Abstract 16659: Importance of Both Hypothermia and Early Reperfusion on Limiting Myocardial Infarct Size After Ventricular Fibrillation Cardiac Arrest and Acute Coronary Occlusion
Introduction: The post resuscitation ECG is unreliable in identifying acutely occluded culprit coronary arteries. AHA/ACCF 2013 STEMI guidelines strongly recommend (Class 1) early coronary reperfusion for the STEMI post cardiac arrest patient, combined with hypothermia if the patient is comatose, but make no comment about those without ST segment elevation on their post arrest ECG. Cohort studies have shown that 1/3 of all post cardiac arrest patients without ST elevation also have an acutely occluded coronary. However, some have suggested that early coronary angiography is not needed for the post resuscitated without ST elevation.
Hypothesis: The early use of hypothermia and reperfusion are both useful for minimizing myocardial infarct size after cardiac arrest.
Methods: The study utilized 20 swine (35±5kg). The animals were randomly assigned (2X2 study design) to one of four treatment groups: A) + Hypothermia & + Reperfusion; B) No Hypothermia & + Reperfusion; C)+ Hypothermia & No Reperfusion; D) No Hypothermia & No Reperfusion. The LAD was occluded by inflating the intracoronary balloon and VF was electrically induced. CPR was begun after 4 min of cardiac arrest. Defibrillation was initially attempted after 2 min of CPR. Reperfusion was performed after 45 min of LAD occlusion. At 4 hours myocardial infarct size was determined in all animals using standard technique with Evans Blue and TTC staining.
Results: Infarct size was smallest in those receiving both hypothermia and early reperfusion and largest in those receiving neither. Infarct size in those treated with hypothermia but not reperfusion was twice as large as those receiving both therapies.
Conclusions: Post resuscitation care should include early coronary angiography for potential emergent reperfusion while simultaneously providing hypothermia for both brain and myocardial protection. Early hypothermia while delaying coronary angiography is not optimal treatment of the post resuscitated patient.
Author Disclosures: K.B. Kern: Research Grant; Significant; Zoll Medical. Consultant/Advisory Board; Modest; PhysioControl Inc.. Consultant/Advisory Board; Significant; Zoll Medical. J. Hanna: None. H. Young: None. C. Hsu: None. M. Zuercher: None.
- © 2014 by American Heart Association, Inc.