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: Background Hypothermia has been reported to reduce infarct size (IS) in patients with ST segment elevation myocardial infarction (STEMI). We aimed to confirm the cardioprotective effects of hypothermia using a combination of cold saline and endovascular cooling. Methods In a multi-center study, 120 patients with STEMI (<6 hours) planned to undergo percutaneous coronary intervention were randomized to hypothermia induced by rapid infusion of 600-2000 ml of cold saline and endovascular cooling or standard of care. Hypothermia was initiated before PCI and continued for 1 hr. after reperfusion. The primary endpoint was IS as % of myocardium at risk (IS/MaR), assessed by cardiac magnetic resonance imaging at 4±2 days. Results Symptom to randomization was 129±56 vs. 132±64 minutes (mean±SD), hypothermia vs. control. Patients randomised to hypothermia achieved a core body temperature of 34.7°C before reperfusion with a 9 min longer door-to-balloon time. IS/MaR was not significantly reduced (hypothermia: 40.5, 29.3-57.8 vs. control: 46.6, 37.8-63.4 (%, interquartile range (IQR), 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 (0-4h) found reduction in IS/MaR of 33%, (p<0.05) and an absolute reduction of IS/left ventricular volume of 6.2%. (p=0.15). Conclusion Hypothermia induced by cold saline and endovascular cooling was feasible, safe, and rapidly reduced core temperature with minor reperfusion delay. The primary endpoint of IS/MaR was not significantly reduced. Lower incidence of heart failure and a possible effect among early anterior STEMI needs confirmation.Journal of the American College of Cardiology 01/2014; · 14.09 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: In order to determine the cardioprotective efficacy of acute reperfusion therapy, assessed as myocardial salvage, in patients with acute coronary occlusion, the final myocardial infarct (MI) size needs to be related to the amount of ischemic myocardium during coronary occlusion, referred to as the myocardium at risk (MaR). There are currently several imaging approaches suggested for available for quantification of both MI size and MaR in vivo of which some have been validated both in pre-clinical and clinical settings. These methods often involve the use of either myocardial perfusion SPECT or cardiac magnetic resonance (CMR). These imaging methods could potentially be used to further develop and validate ECG methods for determination of MI size and MaR. Therefore, the aim of the present review is to give an overview of myocardial perfusion SPECT and CMR methods available for assessment of myocardial salvage by determination of MI size and MaR.Journal of Electrocardiology. 01/2014;