Original article
Is it safe to discharge patients from accident and emergency using a rapid point of care Triple Cardiac Marker test to rule out acute coronary syndrome in low to intermediate risk patients presenting with chest pain?

https://doi.org/10.1016/j.ejim.2008.01.014Get rights and content

Abstract

Purpose

To determine whether patients presenting with chest pain who are at low to intermediate risk for ACS can safely be discharged from Accident and Emergency using Triple Cardiac Marker [TCM] [CK-MB, myoglobin, troponin I] without increasing risk and cost effective use of coronary care facilities.

Methods

Retrospective review of consecutive patients presented to A&E between Dec 2003 and July 2004 was performed and these patients were prospectively followed for six months for future coronary events and hospital admissions. A total of 325 patients presented to A&E with chest pain that were at low to intermediate risk for ACS. Paired TCM and ECGs were performed 2 h apart and the results were used to determine whether hospital admission was required. Follow up data was collected from hospital records, hospital database, GPS and patient interviews.

Results

325 consecutive patients [225 men, 100 women; aged 18–97 years, median—68 years] were included in the study. Paired TCM was negative in 100 patients [30%] and they were discharged from A&E. The re-admission rate for this group of patients was 1% with ACS and no deaths from cardiac cause at six months. 36 [11%] had single TCM negative and were sent home with 3% re-admission rate with ACS and no death at six months. Subgroup analysis shows sensitivity and specificity of 85.7% and 96.5% respectively for TCM to diagnose ACS in this setting.

Conclusion

Almost one third of patients who presented with chest pain and low to intermediate probability of ACS were safely discharged from A&E following paired negative TCM. Six month re-admission rate with ACS in this group of patients was only 1% with no death. Therefore paired TCM can be used to safely discharge this group of patients. This marker has the potential to significantly reduce hospital admissions.

Section snippets

Study population

We enrolled 325 consecutive patients who presented to A&E department of Leighton Hospital, Crewe, U.K, between 1st Dec 2003 and 31st July2004. All these patients were > 18 years old and had chest pain which was thought clinically to represent myocardial ischaemia and potentially required hospital admission. Patients were excluded if the initial ECG is abnormal i.e. showed ST segment elevation, LBBB or ST segment depression or T wave changes. In addition eligible subjects had to be designated as

Study protocol

Patients presenting with possible cardiac chest pain should have 12 lead ECG performed as soon as their arrival. If ECG is abnormal or diagnostic the patient is admitted to the hospital and excluded from the study. If the ECG is normal, the patients' risk stratification is performed and if they are “low to intermediate risk” for having ACS they are included in study. Those patients who are at low to intermediate risk have TCM performed. If the TCM test is positive the patient is admitted to the

Statistical analysis

Sensitivity and specificity, was calculated with gold standard being 12 h TnI level. Positive predictive value of the test was also calculated with false positives and false negatives. Continuous data are expressed as median. Categorical data are expressed as absolute values and percentages.

Results

325 consecutive patients who presented to A&E with cardiac ischaemic sounding chest pain, and are at low to intermediate risk for ACS were included in the study. Their ages ranged from 18–97 years, with a median age of 67 years. 225 [69.2%] were men and 100 [30.8%] women.

110 patients [33%] had positive TCM and were admitted to the hospital with the diagnosis of ACS. 100 patients [30%] had paired TCM negative and paired 2 ECGs negative were discharged home from A&E. These patients were then

Outcomes at six months

1 patient [1%] out of 100 patients discharged home from A&E following 2 negative TCM was admitted to the hospital with acute coronary syndrome at six months. There was no death recorded at six months in this group. There was no readmission or death in the group of patients [n = 30] who were admitted for 12 h TnI levels. There was 1 admission [3%] with ACS in the group of patients [n = 36] who were discharged after 1 negative TCM and there was no cardiac death at six months. On the contrary there

Sensitivity and specificity

Sensitivity and specificity of paired TCM to diagnose ACS with gold standard being 12 h TnI level was high. The sensitivity in this group was 85.7% and specificity of 96.5%. Positive predictive value of TCM was as high as 92.3%. False positive and false negative rates were low at 7.6% and 6.6% respectively.

Discussion

The principal finding from our study was that almost one third of patients presenting to A&E with ischaemic chest pain and who are at low to intermediate risk for ACS can be safely discharged home from A&E after negative paired TCM. The readmission rate with ACS at six months was low [1%] in this group with no death from cardiac cause. Therefore paired TCM can be used to safely discharge this group of patients. This marker has potential to significantly reduce hospital admissions.

Current

Learning points

• Patients presenting with cardiac sounding pain in emergency area utilise lots of resources while they are waiting to rule out acute coronary syndrome and discharged home.

• Paired Triple Cardiac Marker (TnI, CK-MB and myoglobin) performed in A/E area has high sensitivity and specificity to rule out ACS.

• Up to one third of patients presenting with chest pain and at low to intermediate risk of ACS could be safely discharged from A/E utilising Paired Triple Cardiac Marker.

• We have shown that

References (19)

There are more references available in the full text version of this article.

Cited by (13)

  • Comparison of new point-of-care troponin assay with high sensitivity troponin in diagnosing myocardial infarction

    2014, International Journal of Cardiology
    Citation Excerpt :

    No improvement is seen in centres where no change other than assay type was made to these processes [24]. Although there appears to be a shorter time to treatment in those with AMI when POC assays are used, a previous systematic review did not show improvement in outcomes although were also not inferior [25]. It should be noted that many of the studies included in the review used older less sensitive assays.

  • Improved sensitivity of point of care troponin I values using reporting to below the 99th percentile of normals

    2013, Clinical Biochemistry
    Citation Excerpt :

    Venge et al. showed in over 1000 patients presenting to the emergency department that the point of care assays identified only a percentage of patients who subsequently died of cardiac disease [7]. With the advent of higher sensitivity troponin tests in the laboratory there is an emphasis on earlier diagnosis and faster discharge from the emergency department and the gap between point of care troponin and laboratory might widen [18,19] although some studies show that POC troponin assays identify the majority of patients with acute coronary syndromes [20]. The advent of high sensitivity assays in clinical practice might allow earlier identification of patients and faster discharge of troponin negative patients.

  • Cardiac biomarkers in acute myocardial infarction

    2013, International Journal of Cardiology
    Citation Excerpt :

    Goodacre et al. showed that the use of a multi-marker panel in the Emergency Department significantly increased successful discharge, defined as discharge within 4 h and no adverse events including death, non-fatal AMI, emergency revascularization, life-threatening arrhythmia or hospitalization due to myocardial ischaemia within 3 months [254]. Other studies have shown that low risk patients identified by negative early cTnI/CKMB/myoglobin had low (0–3%) death or AMI/ACS rates by 30 days to 6 months [261,264,265]. However, despite these studies suggesting incremental benefit of multiple biomarkers, these studies have been criticized for using, in particular, cTn assays with low analytical sensitivity; negating the advantages that cTn alone may offer [100].

  • A 2-hour thrombolysis in myocardial infarction score outperforms other risk stratification tools in patients presenting with possible acute coronary syndromes: Comparison of chest pain risk stratification tools

    2012, American Heart Journal
    Citation Excerpt :

    Table IV shows the proportion of patients identified as low risk. The most specific pathways were by Rathore et al,15 Goodacre et al,19 Sanchis et al,13 Mitchell et al,2 and Six et al16 and were at or approaching significance for superior specificity compared with the other pathways (P < .001-.127). The least specific were the pathways by Christenson et al14 and Hess et al18 (P < .001 compared with the other pathways).

  • Cardiac troponin: A critical review of the case for point-of-care testing in the ED

    2012, American Journal of Emergency Medicine
    Citation Excerpt :

    Table 2 provides an overview of these randomized clinical trials and those included in the review described previously [37-42]: most of these studies, originating from a broad variety of countries, demonstrated a benefit for point-of-care vs the central laboratory. The finding of reduced time to the application of anti-ischemic therapy associated with the use of point-of-care testing [36] has been confirmed by a study based on a large registry in the United States [43]. In addition, the Randomised Assessment of Treatment using Panel Assay of Cardiac Markers (RATPAC) study demonstrated no significant differences in adverse events (death, myocardial infarction, hospitalization for acute coronary syndromes, life-threatening arrhythmia, or emergency revascularization) between patients randomized to clinical evaluation based on point-of-care measurement of cardiac biomarkers and those randomized to clinical evaluation based on standard care [40,41].

View all citing articles on Scopus
View full text