Patients with low HEAR score may forego troponin testing

A low score in History, Electrocardiogram, Age, and Risk Factors (HEAR) appears to accurately pinpoint patients with a very low risk of 30-day acute myocardial infarction (MI) or death, suggests a study. Such patients may appropriately do without biomarker testing.

“This study of 22,109 emergency department (ED) patients with suspected acute coronary syndrome found that the HEAR score was able to identify patients at very low risk for 30-day acute MI or death, without requiring troponin testing,” the researchers said.

This retrospective cohort study was conducted at 15 EDs between May 2016 and December 2017 and included all adult encounters assessed for possible acute MI with a physician-documented HEART score (History, Electrocardiogram, Age, Risk factors, and Troponin) for health plan members of Kaiser Permanente Southern California.

Those with an ST-segment elevation MI, 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 MI or all-cause mortality for each score.

Of the 22,109 patient encounters in this study, 25 died (0.1 percent, 95 percent confidence interval [CI], 0.0–0.2) and 215 experienced a 30-day acute MI (1.0 percent, 95 percent CI, 0.8–1.1), representing a 1.1-percent (95 percent CI, 0.9–1.2) incidence of the main outcome. [Am J Med 2021;134:499-506.E2]

Additionally, 85 patients did not experience acute MI but underwent coronary artery revascularization (ie, percutaneous coronary intervention and coronary artery bypass graft), resulting in a 1.5-percent (95 percent CI, 1.3–1.5) incidence of major adverse cardiac events at 30 days.

A total of 4,106 patients (19 percent) had a HEAR score <2, of whom three died and two had an acute MI within 30 days (0.1 percent, 95 percent CI, 0.1–0.3). Sensitivity was 97.9 percent, while specificity was 18.8 percent.

“This study showed that in patients with a HEAR score <2, the risk of 30-day acute MI or death was lower than 0.3 percent,” the researchers said. “A HEAR score <2 suggests that workup should be focused toward differentials of acute MI and that these patients might not need urgent referral to the ED for ruling out acute MI.”

Since patients with a low HEAR score have favourable short-term outcomes, urgent evaluation for coronary artery disease could be deferred and electively performed in outpatient settings, they added.

Furthermore, “in a low-risk category identified with the HEAR score, a positive troponin result is likely to represent myocardial injury not related to acute MI. The yield of a troponin test in those low-risk patients is low and may lead to unnecessary testing,” according to the researchers.

Current guidelines for patients with suspected acute MI are based on troponin testing, which requires an ED visit. Deduced from the HEART score, HEAR score is a risk stratification tool validated in Europe and already implemented in clinical practice.

“Future research is warranted to assess the impact of implementing the HEAR score into routine clinical practice,” the researchers said.