Survival outcomes in hypothermia and normothermia after cardiac arrest

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The following is a summary of “Hypothermia versus normothermia in cardiac arrest patients with shockable rhythm: a secondary analysis of the TTM-2 trial,” published in the October 2024 issue Intensive care by Taccone et al.

Researchers conducted a retrospective study to determine whether hypothermia resulted in higher survival and improved functional outcomes compared to normothermia in patients with OHCA. They focused on patients with characteristics like those in previous studies who had benefits with hypothermia.

They analyzed a subset of patients from a randomized clinical trial (TTM-2, NCT02908308) with similar characteristics to patients in a previous study, focusing on patients randomized to hypothermia at 33°C or normothermia (target).

The results showed that of 1,891 participants in the TTM-2 study, 600 (31.7%) were analyzed, including 294 in the hypothermia group and 306 in the normothermia group. At 6 months, survival rates were similar: 70.4% (207/294) in the hypothermia group and 71.8% (220/306) in the normothermia group (relative risk 0.96, 95% CI 0. 81–1.15; P = 0.71). Favorable functional outcomes were observed in 67.3% (198/294) in the hypothermia group and 66.0% (202/306) in the normothermia group (relative risk 1.03, 95% CI 0.87-1.23; P = 0.79). There was a significant increase in arrhythmias in the hypothermia group (21.2%, 62/294) compared to the normothermia group (14.1%, 43/306 – odds ratio 1.49, 95% CI 1, 05-2.14; P = 0.026).

They concluded that hypothermia at 33°C did not improve survival or functional outcomes in a subgroup of patients with similar cardiac arrest characteristics as those who benefited from hypothermia.

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-024-05119-3