Importance of Coronary Artery Disease in Sudden Cardiac Death

V entricular arrhythmias, pulseless electrical activity, and asystole can occur at the early stages of an acute coronary thrombotic occlusion, causing hemodynamic collapse, and resulting in “sudden cardiac death.” Recognizing this common pathway for adult cardiac arrest, the 2012 European Society of Cardiology (ESC) and the 2013 American College of Cardiology Foundation with the American Heart Association ST-segment elevation myocardial infarction (STEMI) guidelines recommended immediate angiography and percutaneous coronary intervention in resuscitated outof-hospital cardiac arrest (OHCA) patients whose electrocardiogram (ECG) shows ST-elevation (class I recommendation). However, clinical and electrocardiographic data alone are poor predictors for coronary artery occlusion in survivors of OHCAs. In a small, prospective study of 84 OHCA patients, Spaulding et al. showed that neither chest pain preceding arrest nor the presence of postresuscitation STEMI are independent predictors of an acute coronary occlusion. Nonrandomized studies suggested that OHCA patients, both with and without evidence of STEMI, have improved survival associated with early cardiac catheterization. This was generally defined as cardiac catheterization performed either immediately upon hospital arrival or during hypothermia treatment when the patients were comatose. The benefit was most transparent in those resuscitated OHCA victims without readily obvious noncardiac cause for their arrest. A retrospective, observational study by Hollenbeck et al. demonstrated that comatose OHCA patients with initial documented rhythm of ventricular arrhythmias, but without electrocardiographic criteria for STEMI postresuscitation, have a significantly better rate of survival (65.6% vs. 48.6%) and favorable neurological outcome (60.7% vs. 44.5%) independently associated with early cardiac catheterization. There appeared to be a high incidence of acute coronary artery occlusion regardless of ECG pattern. It was also observed that early cardiac catheterization provided improved outcomes in patients without obstructive coronary lesions, perhaps through early hemodynamic optimization or mechanical support, but possibly simply as a marker of more aggressive postresuscitation management. It may also trigger a more immediate search for other causes of OHCA once obstructive coronary disease has been ruled out. The European Association for Percutaneous Cardiovascular Interventions/Stent for Life group suggested an algorithm for OHCA survivors without STEMI ECG criteria. They recommended that the patients be evaluated in the emergency department or intensive care unit with selective and appropriate diagnostic tests to exclude noncoronary causes. If a cardiac etiology for the arrest cannot be ruled out, they recommended proceeding to coronary angiography with a view toward intervention if the culprit vessel is identified. If the decision is for coronary angiography, it should be performed immediately (ie, within 2 hours of admission). This recommendation was made in adherence to the 2011 ESC guidelines for management of high-risk non-STEMI acute coronary syndrome with emphasis on hemodynamically unstable patients and those with recurrent malignant ventricular arrhythmias. Stecker et al. report on, in this issue of the Journal of the American Heart Association (JAHA), the incidence of sudden cardiac death between February 1, 2002 and January 31, 2003 in a large, community-wide, prospective cohort study conducted in Multnomah County, Oregon, with a population of 660 000. They found that pre-existing coronary artery disease (lesions >50%) or previous myocardial infarction (MI) were associated with a 50% or greater increase in survival to discharge, compared to those without documented coronary artery disease (CAD). Pre-existing coronary disease was The opinions expressed in this article are not necessarily those of the editors or of the American Heart Association. From the Division of Cardiology, Sarver Heart Center, University of Arizona, Tucson, AZ. Correspondence to: Karl B. Kern, MD, FAHA, The Gordon A. Ewy, MD Distinguished Endowed Chair of Cardiovascular Medicine, Division of Cardiology, University of Arizona College of Medicine, 1501 N Campbell Ave, Tucson, AZ 85724. E-mail: [email protected] J Am Heart Assoc. 2014;3:e001339 doi: 10.1161/JAHA.114.001339. a 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.