Vascular effects and benefits through Helical stent implantation vs. conventional stenting: Methodology and initial Results of The MIMICS FLOW investigator-initiated randomized controlled trial

Abstract

Abstract Aims Endovascular treatment is the primary revascularization strategy for symptomatic peripheral artery disease (PAD), which not only restores tissue perfusion but also affects local lower limb arterial endothelial function. Endothelial dysfunction is the pathophysiologic principle involved in the progression of atherosclerosis and is a prognostically relevant cardiovascular biomarker. A helical stent with a unique 3D helical geometry promotes laminar swirling blood flow elevating wall sheer stress, providing superior hemodynamic advantages and excellent clinical performance as compared to conventional stenting. The potential impact on endothelial homeostasis and the detailed mechanisms following a biomimetic or conventional stent are unknown. To this aim we now determined the effect of the Biomimics or a conventional stent on endothelial and vascular function in symptomatic PAD. Methods The MIMICS-FLOW is an investigator-initiated single-blind, randomized controlled trial (NCT05447052). The influence of novel stent-platforms with improved hemodynamic capabilities with respect to vasomotion of the vessel wall, vascular function and vascular compliance was measured by flow-mediated dilation (FMD) and arterial stiffness indices. Vascular function was determined in 70 PAD patients, Rutherford 2, 3 and 4 randomized to a helical stent and the conventional straight nitinol stent before and after lower limb intervention with a one-month follow-up in the nonstenotic segment of the proximal SFA. Perfusion indices, TLR rate and primary patency were assessed. Results The methodology and initial results regarding endothelial function after 1 month will be presented at ESC. In brief, 70 Patients aged 67 years were 1:1 randomized to each group prior to stent implantation in the SFA. Rutherford and PACSS class and target lesion locations were balanced between groups. One patient in the helical and 2 patients in the Straight group required a reintervention. A higher improvement in SFA FMD was observed in the helical group as compared to conventional stenting (p<0.05). Importantly, this effect was mirrored also by a greater increase in brachial FMD in the helical vs. conventional group (p<0.05). No impact was observed between groups regarding arterial or aortic stiffness. Conclusions Our RCT data provide evidence for an improved vascular function through swirling flow with superior hemodynamics following a helical stent implantation. These findings support the concept for a better mechanistic understanding to enhance endovascular treatment strategies in PAD.