Identifying Patients with Low Risk of Acute Coronary Syndrome Without Troponin Testing: Validation of the HEAR Score

Background: Current guidelines for patients with suspected acute myocardial infarction are mainly based on troponin testing, commonly requiring an emergency department visit. HEAR score (History, Electrocardiogram, Age, and Risk factors) is a risk stratification tool validated in Europe, deduced from the HEART score (History, Electrocardiogram, Age, Risk factors, and Troponin), already implemented in clinical practice. We aimed to validate the HEAR score to rule out an acute myocardial infarction without needing biomarker testing. Methods: Retrospective cohort study at 15 emergency departments between May 2016 and December 2017. All adult encounters evaluated for possible acute myocardial infarction with a physician-documented HEART score for health plan members of Kaiser Permanente Southern California were included. Patients with an ST-segment elevation myocardial infarction, those under hospice care, or with a “do not resuscitate” status were excluded. HEAR scores from 0-8 were calculated for each encounter and used to report 30-day acute myocardial infarction or all-cause mortality for each score. Results: There were 22,109 patient encounters included in the study. Overall, 30-day acute myocardial infarction or death occurred in 1.1% of patients. Among the 4106 patients (19%) with a HEAR score <2, 3 died and 2 experienced an acute myocardial infarction within 30 days (0.1%; 95% confidence interval, 0.1-0.3). Sensitivity and specificity were 97.9% and 18.8%, respectively. Conclusions: A low HEAR score may accurately identify patients with a very low risk of 30-day acute myocardial infarction or death, representing a cohort of patients who might appropriately forego biomarker testing. Future research is warranted to assess the impact of implementing the HEAR score into routine clinical practice.