Jennifer L. Wiler, MD, MBA, FACEP reviewing Greenslade JH et al. Emerg Med J 2017 Mar 31.

Both the Manchester Acute Coronary Syndromes (MACS) and troponin-only MACS decision rules identify patients at very low risk for AMI, but outpatient testing may be needed.

Researchers evaluated the Manchester Acute Coronary Syndromes (MACS) and troponin-only MACS (T-MACS) rules in a secondary analysis of data for 1244 patients who presented to two emergency departments (EDs) in New Zealand and Australia with a complaint of at least 5 minutes of chest pain concerning for acute coronary syndrome (ACS).

MACS and T-MACS probabilities for ACS were calculated with a formula using points assigned for the following variables: ischemic electrocardiogram changes, diaphoresis, vomiting, elevated blood pressure, history of angina, radiating pain, and biomarkers (presenting high-sensitivity troponin T [hs-TnT] level and heart fatty acid–binding protein for MACS; only hs-TnT for T-MACS). The primary outcome was 30-day diagnosis of acute myocardial infarction (AMI), the secondary outcome was 30-day major adverse cardiac event. Patients with a MACS or T-MACS probability less than 2% were deemed very low risk for ACS.

Overall, 10.7% of patients were categorized as very low risk for ACS by the MACS rule and 19.8% by the T-MACS rule. One patient classified as very low risk by both rules was diagnosed with AMI, yielding a sensitivity of 99.1%.

CITATION(S):

Greenslade JH et al. Validating the Manchester Acute Coronary Syndromes (MACS) and Troponin-only Manchester Acute Coronary Syndromes (T-MACS) rules for the prediction of acute myocardial infarction in patients presenting to the emergency department with chest pain. Emerg Med J 2017 Mar 31; [e-pub].

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