One-Year Clinical and Computed Tomography Angiographic Outcomes After Bioresorbable Vascular Scaffold Implantation During Primary Percutaneous Coronary Intervention for ST-Segment-Elevation Myocardial Infarction: The PRAGUE-19 Study

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.

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

AIMS

Early clinical results after implantation of bioresorbable vascular scaffolds (BVS) in ST-elevation myocardial infarction (STEMI) are encouraging, but long-term data are missing. This study evaluates long-term outcome in STEMI patients with implanted BVS.

METHODS AND RESULTS

The PRAGUE-19 study is an academic study enrolling consecutive STEMI patients with the intention to implant BVS. A total of 580 STEMI patients were screened between December 2012 and March 2015; 117 patients fulfilled entry criteria and BVS was successfully implanted in 114 (97%) of them. The primary combined clinical endpoint (death, reinfarction or target vessel revascularisation) occurred in 11.5% during the mean follow-up period of 730±275 days with overall mortality of 4.4%. Definite scaffold thrombosis occurred in two patients in the early phase after BVS implantation; there was no late thrombosis. Quantitative coronary angiography (10 patients) at three years demonstrated late lumen loss of 0.2±0.33 mm and optical coherence tomography showed minimal lumen area of 5.3±1.37 mm2 and neointimal hyperplasia area of 2.9±0.48 mm2. BVS struts were still visible at three years and 99.4% of them were well apposed and covered.

CONCLUSIONS

Encouraging clinical and imaging results after BVS implantation in STEMI patients persist during long-term follow-up.

Bioresorbable vascular scaffolds in patients with acute myocardial infarction: a new step forward to optimized reperfusion?

Bioresorbable vascular scaffolds (BVS) represent a disruptive technology that has caused a new revolution in interventional cardiology. BVS appear to be particularly appealing in patients presenting with an acute myocardial infarction (MI). The available evidence on the value of BVS implantation in this challenging scenario is very promising but still limited. Results come from preliminary small observational studies, prospective registries that include a control group, and from scarce randomized clinical trials with surrogate mechanistic or angiographic primary end-points. Further studies, powered for clinical endpoints, are required to establish the relative safety and efficacy of BVS vs. new-generation metallic drug-eluting stents (DES) in patients with ST-segment elevation acute MI.