A pilot study of rapid cooling by cold saline and endovascular cooling before reperfusion in patients with ST-elevation myocardial infarction.
ABSTRACT 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.
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).
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.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00417638.
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ABSTRACT: Ultrafast and whole-body cooling can be induced by total liquid ventilation with temperature-controlled perfluorocarbons. Our goal was to determine whether this can afford maximal cardio- and neuroprotections through cooling rapidity when coronary occlusion is complicated by cardiac arrest. Prospective, randomized animal study. Academic research laboratory. Male New Zealand rabbits. Chronically instrumented rabbits were submitted to coronary artery occlusion and ventricular fibrillation. After 8 minutes of cardiac arrest, animals were resuscitated and submitted to a normothermic follow-up (control group) or to 3 hours of mild hypothermia induced by total liquid ventilation (total liquid ventilation group) or by combination of cold saline infusion and cold blankets application (saline group). Coronary reperfusion was permitted 40 minutes after the onset of occlusion. After awakening, rabbits were followed up during 7 days. Ten animals were resuscitated in each group. In the control group, all animals secondarily died of cardiac/respiratory failure (8 of 10) or neurological dysfunction (2 of 10). In the saline group, the target temperature of 32°C was achieved within 30-45 minutes after cooling initiation. This slightly reduced infarct size versus control (41% ± 16% vs 54% ± 8% of risk zone, respectively; p < 0.05) but failed to significantly improve cardiac output, neurological recovery, and survival rate (three survivors, six death from cardiac/respiratory failure, and one from neurological dysfunction). Conversely, the 32°C temperature was achieved within 5-10 minutes in the total liquid ventilation group. This led to a dramatic reduction in infarct size (13% ± 4%; p < 0.05 vs other groups) and improvements in cardiac output, neurological recovery, and survival (eight survivors, two deaths from cardiac/respiratory failure). Achieving hypothermia rapidly is critical to improve the cardiovascular outcome after cardiac arrest with underlying myocardial infarction.Critical care medicine 10/2013; · 6.37 Impact Factor
Article: Cardiogenic shock.[show abstract] [hide abstract]
ABSTRACT: Cardiogenic shock (CS) is a condition in which a marked reduction in cardiac output and inadequate end-organ perfusion results from an array of cardiac insults, the most common of which is acute myocardial infarction. CS is a systemic disease involving a vicious cycle of inflammation, ischemia, and progressive myocardial dysfunction, which often results in death. This life-threatening emergency requires intensive monitoring accompanied by aggressive hemodynamic support; other therapies are tailored to the specific pathophysiology. The development of novel therapeutic strategies is urgently required to reduce the unacceptably high mortality rates currently associated with CS.Cardiology clinics 11/2013; 31(4):567-80. · 1.25 Impact Factor
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ABSTRACT: The purpose of this study was to demonstrate the feasibility of a combined cooling strategy started out of hospital as an adjunctive to percutaneous coronary intervention (PCI) in the treatment of ST-elevation acute coronary syndrome (STE-ACS). Non-randomised, single-centre feasibility trial. Department of emergency medicine of a tertiary-care facility, Medical University of Vienna, Vienna, Austria. In cooperation with the Municipal ambulance service of the city of Vienna. Consecutive patients with STE-ACS presenting to the emergency medical service within 6 h after symptom onset. Cooling was initiated with surface cooling pads in the out-of-hospital setting, followed by the administration of 1000-2000 mL of cold saline at hospital arrival and completed by endovascular cooling in the catheterisation laboratory. Feasibility of lowering core temperature below 35.0°C prior to immediately performed revascularisation. Safety and tolerability of the cooling procedure. In enrolled 19 patients (one woman, median age 51 years (IQR 45-59)), symptom onset to first medical contact (FMC) was 45 min (IQR 31-85). A core temperature below 35.0°C at reperfusion of the culprit lesion was achieved in 11 patients (78%) within 100 min (IQR 90-111) after FMC without any cooling-related serious adverse event. Temperature could be lowered from baseline 36.4°C (IQR 36.2-36.5°C) to 34.4°C (IQR 34.1-35.0°C) at the time of reperfusion. With limitations an immediate out-of-hospital therapeutic hypothermia strategy was feasible and safe in patients with STE-ACS undergoing primary PCI. http://www.clinicaltrials.gov/ct2/show/NCT01864343; clinical trials unique identifier: NCT01864343.Heart (British Cardiac Society) 09/2013; · 5.01 Impact Factor