Thrombus formation following transcatheter aortic valve replacement

This paper reviews the published data and reports 3 cases of thrombosis involving CoreValve (Medtronic, Minneapolis, Minnesota) and 1 involving Edward Sapien (Edwards Lifesciences, Irvine, California) devices. Three of these cases had pathological findings at autopsy.

Only a limited number of cases of valve dysfunction with rapid increase of transvalvular aortic gradients or aortic insufficiency post-transcatheter aortic valve replacement (TAVR) have been described. This nonstructural valvular dysfunction has been presumed to be because of early pannus formation or thrombosis.

Through reviews of the published reports and 4 clinical cases, pathological and clinical findings of early valve thrombosis are examined to elucidate methods for recognition and identifying potential causes and treatments.

This paper presents 4 cases, 2 of which had increasing gradients post-TAVR. All 3 pathology cases showed presence of a valve thrombosis in at least 2 TAV leaflets on autopsy, but were not visualized by transthoracic echocardiogram or transesophageal echocardiogram. One case was medically treated with oral anti coagulation with normalization of gradients. The consequence of valve thrombosis in all 3 pathology patients either directly or indirectly played a role in their early demise. At least 18 case reports of early valve thrombosis have been published. In 12 of these cases, the early treatment with anticoagulation therapy resolved the thrombus formation and normalized aortic pressures gradients successfully.

These 4 cases elucidate the occurrence of valve thrombosis post-TAVR. Consideration should be given to treatment with dual antiplatelet therapy and oral anticoagulation in patients post-TAVR with increasing mean pressure gradients and maximum aortic valve velocity. Further research should be conducted to create guidelines for antithrombotic therapy following TAVR procedure.