Sensitivity of Serum D-dimer for Spontaneous Subarachnoid Hemorrhage

Abstract

Study Objective: Subarachnoid hemorrhage (SAH) activates the fibrinolytic system and increases serum D-dimer levels. These levels could prove diagnostically useful if reliably elevated in patients with SAH. Our goal was to calculate the sensitivity of serum D-dimer in detecting spontaneous subarachnoid hemorrhage.
Methods: We reviewed case records of all patients diagnosed with spontaneous SAH at our institution from 1990-2012. We excluded patients who had SAH from traumatic injuries, known intracranial pathology, as well as those having intracerebral hemorrhage. We recorded whether the D-dimer level was assessed in each patient, as well as the timing of the D-dimer measurement.
Results: We identified 368 patients who received a diagnosis of SAH, including 237 meeting inclusion criteria. One hundred eighty-five of these patients had a positive serum D-dimer after symptom onset, yielding a sensitivity of 78.1% (95% confidence interval (CI): 72.9-83.8%). Twenty-two patients had a serum D-dimer drawn within 12 hours of symptom onset, including 19 with positive D-dimer results, to yield a sensitivity of 86.4% (95% CI: 65.1-97.1).
Conclusions: Serum D-dimer levels exhibit high sensitivity among patients with spontaneous SAH. This finding warrants further investigation.