Subclinical leaflet thrombus in patients with severe aortic stenosis and atrial fibrillation -ENRICH-AF TAVI study

TL;DR

This study investigates subclinical leaflet thrombus formation in patients with severe aortic stenosis and atrial fibrillation after TAVI, using imaging and fluid dynamics.

Contribution

The study provides new insights into the acute formation and resolution of subclinical leaflet thrombus after TAVI using novel thrombogenicity and flow analysis methods.

Findings

Subclinical leaflet thrombus was observed in 16.7% of patients at 1 week but decreased to 5.9% at 3 months after TAVI.

Thrombogenicity decreased significantly at 1 week and showed a tendency to increase at 3 months.

Flow stagnation volume was positively associated with increased leaflet thickness.

Abstract

Subclinical leaflet thrombosis (SLT) can be one of the causes of transcatheter heart valve (THV) failure after transcatheter aortic valve implantation (TAVI). We sought to clarify the formation process of SLT and thrombogenicity during the perioperative period of TAVI. This multicenter, prospective, single-arm interventional study enrolled 26 patients treated with edoxaban for atrial fibrillation and who underwent TAVI for severe aortic stenosis between September 2018 and September 2022. We investigated changes in maximal leaflet thickness detected by contrast-enhanced computed tomography between 1 week and 3 months after TAVI in 18 patients and measured the thrombogenicity by Total Thrombus-formation Analysis System (T-TAS) and flow stagnation volume by computational fluid dynamics (CFD) (n = 11). SLT was observed in 16.7% (3/18) at 1 week, but decreased to 5.9% (1/17) at 3 months after TAVI. Patients with SLT at 1 week had a significantly decreased maximal leaflet thickness compared to those without SLT. Thrombogenicity assessed by T-TAS decreased markedly at 1 week and tended to increase at 3 months. The stagnation volume assessed by CFD was positively associated with a higher maximum leaflet thickness. This study showed the course of leaflet thrombus formation and visualization of stagnation in neo-sinus of THV in the acute phase after TAVI.

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