Transcatheter aortic valve replacement (TAVR) is a therapeutic option for low-risk patients with aortic valve stenosis [1]. However, data supporting transcatheter heart valve (THV) durability are still needed [2]. The presence of the THV creates a partitioning of the sinus of Valsalva (SOV) into a neosinus and anatomic (or anatomical) sinus, the latter between the cage (also named as divider) and the SOV wall, as shown in Supplementary Fig. 1A/B [3].

The anatomic sinus space also accommodates the native calcific aortic leaflets following THV expansion [3]. This new anatomical arrangement might disrupt the laminar flow of the Valsalva currents and create an area of blood stasis and stagnation, with the possibility of thrombus formation [3,4]. Subclinical leaflet thrombosis (SLT) is a condition identified with multidetector computed tomography (MDCT), in which thickening of one or more leaflets is observed [5]. It is also known as hypoattenuated leaflets thickening (HALT) [5,6]. HALT can also be associated with restricted leaflet movement (RELM), which varies from mild to severe [5].

While SLT/HALT has been well described as a specific condition that affects the THV leaflets [6], little is known about the frequency and distribution of hypoattenuated lesions at other levels, such as the prosthesis subvalvular frame (the THV ‘skirt’) or the anatomic sinus [7] (Fig. 1A/B/C). Analyses of explanted THV have shown diffuse pericardial tissue remodelling in both the aortic and ventricular sides [7,8].

Preclinical and clinical studies have demonstrated that root anatomy in relation to post-implant THV geometry may influence the development of SLT [[4], [5], [6], [7], [8], [9]]. However, predictors of SLT have been mostly investigated for balloon-expandable valves [10,11], with fewer reports on self-expandable valves [10,13].

Thus, the main aims of this study were as follows:

to describe the frequency and localization of hypoattenuated lesions at both leaflets and extra-leaflets level (anatomic sinus and subvalvular prosthesis frame), following self-expandable THV replacement (Evolut R, Medtronic, Minneapolis, USA).

As a secondary aim, we sought the following:

To determine whether certain anatomical characteristics (specifically, anatomic sinus area, implantation depth (ID), THV commissural alignment, THV leaflet expansion and eccentricity, and bicuspid aortic valve) are associated with the development of subclinical leaflet and extra-leaflet hypoattenuated lesions.

Echocardiographic findings and follow-up events (neurological events) have also been reported.