Aortic Root Thrombus after LVAD Implantation and Aortic Valve Replacement

Abstract

Purpose The risk of developing thromboembolic events is elevated in the first 3 months after an aortic valve replacement (AoVR). Therefore, the current guidelines recommends very early (at day 1) introduction of low dose aspirin or therapeutic warfarin therapy after AoV replacement. Following Left Ventricular Assist Device (LVAD) implantation, AoVR with a bioprothesis is advised in patients with a moderate to severe aortic regurgitation (AR). Aim of this study was to evaluate the clinical outcome of bioprothesis post-LVAD, especially in relation to thromboembolic events. Methods We revised all LVAD implantations in our center (64 HeartMate II and 40 HeartMate 3 LVAD patients) starting from 2006 for AoVR and thromboembolic events diagnosed on CT-angiography (CT-a). Results Nine patients (8.7%; median age 53 years, 89% male) had concomitant AoVR at the time of LVAD implantation, one patient (1.0%; 56 years of age, male) had AoVR 520 days post-LVAD, one patient (1.0%; 59 years of age, female) had a Transcatheter Aortic Valve Implantation (TAVI) after 337 days post-LVAD. An overview of the clinical data is shown in the Table. Median follow-up time on LVAD support was 750 days [range: 86-2065]. Median time to therapeutic heparin/warfarin therapy was 4 days [range: 1-7] and median time to start of aspirin was 11.5 days [range: 5-39] after implantation. Three patients developed an aortic root thrombus within the first month after implantation, all primarily diagnosed with CT-a, and subsequently confirmed by transthoracic echocardiography. Furthermore, two patients suffered from a stroke, one ischemic and one hemorrhagic. Conclusion In our cohort, consisting of eleven patients with LVAD and AoVR, almost one third had LVOT/AoV thrombosis at CT-a, one of them developed an ischemic stroke. We hypothesize that concomitant AoVR at the time of LVAD implantation in selected patients may be associated with less risk for thrombus formation on LVOT/AoV as compared to a later intervention on the aortic valve.