Optimal lesion preparation before implantation of a Magmaris bioresorbable scaffold in patients with coronary artery stenosis: Rationale, design and methodology of the OPTIMIS study

Introduction

Percutaneous coronary intervention with implantation of a bioresorbable scaffold (BRS) provide the vessel support for a limited period allowing the vessel to restore normal vasomotion after degradation of the BRS, opposed to treatment with drug-eluting stents where the metal persist in the vessel wall. Late lumen loss and reduction in lumen area after implantation have been reported. The purpose of this study was to investigate whether intense pre-dilatation before BRS implantation resulted in less reduction of minimal lumen area at 6- and 12-month follow-up after implantation of a Magmaris BRS (MgBRS). Coronary imaging with optical coherence tomography (OCT) and intravascular ultrasound (IVUS) was assessed to track changes in lumen and vessel dimensions.

Methods

The prospective Optimal lesion PreparaTion before Implantation of the Magmaris bioresorbable scaffold In patients with coronary artery Stenosis (OPTIMIS) study randomly assigned eighty-two patients with chronic coronary syndrome to two pre-dilatation treatment strategies. Patients were randomized in a 1:1 ratio to pre-dilatation with either a non-compliant scoring balloon or a standard non-compliant balloon prior to implantation of a MgBRS. The treated segment was evaluated with OCT and IVUS at baseline, after 6 and 12 months to assess changes in lumen and vessel dimensions. The hypothesis was that more intense pre-dilatation with a non-compliant scoring balloon before MgBRS implantation can reduce the risk of late lumen reduction compared to standard pre-dilatation. The power calculation used expected MLA after 6 months (6.22 mm2 for the scoring balloon and 5.01 mm2 for the standard non-compliant balloon), power of 80 %, significance level of 0.05 and expected drop-out rate of 15 %, requiring 82 patients to be enrolled.

Results

Eighty-two patients were included in the study. Enrollment was from December 2020 to September 2023.

Conclusion

The hypothesis was that more intense pre-dilatation with a non-compliant scoring balloon before MgBRS implantation can reduce the risk of late lumen reduction compared to standard pre-dilatation.

Contemporary tools and devices for coronary calcium modification

With the aging population, up to a third of patients referred for percutaneous coronary intervention (PCI) have moderate or severe calcified lesions assessed by coronary angiography. The presence of coronary calcium is associated with difficult device delivery, sub-optimal stent deployment, and prolonged procedures, with more complications. Furthermore, it is known that sub-optimal stent expansion is associated with poor clinical outcomes. In this manuscript we describe how to quantify the severity of coronary calcium, review the armamentarium of contemporary devices available for calcium modification, and provide a systematic approach to device selection, assessment of successful calcium modification, and stent optimization.

Procedural effectiveness with a focused force scoring angioplasty catheter: Procedural and clinical outcomes from the Scoreflex NC trial

BACKGROUND

The Scoreflex NC scoring angioplasty catheter is designed with a short rapid-exchange tip distal to a non-compliant, high-pressure balloon and an integral wire outside of the balloon, such that the guidewire and the integral wire act as scoring elements during balloon inflation. The external scoring elements enable a focal stress pattern facilitating expansion of resistant lesions at lower pressures using a focused force angioplasty effect.

METHODS

Patients undergoing elective percutaneous coronary intervention (PCI) were enrolled in a prospective, single-arm study conducted at 12 centers in the United States. The primary endpoint was device procedural success, defined as the composite of successful device delivery to the target lesion with balloon inflation and deflation; absence of vessel perforation, flow-limiting dissection or reduction in TIMI flow from baseline; and achievement of final TIMI 3 flow.

RESULTS

Among 200 patients (234 lesions), lesion complexities included: bifurcation disease (37.6%), moderate/severe calcification (36.6%), and total occlusions (5.0%). Successful delivery to the target lesion, inflation and removal of the balloon catheter was achieved in 95.5% of patients (191/200). Procedural success was achieved in 93.5% (187/200) of patients, and final TIMI 3 flow was observed in 99.0% of cases (198/200). No unanticipated device-related events occurred. In-hospital major adverse events were reported in 4.5% of patients (9/200), related to periprocedural myocardial infarction (8/200, 4.0%) and target lesion revascularization (1/200, 0.5%).

CONCLUSIONS

Among patients undergoing elective PCI and with varied lesion complexity, these results support the safety and effectiveness of a dilation strategy using the Scoreflex NC scoring catheter.

Bioresorbable Scaffolds: Contemporary Status and Future Directions

Percutaneous coronary intervention, which is safe, effective, and timely, has become an important treatment for coronary artery diseases and has been widely used in clinical practice. However, there are still some problems that urgently need to be solved. Permanent vessel caging through metallic implants not only prevents the process of positive vessel remodeling and the restoration of vascular physiology but also makes the future revascularization of target vessels more difficult. Bioresorbable scaffolds (BRSs) have been developed as a potential solution to avoid the above adverse reactions caused by permanent metallic devices. BRSs provide temporary support to the vessel wall in the short term and then gradually degrade over time to restore the natural state of coronary arteries. Nonetheless, long-term follow-up of large-scale trials has drawn considerable attention to the safety of BRSs, and the significantly increased risk of late scaffold thrombosis (ScT) limits its clinical application. In this review, we summarize the current status and clinical experiences of BRSs to understand the application prospects and limitations of these devices. In addition, we focus on ScT after implantation, as it is currently the primary drawback of BRS. We also analyze the causes of ScT and discuss improvements required to overcome this serious drawback and to move the field forward.

A systematic review and meta-analysis of bioresorbable vascular scaffolds for below-the-knee arterial disease

INTRODUCTION

Different types of bioresorbable vascular scaffolds (BVSs) have been developed and used in below-the-knee (BTK) arterial diseases. This is the first study reviewing and analyzing the literature on BVS treatment for BTK arterial disease.

EVIDENCE ACQUISITION

MEDLINE, Embase, and Cochrane were searched for studies published until October 21, 2019. The search, study selection, quality assessment, and data extraction were performed by 2 authors independently. Articles that studied the treatment of BTK arterial disease by using BVSs were eligible. Exclusion criteria were studies with a variant design (e.g. case reports <5 patients), non-BTK indications for BVS use, and nonhuman studies. Primary endpoint was 12-month primary patency. Secondary endpoints were 12-month freedom from clinically driven target lesion revascularization (CD-TLR), limb salvage, survival, and amputation-free survival (AFS). Study quality was assessed by the Methodological Index for Non-randomized Studies score.

EVIDENCE SYNTHESIS

Five studies representing 155 patients with 160 treated limbs met the inclusion criteria. Pooled 12-month primary patency per limb was 90% (143/160; 95% confidence interval [CI]: 0.84-0.95), freedom from CD-TLR 96% (124/130; 95% CI: 0.91-0.99), limb salvage rate 97% (156/160; 95% CI: 0.94-1.00), survival rate 90% (112/125; 95% CI: 0.82-0.96), and AFS rate 89% (110/125; 95% CI: 0.81-0.94). Subgroup analyses of included Absorb BVS studies showed similar results. All studies were assessed as moderate quality.

CONCLUSIONS

This meta-analysis of case series showed good 12-month patency and clinical results with BVSs for BTK arterial disease, even in patients with multimorbidity and short but complex lesions. These results encourage a revival of this scaffold.

Improved crossability with novel cutting balloon versus scoring balloon in the treatment of calcified lesion

Cutting balloons and scoring balloons are commonly used for the preparation of calcified lesion. However, problems with crossability occasionally limit the use of cutting balloons. We prospectively selected 173 calcified lesions treated using a novel cutting balloon (Wolverine™, C group). As control, we retrospectively analyzed 146 calcified lesions treated using a scoring balloon (Lacrosse NSE ALPHA™, S group). Either intravascular ultrasound (IVUS) or optical coherence tomography (OCT) was used by the operator's discretion. The primary outcome was delivery success, which was defined as successful passage to the target lesion immediately after IVUS or OCT evaluation. The secondary outcome was acute cross-sectional area (CSA) gain, which was defined as post-interventional minimum stent area minus pre-procedural minimum lumen area. A multivariate analysis evaluated the independent predictors for delivery success. The delivery success rate was significantly higher in the C group versus the S group (90.8% versus 79.5%, P = 0.006). However, the acute CSA gain was similar between the two groups (IVUS: 3.2 ± 1.8 mm² versus 3.4 ± 1.9 mm², P = 0.53; OCT: 3.6 ± 1.4 mm² versus 4.1 ± 1.9 mm², P = 0.11). Usage of cutting balloon was an independent predictor for delivery success even after the adjustment for the patient and lesion characteristics [odds ratio (OR): 2.72 (95% confidence interval 1.38-5.33), P = 0.004] as well as the procedural characteristics [OR: 2.34 (1.15-4.86), P = 0.018]. Novel cutting balloons demonstrated better crossability and similar acute CSA gain compared with scoring balloons in calcified lesion.

Characteristics and outcome of patients with complex coronary lesions treated with bioresorbable scaffolds: three-year follow-up in a cohort of consecutive patients

AIMS

The safety of bioresorbable scaffolds (BRS) has recently been challenged. However, it is unclear whether outcomes depend on the complexity of the lesion or on the technique used to implant the device. The aim of this study was to report on the outcomes after BRS implantation in complex lesions.

METHODS AND RESULTS

This investigator-initiated, single-centre, single-arm observational study recruited 657 consecutive patients (79% male, 66.7% acute coronary syndrome, age 63±12 years). Three hundred and twenty-two lesions (42.3%) in 297 (45.2%) patients with type B2 or C lesions were classified as the "complex lesions group". Post-procedural residual stenosis was slightly but significantly greater in the complex lesions group (15.7±11.3% vs. 13.5±10.2%, p=0.0109). The median follow-up was 1,076 (762-1,206) days without difference between groups. The Kaplan-Meier rates of early scaffold thrombosis (3.5% vs. 1.1%, p=0.0478, HR 3.03 [1.06-8.70]) and scaffold restenosis (9.9% vs. 9.1%, p=0.0262, HR 2.34 [1.11-4.94]) were higher in patients with complex lesions than in those with simple lesions. Late/very late thrombosis, death, repeat myocardial infarction, or repeat coronary interventions were not different. In patients in whom strict guidelines for implantation were applied, the incidence of thrombosis was reduced by 76% in complex lesions and by 92% in simple ones, such that there were no differences between groups (2.3% vs. 0.5%, p=0.3899). In contrast, the incidence of scaffold restenosis was reduced by 59% and 89%, and a difference between groups persisted (7.0% vs. 1.6%, p=0.0235).

CONCLUSIONS

BRS implantation in complex lesions is, as expected, associated with higher incidence of events as compared to simple ones. The technique used at the time of the implantation, however, reduces the incidence of adverse outcomes.

Bioresorbable Vascular Scaffold Korean Expert Panel Report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Hybrid Percutaneous Coronary Intervention With Bioresorbable Vascular Scaffolds in Combination With Drug-Eluting Stents or Drug-Coated Balloons for Complex Coronary Lesions

Bioresorbable vascular scaffolds (BVS) have become an attractive option in the percutaneous coronary intervention field due to the potential advantages associated with the complete resorption process that occurs within a few years. However, current-generation BVS have several limitations including thicker struts, reduced radial strength, and limited expansion capability when compared with drug-eluting stents (DES). As a result, complex coronary disease often contains BVS-inappropriate/unfavorable segments. This does not necessarily mean that BVS use must be completely avoided, and minimizing the length of permanent metallic caging may still be advantageous. Operators should fully understand the limitations of current BVS, and when to consider a hybrid strategy of BVS in combination with DES or drug-coated balloons.

Impact of lesion calcification on angiographic outcomes after Absorb everolimus-eluting bioresorbable vascular scaffold implantation: an observation from the ABSORB Japan trial

AIMS

We aimed to investigate the impact of lesion calcification on angiographic outcomes after Absorb everolimus-eluting bioresorbable vascular scaffold (BVS) implantation in comparison with those after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation.

METHODS AND RESULTS

The present post hoc analysis of the ABSORB Japan randomised trial compared post-procedure and 13-month angiographic outcomes between patients implanted with BVS and CoCr-EES based on the presence or absence of calcification, excluding extremely heavily calcified lesions or lesions requiring rotational atherectomy. The study population comprised 384 patients with 384 lesions (including 114 lesions [29.7%] with moderate or severe calcification), classified into two subgroups: calcification, 114 (BVS: n=72 and CoCr-EES: n=42) and non-calcification, 270 (BVS: n=181 and CoCr-EES: n=89). Follow-up angiography was performed in 94.8% of patients. Both post-procedure and follow-up in-device minimal lumen diameters were comparable in both the BVS arm (calcification vs. non-calcification: 2.43±0.32 mm vs. 2.43±0.39 mm, p=0.91 and 2.17±0.49 mm vs. 2.27±0.47 mm, p=0.17) and in the CoCr-EES arm (2.68±0.34 mm vs. 2.65±0.42 mm, p=0.62 and 2.57±0.52 mm vs. 2.47±0.53 mm, p=0.36).

CONCLUSIONS

Moderate or severe lesion calcification (excluding patients with extremely heavily calcified lesions or lesions requiring rotational atherectomy) does not negatively affect angiographic outcomes at both post-procedure and 13-month follow-up after BVS implantation.

Predictors of acute scaffold recoil after implantation of the everolimus-eluting bioresorbable scaffold: an optical coherence tomography assessment in native coronary arteries

This study investigated the predictors of acute recoil after implantation of everolimus-eluting BRS based on optical coherence tomography (OCT). Thirty-nine patients (56 scaffolds) were enrolled. Acute absolute recoil by quantitative coronary angiography was defined as the difference between the mean diameter of the last inflated balloon (X) and the mean lumen diameter of BRS immediately after balloon deflation (Y). Acute percent recoil was defined as (X - Y) × 100/X. Plaque eccentricity (PE) and plaque composition (PC) were assessed by OCT. PC was classified into two different types: calcific (score = 1), fibrous and lipid (score = 0). Based on the mean acute scaffold recoil value of the present study, scaffolds were divided into two groups: the low acute recoil group (LAR, n = 34) and the high acute recoil group (HAR, n = 22). Acute percent and absolute recoil were 6.4 ± 3.0 % and 0.19 ± 0.11 mm. PE, PC score and scaffold/artery ratio were significantly higher in HAR than in LAR. In multivariate logistic regression analysis, PE > 1.49, PC score (score 1) and scaffold/artery ratio >1.07 were significant positive predictors for the occurrence of acute scaffold recoil (OR 10.7, 95 % CI 2.2-51.4, p < 0.01; OR 5.6, 95 % CI 1.9-22.0, p = 0.04; OR 12.4, 95 % CI 2.6-65.4, p < 0.01, respectively). Acute recoil of BRS is influenced by BRS sizing as well as OCT-derived plaque characteristics.

Bioresorbable vascular scaffolds - basic concepts and clinical outcome

The introduction of percutaneous treatment of coronary artery stenosis with balloon angioplasty was the first revolution in interventional cardiology; the advent of metallic coronary stents (bare and drug-eluting) marked the second and third revolutions. However, the latest generation of drug-eluting stents is limited by several factors. Permanent vessel caging impairs arterial physiology, and the incidence of very late stent thrombosis - although lower with the second generation than with the first generation of drug-eluting stents - remains a major concern. This complication is mainly related to the presence of permanent metallic implants, chronic degeneration triggered by an inflammatory response to the coating polymer, and/or adverse effects of antiproliferative drugs on endothelial regeneration. In 2011, self-degrading coronary stents - the bioresorbable vascular scaffolds (BVS) - were introduced into clinical practice, showing good short-term results owing to their adequate strength. The advantage of these devices is the transient nature of vascular scaffolding, which avoids permanent vessel caging. In this Review, we summarize the latest research on BVS, with a particular emphasis on the implantation technique (which is different from that used with metallic stents) to outline the concept that BVS deployment methods have a major effect on procedural success and prognosis of patients with coronary artery stenosis. Furthermore, the clinical outcome of BVS in randomized clinical trials and in phase IV studies are discussed in different pathophysiological settings, such as stable or acute coronary disease. Finally, all the available data on the safety profile of BVS regarding scaffold thrombosis are discussed.