This study, presented in Rome at the European Society of Cardiology Congress 2016 and published simultaneously online in the Journal of the American College of Cardiology (JACC), has identified a post-TAVI valve thrombosis rate of 7% using multidetector computerized tomography (CT). However, the vast majority of cases were completely asymptomatic.
Previous studies had shown thrombosis rates for a transcatheter valve as low as 0.61% and as high as 40%, owing to a lack of standardization in diagnosis.
Warfarin therapy was consistently associated with a lower risk of developing thrombosis, as well as with faster resolution of the finding in those in whom it was diagnosed.
The study assessed 405 patients who received a balloon-expandable Sapien XT or Sapien 3 valve (Edwards Lifesciences) between 2011 and 2016.
Standard post-TAVI therapy usually includes dual antiplatelet therapy with aspirin and clopidogrel. In addition, in the case of patients with indications for anticoagulation (e.g., auricular fibrilation), therapy can include warfarin plus aspirin or clopidogrel, according to physician discretion.
A transesophageal echocardiography was able to identify leaflet thickening or restrictive leaflet movement in 86% of the patients with CT-detected thrombosis.
Obstructive thrombosis associated with symptoms was observed in five patients. The rest were asymptomatic. The rate of valve thrombosis was lower in patients with auricular fibrilation (3.2% vs. 10.1%), which is the result of these patients already taking warfarin.
Of the 28 patients with valve thrombosis detected by CT, 23 initiated warfarin treatment (with or without antiplatelet therapy), and those who were already taking warfarin had their target international normalized ratio (INR) increased to 2.5-3.
Of all patients, 85% had complete thrombus and restored leaflet mobility. Among the five patients with obstructive thrombosis, heart valve function normalized after anticoagulation therapy in four.
Original title: Transcatheter aortic heart valve thrombosis: incidence, predisposing factors, and clinical implications.
Presenter: Nicolaj Hansson.
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