Background: Spontaneous subarachnoid hemorrhage (SSAH) and nontraumatic acute headache patients presented with symptoms similar to headache. This study was to investigate the diagnostic value of D-dimer (DD) in distinguishing patients with SSAH from those with nontraumatic acute headache.
Methods: This retrospective study was performed and data were gathered from medical records of patients with acute headache symptoms from the Emergency Department and Neurology Clinics who were admitted to the Fourth Affiliated Hospital Zhejiang University School of Medicine between January 2015 and January 2019. Of the total 114 patients with headache symptoms enrolled in this study, 46 patients were diagnosed with SSAH (SAH group) and 68 cases with nontraumatic acute headache due to other causes (non-SAH group). The plasmatic levels of PT, INR, APTT, TT, FIB, and DD were compared between the two groups. Student’s t-test of independent samples was adopted for comparing the mean between the two groups. Model discrimination was evaluated using the area under the receiver operating characteristic curve (AUC). Comparison of AUC was performed using the Z-test.
Results: There were no significant statistical differences of the PT, INR, TT and FIB (all p > 0.05). The APTT was significantly decreased in the SSAH group compared with non-SAH group, while DD was significantly increased (all p < 0.001); moreover, AUC in distinguishing patients with SSAH from those with nontraumatic acute headache was 0.721 (95% confidence interval (CI), 0.629 to 0.801) for APTT and 0.886 (95% CI, 0.813 to 0.938) for DD. There was a significant statistical difference (p < 0.01). Finally, the cutoff values were 25.2s in distinguishing patients with SSAH from those with nontraumatic acute headache (specificity 73.53% and sensitivity 60.87%) for APTT and 0.31 mg/L (specificity 83.82% and sensitivity 84.78%) for DD.
Conclusions: As an easy-to-obtain and potential biomarker, DD could demonstrate more accurate and reliable diagnostic value than APTT in distinguishing between SSAH and nontraumatic acute headache.