Influence of temperature management at 33 °C versus normothermia on survival in patients with vasopressor support after out-of-hospital cardiac arrest: a post hoc analysis of the TTM-2 trial

Crit Care. 2022 Jul 31;26(1):231. doi: 10.1186/s13054-022-04107-9.

Abstract

Background: Targeted temperature management at 33 °C (TTM33) has been employed in effort to mitigate brain injury in unconscious survivors of out-of-hospital cardiac arrest (OHCA). Current guidelines recommend prevention of fever, not excluding TTM33. The main objective of this study was to investigate if TTM33 is associated with mortality in patients with vasopressor support on admission after OHCA.

Methods: We performed a post hoc analysis of patients included in the TTM-2 trial, an international, multicenter trial, investigating outcomes in unconscious adult OHCA patients randomized to TTM33 versus normothermia. Patients were grouped according to level of circulatory support on admission: (1) no-vasopressor support, mean arterial blood pressure (MAP) ≥ 70 mmHg; (2) moderate-vasopressor support MAP < 70 mmHg or any dose of dopamine/dobutamine or noradrenaline/adrenaline dose ≤ 0.25 µg/kg/min; and (3) high-vasopressor support, noradrenaline/adrenaline dose > 0.25 µg/kg/min. Hazard ratios with TTM33 were calculated for all-cause 180-day mortality in these groups.

Results: The TTM-2 trial enrolled 1900 patients. Data on primary outcome were available for 1850 patients, with 662, 896, and 292 patients in the, no-, moderate-, or high-vasopressor support groups, respectively. Hazard ratio for 180-day mortality was 1.04 [98.3% CI 0.78-1.39] in the no-, 1.22 [98.3% CI 0.97-1.53] in the moderate-, and 0.97 [98.3% CI 0.68-1.38] in the high-vasopressor support groups with regard to TTM33. Results were consistent in an imputed, adjusted sensitivity analysis.

Conclusions: In this exploratory analysis, temperature control at 33 °C after OHCA, compared to normothermia, was not associated with higher incidence of death in patients stratified according to vasopressor support on admission. Trial registration Clinical trials identifier NCT02908308 , registered September 20, 2016.

Keywords: Cardiac arrest; Heart arrest; Hypothermia induced; Mortality; Shock; Sudden.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cardiopulmonary Resuscitation* / methods
  • Epinephrine / therapeutic use
  • Humans
  • Hypothermia, Induced* / methods
  • Norepinephrine / therapeutic use
  • Out-of-Hospital Cardiac Arrest* / drug therapy
  • Temperature
  • Vasoconstrictor Agents / therapeutic use

Substances

  • Vasoconstrictor Agents
  • Norepinephrine
  • Epinephrine

Associated data

  • ClinicalTrials.gov/NCT02908308