In-stent Flow Hemodynamics and the Risk of STent Failure Following Bioresorbable Vascular ScAFFolds Implantation – the STAFF Study

Abstract

Abstract Background: Myocardial revascularization procedures have undergone important developments over the last decades, which led to a major shift in current clinical practice and therapeutic guidelines across the world. Bare metal and drug-eluting stents present several limitations, all centered on the concept of disturbed coronary hemodynamics after implantation, which can be surpassed by bioresorbable vascular scaffolds (BVS). BVSs are fourth-generation stents used in coronary revascularization procedures, but despite all the promising initial results published on their efficiency, several clinical trials have reported unsatisfactory results, and the main explanation was accredited to improper implantation method. Shear stress is a central element of intravascular homeostasis; it controls vascular remodeling, as well as the development, progression, and destabilization of atheromatous plaques. This study aims to assess the role of in-stent flow hemodynamics (evaluated by computational determination of shear stress via coronary CT imaging) in predicting the clinical evolution following BVS implantation. Material and methods: This case-control observational study will include patients with BVSs implanted at least 12 months prior to randomization. Each patient will undergo a complete evaluation of the demographic and clinical characteristics, cardiovascular risk factors, and imaging acquisitions via coronary CT angiography, based on which the endothelial shear stress will be calculated before and after BVS implantation. Post-processing of CT imaging data will evaluate the shear stress and the composition of the coronary plaques along the entire coronary tree. The primary endpoint will be the major adverse cardiovascular events (MACE) in patients with altered vs. non-altered BVS-related shear stress, and the secondary endpoints will comprise evaluating the rate of progression of stent resorption and progression of shear stress alteration. Conclusions: The findings of the STAFF study can be extremely useful in clinical practice for providing an answer to a key question that is still under debate: why do BVSs fail and how can we prevent this?.