1 Department of Clinical Medicine - The Department of Cardiological Medicine B, Department of Clinical Medicine, Health, Aarhus University2 Department of Cardiology, Lund University, 221 85, Lund, Sweden. Electronic address: email@example.com Department of Cardiology, Lund University, 221 85, Lund, Sweden.4 Dept of Cardiology & Dept of Emergency Medicine, Medical University of Vienna, Vienna, Austria.5 Center for Intensive Internal Medicine, Ljubliana, Slovenia.6 Institut for Klinisk Medicin7 Cardiology Unit, Dept of Medicine, Karolinska University Hospital, Stockholm, Sweden.8 Dept of Cardiology, Innsbruck, Austria.9 Uppsala Clinical Research Center and Department of Medical Sciences, Uppsala University, Uppsala, Sweden.10 Dept of Cardiology. Sahlgrenska University, Gothenburg, Sweden.11 Ph.d.-studienævnet for Medicin12 Department of Clinical Physiology, Lund University, Lund, Sweden.13 Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden.14 Department of Clinical Medicine - The Department of Cardiological Medicine B, Department of Clinical Medicine, Health, Aarhus University
a randomized controlled study of the use of central venous catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction
OBJECTIVES: The aim of this study was to confirm the cardioprotective effects of hypothermia using a combination of cold saline and endovascular cooling. BACKGROUND: Hypothermia has been reported to reduce infarct size (IS) in patients with ST-segment elevation myocardial infarctions. METHODS: In a multicenter study, 120 patients with ST-segment elevation myocardial infarctions (<6 h) scheduled to undergo percutaneous coronary intervention were randomized to hypothermia induced by the rapid infusion of 600 to 2,000 ml cold saline and endovascular cooling or standard of care. Hypothermia was initiated before percutaneous coronary intervention and continued for 1 h after reperfusion. The primary end point was IS as a percent of myocardium at risk (MaR), assessed by cardiac magnetic resonance imaging at 4 ± 2 days. RESULTS: Mean times from symptom onset to randomization were 129 ± 56 min in patients receiving hypothermia and 132 ± 64 min in controls. Patients randomized to hypothermia achieved a core body temperature of 34.7°C before reperfusion, with a 9-min longer door-to-balloon time. Median IS/MaR was not significantly reduced (hypothermia: 40.5% [interquartile range: 29.3% to 57.8%; control: 46.6% [interquartile range: 37.8% to 63.4%]; relative reduction 13%; p = 0.15). The incidence of heart failure was lower with hypothermia at 45 ± 15 days (3% vs. 14%, p < 0.05), with no mortality. Exploratory analysis of early anterior infarctions (0 to 4 h) found a reduction in IS/MaR of 33% (p < 0.05) and an absolute reduction of IS/left ventricular volume of 6.2% (p = 0.15). CONCLUSIONS: Hypothermia induced by cold saline and endovascular cooling was feasible and safe, and it rapidly reduced core temperature with minor reperfusion delay. The primary end point of IS/MaR was not significantly reduced. Lower incidence of heart failure and a possible effect in patients with early anterior ST-segment elevation myocardial infarctions need confirmation. (Efficacy of Endovascular Catheter Cooling Combined With Cold Saline for the Treatment of Acute Myocardial Infarction [CHILL-MI]; NCT01379261).
Journal of the American College of Cardiology, 2014, Vol 63, Issue 18, p. 1857-65