Heartbeat: Rapid rule-out pathways for acute myocardial infarction

Clinical decision making in patients presenting to the Emergency Department with chest pain remains a challenge; while only 10% to 20% are ultimately diagnosed with acute myocardial infarction (AMI), it is important to not miss any patient with an AMI. The European Society of Cardiology (ESC) 0/1 algorithm allows rapid triage of chest pain patients based on the change in high-sensitivity cardiac troponin (hs-cTn) over the first hour after presentation, dividing patients into rule-out, observation and rule-in categories. However, there appears to be some variation in the accuracy of this approach across different population cohorts and there is little data on outcomes in the rule-out and observation categories. To better understand the accuracy and prognostic value of the ESC 0/1 algorithm globally, Chiang and colleagues1 performed a systematic review and meta-analysis that identified that 10 cohorts with over 11 000 patients -- about 18% were assigned to rule-in, 27% to observation and 55% to rule-out categories, depending on the specific c-Tn assay. The pooled sensitivity of the ESC 0/1 algorithm for AMI diagnosis was over 98% with a mortality rate in the rule-out category of only 0.1% (95% CI=0.0% to 0.4%) at 30 days and 0.8% (95% CI=0.5% to 1.2%) at 1 year. However, the mortality rate for patients in the observation group was 0.7% (95% CI=0.3% to 1.2%) at 30 days and increased to 8.1% (95% CI=6.1% to 10.4%) at 1 year, similar to the mortality rate in the rule-in group. In an editorial, Chapman and Mills2 summarise these data (figure 1) and conclude: “While many emergency departments …