A pilot study of rapid cooling by cold saline and endovascular cooling before reperfusion in patients with ST-elevation myocardial infarction.
BACKGROUND
Experimental studies have shown that induction of hypothermia before reperfusion of acute coronary occlusion reduces infarct size. Previous clinical studies, however, have not been able to show this effect, which is believed to be mainly because therapeutic temperature was not reached before reperfusion in the majority of the patients. We aimed to evaluate the safety and feasibility of rapidly induced hypothermia by infusion of cold saline and endovascular cooling catheter before reperfusion in patients with acute myocardial infarction.


RESULTS
Twenty patients with acute myocardial infarction scheduled to undergo primary percutaneous coronary intervention were enrolled in this prospective, randomized study. After 4 ± 2 days, myocardium at risk and infarct size were assessed by cardiac magnetic resonance using T2-weighted imaging and late gadolinium enhancement imaging, respectively. A core body temperature of <35°C (34.7 ± 0.3°C) was achieved before reperfusion without significant delay in door-to-balloon time (43 ± 7 minutes versus 40 ± 6 minutes, hypothermia versus control, P=0.12). Despite similar duration of ischemia (174 ± 51 minutes versus 174 ± 62 minutes, hypothermia versus control, P=1.00), infarct size normalized to myocardium at risk was reduced by 38% in the hypothermia group compared with the control group (29.8 ± 12.6% versus 48.0 ± 21.6%, P=0.041). This was supported by a significant decrease in both peak and cumulative release of Troponin T in the hypothermia group (P=0.01 and P=0.03, respectively).


CONCLUSIONS
The protocol demonstrates the ability to reach a core body temperature of <35°C before reperfusion in all patients without delaying primary percutaneous coronary intervention and that combination hypothermia as an adjunct therapy in acute myocardial infarction may reduce infarct size at 3 days as measured by MRI.


BACKGROUND
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00417638.
Götberg
Matthias
M
Department of Coronary Heart Disease, Skane University Hospital, Lund University, Lund, Sweden.
Olivecrona
Göran K
GK
Koul
Sasha
S
Carlsson
Marcus
M
Engblom
Henrik
H
Ugander
Martin
M
van der Pals
Jesper
J
Algotsson
Lars
L
Arheden
Håkan
H
Erlinge
David
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D017130:Angioplasty; D001831:Body Temperature; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D010865:Pilot Projects; D015424:Reperfusion; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage; D020107:Troponin T / Q000378:metabolism
D012462:Saline Solution, Hypertonic; D020107:Troponin T