From the Guidelines
The protocol for ruling out Acute Coronary Syndrome (ACS) in a patient with chest pain requiring admission should include immediate ECG acquisition and review for STEMI within 10 minutes of arrival, measurement of cardiac troponin (cTn) as soon as possible after presentation, and a structured assessment of clinical elements. The assessment should begin with "ADMISSION FOR CHEST PAIN/RULE OUT ACS" followed by presenting symptoms (onset, duration, quality, radiation, associated symptoms), vital signs, risk factors (hypertension, diabetes, smoking, family history, hyperlipidemia), initial ECG findings, and initial troponin results 1. Key elements to include are:
- Current medications, especially cardiac medications and anticoagulants
- Initial management including aspirin administration (325mg loading dose), additional antiplatelet therapy if indicated (clopidogrel 300-600mg or ticagrelor 180mg loading dose), anticoagulation status (heparin drip or enoxaparin 1mg/kg BID), and pain management (nitroglycerin, morphine as needed)
- Plan for serial troponins (typically q3-6h for three sets), repeat ECGs, and timing for stress testing or cardiac catheterization if indicated
- Disposition planning criteria for discharge or continued hospitalization based on test results, as outlined in the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain 1. This approach ensures systematic documentation of critical elements, facilitating appropriate clinical decision-making and continuity of care for patients presenting with possible acute coronary syndrome, and is supported by the most recent and highest quality evidence 1.
From the Research
Protocol for Ruling Out Acute Coronary Syndrome (ACS)
The protocol for ruling out ACS in a patient with chest pain requiring admission involves several steps:
- Evaluation begins with an electrocardiogram (ECG) obtained within 10 minutes of presentation 2
- If ST-segment elevation is present, ST-segment elevation MI (STEMI) is diagnosed 2
- If STEMI is not present, troponin levels should be measured using one of several recommended protocols 2
- Troponin levels greater than 99th percentile of the upper reference limit are consistent with ACS 2
- If the ECG finding is normal and results of two troponin tests are negative, risk stratification should be calculated using Thrombosis in Myocardial Infarction (TIMI) or HEART (History, ECG, Age, Risk factors, initial Troponin) score 2
Risk Stratification and Further Evaluation
- Based on the score, further evaluation to exclude coronary artery disease (CAD) is completed during hospitalization or after discharge, using exercise treadmill testing, stress echocardiography, myocardial perfusion scintigraphy, or coronary computed tomography angiography 2
- Clinical features such as age, male gender, indigestion or burning-type pain, pain radiating to the left or right arm, vomiting, and previous or current smoking are independent predictors of ACS 3
- The Global Registry of Acute Coronary Events (GRACE) score can also be used to predict the risk of ACS 4
Noninvasive Cardiac Imaging
- Noninvasive cardiac imaging modalities such as chest radiography, single photon-emission CT myocardial perfusion imaging, echocardiography, multidetector CT, PET, and MRI can be used to exclude ischemia as an etiology and establish noncoronary etiologies for chest pain 5
- Noncardiac etiologies of chest pain include aortic dissection, aortic aneurysm, pulmonary embolism, pericardial disease, and lung parenchymal disease 5
Management of Patients with ACS
- Antiplatelet agents, percutaneous coronary intervention, and glycoprotein (GP) IIb/IIIa inhibitors can be used in patients with ACS based on risk stratification 6
- An early invasive strategy in high-risk patients is associated with lower mortality over the long term compared with conservative treatment 6
- The optimal management of patients with ACS continues to change as new therapies and strategies of care are developed and proven effective 6