Long-term implications of left atrial appendage thrombus identified incidentally by pre-procedural cardiac computed tomography angiography in patients undergoing transcatheter aortic valve replacement

Abstract

The prevalence and prognostic implications of left atrial appendage (LAA) thrombus (LAAT) in patients considered for transcatheter aortic valve replacement (TAVR) are incompletely defined. We, therefore, studied pre-procedural cardiac computed tomography angiography (CCTA) scans of TAVR candidates to determine the prevalence of LAAT and its association with late outcomes. Baseline clinical variables and CCTA findings from a prospective TAVR registry were analysed for the prevalence of pre-procedural LAAT and its impact on in-hospital outcomes and late mortality. LAAT was differentiated from LAA filling defects (LAAFD) reflecting stasis without clot. Patients (n = 561) with complete in-hospital and late mortality data were included in the study (median follow-up 31.6 months). LAAT and LAAFD were evidenced on pre-procedural CCTA in 24 (4.3%) and 26 (4.6%) patients, respectively. One hundred fourteen (20.3%) patients died during the study period. Though in-hospital adverse event rates (including stroke) did not differ among groups, mortality at long-term follow-up was higher among LAAT patients compared with those with or without LAAFD (58.3% vs. 11.5% vs. 19.0%, respectively; P < 0.003). By multivariable analysis, LAAT (but not LAAFD) was independently associated with all-cause mortality [hazard ratio (HR) = 3.33 (1.83-6.00), P < 0.001]. In patients with LAAT, oral anticoagulation at discharge was associated with lower mortality risk, independently of atrial fibrillation status. LAAT visualized by pre-procedural CCTA is an independent predictor of late mortality following TAVR, but not peri-procedural stroke. When reporting TAVR-CCTA, particular note should be made of LAA features and presence of LAAT which may have prognostic and management implications.