Clinical Leaflet Thrombosis in Transcatheter and Surgical Bioprosthetic Aortic Valves by Four-Dimensional Computed Tomography

Abstract

Background: The incidence of leaflet thrombosis after transcatheter aortic valve replacement (TAVR) with active surveillance by four-dimensional computed tomography (4DCT) ranges from 7% to 14%. The incidence of leaflet thrombosis when 4DCT is performed for clinical and echocardiographic indications is unknown.

Methods: All patients with prior TAVR or surgical aortic valve replacement (SAVR) who underwent evaluation between October 2015 and January 2017 at our institution and had clinical or echocardiographic indications of leaflet thrombosis were evaluated by 4DCT. Indications for 4DCT by echocardiography included (1) interval increase in mean gradient of 10 mm Hg or more, (2) interval decrease in ejection fraction of 10% or more, (3) thrombus seen on transthoracic echocardiography, (4) persistent or increasing paravalvular leak, or (5) valve dehiscence or thickened leaflets seen on transthoracic echocardiography. Clinical indicators were (1) stroke, (2) transient ischemic attack, or (3) new or worsening heart failure.

Results: During the study period, 612 patients underwent TAVR, and 101 patients (55 TAVR; 46 SAVR) met the criteria for 4DCT imaging. Leaflet thrombosis was seen in 17 of 55 TAVR patients (30.9%) and 15 of 46 SAVR patients (32.6%). Follow-up imaging with 4DCT after treatment with anticoagulation showed improvement or resolution in thrombus burden and leaflet excursion in all TAVR patients and in two-thirds of SAVR patients.

Conclusions: One-third of patients with clinical or echocardiographic indications suggestive of leaflet thrombosis were found to have evidence of leaflet thrombosis using 4DCT. This allowed tailored anticoagulation therapy with resolution of the thrombus in most patients and avoiding unnecessary anticoagulation in the remaining two-thirds of patients.