Aims: The aim of this study was to compare the hyperaemic flow and vasomotor response to endothelium-dependent stimuli between bioresorbable vascular scaffolds (BVS) and metallic everolimus-eluting stents (EES) at 13 months.
Methods and results: Seventy non-diabetic patients aiming to achieve complete revascularisation were randomised 1:1 to BVS or EES implantation. At 13 months, invasive coronary angiography was performed using intracoronary pressure and Doppler ultrasound measurements at rest and maximal hyperaemia. A vasomotor test to endothelium-dependent (acetylcholine) and independent (nitroglycerine) stimuli and optical coherence tomography (OCT) were also performed. Fifty-nine patients (30 BVS and 29 EES) underwent 13-month examination. Doppler ultrasound average peak velocity (49.0±17.5 vs 49.3±18.3 cm/sec; p=0.95), coronary blood flow (97.4±53.5 vs 88.3±46.7 ml/min; p=0.51), coronary flow reserve (2.6±0.9 vs 2.7±0.8; p=0.84) and fractional flow reserve (0.92±0.06 vs 0.94±0.04; p=0.17) were similar between the groups. The vasomotor test showed vasoconstriction response to acetylcholine in 75.6% proximal and 72.2% distal peri-scaffold segments without differences between study devices. BVS had larger in-scaffold vasoconstriction than EES (60.0% vs 27.6%; p=0.01) despite similar neointima response as assessed by OCT.
Conclusions: BVS and EES had similar microcirculatory response to hyperaemia and predominant vasoconstrictive response in the peri-scaffold segments to endothelium-dependent stimuli. However, BVS exhibited larger vasoconstriction to endothelium-dependent stimuli in the scaffold segment.