Aneurysm rebleeding after poor-grade aneurysmal subarachnoid hemorrhage: Predictors and impact on clinical outcomes

Aneurysm rebleeding is a major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH) and more often occurs in patients with poor-grade aSAH. Limited data on predictors of rebleeding in these patients are available.To investigate predictors of aneurysm rebleeding after poor-grade aSAH and the association of rebleeding with clinical outcomes.A multicenter poor-grade aneurysm study was a prospective and observational registry of consecutive patients who presented with poor-grade aSAH defined as a World Federation of Neurosurgical Societies (WFNS) grade of IV or V. Rebleeding was defined as a new hemorrhage on computed tomography scan. Clinical outcomes were assessed with modified Rankin score. Multivariate logistic regression analyses were used to determine independent predictors of rebleeding and association between the rebleeding and clinical outcomes at 12months.Of the 297 patients included in this study, 30 (10.1%) patients experienced rebleeding. Most rebleeding occurred within 24h after ictus. 22 (73.3%) patients died at discharge. Aneurysm rebleeding was independently associated with poor outcome (odds ratio [OR] 36.37, p<0.001) and associated with mortality (OR 25.03, p<0.001) at 12months. The multivariate analysis showed that a lower Fisher grade (OR 0.49, 95% CI 0.31-0.77; p=0.002), ruptured anterior cerebral artery aneurysms (OR 4.26, 95% CI 1.07-16.90; p=0.039), external ventricular drainage (OR 4.62, 95% CI 1.46-14.59; p=0.009) were independently associated with aneurysm rebleeding.The outcome of aneurysm rebleeding remains very poor. A lower Fisher grade, ruptured anterior cerebral artery aneurysms, external ventricular drainage were associated with increased risk of rebleeding.