The Issue of Subclinical Leaflet Thrombosis After Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has been considered an important therapy for the treatment of symptomatic severe aortic stenosis. Although the devices and the techniques have been improved some complications may occur and several issues still need to be addressed. The issue of subclinical leaflet thrombosis (SLT) has been recognized as a complication after TAVI, and its incidence ranges from 0% to 40%. Nowadays, computed tomography is considered as the standard method for diagnosis of SLT. The concept of hypoattenuated leaflet thickening (HALT), reduced leaflet motion (RELM), and hypoattenuation affecting motion (HAM) have been used in this topic. Most patients who had SLT were taking single or dual antiplatelet therapy. In addition, these medications were not effective in resolving this complication after TAVI. However, there is a suggestion that oral anticoagulants have a protective and therapeutic effect. With the increasing use of TAVI, it is necessary to have better knowledge about several aspects of this complication, because it may have impact on prognosis. Therefore, some aspects of SLT diagnosis, management, and prognosis are not yet fully understood.