Targeted temperature management (TTM) has been used to improve neurological recovery in comatose patients after out-of-hospital cardiac arrest (OHCA). Hypertension (HTN) existing before a cardiac arrest represents a risk of OHCA, but it is not known whether it affects neurological prognosis. This study aimed at investigating the effect of TTM on neurological recovery in OHCA patients with or without underlying HTN. This study was conducted by using the national cardiac arrest registry of OHCA patients with presumed cardiac etiology between 2009 and 2016. The endpoint was cerebral performance category (CPC) 1 and 2 at discharge. We compared outcomes between the TTM and non-TTM groups by using multivariable logistic regression with an interaction term between TTM and HTN for calculating adjusted odd ratios (AORs) and 95% confidence intervals (CIs) after adjusting for potential confounders. Among the 25,985 patients with OHCA who survived till hospital admission, TTM was performed on 12.2%. The TTM group showed better outcomes than the non-TTM group: 28.1% versus 15.5% for good neurologic recovery (p < 0.01). The AOR of TTM for good neurological recovery for all study groups was 1.65 (1.47-1.85). In the interaction model, the AOR of TTM for good neurological recovery was 1.87 (1.26-2.76) in patients without HTN and 0.87 (0.75-1.02) in patients with HTN. The underlying HTN modified the effect of TTM on neurological outcomes for OHCA patients. TTM is associated with good neurological recovery in patients without HTN, but not in patients with HTN.
Keywords: cardiac arrest; hypertension; targeted temperature management.