Early Risk Stratification in ED Chest Pain Patients

Study Overview
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Brief Summary
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In the management of adult chest pain patients presenting to an Emergency Department (ED) with suspected acute coronary syndrome (ACS), we aimed to evaluate the diagnostic accuracy of the combined use of a modified Thrombolysis in Myocardial Infarction (TIMI) score and a modified HEART score with high-sensitive cardiac troponin T (hs-cTnT) to rule out major adverse cardiac events (MACE) in 30-days.

Detailed Description
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Chest pain is one of the most common complaints in patients presenting to emergency departments (ED) globally, representing 2.5% of all ED presentations in Hong Kong. Acute coronary syndrome (ACS) cannot be immediately excluded in the majority of patients presenting with chest pain, and is confirmed in about 15-25% cases. The current evaluation of patients in most EDs is a lengthy process that involves serial ECGs and troponin tests taken 3-6 hours apart. However, challenges over ED crowding and the need for acceptable risk stratification have prompted the search for safe, cheap, but effective accelerated chest pain pathways. An ever increasing evidence base is emerging from emergency departments in different geographical settings, using different combinations of clinical assessment tools, more rapid biochemical tests and variable outcomes. While making an accurate diagnosis is clearly important, from the patients' perspective it is more important to minimize the risk of adverse events. Therefore, the identification of tools which allow risk stratification to permit very low risks of MACE is more clinically relevant to ED specialists than the precise diagnostic label applied to the patient. In the Asia-Pacific region a 2-hour diagnostic protocol involving serial point-of-care biomarkers, such as troponin I, creatine kinase MB, and myoglobin, combined with electrocardiograph (ECG) changes and a Thrombolysis in Myocardial Infarction (TIMI) score has been shown to safely exclude 30-day MACE in low risk patients with chest pain. Highly sensitive troponin T (hs-cTnT) and troponin I (hs-cTnI) perform well in the early diagnosis of acute myocardial infarction (AMI), non-ST elevation myocardial infarction (NSTEMI) and in the prediction of two year mortality. Undetectable levels of hs-cTnT alone at initial blood testing appears to rule-out 60-day NSTEMI with a negative predictive value of 94% and a sensitivity of 90%. A TIMI score incorporating hs-cTnT was no better at predicting 30-day MACE than front-door TIMI alone without measurement of biomarkers, but the value of a TIMI score of zero in ruling-out low risk patients was not demonstrated. Despite evidence favouring early rule out pathways, there is still a need for further validation and refinement of such tools using different diagnostic pathways, in other clinical settings, and with other clinical tools such as HEART. In this study we aimed firstly to evaluate the effectiveness of a combined use of an early modified TIMI score with hs-cTnT and a modified HEART score to rule out MACE in 30 days. Applying this protocol in clinical practice has the potential to reduce ED waiting times, ED crowding and hospital admission rates for chest pain patients.

Official Title
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Improving Early Risk Stratification in Patients Presenting to Emergency Departments With Undifferentiated Chest Pain

Conditions
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Acute Coronary Syndrome

Intervention / Treatment
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* Other: Thrombolysis in myocardial infarction score
* Biological: routine blood test for hs-cTnT
* Other: HEART score


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18 years or over Chest pain within 24 hours of ED presentation Suspected with ACS Exclusion Criteria: No cardiac chest pain based on clinical assessment Hemodynamic or clinical instability (SBP<90 mmHg, clinically significant atrial/ventricular arrhythmias) Initial ECG suggestive of ACS, Acute Myocardial Infarction or other abnormality requiring admission to hospital Previous coronary artery bypass grafting or coronary stent implantation Women with known or suspected pregnancy Unable or unwilling to provide informed consent Unable to be contacted after discharge Contraindication to β-blockade if prescription of β-blockade is required due to a resting heart rate over 80 beats per minute

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Not low risk for MACE in 30 days<br>Patients with not low risk of major adverse cardiac events within 30 days Patients with TIMI>0 or mHEART>2 Routine blood test for hs-cTnT and Thrombolysis in myocardial infarction (TIMI) score were performed on study patients Protocol amendment: In October 2014, mHEART score of the study patients was determined retrospectively | Other: Thrombolysis in myocardial infarction score<br>* An English- and Cantonese-speaking research nurse obtained the TIMI scores which consists of seven variables from each eligible patient.<br>* Other names: TIMI score;Biological: routine blood test for hs-cTnT<br>* Patient had routine venipuncture blood taking for hs-cTnT measurement in the central laboratory of the hospital. Normal level of hs-cTnT is below 14ng/L.<br>* Other names: hs-cTnT;Other: HEART score<br>* The modified HEART score of each patient was determined retrospectively by a research assistant.<br>|
| Low risk for MACE in 30 days<br>Patients with low risk of major adverse cardiac events within 30 days Patients with TIMI=0 and mHEART<=2 Routine blood test for hs-cTnT and Thrombolysis in myocardial infarction (TIMI) score were performed on study patients Protocol amendment: In October 2014, mHEART score of the study patients was determined retrospectively | Other: Thrombolysis in myocardial infarction score<br>* An English- and Cantonese-speaking research nurse obtained the TIMI scores which consists of seven variables from each eligible patient.<br>* Other names: TIMI score;Biological: routine blood test for hs-cTnT<br>* Patient had routine venipuncture blood taking for hs-cTnT measurement in the central laboratory of the hospital. Normal level of hs-cTnT is below 14ng/L.<br>* Other names: hs-cTnT;Other: HEART score<br>* The modified HEART score of each patient was determined retrospectively by a research assistant.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Patients With Major Adverse Cardiac Event | The primary outcome is the number of patients with MACE within 30 days after initial ED presentation. MACE is defined as relating to safety outcome, or effecacy outcome. | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Safety Major Adverse Cardiac Event | Outcome is the number of patients with safety MACE within 30 days after initial ED presentation. Safety MACE is defined as relating to safety outcome,which consists of all-cause mortality (included cardiac death),cardiac arrest,readmission with myocardial infarction and cardiogenic shock | 30 Days | 
| Number of Effecacy MACE | Outcome is the number of patients with effecacy MACE within 30 days after initial ED presentation. Effecacy MACE consists of revascularization (e.g.coronary artery bypass grafting),ventricular arrhythmia needing intervention and high-degree atrioventricular block needing intervention. | 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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High-sensitive troponin, TIMI score, Major adverse cardiac event, HEART score