LEFT ATRIAL STASIS AND VWF-ADAMTS 13 SYSTEM IN AATRIAL FIBRILLATION

Abstract Category: PCI - Valvular; Atrial Fibrillation TherapiesPresentation Number: 2505-439Authors: Waldemar E. Wysokinski, Ewa Konik, Robert D. McBane, II, Susan J. Eifert Rain, Dong Chen, Edyta Sutkowska, Thomas G. McLeod, Paul A. Friedman, Naser M. Ammash, Mayo Clinic, Rochester, MNBackground: Stasis within the left atrial appendage (LAA) is associated with increased risk of left atrial appendage thrombus (LAAT) and stroke in atrial ibrillation (AF). The thrombogenic propensity of von Willebrand factor (VWF) is directly proportional to multimer size regulated by VWF-cleaving protease (ADAMTS-13).Methods: To assess the association between LAA blood stasis and VWF-ADAMTS 13, we measured VWF antigen (VWF Ag) by ELISA, VWF activity (VWF Act) by immunoturbidimetry and ADAMTS 13 activity by ACTIFLUOR assay in 425 consecutive patients with non-valvular AF (age 6314 years; 25% women). All AF patients underwent TEE to assess left atrial appendage emptying velocity (LAAEV), spontaneous echo contrast (SEC), and LAAT. Data were compared to 100 patients (age 6414 years; 39% women) with normal sinus rhythm (NSR).Results: A direct relationship was noted between VWF (Ag and Act) and intensity of SEC (Figure). No relationship was observed between measures of blood stasis and ADAMTS 13. VWF Ag was one of the strongest determinants of LAAT (c-stat=0.711, p=0.0015) together with LAAEV (c-stat=0.959, p=0004) and heart failure (c-stat=0.715, p<0.0001). CONCLUSSION. A direct correlation exists between VWF and the severity of LAA blood stasis in AF patients. Elevated VWF:Ag may identify AF patients at risk for LAAT.