Temporary Rise in Blood Thrombogenicity in Patients with Acute Myocardial Infarction.

Objective  Although blood thrombogenicity seems to be one of the determinant factors for the development of acute myocardial infarction (MI), it has not been dealt with in-depth. This study aimed to investigate blood thrombogenicity and its change in acute MI patients. Methods and Results  We designed a prospective, observational study that included 51 acute MI patients and 83 stable coronary artery disease (CAD) patients who underwent cardiac catheterization, comparing thrombogenicity of the whole blood between: (1) acute MI patients and stable CAD patients; and (2) acute and chronic phase in MI patients. Blood thrombogenicity was evaluated by the Total Thrombus-Formation Analysis System (T-TAS) using the area under the flow pressure curve (AUC ₃₀ ) for the AR-chip. Acute MI patients had significantly higher AUC ₃₀ than stable CAD patients (median [interquartile range], 1,771 [1,585-1,884] vs. 1,677 [1,527-1,756], p  = 0.010). Multivariate regression analysis identified acute MI with initial TIMI flow grade 0/1 as an independent determinant of high AUC ₃₀ ( β  = 0.211, p  = 0.013). In acute MI patients, AUC ₃₀ decreased significantly from acute to chronic phase (1,859 [1,550-2,008] to 1,521 [1,328-1,745], p  = 0.001). Conclusion  Blood thrombogenicity was significantly higher in acute MI patients than in stable CAD patients. Acute MI with initial TIMI flow grade 0/1 was significantly associated with high blood thrombogenicity by multivariate analysis. In acute MI patients, blood thrombogenicity was temporarily higher in acute phase than in chronic phase.