Original articleIs 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?
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
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