Revolutionizing Cardiovascular Frontiers: A Dive Into Cutting-Edge Innovations in Coronary Stent Technology

Plain balloon angioplasty was the initial method used to enlarge the intracoronary lumen size. However, it was linked to acute coronary closure due to early vessel recoil. This led to the invention of coronary stents, which offer mechanical support to open and maintain the vascular lumen. Nevertheless, the metallic scaffold introduced other issues, such as thrombosis and restenosis caused by neointimal proliferation. To address these concerns, polymers were employed to cover the scaffold, acting as drug reservoirs and regulators for controlled drug release. The use of polymers prevents direct contact between blood and metallic scaffolds. Drugs within the stent were incorporated to inhibit proliferation and expedite endothelialization in the healing process. Despite these advancements, adverse effects still arise due to the inflammatory reaction caused by the polymer material. Consequently, resorbable polymers and scaffolds were later discovered, but they have limitations and are not universally applicable. Various scaffold designs, thicknesses, materials, polymer components, and drugs have their own advantages and complications. Each stent generation has been designed to address the shortcomings of the preceding generation, yet new challenges continue to emerge. Conflicting data regarding the long-term safety and efficacy of coronary stents, especially in the extended follow-up, further complicates the assessment.

Impact of preprocedural left ventricular systolic function on the safety and durability of percutaneous coronary intervention

BACKGROUND

Percutaneous coronary intervention (PCI) is considered less safe in patients with reduced ejection fraction (EF), an impression based on older data. Whether the safety and durability of contemporary PCI are different in patients with reduced EF compared with normal EF patients is unknown.

METHODS

Patients from the BIOFLOW II, IV and V clinical trials were grouped as normal EF (≥50%) and reduced EF (30%-50%). Using multivariable logistic regression and cox proportional hazards regression, we determined relations of EF category with procedural safety (a composite of cardiac death, myocardial infarction, stroke and urgent coronary artery bypass grafting within 30 days of PCI) and target lesion failure (TLF; comprising cardiac death, target vessel myocardial infarction, target vessel revascularization within 1 year of PCI) respectively. In sensitivity analyses, we regrouped patients into EF < 45% and ≥55% and repeated the aforementioned analyses.

RESULTS

In 1685 patients with normal EF (mean age 65 years; 27% women; mean EF 61%) and 259 with low EF (mean age 64 years; 17% women; mean EF 41%), 101 safety and 148 TLF events occurred. Compared with patients in the normal EF group, those with reduced EF had neither a statistically significant higher proportion of safety events, nor a higher multivariable-adjusted risk for such events. Similarly, patients with reduced EF and normal EF did not differ in terms of TLF event proportions or multivariable-adjusted risk for TLF. The results were similar in sensitivity analyses with EF groups redefined to create a 10% between-group EF separation.

CONCLUSION

PCI safety and durability outcomes are similar in patients with mild-moderately reduced EF and normal EF.

Evolution of Coronary Stent Platforms: A Brief Overview of Currently Used Drug-Eluting Stents

Cardiovascular disease, including ischemic heart disease, is the leading cause of death worldwide, and percutaneous coronary interventions (PCIs) have been demonstrated to improve the prognosis of these patients on top of optimal medical therapy. PCIs have evolved from plain old balloon angioplasty to coronary stent implantation at the end of the last century. There has been a constant technical and scientific improvement in stent technology from bare metal stents to the era of drug-eluting stents (DESs) to overcome clinical challenges such as target lesion failure related to in-stent restenosis or stent thrombosis. A better understanding of the underlying mechanisms of these adverse events has led DESs to evolve from first-generation DESs to thinner and ultrathin third-generation DESs with improved polymer biocompatibility that seems to have reached a peak in efficiency. This review aims to provide a brief historical overview of the evolution of coronary DES platforms and an update on clinical studies and major characteristics of the most currently used DESs.

Patients with higher-atherothrombotic risk vs. lower-atherothrombotic risk undergoing coronary intervention with newer-generation drug-eluting stents: an analysis from the randomized BIOFLOW trials

BACKGROUND

Patients with atherothrombotic risk are at high hazard of ischemic events. Preventive medicine plays a major role in modifying their outcomes. Whether the choice of a BP-SES or DP-EES can contribute to the occurrence of events remains unclear. We sought to investigate the outcomes of patients with higher atherothrombotic risk (H-ATR) versus lower atherothrombotic risk (L-ATR) undergoing percutaneous coronary intervention (PCI) with either bioresorbable-polymer sirolimus-eluting stent (BP-SES) or durable-polymer everolimus-eluting stent (DP-EES).

METHODS

Patients (n = 2361) from BIOFLOW-II, -IV, and -V randomized trials were categorized into H-ATR vs. L-ATR. L-ATR patients had ≤ 1 and H-ATR ≥ 2 of the following criteria: presentation in ACS, diabetes mellitus, previous myocardial infarction, previous PCI/CABG, or previous stroke. Endpoints were target lesion failure (TLF: cardiac death, target-vessel myocardial infarction [TV-MI], target lesion revascularization [TLR]) and stent thrombosis (ST) at three years.

RESULTS

H-ATR patients (n = 1023) were more morbid than L-ATR patients (n = 1338). TLF rate was significantly higher in H-ATR patients as compared with L-ATR (11.6% vs. 7.0%; HR 1.67, 95% CI 1.27-2.20, p < 0.0001). With BP-SES TLF rates were numerically lower as compared with DP-EES in H-ATR (10.5% vs. 13.5%; HR 0.78, 95% CI 0.54-1.14, p = 0.20) and significantly lower in L-ATR (5.6% vs. 9.8%; HR 0.57, 95% CI 0.38-0.85, p = 0.006).

CONCLUSION

In the era of newer-generation DES, patients with H-ATR still are at hazard for ischemic events. Patients with BP-SES had lower TLF rates as compared with DP-EES, most consistent in L-ATR whereas in H-ATR patients most probably secondary preventive strategies are of higher value.

CLINICAL TRIAL REGISTRATION

Clinicaltrial.gov. NCT01356888, NCT01939249, NCT02389946. https://clinicaltrials.gov/show/NCT01356888 , https://clinicaltrials.gov/show/NCT01939249 , https://clinicaltrials.gov/show/NCT02389946 .

Drug loaded implantable devices to treat cardiovascular disease

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Ultrathin Struts Drug-Eluting Stents: A State-of-the-Art Review

New-generation drug-eluting stents (DESs) represent the standard of care for patients undergoing percutaneous coronary intervention (PCI). Recent iterations in DES technology have led to the development of newer stent platforms with a further reduction in strut thickness. This new DES class, known as ultrathin struts DESs, has struts thinner than 70 µm. The evidence base for these devices consists of observational data, large-scale meta-analyses, and randomized trials with long-term follow-up, which have been conducted to investigate the difference between ultrathin struts DESs and conventional new-generation DESs in a variety of clinical settings and lesion subsets. Ultrathin struts DESs may further improve the efficacy and safety profile of PCI by reducing the risk of target-lesion and target-vessel failures in comparison to new-generation DESs. In this article, we reviewed device characteristics and clinical data of the Orsiro (Biotronik, Bülach, Switzerland), Coroflex ISAR (B. Braun Melsungen, Germany), BioMime (Meril Life Sciences Pvt. Ltd., Gujarat, India), MiStent (MiCell Technologies, USA), and Supraflex (Sahajanand Medical Technologies, Surat, India) sirolimus-eluting stents.

Complex vs. non-complex percutaneous coronary intervention with newer-generation drug-eluting stents: an analysis from the randomized BIOFLOW trials

BACKGROUND

Patients undergoing complex percutaneous coronary intervention (PCI) are at higher risk of adverse outcomes, but data are scarce in the era of newer-generation coronary stents.

AIM

We sought to compare the clinical outcomes after complex PCI with a bioresorbable-polymer sirolimus-eluting stent (BP-SES) versus a durable-polymer everolimus-eluting stent (DP-EES).

METHODS

Patients (n = 2350) from BIOFLOW-II, -IV, and -V randomized trials were categorized into non-complex PCI vs. complex PCI. Complex PCI had at least one of the following criteria: multi-vessel PCI, ≥ 3 lesions treated, ≥ 3 stents implanted, total stent length ≥ 60 mm. Endpoints were target lesion failure (TLF: cardiac death, target-vessel myocardial infarction [TV-MI], or target lesion revascularization [TLR]) and probable/definite stent thrombosis (ST) at three years.

RESULTS

Patients with complex PCI (n = 348) were older and presented more often with acute coronary syndrome than non-complex PCI patients (n = 2002). Complex PCI lesions were more often type B2/C and bifurcation lesions and required more pre- and post-dilatation. Complex PCI patients had higher rates of TLF (14.6% vs. 8.1%; aHR 1.89, 95% CI [1.31-2.73], p = 0.001), TV-MI (10.2% vs. 4.4%, aHR 2.17, 95% CI [1.40-3.37], p = 0.001), and ST (1.5% vs. 0.4%, p = 0.025) as compared with non-complex PCI. TLF was not lower with BP-SES as compared to DP-EES in complex PCI (12.6% vs 18.2%, p = 0.16).

CONCLUSION

Patients undergoing complex PCI with the newer-generation DES still sustain a higher risk of TLF, TV-MI and stent thrombosis as compared with non-complex PCI. This adverse outcome was not significantly modified by the stent platform (BP-SES vs. DP-EES).

CLINICAL TRIAL REGISTRATION

Clinicaltrial.gov NCT01356888, NCT01939249, NCT02389946, https://clinicaltrials.gov/show/NCT01356888 ; https://clinicaltrials.gov/show/NCT01939249 ; https://clinicaltrials.gov/show/NCT02389946 .

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

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

Differential Effects of Newer-Generation Ultrathin-Strut Versus Thicker-Strut Drug-Eluting Stents in Chronic and Acute Coronary Syndromes

OBJECTIVES

The authors sought to compare the differential effects of ultrathin-strut and thicker-strut drug-eluting stents (DES) in patients with chronic (CCS) versus acute (ACS) coronary syndromes.

BACKGROUND

Newest-generation ultrathin-strut DES reduce target lesion failure (TLF) compared with thicker-strut second-generation DES in patients undergoing percutaneous coronary intervention.

METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched for randomized controlled trials comparing newer-generation ultrathin-strut (<70 μm) versus thicker-strut (≥70 μm) DES. Patients were divided based on baseline clinical presentation (CCS versus ACS). The primary endpoint was TLF, a composite of cardiac death, target vessel myocardial infarction, or clinically indicated target lesion revascularization (TLR).

RESULTS

A total of 22,766 patients from 16 randomized controlled trials were included, of which 9 trials reported TLF rates in ACS patients. At a mean follow-up of 12.2 months, the risk of TLF was lower among patients treated with ultrathin-strut compared with thicker-strut DES (risk ratio [RR]: 0.85; 95% CI: 0.75-0.95; P = 0.006). The difference was driven by a lower risk of clinically-indicated TLR (RR: 0.75; 95% CI: 0.63-0.89; P < 0.001) among patients treated with ultrathin-strut DES. The treatment effect was consistent between patients presenting with CCS and ACS (relative RR: 0.97; 95% CI: 0.73-1.31; P for interaction = 0.854). In patients with ST-segment elevation myocardial infarction, TLF risk was lower among those treated with ultrathin- compared with thicker-strut DES (RR: 0.74; 95% CI: 0.54-0.99; P = 0.049).

CONCLUSIONS

Ultrathin-strut DES reduce the risk of TLF compared with thicker-strut second-generation DES in patients undergoing percutaneous coronary intervention, a difference caused by a lower risk of ischemia-driven TLR. The treatment effect was consistent among patients with CCS and ACS.

Individual patient data analysis of the BIOFLOW study program comparing safety and efficacy of a bioresorbable polymer sirolimus eluting stent to a durable polymer everolimus eluting stent

OBJECTIVES

This analysis of pooled individual patient data (IPD) aimed to evaluate the safety and efficacy of a bioresorbable polymer sirolimus eluting stent system (BP-SES; Orsiro) compared to a durable polymer everolimus eluting stent system (DP-EES; Xience) in the pooled population as well as in subgroups.

METHODS

IPD with up to 12 months follow-up of the randomized controlled trials BIOFLOW-II (NCT01356888), -IV (NCT01939249), and -V (NCT02389946) as well as the all comers registry BIOFLOW-III (NCT01553526) were pooled. A total of 3,717 subjects (2,923 in BP-SES and 794 in DP-EES) with 5,328 lesions (4,225 lesions in BP-SES and 1,103 in DP-EES) were included in the IPD. The primary endpoint was target lesion failure (TLF) at 12 months follow-up. Subgroups analyzed included diabetes, age (≥65 years), gender, complex lesions (B2/C), small vessels (reference vessel diameter ≤2.75 mm), multivessel treatment, renal disease, and patients with acute coronary syndrome.

RESULTS

Overall, TLF at 12 months was significantly lower with 5.2%in the BP-SES group versus 7.6% in the DP-EES group (p = .0098). Similarly, target vessel myocardial infarction (TV-MI) was 3.1 versus 5.7% (p = .0005). The rate of stent thrombosis was similar in both groups (0.004%). By regression analysis, an independent stent effect in favor of BP-SES was observed for TLF (p = .0043) and TV-MI (p = .0364) in small vessels.

CONCLUSION

Results of this IPD analysis suggest that the BP-SES with ultrathin struts is as safe as and more efficacious than DP-EES in the overall cohort and especially in small vessels.

Clinical outcomes of an ultrathin-strut sirolimus-eluting stent in all-comers population: Thailand Orsiro registry

Background

Despite numerous studies supporting the outperformance of ultrathin-strut bioresorbable polymer sirolimus-eluting stent (Orsiro SES, Biotronik AG), the generalizability of the study results remains unclear in the Asian population. We sought to evaluate the clinical outcomes of the Orsiro SES in unselected Thai population.

Methods

The Thailand Orsiro registry was a prospective, open-label clinical study evaluating all patients with obstructive coronary artery disease implanted with Orsiro SES. The primary endpoint was target lesion failure (TLF) at 12 months. TLF is defined as a composite of cardiac death, target vessel myocardial infarction (TVMI), emergent coronary artery bypass graft (CABG), and clinically driven target lesion revascularization (CD-TLR). Patients with diabetes, small vessels (≤ 2.75 mm), chronic total occlusions (CTOs), and acute myocardial infarction (AMI) were pre-specified subgroups for statistical analysis.

Result

A total of 150 patients with 235 lesions were included in the analysis. Half of the patients (53.3%) presented with AMI, and 24% had diabetes. Among 235 lesions, 93(39.4%) were small vessels, and 24(10.2%) were chronic total occlusions. The primary endpoint, TLF at 12 months, occurred in eight patients (5.3%), predominately caused by cardiac death. By contrast, the incidences of TVMI and CD-TLR were null. The outcomes in pre-specified subgroup were not different from the overall population (all p > 0.05). One definite late stent thrombosis(0.7%) was incidentally observed during primary percutaneous coronary intervention to the non-target vessel.

Conclusion

The safety and efficacy of the ultrathin strut sirolimus-eluting stent in unselected cases are confirmed in the Thailand Orsiro registry. Despite the high proportion of pre-specified high-risk subgroups, the excellent stent performance was consistent with the overall population.

Trial Registration TCTR20190325001.

The relationship between coronary stent strut thickness and the incidences of clinical outcomes after drug-eluting stent implantation: A systematic review and meta-regression analysis

BACKGROUND

Drug-eluting stents (DESs) have been developed with thinner stent struts, and more biocompatible polymers and anti-proliferative drugs to improve the clinical performance. However, it remains unclear whether thinner struts are associated with favorable short- and long-term clinical outcomes such as target lesion revascularization (TLR), periprocedural myocardial infarction (PMI), and stent thrombosis (ST).

METHODS

We searched MEDLINE, Embase and other online sources for randomized controlled trials (RCTs) comparing clinical outcomes between a DES and other stent(s), with independent clinical event adjudication. We investigated stent-related events (TLR, PMI, and ST) in 5 years. Each outcome was analyzed with random-effects meta-regression model against strut thickness, then adjusted for DES generation and patient and lesion characteristics.

RESULTS

We identified 49 RCTs enrolling 97,465 patients, of which strut thickness ranged from 60 to 140 μm. Incidences of 1-year TLR, PMI, and early ST were reduced with thinner stent struts, when adjusted for stent generation (adjusted relative risk [RR] per 10 μm increase 1.12 [95% CI 1.04-1.21], 1.15 [95% CI 1.05-1.26], and 1.15 [95% CI 1.06-1.25], respectively). Strut thickness was not independently associated with incidences of 5-year TLR, late and very late ST. In addition, early DESs contributed to a higher incidence of very late ST (adjusted RR 2.97 [95% CI 1.36-6.50]).

CONCLUSIONS

In this meta-regression analysis, a thinner strut thickness was associated with reduced incidences of early stent-related adverse events (1-year TLR, PMI, and early ST), but not with later events (5-year TLR, late ST, and very late ST).

Long-term follow-up after ultrathin vs. conventional 2nd-generation drug-eluting stents: a systematic review and meta-analysis of randomized controlled trials

AIMS

Contemporary 2nd-generation thin-strut drug-eluting stents (DES) are considered standard of care for revascularization of patients undergoing percutaneous coronary intervention. A previous meta-analysis of 10 randomized controlled trials (RCTs) with 11 658 patients demonstrated a 16% reduction in the 1-year risk of target lesion failure (TLF) with ultrathin-strut DES compared with conventional 2nd-generation thin-strut DES. Whether this benefit is sustained longer term is not known, and newer trial data may inform these relative outcomes. We therefore sought to perform an updated systematic review and meta-analysis of RCTs comparing clinical outcomes with ultrathin-strut DES (≤70 µm strut thickness) with conventional 2nd-generation thin-strut DES.

METHODS AND RESULTS

We performed a random-effects meta-analysis of all RCTs comparing ultrathin-strut DES to conventional 2nd-generation thin-strut DES. The pre-specified primary endpoint was long-term TLF, a composite of cardiac death, myocardial infarction (MI), or clinically driven target lesion revascularization (CD-TLR). Secondary endpoints included the components of TLF, stent thrombosis (ST), and all-cause death. There were 16 eligible trials in which 20 701 patients were randomized. The weighted mean follow-up duration was 2.5 years. Ultrathin-strut DES were associated with a 15% reduction in long-term TLF compared with conventional 2nd-generation thin-strut DES [relative risk (RR) 0.85, 95% confidence interval (CI) 0.76-0.96, P = 0.008] driven by a 25% reduction in CD-TLR (RR 0.75, 95% CI 0.62-0.92, P = 0.005). There were no significant differences between stent types in the risks of MI, ST, cardiac death, or all-cause mortality.

CONCLUSIONS

At a mean follow-up of 2.5 years, ultrathin-strut DES reduced the risk of TLF, driven by less CD-TLR compared with conventional 2nd-generation thin-strut DES, with similar risks of MI, ST, cardiac death, and all-cause mortality.

Ultrathin biodegradable polymer sirolimus-eluting stent versus contemporary durable polymer everolimus-eluting stent for percutaneous coronary intervention: a meta-analysis of randomized trials

INTRODUCTION

Improvements in coronary drug-eluting stent technology has focused on reducing the long-term complications associated with the effects of the residual footprint on the vessel wall. Although many of the newer stents have exhibited noninferiority to the durable polymer everolimus-eluting stent (DP-EES), they have yet to exhibit clear superiority. We compared the performance of the latest ultrathin strut biodegradable polymer sirolimus-eluting stents (BP-SES) to DP-EES.

METHODS

We searched the electronic databases for randomized controlled trials comparing BP-SES to DP-EES. A random effect meta-analysis was performed using the Poisson regression model. The primary end point was target lesion failure (TLF), a composite of target vessel myocardial infarction (TVMI), cardiac death and target lesion revascularization (TLR).

RESULTS

There was no difference between the stents in stent thrombosis [incidence rate ratio (IRR) = 0.79, 95% confidence interval (CI) 0.58-1.06), TLR (IRR = 0.88, 95% CI 0.57-1.38), TVMI (IRR = 0.79, 95% CI 0.61-1.01), cardiac death (IRR = 0.99, 95% CI 0.76-1.29) and target vessel failure (IRR = 0.82, 95% CI 0.64-1.06). In addition, there was no difference in TLF (IRR = 0.82, 95% CI 0.64-1.06). There was evidence of reduced TLF in small vessels with BP-SES based on definition used (defined as ≤2.75 mm; IRR 0.64, 95% CI 0.46-0.91 versus ≤3 mm; IRR 1.11, 95% CI 0.90-1.36).

CONCLUSION

In our study, the performance of the latest generation BP-SES was comparable to DP-EES but failed to show superiority. The possible benefit in patients with small vessels should be explored future trials.

Predictors and outcomes of acute recoil after ultrathin bioresorbable polymer sirolimus-eluting stents implantation: an intravascular ultrasound in native coronary arteries

BACKGROUND

Ultrathin bioresorbable polymer sirolimus-eluting stents (BP-SESs) may easily lead to acute recoil. This study investigated acute recoil after BP-SES implantation on the basis of intravascular ultrasound (IVUS).

METHODS

We enrolled 40 consecutive stents. Absolute acute recoil by quantitative coronary angiography was defined as the difference between the mean diameter of the last inflated balloon (X) and mean lumen diameter of the BP-SES immediately after balloon deflation (Y). Percent (%) acute recoil was defined as (X-Y)×100/X. IVUS was performed within the culprit lesion. Plaque eccentricity, % plaque burden and calcification grade score were assessed using IVUS. Calcification grade was scored on the basis of quadrants. On the basis of the median acute recoil value of 5.0%, the stents were divided into two groups: low (LAR, n = 20) and high % acute recoil (HAR, n = 20).

RESULTS

Mean % acute recoil was 5.8 ± 5.3%. Plaque eccentricity, % plaque burden and stent/artery ratio were significantly higher in the HAR group than in the LAR group. Significant differences in % acute recoil were not observed regarding the types of stent diameter. In multivariate logistic regression and multiple linear regression analysis, plaque eccentricity and % plaque burden in the culprit plaque were significant positive predictors for the occurrence of % acute recoil. No significant differences, including clinical outcomes, were found between both groups at follow-up.

CONCLUSION

Acute recoil of BP-SESs may be influenced by an eccentric plaque with a large burden, which did not affect long-term outcomes. However, the present study might suggest the proper strategy (e.g. a more exhaustive plaque preparation) before BP-SES implantation in a case with these IVUS characteristics.

Impact of Coronary Calcification on Clinical Outcomes After Implantation of Newer-Generation Drug-Eluting Stents

Background

Percutaneous coronary intervention of calcified lesions was associated with worse outcomes in the era of bare‐metal and first‐generation drug‐eluting stents. Data on percutaneous coronary intervention of calcified lesions with newer‐generation drug‐eluting stents are scarce. Therefore, we investigated the impact of lesion calcification on clinical outcomes in patients undergoing percutaneous coronary intervention with a bioresorbable‐polymer sirolimus‐eluting stent or a durable‐polymer everolimus‐eluting stent.

Methods and Results

Patients (n=2361) from BIOFLOW II, IV, and V trials were categorized into moderate/severe versus none/mild lesion calcification by a core laboratory. End points were target‐lesion failure (TLF) (cardiac death, target‐vessel myocardial infarction, or target‐lesion revascularization) and probable/definite stent thrombosis at 2 years. The agreement in calcification assessment between the operator and the core laboratory was weak (weighted κ, 0.23). Patients with moderate/severe calcification (n=303; 16%) had higher TLF (13.5% versus 8.4%; P=0.003) and stent thrombosis rates (2.1% versus 0.2%; P<0.0001), whereas target‐lesion revascularization was not different between the groups (5.0% versus 3.9%; P=0.302). After adjustment, calcification did not emerge as an independent predictor of TLF (adjusted hazard ratio [aHR], 1.37; 95% CI, 0.89–2.08; P=0.148) but did for target‐vessel myocardial infarction (aHR, 1.66; 95% CI, 1.03–2.68; P=0.037). TLF rates were similar between bioresorbable‐polymer sirolimus‐eluting stent and durable‐polymer everolimus‐eluting stent (12.6% versus 15.4%, P=0.482) in moderate/severe calcification. In none/mild calcification, the bioresorbable‐polymer sirolimus‐eluting stent showed lower TLF (7.5% versus 10.3%, P=0.045).

Conclusions

With newer‐generation drug‐eluting stents, moderate/severe lesion calcification was not associated with more TLF after adjustment for the higher risk of patients with coronary calcification, whereas the rate of target‐vessel myocardial infarction was higher. The bioresorbable‐polymer sirolimus‐eluting stent and durable‐polymer everolimus‐eluting stent were equally effective and safe in calcified lesions.

Registration

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01356888, NCT01939249, NCT02389946.

Outcomes of patients treated with a biodegradable-polymer sirolimus-eluting stent versus durable-polymer everolimus-eluting stents after rotational atherectomy

OBJECTIVE

To compare Orsiro biodegradable-polymer sirolimus-eluting stent (Orsiro BP-SES) with durable-polymer everolimus-eluting stent (DP-EES) regarding target lesion failure (TLF) after rotational atherectomy (RA), with a focus on small stents (diameter ≤ 3 mm) where Orsiro BP-SES has 60 µm strut thickness, while DP-EES remains with 81 µm strut thickness.

BACKGROUND

New-generation drug-eluting stent (DES) is superior to early-generation DES in all percutaneous coronary intervention (PCI) settings including RA. Recently, the Orsiro BP-SES was superior to a DP-EES in an all comer's population.

METHODS

Among patients who underwent RA at a single center, 121 were treated with Orsiro BP-SES and 164 with DP-EES (Promus and Xience). Those treated with other stent types, presenting with acute myocardial infarction or had a chronic total occlusion were excluded. Incidence of TLF was assessed.

RESULTS

After 2 years, the TLF rate in Orsiro BP-SES and DP-EES groups was 10% and 18%, respectively (adjusted HR 0.55, 95%CI 0.26-1.16, p = 0.115). The rate of TLF was significantly lower in small Orsiro BP-SES with ultra-thin struts as compared to DP-EES with the same diameters (adjusted HR 0.19, 95% CI 0.04-0.87, p = 0.032), driven by lower rates of clinically driven target lesion revascularization (log-rank p = 0.022). Age (p = 0.035), total stent length (p = 0.007) and diabetes mellitus (p = 0.011) emerged as independent predictors of TLF in the whole population.

CONCLUSION

In the whole cohort, Orsiro BP-SES and DP-EES had comparable rates of long-term TLF after RA. In the small stent subgroup, the Orsiro BP-SES with ultra-thin struts showed significant lower rate of TLF at 2 years.

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

BACKGROUND

Target lesion failure remains an issue with contemporary drug-eluting stents. Thus, the dual-therapy sirolimus-eluting and CD34+ antibody-coated Combo stent (DTS) was designed to further improve early healing. This study aimed to investigate whether the DTS is noninferior to the sirolimus-eluting Orsiro stent (SES) in an all-comers patient population.

METHODS

The SORT OUT X (Combo Stent Versus Orsiro Stent) trial, was a large-scale, randomized, multicenter, single-blind, 2-arm, noninferiority trial with registry-based follow-up. The primary end point target lesion failure was a composite of cardiac death, myocardial infarction, or target lesion revascularization within 12 months, analyzed using intention-to-treat. The trial was powered for assessing target lesion failure noninferiority of the DTS compared with the SES with a predetermined noninferiority margin of 0.021.

RESULTS

A total of 3146 patients were randomized to treatment with the DTS (1578 patients; 2008 lesions) or SES (1568 patients; 1982 lesions). At 12 months, intention-to-treat analysis showed that 100 patients (6.3%) assigned the DTS and 58 patients (3.7%) assigned the SES met the primary end point (absolute risk difference, 2.6% [upper limit of 1-sided 95% CI, 4.1%]; P (noninferiority)=0.76). The SES was superior to the DTS (incidence rate ratios for target lesion failure, 1.74 [95% CI, 1.26-2.41]; P=0.00086). The difference was explained mainly by a higher incidence of target lesion revascularization in the DTS group compared with the SES group (53 [3.4%] vs. 24 [1.5%]; incidence rate ratio, 2.22 [95% CI, 1.37-3.61]; P=0.0012).

CONCLUSIONS

The DTS did not confirm noninferiority to the SES for target lesion failure at 12 months in an all-comer population. The SES was superior to the DTS mainly because the DTS was associated with an increased risk of target lesion revascularization. However, rates of death, cardiac death, and myocardial infarction at 12 months did not differ significantly between the 2 stent groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03216733.

Factors associated with long-term major adverse cardiac events of coronary bioresorbable vascular scaffold

The long-term clinical outcomes after implantation of bioresorbable vascular scaffolds (BVS) in a real-world cohort were not well described. To identify factors associated with major adverse cardiovascular events (MACE) on long-term follow-up after implantation of BVS in patients undergoing elective percutaneous coronary intervention (PCI). This was an observational study based on a hospital registry of percutaneous coronary intervention. Participants were consecutive patients who underwent PCI and implanted with at least one everolimus-eluting BVS (Absorb^®) in a single center between 2014 and 2017. Among the 170 cases analyzed (mean age 60.4 ± 10.7), a total of 203 Absorb BVS were implanted. MACE developed in 33 (19.4%) patients over a median follow-up period of 61 months, including 9 (5.3%) deaths, 13 (7.6%) non-fatal myocardial infarction and 19 (11.2%) ischemia driven target vessel revascularization. Definite or probable stent thrombosis developed in 4 (2.4%) patients. In crude analysis, history of smoking and initial presentation of non-ST elevation-acute coronary syndrome (NSTE-ACS) were predictors of long-term MACE. In adjusted analysis, presentation with NSTE-ACS was an independent predictor of long-term MACE [adjusted odds ratio (OR) 4.52; 95% confidence interval (95% CI) 1.50 to 13.6, P = 0.007]. Among patients receiving implantation of ABSORB BVS, presentation with NSTE-ACS was an independent predictor of MACE after a median follow-up period of 61 months. Future research is needed to confirm these findings and to determine the long-term safety of BVS in patients with NSTE-ACS.

Ultrathin-strut biodegradable polymer versus durable polymer drug-eluting stents: a meta-analysis

Objectives

Determine whether an ultrathin biodegradable polymer sirolimus-eluting stent (‘Orsiro’—BP-SES) has clinical benefits over second-generation durable polymer drug-eluting stents (DP-DES).

Methods

We conducted a prospective systematic review and meta-analysis of randomised clinical trials comparing Orsiro BP-SES against DP-DES (PROSPERO Registration: CRD42019147136). The primary outcome was target lesion failure (TLF): composite of cardiac death, target vessel myocardial infarction (TVMI) and clinically indicated target lesion revascularisation (TLR)) evaluated at the longest available follow-up.

Results

Nine trials randomised 11 302 patients to either Orsiro BP-SES or DP-DES. At mean weighted follow-up of 2.8 years, the primary outcome (TLF) occurred in 501 of 6089 (8.2%) participants with BP-SES compared with 495 of 5213 (9.5%) participants with DP-DES. This equates to an absolute risk reduction of 1.3% in TLF in favour of Orsiro BP-SES (OR 0.82; 95% CI 0.69 to 0.98; p=0.03). This was driven by a reduction in TVMI (OR 0.80; 95% CI 0.65 to 0.98; p=0.03). There were no significant differences in other clinical endpoints: cardiac death, TLR and stent thrombosis.

Conclusion

The Orsiro BP-SES shows promising clinical outcomes in patients undergoing percutaneous coronary intervention compared with contemporary second-generation DES at a short to medium term follow-up. More research is warranted to evaluate performance over a longer follow-up period and in different clinical and lesion subsets.

Angiographic and clinical outcomes of patients implanted with ultrathin, biodegradable polymer sirolimus-eluting stents versus durable polymer drug-eluting stents for percutaneous coronary intervention: an updated meta-analysis based on randomized controlled trials

INTRODUCTION

Whether sirolimus-eluting stents constituted with ultrathin-strut and biodegradable polymers (BP-SESs) can achieve a preferable effect over current drug-eluting stents with durable polymers (DP-DESs) remains highly controversial. The aim of this analysis based on randomized controlled trials (RCTs) was to detect the clinical and angiographic differences between ultrathin (defined as a strut thickness <70 µm) BP-SESs and DP-DESs.

EVIDENCE ACQUISITION

We searched seven databases to identify eligible articles. Late lumen loss (LLL) and target lesion failure (TLF) were assessed as the primary endpoints for angiographic and clinical outcomes, respectively.

EVIDENCE SYNTHESIS

Nineteen articles containing thirteen RCTs with 14801 patients were analyzed. For the 9-month angiographic outcomes, similar results were discovered between BP-SESs and DP-DESs in terms of in-stent LLL (mean difference [MD]: -0.02 [-0.05, 0.01], P=0.23), in-segment LLL (MD: -0.01 [-0.04, 0.03], P=0.74), in-stent minimum lumen diameter (MLD) (MD: -0.01 [-0.06, 0.04], P=0.72), in-segment MLD (MD: -0.01 [-0.06, 0.05], P=0.75), in-stent diameter stenosis (DS) (MD: -1.10 [-3.36, 1.15], P=0.34), in-segment DS (MD: -0.78 [-1.97, 0.40], P=0.20), in-stent binary restenosis (BR) (risk ratio [RR]: 2.27 [0.99, 5.21], P=0.05) and in-segment BR (RR: 1.46 [0.78, 2.75], P=0.24). Regarding the 12-month clinical outcomes, there was a significant decrease in TLF and a trend of a lower incidence of target vessel failure (RR: 0.89 [0.78,1.01], P=0.08), myocardial infarction (MI) and target vessel MI.

CONCLUSIONS

With similar angiographic results, BP-SESs appeared to be superior to DP-DESs with better clinical prognoses, especially for female patients, patients with STEMI and ACS and patients without diabetes. More high-quality randomized controlled trials are needed to confirm these results.

Drug-Coated Balloon for De Novo Coronary Artery Disease: JACC State-of-the-Art Review

Percutaneous coronary intervention with a drug-eluting stent is the most common mode of revascularization for coronary artery disease. However, restenosis rates remain high. Non-stent-based local drug delivery by a drug-coated balloon (DCB) has been investigated, as it leaves no metallic mesh. A DCB consists of a semicompliant balloon coated with antiproliferative agents encapsulated in a polymer matrix, which is released into the wall after inflation and contact with the intima. DCB have demonstrated effectiveness in treating in-stent restenosis. Clinical studies using DCB in de novo coronary artery disease have shown mixed results, with a major benefit in small-vessel disease. Differences in study results are not only due to variations in DCB technology but also to disparity in procedural approach, "leave nothing behind" or "combination therapy," and vessel size. This review focuses on the available evidence from randomized trials and proposes a design for future clinical trials.

Comparison of Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stents and Thin, Durable-Polymer Everolimus-Eluting Stents in Calcified or Small Vessel Lesions

Background:

The ultrathin-strut bioresorbable-polymer sirolimus-eluting stent (BP-SES) demonstrated comparable performance to durable-polymer everolimus-eluting stent (DP-EES) in randomized controlled trials. The purpose of this study was to evaluate the performance of a BP-SES compared with a DP-EES in calcified or small vessel lesions, which represent higher risk of restenosis.

Methods:

From the pooled BIOFLOW (BIOFLOW-II, IV, and V; BIOTRONIK - A Prospective Randomized Multicenter Study to Assess the Safety and Effectiveness of the Orsiro Sirolimus Eluting Coronary Stent System in the Treatment of Subjects With up to Three De Novo or Restenotic Coronary Artery Lesions ) randomized controlled trials, a total of 1553 BP-SES and 784 DP-EES patients with valid 1-year follow-up data were available. Coronary lesions were assessed for the presence of moderate-to-severe calcification or small vessels (reference vessel diameter, ≤2.75 mm) by core laboratory analysis. One-year clinical outcomes were assessed with or without the lesion subsets between BP-SES and DP-EES.

Results:

Baseline characteristics were similar between the groups. Among patients with small vessel disease, target lesion failure (8.0% versus 12.4%; P <0.01) and target vessel myocardial infarction (4.2% versus 7.6%; P <0.01) were significantly lower in BP-SES than in DP-EES. No difference in the outcome between the stents was shown in patients with non-small vessel lesions. In patients with calcified lesions, target lesion failure (12.2% versus 6.9%; P =0.056), and cardiac death (1.9% versus 0.3%; P =0.081) were numerically higher in DP-EES than in BP-SES. In the noncalcified lesion analysis, target vessel myocardial infarction in DP-EES was significantly higher than in BP-SES. Stent thrombosis was similar between the stents in both lesion groups.

Conclusions:

Among patients with more complex disease representing a higher risk of target lesion failure, the effectiveness of an ultrathin-strut BP-SES compared with a thin-strut DP-EES was maintained through 1 year.

Registration:

URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01356888, NCT01939249, NCT02389946.

Thin, very thin, or ultrathin-strut biodegradable or durable polymer-coated drug-eluting stents

PURPOSE OF REVIEW

The current article will review recently published clinical studies that evaluate very thin or ultrathin-strut drug-eluting stents (DES), focusing on major randomized clinical trials in broad patient populations.

RECENT FINDINGS

Multiple randomized trials recently assessed the clinical performance of novel very thin to ultrathin-strut DES. Most randomized trials established noninferiority of the novel device. To date, only one major randomized clinical trial (i.e., BIOFLOW V) showed superiority of an ultrathin-strut biodegradable polymer-coated sirolimus-eluting stent over a very thin-strut durable polymer-coated everolimus-eluting stent in a relatively broad patient population. There are signals that the same ultrathin-strut biodegradable polymer-coated sirolimus-eluting stent may improve clinical outcome in specific patient populations. For example, in the randomized BIOSTEMI trial, 1-year superiority of the ultrathin-strut DES was found in patients presenting with an acute ST-segment elevation myocardial infarction. Yet, substudies of large randomized trials that assessed patients with small-vessel treatment showed equivocal results.

SUMMARY

Although two randomized trials showed advantages for ultrathin-strut DES, other clinical trials provided no significant evidence that ultrathin-strut DES improve clinical outcome. The question whether ultrathin-strut DES may reduce the repeat revascularization risk following implantation in small vessels is a matter of further debate and future research.

Safety and Performance of the Orsiro Sirolimus-Eluting Stent in the Treatment of All-Comers Patient Population in Daily Clinical Practice

BACKGROUND

The BIOFLOW-III Canada registry aimed to evaluate the safety and efficacy of Orsiro sirolimus-eluting stents (SES) with biodegradable polymer, in an all-comers patient population.

METHODS

We conducted a prospective, non-randomized, multi-center, observational all-comers registry of patients undergoing percutaneous coronary intervention (PCI) with Orsiro SES at two high-volume Canadian centers. The primary endpoint was one-year target lesion failure (TLF) defined as a composite of cardiac death, target-vessel myocardial infarction (MI), coronary artery bypass grafting and clinically driven target lesion revascularization. Four subgroups were pre-defined: i) diabetic patients; ii) small vessels (≤2.75 mm); iii) chronic total occlusions (CTO) and iv) acute MI.

RESULTS

From May 2014 to July 2016, 250 patients (mean age 66.2 ± 10.8 years, 75.6% males, 30% diabetes) underwent PCI with Orsiro SES for 385 coronary lesions. The mean stent diameter was 2.98 ± 0.50 mm and the mean stent length was 22 ± 8 mm. Clinical device and procedural success rates were with 99.5% and 97.6%, respectively. The overall one-year TLF rate was 2.8% [95% confidence interval (CI) 1.4-5.8%], whereas TLF rates were 4.1% [95%CI 1.3-12.2%], 3.2% [95%CI 1.2-8.4%], 8.3% [95%CI 2.2-29.4%], and 2.6% [95%CI 0.7-9.9%] in patients with diabetes, small vessels, CTO, and acute MI, respectively. One case of possible stent thrombosis (ST) was reported (0.4% [95%CI 0.1-2.8%]), while no cases of definite/probable ST was observed at one year.

CONCLUSION

Our data provide further evidence of the safety and clinical performance of Orsiro SES in an unselected, real-world, complex patient population.

CONDENSED ABSTRACT

The BIOFLOW-III Canada registry is a prospective, non-randomized, multi-center, observational all-comers registry designed to evaluate the safety and performance of the Orsiro SES in non-selected, real-world patients. A total of 250 patients (mean age 66.2 ± 10.8 years, 75.6% males, 30% diabetes) who underwent PCI with Orsiro SES, were enrolled at two high-volume Canadian centers. The overall rate of TLF at one year was 2.8% [95%CI 1.4-5.8%], whereas TLF rates were 4.1%, 3.2%, 8.3%, and 2.6% in patients with diabetes, small vessels ≤2.75 mm, CTO, and acute MI, respectively. No case of definite/probable ST was observed.

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.

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.