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.