HACA 2002.

Study characteristics
Methods	Study type: RCT Aim of the study: efficacy Participating sites: 9 university and community hospitals in 5 European countries Language: English Start date, end date: March 1996 to January 2001
Participants	Number randomised: 275 Inclusion criteria: in‐hospital and out‐of‐hospital bystander‐witnessed cardiac arrest of presumed cardiac cause, VF or non‐perfusing VT as first cardiac rhythm, comatose after resuscitation Exclusion criteria: a tympanic‐membrane temperature < 30 °C on admission, comatose state before the cardiac arrest due to the administration of drugs that depress the central nervous system, pregnancy, response to verbal commands after the ROSC and before randomisation, evidence of hypotension (mean arterial pressure, < 60 mmHg) for > 30 minutes after ROSC and before randomisation, evidence of hypoxaemia (arterial oxygen saturation, < 85%) for > 15 minutes after ROSC and before randomisation, terminal illness that preceded the arrest, factors that made participation in follow‐up unlikely, enrolment in another study, occurrence of cardiac arrest after arrival of emergency medical personnel, or a known pre‐existing coagulopathy Mean age: 59 years Women: 24% Cardiac arrest location: in‐hospital and out‐of‐hospital Cause of cardiac arrest: cardiac Primary cardiac rhythm: VF or non‐perfusing VT Witnessed cardiac arrest: 100% Bystander CPR: 46% Timing cardiac arrest (out‐of‐hospital cardiac arrest): total collapse time (minutes, mean): 22.79 (IQR 17–32) (intervention); 21 (IQR 15–28) (control) Temperature on admission/at start of cooling: 35.9 °C (intervention); 35.5 °C (control) Subgroups reported: participants who died within 6 months after discharge from hospital
Interventions	Number randomised: 137 (intervention); 138 (control) Prehospital cooling: no Target temperature intervention: 32–34 °C Duration of intervention (median): 24 hours Description of intervention: cooling blanket that covered the whole body and released cooled air Was intervention started within 2 hours after ROSC: yes Was target temperature reached within 4 hours of ROSC: no Co‐interventions: no Was rewarming controlled: no Rewarming rate (per protocol): 0.37 °C/hour Time from (minutes): ROSC to start of TTM: 105 ROSC to target temperature: 480
Outcomes	Best CPC of 1, 2 vs CPC of 3, 4, 5 for 6 months Mortality at 6 months, rate of complication during first 7 days after cardiac arrest (bleeding of any severity) Pneumonia, sepsis, pancreatitis, renal failure, pulmonary oedema, seizures, arrhythmias and pressure sores Best ever reached CPC during hospital stay and CPC discharge provided
Control group treatment	Participants randomly assigned to the normothermia group were placed on a conventional hospital bed, and normothermia was maintained.
Funding source	Grants from the Fourth Research and Technological Development (RTD) Framework Programme 1994 to 1998 of the European Union (Fourth Framework Programme), the Austrian Ministry of Science and Transport and the Austrian Science Foundation (FWF).
Notes	Randomisation: computer‐generated random sequence Centre‐specific subsets of this study are also published as Tiainen 2003 (70 participants), Tiainen 2005 (60 participants) and Tiainen 2007 (70 participants) with more detailed investigations of neuropsychological and laboratory outcomes.