Original Contribution
Effects of emergency department boarding on mortality in patients with ST-segment elevation myocardial infarction

https://doi.org/10.1016/j.ajem.2019.158400Get rights and content

Abstract

Objective

Patients with ST-segment elevation myocardial infarction (STEMI) are sometimes boarded in the emergency department (ED) after percutaneous coronary intervention (PCI). We evaluated the effects of direct and indirect admission to the CCU on mortality and the effect on length of stay (LOS) in patients with STEMI.

Method

This was a retrospective observational study of patients with STEMI between Jan 2014 and Nov 2017. The patients were divided into the direct admission (DA) group, who were admitted into the CCU immediately after PCI, and the indirect admission (IA) group, who were admitted after boarding in the ED. The primary endpoint was in-hospital mortality. Secondary endpoints were 3-month mortality, LOS in CCU and hospital, and LOS under intensive care.

Results

During the study period, 780 patients were enrolled and analyzed. The in-hospital mortality rate and 3-month mortality rate were 5.9% (46 patients) and 8.5% (66 patients). The DA group and IA group had similar in-hospital and 3-month mortality rates (P = .50, P = .28). The median CCU LOS and hospital LOS was similar for both groups (P = .28, P = .46). However, LOS under in intensive care for the IA group was significantly longer than that of the DA group (DA, 31.9 h; IA, 38.7 h; P < .001).

Conclusion

This study suggests that direct admission after PCI and indirect admission was not associated with mortality in patients with STEMI. In addition, the stay in ED also appears to be associated with the duration of stay under critical care.

Introduction

Ischemic heart disease is a major cause of death worldwide [1]. ST-segment elevation myocardial infarction (STEMI) is the most severe form of ischemic heart disease [2]. Patients with STEMI require rapid reperfusion therapy, such as percutaneous coronary intervention (PCI) or fibrinolytic therapy, within 12 h of the onset of symptoms [1,3]. Patients undergoing reperfusion therapy must be admitted for observation and treatment, but many patients are boarded in the emergency department (ED) due to limited availability of the coronary care unit (CCU) or an equivalent unit bed [1,4]. Hence, the ED serves as an area for post-reperfusion treatment as well as initial treatment for patients with STEMI.

A few studies have assessed boarding of patients with myocardial infarction (MI) in the ED. [[5], [6], [7]] They showed that boarding in the ED did not affect mortality rates in patients with MI. One study reported similar mortality rates in three groups of patients with MI who were admitted to the CCU, intermediate care unit, and ward after at least 24 h of ED boarding [5]. However, most patients who were admitted to the intermediate care unit and ward after 24 h of ED boarding did not undergo reperfusion therapy and did not show ST elevation in an electrocardiogram. Another study demonstrated that a length of stay (LOS) in the ED of >8 h after reperfusion therapy was not associated with mortality in patients with STEMI [6]. This 8 h criterion was based on a study of non-ST-segment elevation myocardial infarction (NSTEMI) that did not include patients who underwent PCI within 12 h of presentation [7]. In addition, the most risky period for arrhythmia in patients with STEMI is during and immediately after PCI [8]. As this period were included in both study group [6], the risk of ED boarding has not been clearly demonstrated.

In this study, we hypothesized that the clinical outcomes of patients who are admitted directly to the CCU might be different from those of patients who board in the ED immediately following PCI. We also wondered whether the stay in the ED during the period immediately after PCI might affect the LOS in the CCU and hospital.

The aim of this study was the effects of direct and indirect admission to the CCU on mortality and on LOS in patients with STEMI who underwent PCI.

Section snippets

Study setting and participants

This was a retrospective observational study based on prospectively recorded MI registry data from a tertiary university hospital. The study period was from Jan 2014 to Nov 2017.

Regional cardiocerebrovascular centers supported by the Ministry of Health and Welfare operate nationwide. In December 2012, our hospital was designated the regional cardiocerebrovascular center. Our center acts as a final referral center in this region because the nearest similar center is >100 km away. Our center

Results

During the study period, 1924 patients with MI arrived at our ED, but 1144 patients were excluded from the analyses: 1042 patients with NSTEMI, 59 patients who went into cardiac arrest before presentation, 19 patients who did not choose PCI as primary reperfusion therapy, and 24 patients who were not admitted to the CCU, hence 780 patients were enrolled and analyzed in this study (Fig. 1).

Median (IQR) age was 65.0 (55.0–76.0) years old and males accounted for 53.5% (417 patients) of the sample.

Discussion

The mortality rates were similar for direct admission to the CCU and indirect admission to the CCU after ED boarding in patients with STEMI who underwent PCI. However, the LOS under intensive care was significantly longer in the patients with indirect admission to the CCU.

To the best of our knowledge, this is the first study to compare outcomes between direct and indirect admission to the CCU after PCI. Many previous studies have focused on the admission of STEMI patients, and direct admission

Conclusion

This study suggests that direct admission from the catheterization lab after PCI and indirect admission with ED boarding after PCI were not associated with mortality in patients with STEMI. The stay in the ED also appears to be associated with the duration of stay under critical care.

Funding source

The authors have no financial relationships relevant to this article to disclose.

Authors' contributions

Jin Hee Jeong: Dr. Jeong conceptualized and designed the study, analyzed the data, drafted the initial manuscript, approved the final manuscript as submitted, and agreed to be accountable for all aspects of the work.

Dong Hoon Kim: Dr. Kim conceptualized and designed the study, analyzed the data, drafted the initial manuscript, critically reviewed the manuscript, approved the final manuscript as submitted, and agreed to be accountable for all aspects of the work.

Tae Yun Kim MD: Dr. Kim

Declaration of competing interest

The authors have no conflicts of interest to disclose.

References (29)

  • D.B. Chalfin et al.

    Impact of delayed transfer of critically ill patients from the emergency department to the intensive care unit

    Crit Care Med

    (2007)
  • H.-C. Chen et al.

    The impacts of prolonged emergency department length of stay on clinical outcomes of patients with ST-segment elevation myocardial infarction after reperfusion

    Intern Emerg Med

    (2016)
  • B. Gorenek et al.

    Cardiac arrhythmias in acute coronary syndromes: position paper from the joint EHRA, ACCA, and EAPCI task force

    Europace

    (2014)
  • A. Bagai et al.

    Bypassing the emergency department and time to reperfusion in patients with prehospital ST-segment-elevation: findings from the reperfusion in acute myocardial infarction in Carolina Emergency Departments project

    Circ Cardiovasc Interv

    (2013)

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