Decreased timing to vasospasm prophylaxis improves outcomes among patients with aneurysmal subarachnoid hemorrhage (aSAH) on prehospital CCBs, ARBs, or ACE-inhibitors.

Introduction: Aneurysmal subarachnoid hemorrhage (aSAH) patients are given calcium channel blockers (CCBs) to prevent brain vessel vasospasm. We hypothesized that preinjury antihypertensive use may protect against vasospasm. It remains unclear whether the timing of in-hospital CCB initiation affects the vasospasm risk in this population.

Methods: This retrospective cohort study included aSAH patients (≥18 y/o) at a Comprehensive Stroke Center (1/18-11/21). Patients taking prehospital antihypertensives [CCBs, Angiotensin-converting enzyme (ACE) inhibitors or Angiotensin II receptor blockers (ARBs)] were compared to those who were not. Results were stratified by patients receiving vasospasm prophylaxis ('in-hospital CCBs') ≤1.2 h of arrival vs. >1.2 h from arrival. Outcomes included vasospasm, hospital length of stay (LOS), and mortality.

Results: Of 251 patients, 18% were taking prehospital antihypertensives. Patients were comparable in baseline characteristics. There was no difference in the rate of vasospasm when compared by prehospital antihypertensive use. For those on prehospital antihypertensives, the time to in-hospital CCBs was significantly longer for patients who developed vasospasm than for those who did not (1.2 vs. 4.9 h, respectively, p = 0.02). For those on prehospital antihypertensives, receipt of in-hospital CCBs within 1.2 h of arrival was associated with a significantly lower vasospasm rate (6% vs. 39%, p = 0.03) and LOS (14 vs. 20 d, p = 0.01) when compared to receiving in-hospital CCBs > 1.2 h of arrival, respectively. The mortality rate (50% vs. 26%, p = 0.06) was statistically similar between groups, respectively. These results were not observed among patients who were not on prehospital antihypertensives. The timing to in-hospital CCB initiation had no effect on vasospasm (p = 0.23), death (p = 0.08), or LOS (p = 0.31) for patients not on prehospital antihypertensives.

Conclusions: Enhancing the efficiency of in-hospital CCB initiation for patients on prehospital antihypertensives may decrease the occurrence of vasospasm and lead to a shorter LOS.