AbstractBackgroundHypertension induction (HTI) is often used for treating delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH); however, high‐quality studies on its efficacy are lacking. We studied immediate and 3−/6‐month clinical efficacy of HTI in aSAH patients with clinical DCI.MethodsA retrospective, multicenter, comparative, observational cohort study in aSAH patients with clinical deterioration due to DCI, admitted to three tertiary referral hospitals in the Netherlands from 2015 to 2019. Two hospitals used a strategy of HTI (HTI group) and one hospital had no such strategy (control group). We calculated adjusted relative risks (aRR) using Poisson regression analyses for the two primary (clinical improvement of DCI symptoms at days 1 and 5 after DCI onset) and secondary outcomes (DCI‐related cerebral infarction, in‐hospital mortality, and poor clinical outcome [modified Rankin Scale 4–6] assessed at 3 or 6 months), using the intention‐to‐treat principle. We also performed as‐treated and per‐protocol analyses.ResultsThe aRR for clinical improvement on day 1 after DCI in the HTI group was 1.63 (95% CI 1.17–2.27) and at day 5 after DCI 1.04 (95% CI 0.84–1.29). Secondary outcomes were comparable between the groups. The as‐treated and per‐protocol analyses yielded similar results.ConclusionsNo clinical benefit of HTI is observed 5 days after DCI due to spontaneous reversal of DCI symptoms in patients treated without HTI. The 3−/6‐month clinical outcome was similar for both groups. Therefore, these data suggest that one may consider to not apply HTI in aSAH patients with clinical DCI.