Long-term follow-up after bioresorbable vascular scaffold implantation in STEMI patients: PRAGUE-19 study update

Everolimus-eluting bioresorbable scaffold versus everolimus-eluting metallic stent in primary percutaneous coronary intervention of ST-segment elevation myocardial infarction: a randomized controlled trial

BACKGROUND

Primary percutaneous coronary intervention with implantation of a metallic drug-eluting stent (DES) is the standard treatment for patients presenting with ST-elevation myocardial infarction (STEMI). Implantation of a bioresorbable scaffold (BRS) during STEMI represents a novel strategy without intravascular metal.

OBJECTIVE

The aim of the study was to investigate 12-month healing response in an STEMI population after implantation of either the Absorb BRS or Xience DES (Abbott Vascular, USA).

METHODS

The present trial was a prospective, randomized, controlled, nonblinded, noninferiority study with planned inclusion of 120 patients with STEMI. Patients were randomly assigned 1:1 to treatment with Absorb BRS or Xience DES. Implantation result and healing response were evaluated by angiography and optical coherence tomography (OCT) at baseline and 12-month follow-up. The primary endpoint was minimum flow area (MFA) assessed at 12 months. Coronary stent healing index (CSHI) was calculated from OCT images.

RESULTS

Out of 66 included patients, 58 had follow-up OCT after 12 months, and 49 entered matched analysis. One death occurred in each group; none were stent-related. MFA was 5.13 ± 1.70 mm2 (95% CI, 4.44-5.82) in the BRS group compared with 6.30 ± 2.49 mm2 (95% CI, 5.22-7.37) (P = 0.06) in the DES group. Noninferiority could not be evaluated. CSHI for both groups had a median score of 3.

CONCLUSION

The DES group performed numerically better in primary and secondary endpoints, but the CSHI showed good stent healing in both groups.

Comparison of a Bioresorbable, Magnesium-Based Sirolimus-Eluting Stent with a Permanent, Everolimus-Eluting Metallic Stent for Treating Patients with Acute Coronary Syndrome: the PRAGUE-22 Study

BACKGROUND

Magnesium-based bioresorbable Magmaris stents are rapidly resorbed. Few randomized studies have evaluated the efficacy of such stents in patients with acute coronary syndrome.

AIM

To investigate late lumen loss as assessed via quantitative coronary angiography (QCA) and optical coherence tomography (OCT) in patients with acute coronary syndrome treated with Magmaris stents or permanent, everolimus-eluting metallic Xience stents.

METHODS AND RESULTS

This PRAGUE-22 study was a two-centre, investigator-initiated, randomized study. Fifty patients were randomized based on the inclusion criteria for acute coronary syndrome and the anatomical suitability to receive Magmaris or Xience stents. The patient characteristics did not differ between the Magmaris group (n = 25) and Xience group (n = 25). The mean ages were 57.0 ± 10.5 vs. 55.5 ± 9.2 years (p = 0.541) and the total implanted stent length was 24.6 ± 10.7 mm vs. 27.6 ± 11.1 mm (p = 0.368), respectively. Four clinical events occurred in the Magmaris group and one in the Xience group during 12 months of follow-up. The extent of late lumen loss (assessed via QCA) at 12 months was greater in the Magmaris group than in the Xience group (0.54 ± 0.70 vs. 0.11 ± 0.37 mm; p = 0.029). The late lumen loss diameter (measured via OCT) in the Magmaris group was also significantly larger than that in the Xience group (0.59 ± 0.37 vs. 0.22 ± 0.20 mm; p = 0.01).

CONCLUSION

Implantation of a magnesium-based bioresorbable stent in patients with acute coronary syndrome is associated with a greater extent of late lumen loss at the 12-month follow-up compared with implantation of a permanent, everolimus-eluting metallic stent.

TRIAL REGISTRATION

ISRCTN89434356.

Current perspectives on bioresorbable scaffolds in coronary intervention and other fields

Introduction: The first-generation bioresorbable scaffolds (BRSs) had a large strut profile to compensate for the insufficient radial strength of bioresorbable polymer materials, resulting in higher scaffold thrombosis rates than conventional drug-eluting stents. To improve the clinical safety and efficacy, the new generation BRSs have been improved by optimal structure design, post-processing of bioresorbable polymer materials, or altering bioresorbable metallic alloys.Areas covered: This review summarizes the lessons learned from the first-generation BRS, updates the clinical outcomes of trials evaluating ABSORB bioresorbable vascular scaffold at long-term and bioresorbable metallic alloy-based devices, and examines recent outcomes of BRS treated in STEMI patients. This review also provides an overview of the current clinical data of seven BRSs manufactured in Asia, and of the BRSs extended application in other clinical arenas.Expert opinion: Drawbacks of the first-generation BRSs need to be addressed by the next generation of these stents with novel materials and technologies. Clinical research, including randomized controlled trials, are required to further evaluate BRSs application in coronary artery disease. The encouraging results of BRSs innovation applied in the peripheral arteries and gastrointestinal tracts support other potential clinical applications of BRS technology.

Bioresorbable scaffold implantation in STEMI patients: 5 years imaging subanalysis of PRAGUE-19 study

Background

Bioresorbable scaffold (BRS) Absorb™ clinical use has been stopped due to higher rate of device thrombosis. Scaffold struts persist longer than 2 years in the vessel wall. Second generation devices are being developed. This study evaluates long-term invasive imaging in STEMI patients.

Methods

PRAGUE-19 study is an academic study enrolling consecutive STEMI patients with intention to implant Absorb™ BRS. A total of 83 STEMI patients between December 2012 and March 2014 fulfilled entry criteria. Coronary angiography and optical coherence tomography at 5 year follow-up was performed in 25 patients.

Results

Primary combined clinical endpoint (death, myocardial infarction or target vessel revascularization) occurred in 12.6% during the five-year follow-up with overall mortality 6.3%. Definite scaffold thrombosis occurred in 2 patients in the early phase after BRS implantation. Quantitative coronary angiography after 5 years demonstrated low late lumen loss of 0.11 ± 0.35 mm with binary restenosis rate of 0%. Optical coherence tomography demonstrated complete resorption of scaffold struts and mean lumen diameter of 3.25 ± 0.30 and 3.22 ± 0.49 (P = 0.73) at baseline and after 5 years, respectively. Three patients developed small coronary artery aneurysm in the treated segment.

Conclusion

Invasive imaging results 5 years after BRS implantation in STEMI showed complete resorption of scaffold struts and stable lumen vessel diameter.

Trial registration ISRCTN43696201 (retrospectivelly registred, June 7th, 2019). https://www.isrctn.com/ISRCTN43696201.

Bioresorbable Vascular Scaffolds-Dead End or Still a Rough Diamond?

Percutaneous coronary interventions with stent-based restorations of vessel patency have become the gold standard in the treatment of acute coronary states. Bioresorbable vascular scaffolds (BVS) have been designed to combine the efficiency of drug-eluting stents (DES) at the time of implantation and the advantages of a lack of foreign body afterwards. Complete resolution of the scaffold was intended to enable the restoration of vasomotor function and reduce the risk of device thrombosis. While early reports demonstrated superiority of BVS over DES, larger-scale application and longer observation exposed major concerns about their use, including lower radial strength and higher risk of thrombosis resulting in higher rate of major adverse cardiac events. Further focus on procedural details and research on the second generation of BVS with novel properties did not allow to unequivocally challenge position of DES. Nevertheless, BVS still have a chance to present superiority in distinctive indications. This review presents an outlook on the available first and second generation BVS and a summary of results of clinical trials on their use. It discusses explanations for unfavorable outcomes, proposed enhancement techniques and a potential niche for the use of BVS.

Long-term outcomes of bioresorbable vascular scaffold in ST-elevation myocardial infarction

BACKGROUND

Bioresorbable vascular scaffolds (BVS) implantation in selected patients with stable angina has been demonstrated feasible and safe. However, limited data are currently available on long-term outcomes after BVS implantation for ST-elevation myocardial infarction (STEMI). Therefore, we sought to assess the safety, efficacy and long-term results of BVS implantation in STEMI patients.

METHODS

Retrospective review of all STEMI patients treated with the Absorb^® BVS (Abbott Vascular, Santa Clara, CA) or conventional drug eluting stent (DES) between 1 April 2013 and 30 March 2014. Primary outcomes were procedural success, device thrombosis and device-oriented composite endpoint (DOCE) including cardiac death, target vessel myocardial infarction and target lesion revascularization. The study included 54 BVS patients and 121 DES patients.

RESULTS

Patients were slightly younger in the BVS group (60 vs. 63 years old, p = .03). Other baseline characteristics were comparable between the two groups. Procedural success was achieved in all patients. Median follow-up was 901 days and 849 days for BVS and DES patients, respectively (p = .01). The cumulative incidence of DOCE was not significantly different between the BVS and DES groups (7.5% vs. 9.1%, hazard ratio [HR]: 0.74 [95% confidence interval (CI): 0.26-2.2], p = NS). Rate of probable/definite device thrombosis were not statistically different between both groups (3.7% vs. 3.3%, p = NS).

CONCLUSIONS

The results of this single-centre retrospective study, one of the first assessing long-term safety and efficacy of BVS in STEMI, seems reassuring with similar long-term results as compared with patients treated with conventional DES.

Are acute coronary syndromes an ideal scenario for bioresorbable vascular scaffold implantation?

Bioresorbable vascular scaffolds (BRS) represent the latest innovation in the field of interventional cardiology. BRS have recently been introduced in routine clinical practice and their use has progressively extended in everyday clinical practice. The BRS use appears theoretically attractive in patients presenting with acute coronary syndromes (ACS) as they are generally young with long life expectancy, thus possibly benefiting more of the so-called vascular reparative therapy. Furthermore, "culprit" lesions are usually softer and more easily expandable by current BRS compared to stable chronic lesions. However an increased risk of BRS thrombosis has been reported in clinical trials excluding ACS patients. Therefore, concerns have been raised on the safety of BRS implantation in the ACS setting in which the risk of thrombotic recurrences is definitely higher (compared to stable lesions) independently by the device implanted. Aim of this review is to provide an overview of the available data on the BRS performance in ACS patients.

Mid- to long-term outcome of patients treated with everolimus-eluting bioresorbable vascular scaffolds: Data of the BVS registry Göttingen predominantly from ACS patients

BACKGROUND

Bioresorbable vascular scaffolds (BVS) are widely used in routine clinical practice. While previous studies reported acceptable short- to midterm outcome after BVS implantation, data on longer-term outcome are rare.

METHODS

Patients treated with at least one Absorb®-BVS were consecutively enrolled. Follow-up data were assessed after 834.0 [769.0-1026.0] days. The primary device-oriented composite endpoint (DOCE) was defined as cardiovascular death, myocardial infarction (MI) and/or target lesion revascularization (TLR).

RESULTS

Between 2012 and 2014, 195 patients were included into study analysis. Overall, 244 BVS were implanted. Mean patient age was 64.0[54.3-74.0] years. Three-quarter of patients had an ACS; of those 42.9% had ST-elevation-MI and 40.8% had non-ST-elevation-MI. DOCE occurred in 3.1%, 6.7%, 11.8% and 15.4% of patients during hospital stay, within 6-months, 18-months or during the complete follow-up period, respectively. In those patients, median time until DOCE was 211.5[43.25-567.25] days. In 11 (36.7%) patients DOCE occurred after >12months. Using univariable analysis, bifurcation stenting was associated with a hazard ratio (HR) of 11.8[2.38-58.57] for TLR (p=0.002) and 2.1[1.02-4.49] for DOCE (p=0.045). Similarly, in ACS patients, bifurcation stenting was associated with an increased risk for TLR (HR=10.4[2.01-53.56]; p=0.005) and for DOCE (HR=2.4[1.09-5.32]; p=0.029) and in multivariable analysis, it remained an independent predictor of DOCE (HR=3.0; p=0.018).

CONCLUSIONS

Although, the rates of (potentially) device-related complications following BVS implantation are acceptable, they are nonetheless not negligible. Interestingly, they did not decline over time. Bifurcation stenting could be found as relevant procedure-related predictor of DOCE, especially in ACS patients. Randomized trials are warranted to confirm these findings.

Follow-up of coronary artery patency after implantation of bioresorbable coronary scaffolds: The emerging role of magnetic coronary artery imaging

Bioresorbable vascular scaffolds (BVSs) represent the newest tool in the treatment of coronary artery disease (CAD). Conversely to the previous metal stents and thanks to the polylactate-based backbone, BVSs could be visualized by magnetic resonance imaging (MRI) without artifacts. These properties allow a potential non-invasive assessment of coronary artery patency after percutaneous coronary intervention (PCI), avoiding cardiac catheterization included iodine contrast and radiation exposure, and potentially more sophisticated imaging tool as the optical coherence tomography (OCT). We reviewed the available medical literature on the coronary MRI evaluation of BVS after PCI, also discussing its potential diagnostic role in the long-term follow-up of these patients.

The Absorb bioresorbable vascular scaffold for the treatment of coronary artery disease

INTRODUCTION

Every decade the field of interventional cardiology is revolutionized by new technology. The fully bioresorbable everolimus-eluting scaffold (ABSORB BVS) technology would preserve the benefits of metallic stents by sealing balloon-induced dissections, avoiding elastic recoil and vessel occlusion. The polymeric scaffold would be resorbed to restore the natural integrity of the vessel, superseding the consequence of the permanent presence of a foreign body in the coronary artery.

AREAS COVERED

This technology evaluation focuses on the clinical evidence for the use of bioresorbable everolimus-eluting scaffold for the treatment of coronary artery disease.

EXPERT OPINION

The current generation of the bioresorbable scaffold has structural and mechanical limitations that might preclude the widespread use in clinical practice. The strut thickness (150 µm) limits deliverability and creates laminar flow disruptions that might be the nidus of an increased rate of scaffold thrombosis. In the next generation of bioresorbable scaffolds, the resorption process should be faster and in particular, strut thickness must be reduced. This will probably represent a significant step forward in an attempt to increase the efficacy and safety profile of the device and achieve a similar performance with the current generation drug-eluting stent even in complex scenarios.