A study of blood coagulation and fibrinolytic system in spontaneous subarachnoid hemorrhage: Correlation with hunt-hess grade and outcome

Abstract

BACKGROUND Subarachnoid hemorrhage (SAH) has been studied from various standpoints with the purpose of discovering criteria that might be useful in predicting the prognosis. In the literature a high incidence of coagulative and fibrinolytic disorders has been reported in SAH patients. A prospective study was performed to evaluate hemostatic plasmatic parameters in SAH patients. METHODS Hemostatic plasmatic parameters were prospectively studied in 76 patients with SAH. Both the coagulative (PT, APTT, fibrinogen, thrombin/antithrombin complex: TAT, and modified antithrombin III: MAT) and fibrinolytic ( d-dimer) plasmatic systems were evaluated. Von Willebrand factor was also tested. RESULTS PT, APTT, and fibrinogen were within normal limits. High TAT levels were associated with clinical outcome since 16 patients out of 27 (59%) with unfavorable outcomes displayed TAT levels >20 ngzaq/L, as compared with 10 patients out of 38 (26%) with favorable outcomes. Plasmatic d-dimer, an index of subarachnoid clot lysis, was invariably found to be elevated. Nevertheless, very high levels (>1000 mcg/mL) were found in 16 patients out of 22 (73%) with unfavorable outcomes but in only 9 patients out of 38 (26%) with favorable outcomes. Significant d-dimer elevation showed a strong association with severe delayed ischemic deficit (DID). Patients were also tested for von Willebrand factor, displaying a specific increase in all cases. CONCLUSION The study provides evidence for an early activation of the coagulation and fibrinolytic system following SAH. Increase of plasmatic TAT parallels clinical outcome. A generalized increase of d-dimer was observed as well and d-dimer levels in the high range were associated with clinical outcome and poor results with DID. Our analysis shows close statistical significance between plasma levels of TAT, d-dimer, and outcome. A similar statistical significance has been found when comparing other known prognostic factors such as clinical and cerebral computerized tomography scan (CT) grade and outcome.