A prospective, randomized trial of bioresorbable polymer drug-eluting stents versus fully bioresorbable scaffolds in patients undergoing coronary stenting

Background: The performance of an everolimus-eluting bioresorbable scaffold (BRS) was inferior to an everolimus-eluting metallic drug-eluting stent (DES) with permanent polymer, mainly due the mechanical features of BRS technology. The performance of BRS as compared to metallic DES with bioresorbable polymers remains unstudied.

Methods: This prospective, randomized, multicenter, clinical trial enrolled patients who underwent coronary stenting for de novo coronary lesions. Patients were randomly assigned to bioresorbable polymer everolimus-eluting stents (BP-EES) or everolimus-eluting BRS. The primary endpoint was percentage diameter stenosis (in-device) at 6- to 8-month angiographic surveillance. The main secondary endpoint was the device-oriented composite endpoint (DOCE) of cardiac death/target vessel-myocardial infarction/target lesion revascularization assessed after 12 months and 5 years.

Results: The trial was prematurely terminated after the enrollment of 117 of 230 patients (BP-EES, n = 60; BRS, n = 57) due to safety issues associated with BRS technology. The primary endpoint of in-device diameter stenosis at angiographic surveillance was 12.5 ± 7.7% with BP-EES versus 19.3 ± 16.5% with BRS (p = 0.01). The DOCE occurred in 5.0% in the BP-EES group versus 12.3% of patients in the BRS group (hazard ratio [HR] 2.48, 95% confidence interval [CI] 0.64-9.58, p = 0.19) after 12 months and in 11.7% in the BP-EES group versus 26.4% of patients in the BRS group (HR 2.38, 95% CI 0.97-5.84, p = 0.06) after 5 years.

Conclusions: BP-EES showed superior mid-term angiographic performance compared with BRS. Clinical event rates did not differ significantly between the groups up to 5 years of follow-up. These results should be interpreted with caution in view of the premature discontinuation of the study.