Long-Term Coronary Functional Assessment of the Infarct-Related Artery Treated With Everolimus-Eluting Bioresorbable Scaffolds or Everolimus-Eluting Metallic Stents

Objectives The study sought to compare the vasomotor and microcirculatory function of the infarct-related artery (IRA) between bioresorbable vascular scaffolds (BVS) and everolimus-eluting stents (EES) at 3 years. Background The ABSORB STEMI TROFI II study showed similar outcomes between BVS and EES in the context of ST-segment elevation myocardial infarction at 3 years. Methods Sixty-three consecutive event-free patients of the randomized TROFI II study were screened to undergo coronary angiography with vasomotor, microcirculatory, and optical coherence tomography (OCT) examination at 3 years. Vasomotion was defined as >4% change in mean lumen diameter to acetylcholine (ACH) and nitroglycerin as assessed by quantitative angiography. Microcirculatory examination was performed with pressure or thermodilution techniques. Results A total of 38 patients (20 BVS and 18 EES) were included. At 3 years, ≥60% of patients exhibited paradoxical vasoconstriction to ACH in the periscaffold or stent segments. Vasoconstriction to ACH and vasodilatation to nitroglycerin were more often observed in the scaffold or stent segment with BVS than with EES (77.8% vs. 25.0%; p = 0.008 and 61.1% vs. 18.8%; p = 0.018). The IRA-depending microcirculation showed similar index of resistance (23.8 vs. 22.4; p = 0.781), coronary flow reserve (2.4 vs. 1.9; p = 0.523), fractional flow reserve (0.91 vs. 0.93; p = 0.317), and absolute flow (135.5 ml/min vs. 147.3 ml/min; p = 0.791). OCT showed remaining strut footprints and larger number of intraluminal scaffold dismantling (26.3% vs. 0%; p = 0.049) in the BVS group. Conclusions Both endothelium-dependent and -independent vasomotion of the IRA were more evident with BVS, as compared with EES, at 3 years. Functional microcirculatory parameters were mostly adequate and similar between BVS and EES. Clinical implications of these findings warrant further investigations.