Systolic Blood Pressure Variability is a Novel Risk Factor for Rebleeding in Acute Subarachnoid Hemorrhage: A Case–Control Study

Rebleeding of an aneurysm is a major cause of morbidity and mortality after subarachnoid hemorrhage (SAH). Whereas numerous studies have demonstrated predictors of rebleeding and effect of systolic blood pressure variability (SBPV) on stroke, few data on the association between SBPV and rebleeding. Here, we sought to identify the effect of SBPV on rebleeding in acute aneurysmal SAH. Case–control study. From January 2010 to June 2015, 612 patients with aneurysmal SAH were enrolled in our tertiary care medical center. Main outcome measures: Consecutive patients with acute (<3 days from ictus) aneurismal rebleeding or repair or death were retrospectively included. Antihypertensive therapy based on a predefined standardized protocol was prescribed to lower and maintain SBP between 120 and 160 mm Hg. SBP was measured hourly until a censoring event occurred. SBPV was determined as standard deviation (SD) and successive variation (SV). Binary logistic regression was used to assess the association between SBPV and rebleeding. Rebleeding occurred in 61 (10.0%) of the 612 patients. We identified 47 acute rebleeding as cases and 382 early repair or early death as controls. On binary logistic regression analysis, rebleeding was associated with the SD of SBP (odds ratio [OR], 1.254; 95% confidence interval [CI], 1.131–1.391; P < 0.001) and the SV of SBP (OR, 1.131; 95% CI, 1.039–1.231; P = 0.004). No significant difference was seen between rebleeding and mean systolic blood pressure (MSBP). SBPV is associated with increased rates of acute aneurysmal rebleeding. Further prospective research is warranted to confirm that SBP stability prevents acute aneurysm rebleeding.