A Polymeric Bioresorbable Vascular Scaffold Versus an Everolimus-Eluting Stent in ST-Segment Elevation Myocardial Infarction

J INVASIVE CARDIOL 2019;31(9):E271-E272.

Key words: drug-eluting stent, everolimus, meta-analysis

Bioresorbable vascular scaffold (BRS) devices deliver both short-term coronary artery support and drugs. This could potentially be advantageous in patients suffering from ST-segment elevation myocardial infarction (STEMI) featuring large and necrotic thrombus-rich lesions, which are often associated with stent-related complications. Recently, a randomized controlled trial (RCT) comparing a polymeric BRS (Absorb; Abbott Vascular) with a cobalt-chromium everolimus-eluting stent (EES) in STEMI patients reported clinical outcomes.¹ We therefore performed a meta-analysis of available data comparing polymeric BRS versus EES in STEMI patients.

Our search strategy involved screening Medline, Embase, Google Scholar, and Cochrane Register of Controlled Trials; the search was conducted on March 20, 2019. Two independent reviewers (BW and CJ) assessed and extracted data. We included studies investigating humans >18 years old suffering from STEMI treated with either BRS or EES. The most recent report was included. The primary endpoint was the device-oriented composite endpoint (DOCE) at the longest available follow-up (with follow-up ranging from 6 months to median 901 days). We analyzed intention-to-treat cohorts. Heterogeneity was assessed by I² statistic. Pooled event rates were obtained for each study subset and combined in a meta-analysis, with odds ratios (ORs) calculated using random-effects model (Mantel-Haenszel). A sensitivity analysis was performed including only RCTs and only studies reporting follow-up ≥12 months. Trial sequential analysis was performed assuming two-sided testing, type-I error of 5%, power of 80%, and a risk reduction for DOCE of 33%.

Four studies (two RCTs and two propensity-score matched studies) comparing BRS vs drug-eluting stent including 1208 patients were included in the meta-analysis.^1-4 Most patients (95%) were treated for STEMI, while 65 patients were treated for non-ST segment elevation myocardial infarction due to a thrombus-containing lesion. Mean age was 59 ± 12 years, and patients were predominantly male (79%). The vast majority (98%) were on aspirin. Most patients were on dual-antiplatelet therapy consisting of aspirin plus clopidogrel (39%) or ticagrelor (35%). DOCE occurred in 34 of 612 patients in the BRS group vs 31 of 596 patients in the EES group (OR, 1.11; 95% confidence interval [CI], 0.66-1.86; P=.71; I²=0%) (Figure 1). Trial sequential analysis revealed that 31% of required patient number (1208 of 3812) is available. The z-curve did not cross boundaries. Rates of cardiac death were similar between BRS and EES groups (OR, 0.98; 95% CI, 0.43-2.24; P=.96; I²=0%). Target-lesion revascularization (TLR) was not dissimilar between BRS and EES (OR, 1.08; 95% CI, 0.51-2.25; P=.85; I²=0%). Rates of definite device thrombosis were similar (OR, 1.47; 95% CI, 0.45-4.77; P=.52; I²=0%). Sensitivity analysis analyzing only data from RCTs revealed similar outcomes comparing BRS vs EES for DOCE (OR, 1.14; 95% CI, 0.43-3.00; P=.79; I²=0%), cardiac death (OR, 1.03; 95% CI, 0.18-5.73; P=.97; data only from one trial), TLR (OR, 0.96; 95% CI, 0.34-2.72; P=.95; I²=0%), and definite device thrombosis (OR, 0.83; 95% CI, 0.15-4.49; P=.83; I²=0%). Sensitivity analysis of only data from studies reporting follow-up ≥12 months again showed similar outcomes between BRS vs EES for DOCE (OR, 1.08; 95% CI, 0.63-1.83; P=.79; I²=0%), cardiac death (OR, 0.98; 95% CI, 0.43-2.24; P=.96; I²=0%), TLR (OR, 1.01; 95% CI, 0.46-2.19; P=.98; I²=0%), and definite device thrombosis (OR, 1.25; 95% CI, 0.26-5.95; P=.78; I²=33%).

This meta-analysis suggests that STEMI patients treated with a polymeric BRS have similar rates of DOCE, death, TLR, and definite device thrombosis compared with patients treated with EES. Young STEMI patients with specific clinical and anatomic features could represent a “sweet spot” for BRS, particularly following a dedicated implantation strategy.⁵ Treatment with more efficacious dual-antiplatelet therapy indicated for STEMI patients might reduce BRS thrombotic events seen in other settings and earlier trials, especially during the first years after implantation. BRS might provide initial vessel patency and release antiproliferative drugs while degrading. Still, compared to EES, BRS might maintain normal vasomotion and allow for restoration of normal vessel biology. This might result in a reduction in late thrombotic events, particularly at stented areas with impaired re-endothelialization. Younger patients might particularly benefit from an approach using BRS, which would leave them with coronary arteries free of metal.

Similar clinical performance may occur between BRS and EES in STEMI patients: a large RCT using a newer BRS platform is necessary and awaited to confirm and extend these preliminary results.

References

1. Byrne RA, Alfonso F, Schneider S, et al. Prospective, randomized trial of bioresorbable scaffolds vs. everolimus-eluting stents in patients undergoing coronary stenting for myocardial infarction: the Intracoronary Scaffold Assessment a Randomized evaluation of Absorb in Myocardial Infarction (ISAR-Absorb MI) trial. Eur Heart J. 2019;40:167-176.

2. Brugaletta S, Gori T, Low AF, et al. ABSORB bioresorbable vascular scaffold vs. everolimus-eluting metallic stent in ST-segment elevation myocardial infarction (BVS EXAMINATION study): 2-year results from a propensity score matched comparison. Int J Cardiol. 2016;214:483-484.

3. de Hemptinne Q, Picard F, Ly HQ, et al. Long-term outcomes of bioresorbable vascular scaffold in ST-elevation myocardial infarction. Acta Cardiol. 2018;73:276-281.

4. Sabate M, Windecker S, Iniguez A, et al. Everolimus-eluting bioresorbable stent vs. durable polymer everolimus-eluting metallic stent in patients with ST-segment elevation myocardial infarction: results of the randomized ABSORB ST-segment elevation myocardial infarction-TROFI II trial. Eur Heart J. 2016;37:229-240.

5. Ielasi A, Campo G, Rapetto C, et al. A prospective evaluation of a pre-specified Absorb BVS implantation strategy in ST-segment elevation myocardial infarction: the BVS STEMI STRATEGY-IT study. JACC Cardiovasc Interv. 2017;10:1855-1864.

From the ¹Clinic of Internal Medicine II, Department of Cardiology, Paracelsus Medical University, Salzburg, Austria; ²the Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York; ³the Clinical and Interventional Cardiology Unit, Istituto Clinico S. Ambrogio, Milan, Italy; and ⁴the Division of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted April 7, 2019, accepted with revision April 15, 2019, final version accepted April 24, 2019.

Address for correspondence: Christian Jung, MD, PhD, University Hospital Düsseldorf, Department of Medicine, Division of Cardiology, Pulmonary Diseases and Vascular Medicine, 40225 Düsseldorf, Germany. Email: Christian.Jung@med.uni-duesseldorf.de