The Official Journal of EuroPCR and the European Association of Percutaneous Coronary Interventions (EAPCI)

A multicentre, prospective, randomised controlled trial to assess the safety and effectiveness of cooling as an adjunctive therapy to percutaneous intervention in patients with acute myocardial infarction: the COOL AMI EU Pivotal Trial

LBT. DOI: 10.4244/EIJ-D-21-00348

1. University Medical Centre Ljubljana, Ljubljana, Slovenia
2. North-Estonia Medical Centre Foundation, Tallinn, Estonia
3. Clinical Hospital Center Zemun, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
4. Institute of Cardiovascular Diseases of Vojvodina, Sremska Kamenica, Faculty of Medicine, Novi Sad, Serbia
5. University Clinical Center of the Republic of Srpska, Medical Faculty of University of Banja Luka, Banja Luka, Bosnia
6. Heart Center, Balatonfüred, Hungary
7. Military Hospital, Budapest, Hungary
8. University of Szeged, Szeged, Hungary
9. Heart and Vascular Center, Semmelweis University, Budapest, Hungary
10. Stredoslovenski Ustav Srdcovych a Cievnych Chorob, Banska Bystrica, Slovakia
11. Kardiocentrum Nitra s.r.o., Nitra, Slovakia
12. Department of Cardiology, Health Faculty of Medicine, University of Pecs, Hungary
13. Essex Cardiothoracic Centre, Basildon and Thurrock University Hospital NHS Foundation Trust, Basildon, UK
14. Clinical Center of Serbia, Belgrade, Serbia
15. Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
16. University Hospital of Internal Medicine lll/Cardiology and Angiology, Medical University Innsbruck, Innsbruck, Austria
17. The Cardinal Stefan Wyszynski Institute of Cardiology, Warshaw, Poland
18. Pauls Stradins Clinical University Hospital, University of Latvia, Riga, Latvia
19. University Medical Center, Ljubljana, Slovenia
20. Borsod-Abauj-Zemplen County Central Hospital and University Teaching Hospital, 1st Department of Internal Medicine and Cardiology, Miskolc, Miskolc, Hungary
21. University Hospital Center Zagreb, Zagreb, Croatia
22. Department of Cardiology, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, Debrbrecen, Hungary
23. Silesian Center for Heart Diseases, Department of Cardiology, Medical University of Silesia, DMS in Zabrze, Poland
24. Department of Cardiology, Lund University, Clinical Sciences, Skane University Hospital, Lund, Sweden
25. Essex Cardiothoracic Centre, Basildon and Thurrock University Hospital NHS Foundation Trust, Basildon, and Anglia Ruskin School of Medicine, Chelmsford, Essex, UK
26. Essex Cardiothoracic Centre, Basildon and Thurrock University Hospital NHS Foundation Trust, Basildon, UK; Anglia Ruskin School of Medicine, Chelmsford, Essex, UK. Medical University in Łódź, Bieganski Hospital, Łódź, Poland

Background: Despite primary PCI (PPCI), STEMI can still result in large infarct size (IS). New technology with rapid intravascular cooling showed positive signal for reduction in IS in anterior STEMI.

Aims: We investigated the effectiveness and safety of rapid systemic intravascular hypothermia as an adjunct to primary PCI (PPCI) in conscious patients with anterior ST-elevation myocardial infarction (STEMI) without cardiac arrest.

Methods: Hypothermia was induced using ZOLL® Proteus™ Intravascular Cooling System. After randomization of 111 patients, 58 to hypothermia and 53 to control groups, the study was prematurely discontinued by the sponsor due to inconsistent patient logistics between the groups resulting in significantly longer total ischemic delay in hypothermia group (232 vs 188 minutes; p <0.001).

Results: There were no differences in angiographic features and PPCI result between the groups. Intravascular temperature at wire crossing was 33.3+0.9°C. Infarct size/left ventricular mass (IS/LV) by cardiac magnetic resonance (CMR) at day 4-6 was 21.3% in hypothermia group and 20.0% in control group (p=0.540). Major adverse cardiac events (MACE) at 30 days were non significantly increased in hypothermia group (8.6% vs 1.9%; p=0.117) while cardiogenic shock (10.3% vs 0%; p=0.028) and paroxysmal atrial fibrillation (43.1% vs 3.8%; p<0.001) were significantly more frequent in hypothermia group.

Conclusion: Intravascular ZOLL TM Proteus Cooling System reduced temperature to 33.3oC before PPCI in patients with anterior STEMI. Due to inconsistent patient logistics between the groups, this hypothermia protocol resulted in longer ischemic delay, did not reduce IS/LV mass and was associated with increased adverse events.

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