Targeted Temperature Management After In-Hospital Cardiac Arrest: An Ancillary Analysis of Targeted Temperature Management for Cardiac Arrest With Nonshockable Rhythm Trial Data

Abstract

Targeted temperature management (TTM) currently is the only treatment with demonstrated efficacy in attenuating the harmful effects on the brain of ischemia-reperfusion injury after cardiac arrest. However, whether TTM is beneficial in the subset of patients with in-hospital cardiac arrest (IHCA) remains unclear. Is TTM at 33 °C associated with better neurological outcomes after IHCA in a nonshockable rhythm compared with targeted normothermia (TN; 37 °C)? We performed a post hoc analysis of data from the published Targeted Temperature Management for Cardiac Arrest with Nonshockable Rhythm randomized controlled trial in 584 patients. We included the 159 patients with IHCA; 73 were randomized to 33 °C treatment and 86 were randomized to 37 °C treatment. The primary outcome was survival with a good neurologic outcome (cerebral performance category [CPC] score of 1 or 2) on day 90. Mixed multivariate adjusted logistic regression analysis was performed to determine whether survival with CPC score of 1 or 2 on day 90 was associated with type of temperature management after adjustment on baseline characteristics not balanced by randomization. Compared with TN for 48 h, hypothermia at 33 °C for 24h was associated with a higher percentage of patients who were alive with good neurologic outcomes on day 90 (16.4%vs5.8%; P= .03). Day 90 mortality was not significantly different between the two groups (68.5%vs76.7%; P= .24). By mixed multivariate analysis adjusted by Cardiac Arrest Hospital Prognosis score and circulatory shock status, hypothermia was associated significantly with good day 90 neurologic outcomes (OR, 2.40 [95%CI, 1.17-13.03]; P= .03). Hypothermia at 33 °C was associated with better day 90 neurologic outcomes after IHCA in a nonshockable rhythm compared with TN. However, the limited sample size resulted in wide CIs. Further studies of patients after cardiac arrest resulting from any cause, including IHCA, are needed.