Abstract 689: Serial Changes in Von Willebrand Factor-cleaving Protease (ADAMTS13) and Prognosis after Acute Myocardial Infarction
Von WilIebrand factor (VWF) enhances haemostasis and thrombosis as an important cofactor in platelet adhesion and aggregation. Recently, a metalloprotease that cleaves VWF multimers has been identified, namely, VWF-cleaving protease (ADAMTS13). The aim of this study was to investigate serial changes in plasma VWF and ADAMTS13 antigen levels and determine the relationship between these plasma levels and prognosis after AMI. We measured serial changes of plasma VWF and ADAMTS13 antigen levels in 64 AMI patients and 40 control subjects. Plasma VWF antigen levels (mU/ml) increased significantly in AMI patients compared with control group on admission (2019 ± 112 vs. 1488 ± 88, P = 0.001), remained increased until chronic phase (1943 ± 147, P = 0.0217 vs. control group). On the other hand, the plasma ADAMTS13 antigen levels (mU/ml) decreased significantly in AMI patients compared with control group on admission (638 ± 26 vs. 947 ± 40, P < 0.0001), remained decreased until 72 hours after admission (573 ± 24, P < 0.0001 vs. control group). The plasma ADAMTS13 antigen levels gradually returned in chronic phase, while they were significantly lower in AMI patients compared with control group (662 ± 27, P < 0.0001 vs. control group). We calculated the ratio of plasma VWF antigen/ADAMTS13 antigen levels to examine the tendency toward the increased platelet thrombus formation in patients with AMI. The ratio of VWF/ADAMTS13 antigen levels was significantly higher in AMI patients all over the time course compared with control group. Kaplan-Meier analysis demonstrated that patients with high VWF/ADAMTS13 levels at 24 hours after AMI had a significantly higher probability of developing major adverse cardiac events (MACEs) during 1-year follow-up period (p = 0.0012). Furthermore, the univariate Cox analysis showed that high VWF/ADAMTS13 levels at 24 hours after AMI was a significant predictor of 1-year MACEs in AMI patients. These findings suggested that the monitoring of the balance between plasma VWF and ADAMTS13 levels might be important for predicting and preventing MACEs after AMI.