Activation of Blood Coagulation After Aneurysmal Subarachnoid Hemorrhage: A Prospective Observational Trial of Rotational Thromboelastometry

Aneurysmal subarachnoid hemorrhage (aSAH) has been reported to actuate blood coagulation. Rotational thromboelastometry (ROTEM) is a dynamic hemostatic test that can differentiate various coagulation abnormalities. For example, increased coagulation activity can be detected as a wider amplitude of tracing (maximal clot firmness [MCF]). ROTEM had not been used to evaluate coagulation changes after aSAH. We evaluated the on-going coagulation process in patients with aSAH in a prospective, observational study to compare their ROTEM assay results with the control values obtained from patients undergoing clipping of nonruptured aneurysms. ROTEM analyses were performed at 12, 24, 48, and 72 hours after the onset of aSAH and compared with the preoperative analyses from the control group. A total of 17 patients with aSAH treated in the intensive care unit and 16 control patients were enrolled. At 72 hours, EXTEM-MCF was significantly greater in patients with aSAH compared with the baseline values of the control group (68.0 mm [interquartile range (IQR), 66.0–71.0] versus 64.5 mm [IQR, 59.5–66.8]; P = 0.024). This was mainly due to increased fibrin formation and fibrin polymerization. The same comparison in the FIBTEM-MCF analysis yielded similar results (aSAH group, 23.0 mm [IQR, 19.0–25.0] vs. control group, 15.4 mm [IQR, 12.5–17.8], respectively; P = 0.001). Blood coagulation is activated at 72 hours after aSAH onset, which can be detected by ROTEM EXTEM-MCF analysis. Also, the FIBTEM-MCF was elevated, implying that the relative contribution of fibrin formation and fibrin polymerization is essential.