Out-of-hospital initiation of hypothermia in ST-segment elevation myocardial infarction: a randomised trial

Heart. 2019 Apr;105(7):531-537. doi: 10.1136/heartjnl-2018-313705. Epub 2018 Oct 25.


Objective: To evaluate the effect of prereperfusion hypothermia initiated in the out-of-hospital setting in awake patients with ST-segment elevation myocardial infarction (STEMI) on myocardial salvage measured by cardiac MRI (CMR).

Methods: Hypothermia was initiated within 6 hours of symptom onset by the emergency medical service with surface cooling pads and cold saline, and continued in the cath lab with endovascular cooling (target temperature: ≤35°C at time of reperfusion). Myocardial salvage index (using CMR) was compared in a randomised, controlled, open-label, endpoint blinded trial to a not-cooled group of patients at day 4±2 after the event.

Results: After postrandomisation exclusion of 19 patients a total of 101 patients were included in the intention-to-treat analysis (control group: n=54; hypothermia group: n=47). Target temperature was reached in 38/47 patients (81%) in the intervention group. Study-related interventions resulted in a delay in time from first medical contact to reperfusion of 14 min (control group 89±24 min; hypothermia group 103±21 min; p<0.01). Myocardial salvage index was 0.37 (±0.26) in the control group and 0.43 (±0.27) in the hypothermia group (p=0.27). No differences in cardiac biomarkers or clinical outcomes were found. In a CMR follow-up 6 months after the initial event no significant differences were detected.

Conclusion: Out-of-hospital induced therapeutic hypothermia as an adjunct to primary percutaneous coronary intervention did not improve myocardial salvage in patients with STEMI.

Trial registration number: NCT01777750.

Keywords: acute myocardial infarction; percutaneous coronary intervention.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Emergency Medical Services / methods*
  • Female
  • Humans
  • Hypothermia, Induced / methods*
  • Magnetic Resonance Imaging, Cine / methods
  • Male
  • Middle Aged
  • Myocardium / pathology*
  • Percutaneous Coronary Intervention / methods*
  • Preoperative Care / methods*
  • ST Elevation Myocardial Infarction* / diagnosis
  • ST Elevation Myocardial Infarction* / therapy
  • Time-to-Treatment
  • Treatment Outcome

Associated data

  • ClinicalTrials.gov/NCT01777750