (RR 1.05; 95% CI, 0.94-1.17; P = 0.38), and target vessel revascularization (RR 1.05; 95% CI, 0.95-1.16; P = 0.36). Similar outcomes were observed regardless of anti-proliferative drug and duration of dual antiplatelet therapy (all P > 0.05).

CONCLUSION

Our findings demonstrate similar safety and efficacy profiles between BP-DES and second-generation BP-DES, with comparable rates of stent thrombosis.

Comparison between two biodegradable polymer-based sirolimus-eluting stents with differing drug elution and polymer absorption kinetics: two-year clinical outcomes of the PANDA III trial

AIMS

In the PANDA III trial, the novel poly-lactide-co-glycolide polymer-based BuMA sirolimus-eluting stent (SES) was non-inferior to the polylactide polymer-based Excel SES for the primary endpoint of one-year target lesion failure (TLF), with a lower incidence of stent thrombosis. We sought to investigate whether the effectiveness profile of BuMA SES, with more rapid drug elution and polymer absorption kinetics, would persist at two years.

METHODS AND RESULTS

A total of 2,348 patients (mean age, 61.2±10.6 years; 24.3% diabetics; 31.2% with acute myocardial infarction within one month) were randomly assigned to receive either BuMA SES (n=1,174) or Excel SES (n=1,174) in the "all-comer" PANDA III trial. Two-year clinical follow-up was available for 2,262 (96.3%) patients. The incidence of TLF and the patient-oriented composite endpoint (PoCE) was low and similar between the BuMA and Excel groups (7.4% vs. 6.9%, p=0.67, and 13.1% vs. 10.9%, p=0.11, respectively). The rate of any revascularisation was significantly higher with the BuMA SES (6.8% vs. 4.6%, p=0.03). Definite and probable thrombosis occurred in 0.7% and 1.4% of patients in the BuMA and Excel groups, respectively (p=0.10).

CONCLUSIONS

Two-year rates of TLF and PoCE events were low and similar between the two biodegradable polymer-based SES.

Interim Results of the Basket of Real-World Randomised Clinical PRISM Trials for M’Sure-S, a Next-Generation Sirolimus-Eluting Stent, Versus Eliminator, an Everolimus-Eluting Stent

Objective: This study compared sirolimus-eluting stents (SES) with everolimus-eluting stents (EES) in coronary artery disease patients. Methods: A total of 1,174 patients were enrolled in the study; 290 patients (25.28%) were treated with EES and 884 patients (74.72%) were treated with SES. The trial (PRISM) was a randomised (in a 3:1 ratio), multicentre, single-blind, all-comers, single-arm, non-inferiority trial comparing SES and EES-implanted patients with coronary artery disease. The primary endpoint was a composite of safety parameters (including major adverse cardiac events [MACE], cardiac death, and myocardial infarction) and efficacy (parameters concerned to quantitative coronary angiogram). An intention-to-treat analysis was performed at 9 and 18-month follow-ups. Results: The baseline characteristics were similar for both EES and SES groups. At the 9-month follow-up, MACE occurred in 5.86% and 2.43% of patients in the EES and SES groups, respectively. At the 18-month follow-up, this differential remained almost the same (i.e., 5.17 % of patients treated with the EES versus 2.14% treated with the SES). The rate of definite stent thrombosis at 9-month follow-up was lower in the SES group (11 patients [1.24%]) compared to the EES group (9 patients [3.10%]). At 18-month follow-up, the rate was 2.14% (19 patients) in the SES group and 4.13% (12 patients) in the EES group. When censoring the patients at the time of stent thrombosis, no significant differences between the two stent groups were found. Conclusion: In this real-world trial, at 9 and 18-month follow-ups, SES (M’Sure-S) exhibited a better safety and efficacy profile when compared to EES in terms of MACE rates and definite stent thrombosis. However, the difference was not statistically significant and SES was found to be non-inferior to EES.

Ultrathin-strut, biodegradable-polymer, sirolimus-eluting stents versus thin-strut, durable-polymer, everolimus-eluting stents for percutaneous coronary revascularisation: 5-year outcomes of the BIOSCIENCE randomised trial

BACKGROUND

Drug-eluting stents combining an ultrathin cobalt-chromium stent platform with a biodegradable polymer eluting sirolimus have been shown to be non-inferior or superior to thin-strut, durable-polymer, everolimus-eluting stents in terms of 1 year safety and efficacy outcomes.

METHODS

In the randomised, single-blind, multicentre, non-inferiority BIOSCIENCE trial, we compared biodegradable-polymer sirolimus-eluting stents with durable-polymer everolimus-eluting stents in patients with chronic stable coronary artery disease or acute coronary syndromes. Here, we assess the final 5-year clinical outcomes of BIOSCIENCE with regards to the primary clinical outcome of target lesion failure, which was a composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularisation. The primary analysis was done by intention to treat. The BIOSCIENCE trial is registered with ClinicalTrials.gov, number NCT01443104.

FINDINGS

2008 (95%) of 2119 patients recruited between March 1, 2012, and May 31, 2013, completed 5 years of follow-up. Target lesion failure occurred in 198 patients (cumulative incidence 20·2%) treated with biodegradable-polymer sirolimus-eluting stents and in 189 patients (18·8%) treated with durable-polymer everolimus-eluting stents (rate ratio [RR] 1·07, 95% CI 0·88-1·31; p=0·487). All-cause mortality was significantly higher in patients treated with biodegradable-polymer sirolimus-eluting stents than in those treated with durable-polymer everolimus-eluting stents (14·1% vs 10·3%; RR 1·36, 95% CI 1·06-1·75; p=0·017), driven by a difference in non-cardiovascular deaths. We observed no difference between groups in cumulative incidence of definite stent thrombosis at 5 years (1·6% in both groups; 1·02, 0·51-2·05; p=0·950).

INTERPRETATION

5-year risk of target lesion failure among all-comer patients undergoing percutaneous coronary intervention is similar after implantation of ultrathin-strut, biodegradable-polymer, sirolimus-eluting stents or thin-strut, durable-polymer, everolimus-eluting stents. Higher incidences of all-cause and non-cardiovascular mortality in patients treated with biodegradable-polymer stents eluting sirolimus than in those treated with durable-polymer stents eluting everolimus warrant careful observation in ongoing clinical trials.

FUNDING

Clinical Trials Unit of the University of Bern and Biotronik.

Long-term clinical outcomes with biodegradable polymer sirolimus-eluting stents versus durable polymer sirolimus-eluting stents

AIMS

The purpose of this study was to compare the long-term outcomes of a biodegradable polymer, sirolimus-eluting stent (Orsiro) with a durable polymer, sirolimus-eluting stent (CYPHER) to determine if late failure of the CYPHER is caused by the polymer or sirolimus.

METHODS AND RESULTS

A total of 447 patients who underwent percutaneous coronary intervention (PCI) with one of the study stents were retrospectively analysed. The composite of cardiac death, stent thrombosis, and clinically driven target lesion revascularisation (TLR) within two years after PCI occurred in 3.0% of the Orsiro group and 9.6% of the CYPHER group. Multivariable Cox regression results indicated that the Orsiro stent was a significant independent predictor of a lower occurrence of the composite outcome (adjusted HR 0.37, 95% CI: 0.14-0.87), stent thrombosis (adjusted HR 0.07, 95% CI: 0.00-0.65), clinically driven TLR (adjusted HR 0.26, 95% CI: 0.09-0.69), and stent failure (adjusted HR 0.26, 95% CI: 0.09-0.69) within two years after PCI.

CONCLUSIONS

This study has demonstrated that late CYPHER failure is attributable more to its durable polymer than to the antiproliferative drug, sirolimus. This suggests that sirolimus-based, new-generation drug-eluting stents are relatively safe and are expected to show long-term outcomes superior to those of the CYPHER.

Development of a biodegradable antifibrotic local drug delivery system for glaucoma microstents

To prevent implant failure due to fibrosis is a major objective in glaucoma research. The present study investigated the antifibrotic effects of paclitaxel (PTX), caffeic acid phenethyl ester (CAPE), and pirfenidone (PFD) coated microstent test specimens in a rat model. Test specimens based on a biodegradable blend of poly(4-hydroxybutyrate) biopolymer and atactic poly(3-hydroxybutyrate) (at.P(3HB)) were manufactured, equipped with local drug delivery (LDD) coatings, and implanted in the subcutaneous white fat depot. Postoperatively, test specimens were explanted and analyzed for residual drug content. Fat depots including the test specimens were histologically analyzed. In vitro drug release studies revealed an initial burst for LDD devices. In vivo, slow drug release of PTX was found, whereas it already completed 1 week postoperatively for CAPE and PFD LDD devices. Histological examinations revealed a massive cell infiltration in the periphery of the test specimens. Compact fibrotic capsules around the LDD devices were detectable at 4–36 weeks and least pronounced around PFD-coated specimens. Capsules stained positive for extracellular matrix (ECM) components. The presented model offers possibilities to investigate release kinetics and the antifibrotic potential of drugs in vivo as well as the identification of more effective agents for a novel generation of drug-eluting glaucoma microstents.

Safety and efficacy of ultrathin strut biodegradable polymer sirolimus-eluting stent versus durable polymer drug-eluting stents: a meta-analysis of randomized trials

Background

The Orsiro biodegradable polymer sirolimus-eluting stent (O-SES) is a new-generation biodegradable polymer drug-eluting stent with the thinnest strut thickness to date developed to improve the percutaneous treatment of patients with coronary artery disease. We perform a meta-analysis of randomized clinical trials (RCTs) comparing the efficacy and safety of an ultra-thin, Orsiro biodegradable polymer sirolimus-eluting stent (O-SES) compared with durable polymer drug-eluting stents (DP-DESs).

Methods

Medline, Embase, and CENTRAL databases were searched for randomized controlled trials comparing the safety and efficacy of O-SES versus DP-DES. Paired reviewers independently screened citations, assessed risk of bias of included studies, and extracted data. We used the Mantel-Haenszel method to calculate risk ratio (RR) by means of a random-effects model.

Results

Six RCTs with a total of 6949 patients were selected. All included trials were rated as low risk of bias. The O-SES significantly reduced the risk of myocardial infarction (RR 0.78, 95% confidence interval [CI] 0.62–0.98; I² = 0%; 10 fewer per 1000 [from 1 fewer to 18 fewer]; high quality) compared with the DP-DES. There was no significant difference between O-SES and DP-DES in the prevention of stent thrombosis (RR: 0.75; 95% CI: 0.52–1.08), cardiac death (RR: 0.93; 95% CI: 0.63–1.36), target lesion revascularization (RR 1.10, 95% CI 0.86–1.42) and target vessel revascularization (RR 0.97, 95% CI 0.78–1.21).

Conclusion

Among patients undergoing percutaneous coronary intervention, O-SES resulted in significantly lower rates of myocardial infarction than DP-DES and had a trend toward reduction in stent thrombosis.

Safety and clinical performance of a drug eluting absorbable metal scaffold in the treatment of subjects with de novo lesions in native coronary arteries: Pooled 12-month outcomes of BIOSOLVE-II and BIOSOLVE-III

OBJECTIVES

Based on outcomes of the BIOSOLVE-II study, a novel second generation drug-eluting absorbable metal scaffold gained CE-mark in 2016. The BIOSOLVE-III study aimed to confirm these outcomes and to obtain additional 12-month angiographic data.

BACKGROUND

Bioresorbable scaffolds are intended to overcome possible long-term effects of permanent stents such as chronic vessel wall inflammation, stent crushing, and fractures.

METHODS

The prospective, multicenter BIOSOLVE-II and BIOSOLVE-III studies enrolled 184 patients with 189 lesions (123 patients in BIOSOLVE-II and 61 patients in BIOSOLVE-III). Primary endpoints were in-segment late lumen loss at 6 months (BIOSOLVE-II) and procedural success (BIOSOLVE-III).

RESULTS

Mean patient age was 65.5 ± 10.8 years and mean lesion reference diameter was 2.70 ± 0.43 mm. In BIOSOLVE-III, there were significantly more type B2/C lesions than in BIOSOLVE-II (80.3% versus 43.4%, P < 0.0001) and significantly more moderate-to-severe calcifications (24.2% versus 10.7%, P = 0.014). At 12 months, there was no difference in late lumen loss between the two studies; in the overall population, it was 0.25 ± 0.31 mm in-segment and 0.39 ± 0.34 mm in-scaffold. Target lesion failure occurred in six patients (3.3%) and included two cardiac deaths, one target-vessel myocardial infarction, and three clinically driven target lesion revascularizations. No definite or probable scaffold thrombosis was observed.

CONCLUSION

The pooled outcomes of BIOSOLVE-II and BIOSOLVE-III provide further evidence on the safety and performance of a novel drug-eluting absorbable metal scaffold with constant clinical and angiographic performance parameters at 12 months and no definite or probable scaffold thrombosis.

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: Rationale and study design of the Scandinavian Organization for Randomized Trials with Clinical Outcome (SORT OUT) X trial

BACKGROUND

The Combo stent (OrbusNeich, Hoevelaken, the Netherlands) combining an abluminal, bioabsorbable polymer eluting sirolimus with a luminal CD34+ antibody to capture endothelial progenitor cells has been developed to further improve safety and efficacy of coronary interventions. We have designed a large-scale registry-based randomized clinical trial to compare the Combo stent to the Orsiro stent (Biotronik, Bülach, Switzerland) in patients undergoing percutaneous coronary intervention.

METHODS

The SORT OUT X study will randomly assign 3,140 patients to treatment with Combo or Orsiro stents at 3 sites in Western Denmark. Patients are eligible if they are ≥18 years old, have chronic stable coronary artery disease or acute coronary syndromes, and have ≥1 coronary lesion with >50% diameter stenosis requiring treatment with a drug-eluting stent. The primary end point target lesion failure is a composite of cardiac death, myocardial infarction (not related to other than index lesion), or target lesion revascularization within 12 months. Clinically driven event detection will be derived from validated Danish registries. An event rate of 4.2% is assumed in each stent group. With a sample size of 1,570 patients in each treatment arm, a 2-group large-sample normal approximation test of proportions with a 1-sided 5% significance level will have 90% power to detect noninferiority of the Combo stent compared with the Orsiro stent with a predetermined noninferiority margin of 2.1%.

CONCLUSION

The SORT OUT X trial will determine whether the dual-therapy Combo stent is noninferior to the Orsiro stent with respect to clinically driven events (ClinicalTrials.govNCT03216733).

In vitro and in vivo evaluation of a novel polymer-free everolimus-eluting stent by nitrogen-doped titanium dioxide film deposition

Inflammation and thrombosis are linked to the use of polymer-based drug-eluting stents (DES). The aim of this study was to develop a polymer-free everolimus (EVL)-eluting stent using nitrogen-doped titanium dioxide (N-TiO₂) and verify its efficacy by in vitro and in vivo assessment in a porcine coronary model. Various analytical approaches such as scanning electron microscopy and atomic force microscopy, electron spectroscopy, Fourier transform infrared spectrometry and contact angle measurement were employed for the characterization. As a part of biocompatibility assessment, platelet adhesion and smooth muscle cell (SMC) proliferation were examined. Bare metal stent (BMS), N-TiO₂ stent, everolimus-eluting N-TiO₂ (N-TiO₂-EVL) stent, and commercialized EVL-eluting stent (EES) were randomly placed in forty coronary arteries in twenty pigs. After four weeks of implantation, the stents were subjected to histological and quantitative analysis. The N-TiO₂ film used in this study was well coated without any cracks or peeling. Surface hydrophilicity (88.8% of angle decrement) could be associated with the decrease in surface roughness post N-TiO₂ deposition (37.0%). The platelet adhesion on the N-TiO₂ surfaces was less than that on the BMS surface. The proliferation of SMC was suppressed in the N-TiO₂-EVL group (30.2%) but not in the BMS group. In the animal study, the percent area restenosis was significantly decreased in the N-TiO₂-EVL group compared to that in the BMS group. The results (BMS; 47.0 ± 11.00%, N-TiO₂-EVL; 31.7 ± 10.50%, and EES; 29.1 ± 11.21%, n = 10, p < 0.05) were almost at par with those of the commercialized EVL-eluting stent. The introduction of N-TiO₂ deposition during fabrication of polymer-free DES may be an efficient accessorial process for preventing in-stent restenosis and thrombosis.

Comparison of Acute Thrombogenicity for Metallic and Polymeric Bioabsorbable Scaffolds: Magmaris Versus Absorb in a Porcine Arteriovenous Shunt Model

BACKGROUND

A comparison in acute thrombogenicity between the Magmaris sirolimus-eluting bioabsorbable magnesium scaffold and the Absorb bioresorbable vascular scaffold has not been performed. This study assessed acute thrombogenicity of Magmaris compared with Absorb and the Orsiro hybrid drug-eluting stent in a porcine arteriovenous shunt model.

METHODS AND RESULTS

An ex vivo porcine carotid jugular arteriovenous shunt was established and connected to SYLGARD tubing containing the Magmaris, Absorb, and Orsiro scaffolds/stents and allowed to run in the shunt for a maximum of 1 hour. Twelve shunts (2 shunt runs per pig) were run comparing the 3 scaffolds in alternating order. Nested generalized linear mixed models were used to compare variables between scaffold groups while adjusting for variability between shunt runs. Confocal fluorescent microscopy costaining CD61/CD42b demonstrated that both Magmaris (3.0%) and Orsiro (4.6%) had less platelet coverage of the total scaffold compared with Absorb (21.8%). Scanning electron microscopy demonstrated significantly less thrombus deposition to Magmaris as a percentage of the total scaffold compared with Absorb (5.0% versus 16.1%, P=0.02). Magmaris had significantly less PM-1-positive neutrophil and CD14-positive monocyte adherence compared with both Orsiro and Absorb. Orsiro had significantly less monocyte deposition compared with Absorb.

CONCLUSIONS

Despite a similar scaffold strut thickness, the Magmaris sirolimus-eluting bioabsorbable magnesium scaffold was significantly less thrombogenic compared with the Absorb bioresorbable vascular scaffold in an ex vivo porcine arteriovenous shunt model. Further studies are needed to determine whether the reduced thrombogenicity of Magmaris will result in reductions in major cardiovascular events.

Sustained safety and clinical performance of a drug-eluting absorbable metal scaffold up to 24 months: pooled outcomes of BIOSOLVE-II and BIOSOLVE-III

AIMS

We aimed to assess the safety and performance of the DREAMS 2G scaffold up to 24 months post implant.

METHODS AND RESULTS

The present study population comprises a total of 184 patients with 189 lesions who were enrolled in the prospective, multicentre BIOSOLVE-II and BIOSOLVE-III trials. Clinical follow-up was scheduled at one, six, 12, 24 and 36 months. The present report includes pooled follow-up data at six months and BIOSOLVE-II data at 24 months. Patients were 65.5±10.8 years old, and lesions were 12.5±5.1 mm long with reference diameters of 2.7±0.4 mm. Procedural success was obtained in 97.8%. At six months, the composite clinical endpoint target lesion failure was 3.3% (95% CI: 1.2-7.1), based on two cardiac deaths (1.1%, one unknown and one not device-related), one target vessel myocardial infarction (0.6%), and three clinically driven target lesion revascularisations (1.7%). For BIOSOLVE-II at 24 months, the target lesion failure rate was 5.9% (95% CI: 2.4-11.8), based on two cardiac deaths (1.7%), one target vessel myocardial infarction (0.9%) and four target lesion revascularisations (3.4%). There was no definite or probable scaffold thrombosis.

CONCLUSIONS

The present analysis provides additional evidence on the safety of a drug-eluting absorbable metal scaffold with promising clinical outcomes up to 24 months and absence of definite or probable scaffold thrombosis.

Merging the properties of a sirolimus coated balloon with those of a bioresorbable polymer sirolimus eluting stent to address the "diabetes issue". Results from the En-Abl multicenter registry

BACKGROUND

Patients with diabetes mellitus (DM) have poorer outcomes after percutaneous coronary intervention than patients without diabetes. The Abluminus DES+™ drug-eluting stent (DES) features a novel technology of fusion coating of PLLA bioresorbable polymer on both the abluminal surface of the stent and exposed parts of the balloon. The aim of this study was to evaluate the efficacy/safety profile of the Abluminus DES+ in an all-comers population with minimal exclusion criteria and with a specific focus on diabetic patients.

METHODS

Multicenter, prospective, all-comers registry performed in 31 centers in India. Patients were analyzed according to the diagnosis of DM and insulin dependency (ID or Non ID): non-DM (1256 patients), NIDDM (498 patients), IDDM (99 patients). The primary endpoint was a composite of device-oriented major adverse cardiac events (MACE): cardiac death, target vessel-related myocardial infarction (MI), and ischemia-driven target lesion revascularization (TLR)/ target vessel revascularization (TVR) at 1 year. Stent thrombosis (ST) at any time point was also recorded.

RESULTS

The MACE rate at 1 year in the overall population was 2.3% and it was mainly driven by a 1.57% rate of TLR/TVR. Although patients with IDDM showed slightly higher figures for MACE (non-DM 2.3%, NIDDM 2.8%, IDDM 4%, P=0.09), as well as for single end-points, none of them reached statistical significance. The rate of ST was 0.56%, 0.4%, 1% for non-DM, NIDDM and IDDM group, respectively (P=0.6).

CONCLUSIONS

The performance of the Abluminus DES+ is consistent among patients with or without diabetes, regardless the insulin dependency.

Three-months optical coherence tomography analysis of a biodegradable polymer, sirolimus-eluting stent

OBJECTIVE

We aimed to assess early neointimal healing by optical coherence tomography (OCT) 3 months after implantation of the ultrathin Orsiro® sirolimus-eluting stent with biodegradable polymer.

BACKGROUND

New generations of drug-eluting stents with biodegradable polymer have been developed to avoid the continued vascular irritation of durable polymers.

METHODS

In this prospective, open-label study, 34 patients received an Orsiro® sirolimus-eluting stent with biodegradable polymer. In a subgroup of patients (n = 15), the intervention was performed under OCT guidance. All patients underwent OCT-examination at three months. The primary endpoint was 3-month neointimal healing (NIH) score, calculated by weighing the presence of filling defects, malapposed and uncovered struts. Secondary endpoint was maturity of tissue coverage at 3 months.

RESULTS

At 3 months, NIH score was 13.7 (5.4-22), covered struts per lesion were 90% (84-97%), malapposed struts were 2.7% (0.8-5.4%) and rate of mature tissue coverage was 47% (42-53%). No target lesion failure occurred up to 12 months. Patients with OCT-guided stent implantation demonstrated a trend toward earlier stent healing as demonstrated by superior NIH scores (angio guided: 17.6% [8.8-26.4]; OCT-guided: 9.8% [4.0-15.5]; mean difference -8, [95%CI: -18.7-2.9], P = 0.123). This group had significantly more covered struts per lesion (angio-guided: 86% [82-90]; 95% [92-99]; mean difference 9% [95%CI: 3-15], P = 0.001).

CONCLUSION

The Orsiro® sirolimus-eluting stent with biodegradable polymer shows early vascular healing with a high rate of strut coverage at 3-month follow-up. OCT guided stent implantation had a positive impact on early vascular healing.

Bioresorbable Polymer-Coated Orsiro Versus Durable Polymer-Coated Resolute Onyx Stents (BIONYX): Rationale and design of the randomized TWENTE IV multicenter trial

AIM

The aim was to compare in a noninferiority trial the efficacy and safety of 2 contemporary drug-eluting stents (DESs): a novel, durable polymer-coated stent versus an established bioabsorbable polymer-coated stent.

METHODS AND RESULTS

The BIONYX trial (ClinicalTrials.gov-no.NCT02508714) is an investigator-initiated, prospective, randomized, patient- and assessor-blinded, international, multicenter study in all-comer patients with all types of clinical syndromes and lesions who require percutaneous coronary interventions with DES. Patients at 7 study sites in the Netherlands, Belgium, and Israel were randomly assigned (1:1, stratified for gender and diabetes mellitus) to treatment with the novel, zotarolimus-eluting, durable polymer-coated Resolute Onyx stent that has a radiopaque, thin-strut, CoreWire stent platform versus the sirolimus-eluting, bioresorbable polymer-coated Orsiro stent (reference device) that has a very thin-strut, cobalt-chromium stent backbone. The primary end point is the 1-year incidence of the composite clinical end point target vessel failure consisting of cardiac death, target vessel-related myocardial infarction, or clinically indicated target vessel revascularization. A power calculation, assuming a target vessel failure rate of 6.0% (noninferiority margin 2.5%), revealed that 2,470 study patients would give the study 80% power (α level 5%), allowing for up to 3% loss to follow-up. The first patient was enrolled on October 7, 2015; on December 23, 2016, the last patient entered the study.

CONCLUSIONS

BIONYX is a large-scale, prospective, randomized, international, multicenter trial comparing a novel DES with durable coating versus a reference DES with biodegradable coating in all-comers. The study is the first randomized assessment of the Resolute Onyx stent, which is an often-used DES outside the United States.

Challenges in Patients with Diabetes: Improving Clinical Outcomes After Percutaneous Coronary Intervention Through EVOlving Stent Technology

Patients with diabetes have poorer outcomes after percutaneous coronary intervention than patients without diabetes. The Cre8™ EVO drug-eluting stent (DES) has design features that aim to improve clinical outcomes in patients with diabetes. These include Abluminal Reservoir Technology - a proprietary polymer-free drug-release system consisting of reservoirs on the abluminal surface of the stent that control drug release and direct the drug exclusively towards the vessel wall - and the Amphilimus™ drug formulation, which enables enhanced drug-tissue permeation utilising fatty acid transport pathways. The latter is particularly advantageous in patients with diabetes, whose cell metabolism favours increased cellular uptake of fatty acid. Furthermore, evidence suggests that mTOR inhibitors (-limus drugs) utilised in conventional DES are less effective in diabetic cells. The new stent architecture provides high device deliverability and conformability, facilitating clinical use in complex disease patterns and high-risk lesion morphologies. Clinical evidence for the efficacy and safety of the Cre8™ DES in patients with diabetes has been demonstrated in a number of clinical trials and observational registries. These data are reviewed herein, along with an overview of on-going randomised trials.