Coronary arterial repair in patients with stable angina pectoris or acute coronary syndrome after ultrathin biodegradable polymer sirolimus-eluting stent implantation at 1-year follow-up by coronary angioscopy

BACKGROUND

Imaging modality-based evidence is limited that compares the extent of coronary arterial repair after percutaneous coronary intervention between patients with stable angina pectoris (SAP) and those with acute coronary syndrome (ACS).

METHODS

Between December 2018 and November 2021, a single-center, nonrandomized, observational study was conducted in 92 patients with SAP (n = 42) or ACS (n = 50), who were implanted with Orsiro sirolimus-eluting stent (O-SES) providing a hybrid (active and passive) coating and underwent 1-year follow-up by coronary angioscopy (CAS) after implantation. CAS assessed neointimal coverage (NIC), maximum yellow plaque (YP), and mural thrombus (MT).

RESULTS

Baseline clinical characteristics were comparable between the SAP and ACS groups. The follow-up periods were comparable between the two groups (390.1 ± 69.9 vs. 390.6 ± 65.7 days, p = 0.99). The incidences of MT at 1 year after implantation were comparable between the two groups (11.4% vs. 11.1%, p = 0.92). The proportions of "Grade 1" in dominant NIC grades were highest in both groups, and the proportions of maximum YP grades and MT were comparable between the two groups.

CONCLUSION

O-SES-induced coronary arterial repair at the site of stent implantation, irrespective of the types of coronary artery disease.

Health Care Monitoring and Treatment for Coronary Artery Diseases: Challenges and Issues

In-stent restenosis concerning the coronary artery refers to the blood clotting-caused re-narrowing of the blocked section of the artery, which is opened using a stent. The failure rate for stents is in the range of 10% to 15%, where they do not remain open, thereby leading to about 40% of the patients with stent implantations requiring repeat procedure within one year, despite increased risk factors and the administration of expensive medicines. Hence, today stent restenosis is a significant cause of deaths globally. Monitoring and treatment matter a lot when it comes to early diagnosis and treatment. A review of the present stent monitoring technology as well as the practical treatment for addressing stent restenosis was conducted. The problems and challenges associated with current stent monitoring technology were illustrated, along with its typical applications. Brief suggestions were given and the progress of stent implants was discussed. It was revealed that prime requisites are needed to achieve good quality implanted stent devices in terms of their size, reliability, etc. This review would positively prompt researchers to augment their efforts towards the expansion of healthcare systems. Lastly, the challenges and concerns associated with nurturing a healthcare system were deliberated with meaningful evaluations.

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.

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.

Do ultrathin strut bare-metal stents with passive coating improve efficacy in large coronary arteries? Insights from the randomized, multicenter BASKET-PROVE trials

BACKGROUND

The new generation thinner-strut silicon carbide (SiC) coated cobalt chromium (CoCr) bare-metal stents (BMS) are designed to accelerate rapid endothelialisation and reduce thrombogenicity when implanted in coronary arteries. However, smaller studies suggest higher rates of symptomatic restenosis in patients receiving the newer generation BMS. We investigated the efficacy of a newer generation ultrathin strut silicon-carbide coated cobalt-chromium (CoCr) BMS (SCC-BMS) as compared to an older thin-strut uncoated CoCr BMS (UC-BMS) in patients presenting with coronary artery disease requiring stenting of large vessels (≥3.0 mm).

METHODS

All patients randomized to SCC- (n = 761) or UC-BMS (n = 765) in the two BASKET-PROVE trials were included. Design, patients, interventions and follow-up were similar between trials except differing regimens of dual antiplatelet therapy. The primary endpoint was clinically driven target-vessel revascularization within 24 months. Safety endpoints of cardiac death, non-fatal myocardial infarction (MI), and definite/probable stent thrombosis (ST) were also assessed. We used inverse probability weighted proportional hazards Cox regressions adjusting for known confounders.

RESULTS

Demographics, clinical presentation, and risk factors were comparable between the groups, but patients receiving SCC-BMS underwent less complex procedures. The risk for clinically driven TVR was increased om the SCC-BMS group compared to the UC-BMS group (cumulative incidence, 10.6% vs. 8.4%; adjusted relative hazard [HR], 1.49 [95% CI, 1.05-2.10]). No differences in safety endpoints were detected, cardiac death (1.6% vs. 2.8%; HR, 0.62 [CI, 0.30-1.27]), non-fatal MI (3.2% vs. 2.5%; HR, 1.56 [CI, 0.83-2.91]), and definite/probable ST (0.8% vs. 1.1%; HR, 1.17 [CI, 0.39-3.50]). Differences in strut thickness between the two stents did not explain the association between stent type and clinically driven TVR.

CONCLUSIONS

In patients requiring stenting of large coronary arteries, use of the newer generation SCC-BMS was associated with a higher risk of clinically driven repeat revascularization compared to the UC-BMS with no signs of an offsetting safety benefit.

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.

Direct comparison of coronary bare metal vs. drug-eluting stents: same platform, different mechanics?

Background

Drug-eluting stents (DES) compared to bare metal stents (BMS) have shown superior clinical performance, but are considered less suitable in complex cases. Most studies do not distinguish between DES and BMS with respect to their mechanical performance. The objective was to obtain mechanical parameters for direct comparison of BMS and DES.

Methods

In vitro bench tests evaluated crimped stent profiles, crossability in stenosis models, elastic recoil, bending stiffness (crimped and expanded), and scaffolding properties. The study included five pairs of BMS and DES each with the same stent platforms (all n = 5; PRO-Kinetic Energy, Orsiro: BIOTRONIK AG, Bülach, Switzerland; MULTI-LINK 8, XIENCE Xpedition: Abbott Vascular, Temecula, CA; REBEL Monorail, Promus PREMIER, Boston Scientific, Marlborough, MA; Integrity, Resolute Integrity, Medtronic, Minneapolis, MN; Kaname, Ultimaster: Terumo Corporation, Tokyo, Japan). Statistical analysis used pooled variance t tests for pairwise comparison of BMS with DES.

Results

Crimped profiles in BMS groups ranged from 0.97 ± 0.01 mm (PRO-Kinetic Energy) to 1.13 ± 0.01 mm (Kaname) and in DES groups from 1.02 ± 0.01 mm (Orsiro) to 1.13 ± 0.01 mm (Ultimaster). Crossability was best for low profile stent systems. Elastic recoil ranged from 4.07 ± 0.22% (Orsiro) to 5.87 ± 0.54% (REBEL Monorail) including both BMS and DES. The bending stiffness of crimped and expanded stents showed no systematic differences between BMS and DES neither did the scaffolding.

Conclusions

Based on in vitro measurements BMS appear superior to DES in some aspects of mechanical performance, yet the differences are small and not class uniform. The data provide assistance in selecting the optimal system for treatment and assessment of new generations of bioresorbable scaffolds.

Trial registration: not applicable

The Newest Generation of Drug-eluting Stents and Beyond

There has been a great evolution in the development of coronary stents in order to avoid both restenosis and thrombosis. Improvements have led to improvements in the design and conformation of metallic or resorbable structures, with an adequate balance between trackability and radial force, the development of antiproliferative drugs and the polymers to control release and allow adequate endothelialisation and an optimal duration of the antiplatelet regimen. Some suggestions are provided about the ideal characteristics of future coronary stents.

Primary endpoint results of the OMEGA Study: One-year clinical outcomes after implantation of a novel platinum chromium bare metal stent

BACKGROUND/PURPOSE

Bare metal stents (BMS) have similar rates of death and myocardial infarction (MI) compared to drug-eluting stents (DES). DES lower repeat revascularization rates compared to BMS, but may have higher rates of late stent thrombosis (ST) potentially due to impaired endothelialization requiring longer dual anti-platelet therapy (DAPT). OMEGA evaluated a novel BMS designed to have improved deliverability and radiopacity, in comparison to currently available platforms.

METHODS/MATERIALS

OMEGA was a prospective, multicenter, single-arm study enrolling 328 patients at 37 sites (US and Europe). Patients received the OMEGA stent (bare platinum chromium element stent) for the treatment of de novo native coronary artery lesions (≤28 mm long; diameter ≥2.25 mm to ≤4.50mm). The primary endpoint was 9-month target lesion failure (TLF: cardiac death, target vessel-related MI, target lesion revascularization [TLR]) compared to a prespecified performance goal (PG) based on prior generation BMS. All major cardiac events were independently adjudicated. DAPT was required for a minimum of 1 month post procedure.

RESULTS

In the OMEGA study, the mean age was 65; 17% had diabetes mellitus. The primary endpoint was met; 9 month TLF rate was 11.5%, and the upper 1-sided 95% confidence bound of 14.79% was less than the prespecified PG of 21.2% (p<0.0001). One-year event rates were low including a TLF rate of 12.8% and an ST rate of 0.6% at 12 months.

CONCLUSIONS

One-year outcomes of OMEGA show low rates of TLF, revascularization and ST. This supports safety and efficacy of the OMEGA BMS for the treatment of coronary artery disease.

Ultrathin strut biodegradable polymer sirolimus-eluting stent versus durable polymer everolimus-eluting stent for percutaneous coronary revascularisation (BIOSCIENCE): a randomised, single-blind, non-inferiority trial

BACKGROUND

Refinements in stent design affecting strut thickness, surface polymer, and drug release have improved clinical outcomes of drug-eluting stents. We aimed to compare the safety and efficacy of a novel, ultrathin strut cobalt-chromium stent releasing sirolimus from a biodegradable polymer with a thin strut durable polymer everolimus-eluting stent.

METHODS

We did a randomised, single-blind, non-inferiority trial with minimum exclusion criteria at nine hospitals in Switzerland. We randomly assigned (1:1) patients aged 18 years or older with chronic stable coronary artery disease or acute coronary syndromes undergoing percutaneous coronary intervention to treatment with biodegradable polymer sirolimus-eluting stents or durable polymer everolimus-eluting stents. Randomisation was via a central web-based system and stratified by centre and presence of ST segment elevation myocardial infarction. Patients and outcome assessors were masked to treatment allocation, but treating physicians were not. The primary endpoint, target lesion failure, was a composite of cardiac death, target vessel myocardial infarction, and clinically-indicated target lesion revascularisation at 12 months. A margin of 3·5% was defined for non-inferiority of the biodegradable polymer sirolimus-eluting stent compared with the durable polymer everolimus-eluting stent. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT01443104.

FINDINGS

Between Feb 24, 2012, and May 22, 2013, we randomly assigned 2119 patients with 3139 lesions to treatment with sirolimus-eluting stents (1063 patients, 1594 lesions) or everolimus-eluting stents (1056 patients, 1545 lesions). 407 (19%) patients presented with ST-segment elevation myocardial infarction. Target lesion failure with biodegradable polymer sirolimus-eluting stents (69 cases; 6·5%) was non-inferior to durable polymer everolimus-eluting stents (70 cases; 6·6%) at 12 months (absolute risk difference -0·14%, upper limit of one-sided 95% CI 1·97%, p for non-inferiority <0·0004). No significant differences were noted in rates of definite stent thrombosis (9 [0·9%] vs 4 [0·4%], rate ratio [RR] 2·26, 95% CI 0·70-7·33, p=0·16). In pre-specified stratified analyses of the primary endpoint, biodegradable polymer sirolimus-eluting stents were associated with improved outcome compared with durable polymer everolimus-eluting stents in the subgroup of patients with ST-segment elevation myocardial infarction (7 [3·3%] vs 17 [8·7%], RR 0·38, 95% CI 0·16-0·91, p=0·024, p for interaction=0·014).

INTERPRETATION

In a patient population with minimum exclusion criteria and high adherence to dual antiplatelet therapy, biodegradable polymer sirolimus-eluting stents were non-inferior to durable polymer everolimus-eluting stents for the combined safety and efficacy outcome target lesion failure at 12 months. The noted benefit in the subgroup of patients with ST-segment elevation myocardial infarction needs further study.

FUNDING

Clinical Trials Unit, University of Bern, and Biotronik, Bülach, Switzerland.

Clinical and angiographic experience with a third-generation drug-eluting Orsiro stent in the treatment of single de novo coronary artery lesions (BIOFLOW-I): a prospective, first-in-man study

AIMS

To report the four-month and nine-month angiographic results as well as one-year clinical follow-up from the first-in-man study with the silicon carbide and sirolimus-eluting bioabsorbable polymer (poly-L-lactic acid (PLLA) polymer) -coated cobalt-chromium Orsiro stent.

METHODS AND RESULTS

A group of 30 patients with documented myocardial ischaemia related to a single de novo coronary stenosis up to 22 mm in length, in vessels with a 2.5 to 3.5 mm reference diameter, and between >50% and <90% diameter stenosis were enrolled at two sites. The primary endpoint of the study was in-stent late lumen loss at nine months. The secondary endpoints included major adverse cardiac events (MACE) at one year defined as the composite of cardiac death, ischaemia-driven target lesion revascularisation (TLR) and target vessel myocardial infarction (MI). Procedural success was 100%. Angiographic late lumen loss was 0.12±0.19 mm and 0.05±0.22 mm at four and nine months respectively. At one-year clinical follow-up, the composite MACE was 10% with one patient who died from cardiac death and two patients who had ischaemia-driven target lesion revascularisation. There was no report of MI or stent thrombosis.

CONCLUSIONS

The Orsiro drug-eluting stent demonstrated potency with low rates of in-stent neointimal hyperplasia and cardiovascular events but warrants further evaluation in a larger population cohort with longer follow-up time points.

Difference in clinical target lesion revascularization between a silicon carbide-coated and an uncoated thin strut bare-metal stent: the PRO-Vision study

BACKGROUND

Bare-metal stents trigger a foreign body reaction, resulting in neointima formation and restenosis. Silicon carbide (SiC) coating shields the metal from circulating blood and vessel wall, both potential sources of neointima smooth muscle cells.

METHODS

We investigated whether SiC-coated stents (PRO-Kinetic) have lower clinical target lesion revascularization (TLR) rates than do uncoated bare-metal stents (Vision). Stents were implanted in 2731 patients during 2 consecutive 18-month periods. Clinical TLR was evaluated at 1 year.

RESULTS

In the PRO-Kinetic group, TLR was significantly higher (9.0% vs 5.6%; unadjusted odds ratio, 1.61; 95% confidence interval [CI], 1.24-2.08; P < 0.001) compared with the Vision group. After adjustment for postintervention minimal luminal diameter (adjusted odds ratio [AOR], 0.56; 95% CI, 0.42-0.73), total implanted stent length (AOR, 1.01; 95% CI, 1.00-1.02), non-ST-segment elevation myocardial infarction or unstable angina at initial presentation (AOR, 1.89; 95% CI, 1.41-2.54), and triple vessel stenting (AOR, 2.68; 95% CI, 1.02-7.05), the use of PRO-Kinetic stents remained an independent predictor for revascularization (AOR, 1.57; 95% CI, 1.18-2.10; P = 0.002). Because strut thickness is lower in 2.0- to 3.0-mm PRO-Kinetic stents, a subgroup analysis (n = 2382 lesions) was performed. Even in this subgroup, PRO-Kinetic implantation proved an independent predictor of TLR (AOR, 1.62; 95% CI, 1.17-2.23; P = 0.003).

CONCLUSION

In contrast to theoretical expectations, the SiC-coated PRO-Kinetic stent was associated with greater target lesion revascularization rates at 1 year compared with the uncoated Vision stent.

The CID Chrono cobalt-chromium alloy carbofilm-coated coronary stent system

BACKGROUND

In an attempt to improve the stent's safety, development of bare metal stents (BMS) continues, with new materials and geometry. Chrono (CID, Italy) is a thin strut cobalt-chromium (Co-Cr) stent combining the clinical benefits of the bio- and haemo-compatible Carbofilm coating.

METHODS

We assessed the safety and efficacy of percutaneous coronary interventions (PCI) using the new Co-Cr Chrono stent in patients undergoing elective PCI for de novo lesions in native coronary vessels. The patients were followed for 12 months for the occurrence of major cardiac events (MACE, defined as death, myocardial infarction, repeat PCI and bypass surgery). Patients with complex (B2/C) lesions were compared to those with non-complex lesions (A/B1).

RESULTS

A total of 340 consecutive patients were analysed: 155 patients with complex lesions (Complex group) and 185 patients with non-complex lesions (Non-complex group). Dual antiplatelet therapy was maintained >1 month in 21% of patients in both Complex and Non-complex group. Stent length was longer in the Complex group (25 ± 10 mm versus 17 ± 6 mm; p<0.001). Stent diameter <3.0 mm was most frequent in the Complex group (35.5% versus 27.5%; p<0.05). During the 12-month follow-up period MACE occurred in 10.6% of the global population (12.3% in the Complex group and 9.2% in the Non-complex group; p=0.43). Repeat PCI was most frequent in the Complex group (9.7% versus 3.8%; p=0.044). The incidence of definite and probable stent thrombosis (ARC criteria) was 1.29% in the Complex group and 1.08% in the Non-complex group (p=1.0).

CONCLUSIONS

Implantation of the Co-Cr Chrono stent results in a good safety and efficacy for both complex and non-complex de-novo coronary artery lesions.