TOPLINE

Among patients with in-hospital cardiac arrest, a maximum temperature of 36.8 °C to less than 37.3 °C in the first 24 hours after return of spontaneous circulation (ROSC) was associated with the highest rate of survival to hospital discharge, while both higher and lower temperature ranges were associated with progressively lower survival.

METHODOLOGY

• Using data from the Get With The Guidelines-Resuscitation registry, researchers analyzed adults who had an index in-hospital cardiac arrest and ROSC between 2015 and 2024 and survived at least 24 hours after resuscitation.
• A total of 36,514 patients were included; the mean age was 64.2 years, 61.8% were men, and 69.4% were White individuals.
• Patients who received therapeutic hypothermia after ROSC were excluded to better understand the natural history of postresuscitation temperature.
• Maximum temperature within 24 hours after ROSC was categorized by 0.5 °C intervals ranging from less than 36.3 °C to 38.8 °C or higher.
• The primary outcome was survival to hospital discharge; the secondary outcome was favorable neurological survival, defined as survival with a discharge Cerebral Performance Category score of 1 or 2.

TAKEAWAY

• The median maximum temperature was 37.2 °C; overall, 66.3% survived to hospital discharge.
• The temperature range of 36.8 °C to less than 37.3 °C (reference group) was associated with the highest survival rate (72.7%); all other temperature groups showed lower survival rates (P < .001), yielding an inverted U-shaped association.
• Patients in the lowest temperature range (less than 36.3 °C) had a survival rate of 48.4% (adjusted odds ratio [aOR], 0.42; P < .0001), while those in the highest range (38.8 °C or higher) had a survival rate of 51.5% (aOR, 0.40; P < .0001).
• Overall, 57.0% of patients had favorable neurological survival and the rates were highest (64.4%) in the reference temperature group. A similar inverted U-shaped pattern was seen for favorable neurological survival, with the lowest rates at the temperature extremes: 38.4% at temperatures below 36.3 °C (aOR, 0.38; P < .0001) and 40.2% at temperatures at or above 38.8 °C (aOR, 0.38; P < .0001).

IN PRACTICE

"Among patients successfully resuscitated from IHCA [in-hospital cardiac arrest] and not treated with therapeutic hypothermia, the highest survival was observed in those with a maximum temperature between 36.8 °C and 37.3 °C during the first 24 hours after ROSC compared with those with higher or lower postresuscitation temperature ranges," the authors concluded.

SOURCE

The study was led by Omar Cantu-Martinez, MD, MSc, Saint Luke's Mid America Heart Institute in Kansas City, Missouri. It was published online on August 20, 2026, in the Journal of the American Heart Association.

LIMITATIONS

Temperature measurements were limited to the maximum value within 24 hours, which may not have fully captured temperature variability or duration of exposure. Nearly one third of eligible patients were excluded because of missing temperature data. Participation in the registry was voluntary, which may have affected the generalizability of the findings.

DISCLOSURES

The Get With The Guidelines programs were provided by the American Heart Association. Four authors were supported by grants from the National Heart, Lung, and Blood Institute. One author reported consulting for Optum Rx and receiving funding from the American Heart Association; he recused himself from all scoring and decision-making related to this study's approval, in accordance with registry policy. Another author reported consulting relationships with multiple pharmaceutical and healthcare companies, research funding from two of them, and ownership of several widely used patient-reported outcome questionnaires. Full disclosures are reported in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.