Elsevier

Resuscitation

Volume 85, Issue 1, January 2014, Pages 88-95
Resuscitation

Clinical Paper
Early cardiac catheterization is associated with improved survival in comatose survivors of cardiac arrest without STEMI

https://doi.org/10.1016/j.resuscitation.2013.07.027Get rights and content

Abstract

Aim

To determine if early cardiac catheterization (CC) is associated with improved survival in comatose patients who are resuscitated after cardiac arrest when electrocardiographic evidence of ST-elevation myocardial infarction (STEMI) is absent.

Methods

We conducted a retrospective observational study of a prospective cohort of 754 consecutive comatose patients treated with therapeutic hypothermia (TH) following cardiac arrest.

Results

A total of 269 (35.7%) patients had cardiac arrest due to a ventricular arrhythmia without STEMI and were treated with TH. Of these, 122 (45.4%) received CC while comatose (early CC). Acute coronary occlusion was discovered in 26.6% of patients treated with early CC compared to 29.3% of patients treated with late CC (p = 0.381). Patients treated with early CC were more likely to survive to hospital discharge compared to those not treated with CC (65.6% vs. 48.6%; p = 0.017). In a multivariate regression model that included study site, age, bystander CPR, shock on admission, comorbid medical conditions, witnessed arrest, and time to return of spontaneous circulation, early CC was independently associated with a significant reduction in the risk of death (OR 0.35, 95% CI 0.18–0.70, p = 0.003).

Conclusions

In comatose survivors of cardiac arrest without STEMI who are treated with TH, early CC is associated with significantly decreased mortality. The incidence of acute coronary occlusion is high, even when STEMI is not present on the postresuscitation electrocardiogram.

Introduction

Cardiac arrest is a devastating manifestation of coronary artery disease, occurring in an estimated 382,000 Americans each year.1 In the minority of patients who achieve return of spontaneous circulation (ROSC) and survive to hospital admission, mortality rates ranging from 50% to 62% have been reported.2, 3 The high mortality rate is often due to the “post-cardiac arrest syndrome,” a complex condition characterized by multi-organ ischemic reperfusion injury, particularly in the brain and myocardium.4 Neurologic injury is a prominent feature of this syndrome, and is reported as the cause of death in the majority of patients who die in the hospital following a cardiac arrest.2 Therapeutic hypothermia (TH) is now an established and recommended therapy to improve neurologic outcome and survival in survivors of cardiac arrest from ventricular arrhythmias.5, 6, 7

Acute coronary syndromes (ACS) account for a significant proportion of cases of cardiac arrest in adults,8, 9 and several recent studies have shown that early cardiac catheterization (CC) and successful immediate percutaneous coronary intervention (PCI) are associated with improved survival following cardiac arrest.10, 11 However, many patients included in these studies had ST-elevation myocardial infarction (STEMI). While immediate CC and revascularization in the setting of STEMI is generally accepted as the standard of care following cardiac arrest,12 data on early CC in comatose post-arrest patients without evidence of STEMI are very limited. The selection of appropriate patients for early CC can be challenging in the absence of STEMI. The post-resuscitation electrocardiogram (ECG) is often unreliable, and ST-elevation has very poor sensitivity for the diagnosis of acute coronary occlusion in this setting.9, 10, 13

The aim of this study was to determine if early CC is associated with improved survival in comatose patients who are resuscitated after cardiac arrest due to ventricular arrhythmia when electrocardiographic evidence of STEMI is absent.

Section snippets

Study design

We conducted a retrospective observational study of a prospectively collected cohort of 754 consecutive comatose patients who survived to hospital admission following cardiac arrest. Study sites included six large tertiary care medical centers in the U.S. The study was approved by each center's Institutional Review Board with a waiver of consent due to the observational nature of the study. All sites participated in the International Cardiac Arrest Registry (INTCAR) (Appendix 1). Data have been

Results

Between January 2005 and November 2011, 754 encephalopathic patients were admitted to the six study sites following cardiac arrest (Fig. 1). Of these, 432 (57.3%) had a ventricular arrhythmia as their initial documented rhythm, and 556 (73.7%) had no ECG evidence of STEMI. A total of 269 patients (35.7%) had cardiac arrest due to a ventricular arrhythmia without STEMI, were treated with TH, and thus comprised the study population. Of these, 122/269 (45.3%) patients received early CC, and

Discussion

The principal finding of this study is that early cardiac catheterization is associated with significantly improved survival in comatose victims of cardiac arrest without STEMI. This study is important in that we studied a specific population of patients in whom there is no consensus regarding the appropriate timing of catheterization. While our findings are consistent with previous studies demonstrating that early CC and PCI are associated with reduced mortality following cardiac arrest,10, 11

Conclusions

In comatose survivors of cardiac arrest without STEMI, early CC is associated with significantly decreased mortality. A significant number of patients without STEMI were found to have acute coronary occlusion. It appears that patients without obstructive coronary lesions also benefit from early CC, possibly through the early facilitation of hemodynamic optimization in the cardiac catheterization lab. Additional studies are needed to determine the mechanism responsible for this association.

Conflict of interest statement

Kern serves as a consultant for Zoll Medical, Inc., and is a member of the Zoll Medical, Inc. scientific advisory board. McPherson has served as a consultant for Abbott Vascular Corporation, CardioDx, Inc., and Gilead Pharmaceuticals. All other authors declare that they have no conflicts of interest.

Acknowledgements

INTCAR is supported, in part, by the Scandinavian Society of Anesthesiology and Intensive Care, and the Stig and Ragna Gorthon Foundation.

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  • Cited by (0)

    A Spanish translated version of the summary of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2013.07.027.

    1

    These authors contributed equally to the writing of this paper.

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