Long-Term Effect of Ultrathin-Strut Versus Thin-Strut Drug-Eluting Stents in Patients With Small Vessel Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

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.

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.

Drug-coated balloon: an effective alternative to stent strategy in small-vessel coronary artery disease-a meta-analysis

Background

Small-vessel coronary artery disease (CAD) is frequently observed in coronary angiography and linked to a higher risk of lesion failure and restenosis. Currently, treatment of small vessels is not standardized while having drug-eluting stents (DES) or drug-coated balloons (DCBs) as possible strategies. We aimed to conduct a meta-analytic approach to assess the effectiveness of treatment strategies and outcomes for small-vessel CAD.

Methods

Comprehensive literature search was conducted using PubMed, Embase, MEDLINE, and Cochrane Library databases to identify studies reporting treatment strategies of small-vessel CAD with a reference diameter of ≤3.0 mm. Target lesion revascularization (TLR), target lesion thrombosis, all-cause death, myocardial infarction (MI), and major adverse cardiac events (MACE) were defined as clinical outcomes. Outcomes from single-arm and randomized studies based on measures by means of their corresponding 95% confidence intervals (CI) were compared using a meta-analytic approach. Statistical significance was assumed if CIs did not overlap.

Results

Thirty-seven eligible studies with a total of 31,835 patients with small-vessel CAD were included in the present analysis. Among those, 28,147 patients were treated with DES (24 studies) and 3,299 patients with DCB (18 studies). Common baseline characteristics were equally distributed in the different studies. TLR rate was 4% in both treatment strategies [0.04; 95% CI 0.03-0.05 (DES) vs. 0.03-0.07 (DCB)]. MI occurred in 3% of patients receiving DES and in 2% treated with DCB [0.03 (0.02-0.04) vs. 0.02 (0.01-0.03)]. All-cause mortality was 3% in the DES group [0.03 (0.02-0.05)] compared with 1% in the DCB group [0.01 (0.00-0.03)]. Approximately 9% of patients with DES developed MACE vs. 4% of patients with DCB [0.09 (0.07-0.10) vs. 0.04 (0.02-0.08)]. Meta-regression analysis did not show a significant impact of reference vessel diameter on outcomes.

Conclusion

This large meta-analytic approach demonstrates similar clinical and angiographic results between treatment strategies with DES and DCB in small-vessel CAD. Therefore, DES may be waived in small coronary arteries when PCI is performed with DCB.

Is There an Advantage of Ultrathin-Strut Drug-Eluting Stents over Second- and Third-Generation Drug-Eluting Stents?

In patients undergoing percutaneous coronary intervention, the second-generation drug-eluting stents (DES) are considered the gold standard of care for revascularization. By reducing neointimal hyperplasia, drug-eluting coronary stents decrease the need for repeat revascularizations compared with conventional coronary stents without an antiproliferative drug coating. It is important to note that early-generation DESs were associated with an increased risk of very late stent thrombosis, most likely due to delayed endothelialization or a delayed hypersensitivity reaction to the polymer. Studies have shown a lower risk of very late stent thrombosis with developing second-generation DESs with biocompatible and biodegradable polymers or without polymers altogether. In addition, research has indicated that thinner struts are associated with a reduced risk of intrastent restenosis and angiographic and clinical results. A DES with ultrathin struts (strut thickness of 70 µm) is more flexible, facilitates better tracking, and is more crossable than a conventional second-generation DES. The question is whether ultrathin eluting drug stents suit all kinds of lesions. Several authors have reported that improved coverage with less thrombus protrusion reduced the risk of distal embolization in patients with ST-elevation myocardial infarction (STEMI). Others have described that an ultrathin stent might recoil due to low radial strength. This could lead to residual stenosis and repeated revascularization of the artery. In CTO patients, the ultrathin stent failed to prove non-inferiority regarding in-segment late lumen loss and showed statistically higher rates of restenosis. Ultrathin-strut DESs with biodegradable polymers have limitations when treating calcified (or ostial) lesions and CTOs. However, they also possess certain advantages regarding deliverability (tight stenosis, tortuous lesions, high angulation, etc.), ease of use in bifurcation lesions, better endothelialization and vascular healing, and reducing stent thrombosis risk. In light of this, ultrathin-strut stents present a promising alternative to existing DESs of the second and third generation. The aims of the study are to compare ultrathin eluting stents with second- and third-generation conventional stents regarding procedural performance and outcomes based on different lesion types and specific populations.

Neoatherosclerosis prediction using plaque markers in intravascular optical coherence tomography images

Introduction

In-stent neoatherosclerosis has emerged as a crucial factor in post-stent complications including late in-stent restenosis and very late stent thrombosis. In this study, we investigated the ability of quantitative plaque characteristics from intravascular optical coherence tomography (IVOCT) images taken just prior to stent implantation to predict neoatherosclerosis after implantation.

Methods

This was a sub-study of the TRiple Assessment of Neointima Stent FOrmation to Reabsorbable polyMer with Optical Coherence Tomography (TRANSFORM-OCT) trial. Images were obtained before and 18 months after stent implantation. Final analysis included images of 180 lesions from 90 patients; each patient had images of two lesions in different coronary arteries. A total of 17 IVOCT plaque features, including lesion length, lumen (e.g., area and diameter); calcium (e.g., angle and thickness); and fibrous cap (FC) features (e.g., thickness, surface area, and burden), were automatically extracted from the baseline IVOCT images before stenting using dedicated software developed by our group (OCTOPUS). The predictive value of baseline IVOCT plaque features for neoatherosclerosis development after stent implantation was assessed using univariate/multivariate logistic regression and receiver operating characteristic (ROC) analyses.

Results

Follow-up IVOCT identified stents with (n = 19) and without (n = 161) neoatherosclerosis. Greater lesion length and maximum calcium angle and features related to FC were associated with a higher prevalence of neoatherosclerosis after stent implantation (p < 0.05). Hierarchical clustering identified six clusters with the best prediction p-values. In univariate logistic regression analysis, maximum calcium angle, minimum calcium thickness, maximum FC angle, maximum FC area, FC surface area, and FC burden were significant predictors of neoatherosclerosis. Lesion length and features related to the lumen were not significantly different between the two groups. In multivariate logistic regression analysis, only larger FC surface area was strongly associated with neoatherosclerosis (odds ratio 1.38, 95% confidence interval [CI] 1.05-1.80, p < 0.05). The area under the ROC curve was 0.901 (95% CI 0.859-0.946, p < 0.05) for FC surface area.

Conclusion

Post-stent neoatherosclerosis can be predicted by quantitative IVOCT imaging of plaque characteristics prior to stent implantation. Our findings highlight the additional clinical benefits of utilizing IVOCT imaging in the catheterization laboratory to inform treatment decision-making and improve outcomes.

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.

Evolutionary perspective of drug eluting stents: from thick polymer to polymer free approach

Background

Introduction of Bare Metal Stents (BMS) was itself a revolutionary step in the history of the medical industry; however, Drug Eluting Stents (DES) maintained its superiority over BMS in every aspect from restenosis rate to late lumen loss. The reason behind the magnanimous position of the DES in the stent market is the degree of improvement with which it evolves. New and better stents come into the market every year, surpassing their predecessors by many folds.

Literature review

This review paper discusses the journey of DES with supporting clinical trials in detail. In the first generation, there were stainless-steel stents with thicker coatings. Although they had superior results compared to BMS, there was still room for improvement. Afterward came the second-generation stents, which had superior metal platforms with thinner struts and thin coatings. The drugs were also changed from Paclitaxel and Sirolimus to Zotrolimus and Everolimus. These stents performed best; however, there was an issue of permanent coating, which remained intact over the stent surface after complete drug elution and started to cause issues in longer-term studies. Hence, an improved version of DES was introduced to these permanent coatings called the third generation of drug eluting stents, which initially utilized biodegradable polymer and ultimately moved towards polymer free drug coatings. This generation has introduced a unique amalgam of technologies to achieve its polymer free coatings; however, researchers have numerous prospects of growth in this field. This review paper highlights the major coups of stent technology evolution from BMS to DES, from thick polymeric coatings to thin coatings and from durable polymers to polymer free DES.

Conclusion

In conclusion, though the medical industry promptly accepted BMS as the best treatment option for cardiovascular diseases; however, DES has provided even better results than BMS. In DES, the first and second generation has ruled the technology for many years and are still on the shelves. Still, the issues aroused due to durable polymer shifted the attention towards biodegradable drug eluting stents, the third generation growing rapidly. But the scientific community has not restricted themselves and is investigating bioresorbable stents that completely eliminate the polymer intervention in drug eluting stent technology.

Real-World Long-Term Clinical Outcomes of Ultrathin Strut Biodegradable Polymer Drug-Eluting Stents in Korean ST-Segment-Elevation Myocardial Infarction (STEMI) Patients with or without Acute Heart Failure Undergoing Primary Percutaneous Coronary Intervention

Biodegradable polymers (BDPs) and ultrathin struts were recently introduced to drug-eluting stents (DES) to further improve outcomes. In this study, we analyzed and compared the effect of the ultrathin strut BDP-DES (UBDP-DES) with the conventional durable polymer-DES (DP-DES) in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PPCI). A total of 356 STEMI patients (n = 160 in the UBDP-DES group and n = 196 in the DP-DES group) were enrolled. The primary endpoint was target lesion failure (TLF), including cardiac death, target vessel myocardial infarction, and ischemic-driven, target lesion revascularization (ID-TLR). The mean age was 60.3 ± 12.7 years (male 81.7%), and the median follow-up duration was 63.8 months. TLF was numerically more frequent in the UBDP-DES group (8.1% vs. 4.1%; HR 2.14; 95% CI 0.89-5.18; p = 0.091). Propensity score matching (PSM) was performed to balance discrepancies in the baseline characteristics due to patients in the UBDP-DES group initially having more unstable vital signs. However, after PSM (n = 116 in each group), there was no significant difference in TLF (5.3% vs. 5.3%; HR 1.04, 95% CI 0.34-3.22; p = 0.947) or other secondary endpoints including ID-TLR. In the subgroup analysis, subjects with initial acute heart failure (AHF), defined as Killip class ≥ 3, were associated with 13.6% chance of 30-day mortality (9-fold of those without AHF), although chances of repeat revascularization were low (3.0%). Among patients with AHF, the UBDP-DES group was associated with a numerically higher chance of TLF compared with the DP-DES group. There was no difference in TLF between groups in patients without AHF. This study showed that UBDP-DES has long-term clinical outcomes similar to those of conventional DP-DES in real-world Korean STEMI patients receiving PPCI, especially in those without initial AHF.

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.

Scoring model to predict low image quality of drug-eluting stent evaluated by computed tomography coronary angiography

Evaluation of in-stent restenosis (ISR) by computed tomography coronary angiography (CTCA) is less invasive but often impossible. We aimed to create a scoring model for predicting which drug-eluting stents (DES) cannot be evaluated with CTCA. We enrolled 757 consecutive implanted DES assessed with CTCA. Non-diagnostic evaluation was defined as poor/not evaluative by two different observers. These stents were randomly divided into a derivation (n = 379) and validation (n = 378) group. In the derivation group, we assessed predictors using logistic regression analysis and created a scoring model that would stratify non-diagnostic evaluation of DES-ISR. The validity of this scoring model was evaluated in the validation group using receiver-operating characteristic analysis. The percentage of non-diagnostic stents was 19/21% in the derivation/validation group (p = 0.71). Non-diagnostic evaluation was independently associated with implanted stent diameter (2.25-2.5. vs. 2.5-3 vs. > 3.0 mm), severe calcification, stent-in-stent lesion, and type of DES (stainless vs. CoCr vs. PtCr) in the derivation group. The predicting system of implanted DES non-diagnostic by CTCA (PIDENT) for non-diagnostic evaluation, including these four baseline factors, was derived (C-statistic = 0.86 in derivation group, cutoff: 8 points). The PIDENT score had a high predictive value for non-diagnostic DES in the validation model (C-statistic = 0.87, sensitivity 86%, specificity 74%, cutoff 8 points, p < 0.001). The PIDENT score, consisting of baseline characteristics including implanted stent diameter, severe calcification, stent-in-stent lesion, and type of DES, could identify non-diagnostic evaluation of DES-ISR with CTCA. The PIDENT score was valuable in reducing nonevaluable and meaningless CTCA for DES-ISR.

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.

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.

Differences in lesion characteristics and patient background associated with the medium-term clinical outcomes of bare-metal and first-, second- and third-generation drug-eluting stents

We investigated the lesion characteristics and patient background factors associated with the medium-term incidence of major adverse cardiac events (MACEs) for bare-metal stents (BMS) and 1st-, 2nd- and 3rd-generation drug-eluting stents (DES) using the PCI-Registry (FU-Registry). Between January 2003 and March 2016, 2967 cases/3508 lesions for which percutaneous coronary intervention was performed at Fukuoka University Hospital and related facilities were enrolled. Patients were divided into BMS and 1st-, 2nd- and 3rd-generation drug-eluting stent (DES) groups. The incidence of MACEs in the BMS group (26.2%) was significantly higher than those in the 1st, 2nd and 3rd DES groups (18.0%, 12.5%, and 11.0%, respectively). The incidence of MACEs in the BMS group was strongly associated with insulin use, hemodialysis, low high-density lipoprotein cholesterol, stent minimum lesion diameter, stent length, severe calcification and a small vessel diameter of less than 2.5 mm. Some of these factors showed no association with MACEs among the drug-elution groups, and only hemodialysis, arteriosclerosis obliterans and severe calcification showed a strong correlation in the 2nd DES group. In the 3rd DES group, none of the factors considered were associated with MACEs. In conclusion, in stent implantation, the number of factors associated with MACEs has gradually decreased as the stent generation increased.

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.

Durable polymer everolimus-eluting stents: history, current status and future prospects

INTRODUCTION

Coronary percutaneous interventions have evolved from plain old balloon angioplasty (POBA) to stent implantation, which itself evolved from bare-metal stents (BMS) to the new biodegradable stents which try to restore endothelial function. Currently, the most commonly used stent is the everolimus-eluting stent.

AREAS COVERED

This review will cover the current status of durable polymer everolimus-eluting stent, its history, and future perspectives. Nowadays, the everolimus-eluting stent is the most used device in the acute and chronic settings due to its safety and efficacy.

EXPERT OPINION

Durable polymer everolimus-eluting stent, supported by much evidence, has demonstrated its efficacy and safety, not only in de novo artery lesions, but in multiples scenarios, such as the acute setting and diabetic population, becoming one of the most polyvalent stents available. Nowadays, research is focused on the reduction of antiplatelet treatment duration. Similar rates of stent thrombosis with short dual antiplatelet treatment regimens of 1 to 3 months compared to pronged treatment have been observed. However, specific studies should be performed to evaluate this possibility.

1-Year Outcomes with COMBO Stents in Small-Vessel Coronary Disease: Subgroup Analysis From the COMBO Collaboration

BACKGROUND

Small vessel diameter is associated with higher risk of target lesion revascularization (TLR) after percutaneous coronary intervention (PCI). The COMBO sirolimus-eluting biodegradable-polymer stent has a proprietary anti-CD34 antibody layer to enhance homogeneous endothelialization, which may be advantageous in treating small vessels.

OBJECTIVE

We examined for differences in 1-year clinical outcomes after PCI by maximum implanted stent diameter from the COMBO collaboration.

METHODS

The COMBO collaboration (n = 3614) is a patient-level pooled dataset of patients undergoing PCI with COMBO stents in the MASCOT and REMEDEE multicenter registries. Stent diameter was available in 3590 (99.3%) patients. We compared patients receiving COMBO stents <3 mm versus ≥3 mm. The primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, target vessel-myocardial infarction (TV-MI) or clinically driven TLR. Secondary outcomes included stent thrombosis (ST). Adjusted outcomes were assessed using Cox regression methods.

RESULTS

The study included 792 (22%) patients with small stents <3 mm and 2798 (78%) patients with large stents ≥3 mm. Small stent patients included more women with lower body mass index and higher prevalence of diabetes but similar prevalence of acute coronary syndrome. Risk of 1-year TLF was similar in small and large stent groups (4.4% vs. 3.8%, HR 1.12, 95% CI 0.74-1.72, p = 0.58). There were no differences in the rates of cardiac death (1.7% vs. 1.5%, p = 0.74), TV-MI (1.4% vs. 1.2%, p = 0.58) or TLR (2.7% vs. 2.1%, p = 0.31). Definite or probable ST occurred in 1.3% of the small stent and 0.7% of the large stent PCI patients, p = 0.14, HR 2.13, 95% CI 0.93-5.00, p = 0.07.

CONCLUSIONS

One-year ischemic outcomes after COMBO PCI were similar irrespective of stent diameter in this all-comers international cohort.

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.

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.