Ultrasound arteriaL Stiffness evaluatIon and vaScular Complications in Patients Undergoing Transfemoral tranScatheter Aortic valvE Implantation: ULISSE Study.

Background Transcatheter aortic valve implantation (TAVI) is an established treatment modality in patients ≥ 75 years old with severe symptomatic aortic stenosis after Heart Team evaluation (1). Patients with high/prohibitive surgical risk and life expectancy ≥ 1 years are candidates for TAVI according to the current guidelines (1). Nowadays is expected a progressive increase of TAVI procedures, in relationship to aging and increased life expectancy (2). Percutaneous, particularly trans-femoral, access represents the best choice in the vast majority of TAVI patients, because of its minimal invasiveness and reduced mortality, due to lower rates of periprocedural bleedings and strokes (3,4). Technical advancements, improving expertise and simplification of procedure, lead to reduction of vascular complications, still significant, and linked with worst patients' outcome (5). Some factors are considered to increase the risk of vascular complication: patient related and procedural related factors. Patient-related factors include female gender, severe vascular calcification and peripheral vascular disease. Procedural related risk factors consist of increased sheath to femoral artery ratio (SFAR) and TAVI centre experience/case load (5). Considering the last 10 years progress in techniques, devices technology and clinical outcome, a new Valve Academic Research Consortium (VARC) consensus manuscript was published to provide an update of these emerging clinical and research issues in aortic valve therapy (6).

Arterial stiffness is a physiologic phenomenon occurring with age and involving changes in extracellular matrix components of the arterial wall. Particularly, the elastin fibres undergo proteolytic degradation and chemical alteration, with consequent increased production of collagen, by vascular smooth muscle cells with progressive arterial wall stiffening (7). Arterial stiffness appears to be accelerated under pathological conditions, such as hypertension, smoking, diabetes mellitus (DM) and kidney disease (8), furthermore has been shown to have two-fold higher incidence in women compared to men (9).

TAVI patients have higher median age and comorbidities, directly correlated with arterial stiffness (7), and female gender is a considered high-risk feature for vascular complication independently from SFAR and atherosclerosis (5).

Arterial stiffness induces progressive reduction of tensile strength, elongation and burst pressure with consequent drop of vessels breakpoint (10), that could be associated with vascular complications. Particularly, femoral artery stiffness could predispose to microlesions formation at TAVI device access, inducing vascular closure devices failure and vascular complications. Furthermore, vessel rigidity can be associated with a higher resistance during TAVI device delivery and increased probability of vessels injury (especially in presence of tortuosity and small artery diameters). Nowadays, there are no studies evaluating the relationship between arterial stiffness and TAVI vascular complications.

Aim The aim of this study is to evaluate the relationship between arterial stiffness and TAVI vascular complications, defining a new predictor of vascular complications in order to give more accurate information for procedures planning.