Abstract 685: Reduced von Willebrand Factor-cleaving Protease (ADAMTS13) Activity in Acute Myocardial Infarction

Backgrounds: High plasma levels of von Willebrand factor (VWF) are associated with an increased risk of acute myocardial infarction (AMI). The hemostatic activity of VWF is strongly dependent on its multimeric structure, with the highest activity in unusually large VWF multimers (ULVWF). Recent studies have shown that ULVWF is regulated by VWF-cleaving protease (ADAMTS13). The aim of this study was to examine the relationship between VWF and ADAMTS13 levels in plasma and coronary thrombi in patients with AMI. Methods and Results: Plasma VWF antigen, ADAMTS13 antigen and activity levels (mU/ml) were examined in 41 patients with AMI, 33 with stable exertional angina (SEA) and 30 with chest pain syndrome (CPS). Plasma VWF and ADAMTS13 antigen levels were measured by ELISA. ADAMTS13 activity was measured by detecting fluorescence intensity obtained from the mixture with FRETS-VWF73. Plasma VWF antigen levels increased significantly in patients with AMI compared with SEA and CPS on admission (2151 ± 97, 1445 ±...