Optimal subarachnoid hemorrhage treatment occurs within 12.5 hours of symptom onset

Surgical treatment at approximately 12.5 hours after aneurysmal subarachnoid hemorrhage correlated with improved outcomes, according to results of a cohort study published in JAMA Network Open.

“Neurosurgical or endovascular treatment within 24, 48 or 72 hours of onset has been associated with improved clinical outcomes,” Marie-Jeanne Buscot, PhD, of the Menzies Institute for Medical Research at the University of Tasmania in Australia, and colleagues wrote. “However, the data are heterogenous, with a significant risk of bias from the subjective stratification of timing, restriction to one treating center or treatment type, and exclusion of some groups of patients (eg, poor grade or transfers). Robust evidence on the optimal timing of surgery is therefore still lacking.”

Buscot and colleagues aimed to examine the optimal onset-to-treatment time following aneurysmal subarachnoid hemorrhage to maximize patients’ surgical outcomes. They included 575 retrospectively identified cases of first-ever aneurysmal subarachnoid hemorrhage reported within the referral networks of two major tertiary hospitals in Australia between January 2010 and December 2016. Onset-to-treatment time, or the time between onset of symptoms and aneurysm surgical treatment in hours, derived via medical records served as the main exposure.

Further, Buscot and colleagues used clinical characteristics, complications and discharge destination, which they extracted from medical records, as well as 12-month survival obtained via data linkage, as the main outcomes and measures. They examined whether associations existed between onset-to-treatment time and discharge destination of survivors, 12-month survival and neurologic complications, including rebleed, delayed cerebral ischemia, meningitis, seizure, hydrocephalus and delayed cerebral injury.

Among 575 patients with aneurysmal subarachnoid hemorrhage, researchers assessed 482 (mean age, 55 years; 69.9% women) who received endovascular coiling or neurosurgical clipping. They reported a nonlinear association between treatment delay and likelihood of being discharged home vs. rehabilitation. A similar nonlinear association remained significant after they adjusted for sex, treatment modality, severity, Charlson Comorbidity Index, hypertension history and hospital transfer. Further, they observed in both unadjusted and adjusted cox regression models a nonlinear association between time to treatment and 12-month mortality with the lowest risk for death with receipt of treatment at 12.5 hours following symptom onset; however, the nonlinear term became nonsignificant after adjustment. Likelihood of being discharged home increased with treatment before 20 hours after onset, with the likelihood of being discharged home vs. rehabilitation or other hospitalization increased by approximately 10% when treatment receipt occurred within the first 12.5 hours following symptom onset and increased by a further 5% from 12.5 to 20 hours. Researchers found no associations between time to treatment and any complications.

“This cohort study suggests that treatment for aneurysmal [subarachnoid hemorrhage] should ideally be provided within 12.5 hours after onset but not beyond 24 hours, because this results in improved 12-month survival and a greater likelihood of discharge home, independent of severity of the aneurysmal [subarachnoid hemorrhage] and other confounders,” Buscot and colleagues wrote. “Too few people with aneurysmal [subarachnoid hemorrhage] are treated within the 12.5- or 24-hour window associated with the best outcomes. Interventions to reduce time to treatment may be warranted if these findings are confirmed in other cohorts.”