An interventional study of Induced hypothermia at 33°C and Control normothermia in Cardiac Arrest, sponsored by Nantes University Hospital. Recruiting at 31 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-17.
Sponsored by Nantes University Hospital · Not applicable, Interventional, and Treatment
The IH-TTM trial is designed to determine whether survival with a favorable neurological outcome is improved by induced hypothermia at 33°C in comatose critically ill patients admitted after resuscitated in-hospital cardiac arrest (IHCA). Recent evidence suggests that targeted temperature management (TTM) at 33°C may provide no survival benefits compared to controlled normothermia in unselected patients with out-of-hospital cardiac arrest (OHCA). However, this evidence is relevant only to OHCA of presumed cardiac origin, chiefly witnessed and immediately followed by resuscitation efforts. Only scant data are available for cardiac arrest (CA) of other origins and for IHCA.
In a randomized clinical trial of patients with CA in an initial non-shockable rhythm, the subgroup with IHCA had significantly better outcomes when treated with TTM at 33°C versus controlled normothermia; nevertheless, the sample size was limited. Another randomized controlled trial done specifically in patients with IHCA failed to show benefits of TTM at 33°C compared to controlled normothermia but was underpowered. Thus, whether therapeutic hypothermia is indicated after IHCA remains unclear. IH-TTM will be the largest trial assessing TTM after IHCA.
926 studies on the registry are indexed under Heart Arrest; 226 are open to participants now.
This study's planned enrollment of 788 is above the median of 100 across 518 interventional studies indexed under Heart Arrest.
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Inclusion Criteria:
Exclusion Criteria:
Other: Induced hypothermia at 33°C
Other: Control normothermia
Cooling and maintenance phase : The aim is to achieve the target temperature of 33±0.5°C within 60 minutes after randomization. The target temperature of 33±0.5°C and device setting of 33°C will be maintained until 28 hours after randomization. \- Rewarming: Normothermia will be restored by gradual rewarming at a rate of 0.2°C/h. \- After rewarming: After 40 hours, in those participants who are still comatose or sedated, normothermia (36.5-37.7°C) will be maintained until 72 hours after randomization, and active warming will be avoided.
Participants whose initial temperature is below 33°C may be actively rewarmed to 36.5°-37.7°C, at which point active rewarming will be stopped and passive rewarming performed according to the latest guidelines. Participants whose initial temperature is above 33°C will not be actively rewarmed to normothermia. The goal will be to maintain temperature no higher than 37.8°C. After 40 hours, in those participants who are still comatose or sedated, normothermia (36.5-37.7°C) will be maintained until 72 hours after randomization, and active warming will be avoided.
To assess whether induced hypothermia (TTM at 33°C) is superior to targeted normothermia in providing a favorable neurological outcome, defined as a modified Rankin Scale (mRS) score of 0 to 3 at 6 months.
The primary endpoint is a favorable neurological outcome at 6 months, defined as an mRS score between 0 and 3.
Time frame: 6 months after randomization
All-cause mortality 2 months after randomization
Causes of death (refractory hemodynamic shock, life-support withdrawal for neurological reasons, life-support withdrawal due to comorbidities, respiratory failure, sudden cardiac death, brain death)
Time frame: 2 months after randomization
All-cause mortality 3 months after randomization
Causes of death (refractory hemodynamic shock, life-support withdrawal for neurological reasons, life-support withdrawal due to comorbidities, respiratory failure, sudden cardiac death, brain death)
Time frame: 3 months after randomization
All-cause mortality 4 months after randomization
Causes of death (refractory hemodynamic shock, life-support withdrawal for neurological reasons, life-support withdrawal due to comorbidities, respiratory failure, sudden cardiac death, brain death)
Time frame: 4 months after randomization
All-cause mortality 6 months after randomization
Causes of death (refractory hemodynamic shock, life-support withdrawal for neurological reasons, life-support withdrawal due to comorbidities, respiratory failure, sudden cardiac death, brain death)
Time frame: 6 months after randomization
ICU lengths of stay
Time frame: from day of randomization until the day of discharge from ICU, an average of 20 days.
Hospital lengths stay
Time frame: from day of randomization until the day of discharge from hospital, an average of 20 days.
Neurological outcome measured by modified Rankin Scale (mRS) score, ranging from 0 to 6 at 2 months after randomization
Time frame: 2 months after randomization
Neurological outcome measured by modified Rankin Scale (mRS) score, ranging from 0 to 6 at 3 months after randomization
A score of 0 to 3 is considered a favorable neurological outcome.
Time frame: 3 months after randomization
Neurological outcome measured by modified Rankin Scale (mRS) score ranging from 0 to 6 at 4 months after randomization
A score of 0 to 3 is considered a favorable neurological outcome.
Time frame: 4 months after randomization
Mechanical ventilation duration
A score of 0 to 3 is considered a favorable neurological outcome.
Time frame: from time of randomization to final extubation or up to 28 days
Biomarkers concentration : neuron-specific enolase (NSE) on day 0
Time frame: at day 0
Biomarkers concentration : neuron-specific enolase (NSE) on day 2
Time frame: at day 2
Biomarkers concentration : neuron-specific enolase (NSE) on day 3
Time frame: at day 3
Biomarkers concentration : neurofilament light chain (NFL) on day 2
Time frame: at day 2
Health-related quality of life (HRQoL) assessed using the 36-item Short Form Health Survey (SF-36) 6 months after randomization
Time frame: 6 months after randomization
Cognitive dysfunction assessed using the Montreal Cognitive Assessment (MoCA) 6 months after randomization
Time frame: 6 months after randomization
Complications during ICU stay : nosocomial infections
Time frame: from day of randomization until the day of discharge from ICU, or up to 28 days.
Complications during ICU stay : severe arrhythmias
Time frame: from day of randomization until the day of discharge from ICU, or up to 28 days.
Complications during ICU stay : venous thromboembolism
Time frame: from day of randomization until the day of discharge from ICU, or up to 28 days.
Complications during ICU stay : ischemic complications
Time frame: from day of randomization until the day of discharge from ICU, or up to 28 days.
Complications during ICU stay : sedations complications
Time frame: from day of randomization until the day of discharge from ICU, or up to 28 days.
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