Therapeutic hypothermia fails to benefit children surviving in-hospital cardiac arrest

Comatose children surviving in-hospital cardiac arrest did not have better 1-year survival with good functional outcome if treated with therapeutic hypothermia, according to results from the THAPCA-IH trial.

Researchers randomly assigned comatose children older than 48 hours and younger than 18 years who had in-hospital cardiac arrest at 37 centers to receive, within 6 hours after return of circulation, therapeutic hypothermia with a target temperature of 33°C or therapeutic normothermia with a target temperature of 36.8°C. They presented their findings at the Society of Critical Care Medicine’s Critical Care Congress and published them in The New England Journal of Medicine.

“This trial addresses pediatric cardiac arrest in a hospital setting, for which no previous data existed,” researcher Victoria Pemberton, RNC, MS, CCRC, program officer for the NHLBI, told Cardiology Today. “Children who arrest within the hospital differ from children who arrest outside of the hospital, in that they are more likely to have preexisting conditions, pre-arrest neurodevelopment and different etiologies for their arrest. Response times and quality of resuscitation differ as well.”

The primary efficacy outcome was survival at 12 months among patients with a score of at least 70 on the VABS-II scale before cardiac arrest.

Trial stopped early

Frank W. Moler, MD, from the University of Michigan, Ann Arbor, and colleagues reported that the trial was terminated for futility after 329 patients, 257 of whom could be evaluated for the primary outcome, were enrolled.

The decision to stop the trial was “primarily due to low conditional power to show a treatment effect,” Pemberton told Cardiology Today. “The positive aspect of this is that resuscitation within hospitals is improving with the advent of rapid response teams and increasing skills in [cardiopulmonary resuscitation], which led to fewer eligible patients … for this trial.”

Among those who could be evaluated for the primary efficacy outcome, the rate was 36% in the hypothermia group and 39% in the normothermia group (RR = 0.92; 95% CI, 0.67-1.27), according to the researchers.

Among the 317 patients who could be evaluated for change in VABS-II score, there was no difference between the group at 12 months (P = .7).

All but two patients were evaluated for survival at 1 year; the rates were 49% in the hypothermia group and 46% in the normothermia group (RR = 1.07; 95% CI, 0.85-1.34), according to the researchers.

“Preventing fever via an active intervention — either hypothermia or normothermia — may increase survival with good neurobehavioral outcome in children,” Pemberton told Cardiology Today.

Moler and colleagues also reported no differences between the groups in blood-product use, infection, serious adverse events and 28-day mortality.

Findings consistent

The findings “are consistent with those of recent trials investigating the efficacy of hypothermia vs. normothermia after out-of-hospital cardiac arrest,” the researchers wrote.

In the future, “investigation of a shorter therapeutic window to attain goal temperature is warranted, although may be difficult to achieve,” Pemberton said in an interview. “A study of different durations of temperature control with or without neuroprotective pharmaceutical agents might be considered.” – by Erik Swain

References:

Moler FW, et al. Hot Topics and Late-Breaking Science II: Hold the Press, Late-Breaking Journal Articles. Presented at: Society of Critical Care Medicine’s Critical Care Congress; Jan. 20-25, 2017; Honolulu.

Moler FW, et al. N Engl J Med. 2017;doi:10.1056/NEJMoa1610493.

Disclosure: Moler and Pemberton report no relevant financial disclosures. Please see the full study for a list of the other researchers’ relevant financial disclosures.