Introduction: Plasma D-dimer levels elevate during acute stage of aneurysmal subarachnoid hemorrhage (SAH) and are associated with poor functional outcomes. However, the mechanism in which D-dimer elevation on admission affects functional outcomes remains unknown.
Hypothesis: We hypothesize that D-dimer levels on admission are correlated with systemic complications rather than neurological complications, and therefore have an additive predictive value on conventional risk factors for poor functional outcomes.
Methods: A total of 187 patients with aneurymal SAH were retrospectively analyzed from a single center, observational cohort database. Correlations of plasma D-dimer levels on admission with patients’ characteristics, initial presentation, neurological complications, and systemic complications were identified. We also evaluated additive value of D-dimer elevation on admission for poor functional outcomes by comparing predictive models with and without D-dimer.
Result and Conclusions: D-dimer elevation on admission was associated with increasing age, women, and severity of SAH. Patients with higher D-dimer levels had increased likelihood of nosocomial infections (OR 1.22 [95% CI 1.07-1.39], p = 0.004), serum sodium disorders (OR 1.11 [95% CI 1.01-1.23], p = 0.033), and cardiopulmonary complications (OR 1.20 [95% CI 1.04-1.37], p = 0.01) by multivariable analysis. D-dimer elevation was an independent risk factor of poor functional outcomes (modified Rankin scale 3-6, OR 1.50 [95% CI 1.15-1.95], p = 0.003). A novel prediction model with D-dimer had significantly better discrimination ability for poor outcomes than conventional models without D-dimer, evaluated by C statistics, net reclassification improvement, and integrated discrimination improvement methods. These results suggest that elevated D-dimer levels on admission were independently correlated with systemic complications, and had an additive value for outcome prediction on conventional risk factors after aneurysmal SAH.