Single Troponin Tests could be Enough for Emergency Department Discharge

Maereg Wassie, MD (Kaiser Permanente)

Chest pain is 1 of the most common reasons for emergency department visits in the US, but the majority of patients are at a low risk of acute coronary syndrome and suffer from low rates of cardiac adverse outcome rates.

In the initial assessment of acute coronary syndrome, biomarker testing with troponin levels could improve screening for the disease in clinical practice, but patients can also be discharged if they are deemed at a low risk following a single negative troponin test result.

A team, led by Maereg Wassie, MD, Division of Cardiology, Kaiser Permanente Southern California, examined the clinical outcomes of patients discharged following a single negative troponin test result compared to patients discharged after serial troponin measurements.

The Study

In the retrospective cohort study, the investigators examined emergency department encounters from May 2016 and December 2017 across 15 community emergency departments within an integrated health care system in southern California. The cohort ultimately included 27,918 adult emergency department encounters in which patients were evaluated for acute coronary syndrome with a HEART (history, electrocardiogram, age, risk factors, and troponin) score and an initial conventional troponin-I measurement below the level of detection (<0.02 ng/mL).

The investigators sought primary outcomes of acute myocardial infarction or cardiac mortality, as well as secondary outcomes of coronary artery bypass graft, percutaneous coronary intervention, invasive coronary angiography, and unstable angina within 30 days of discharge.

The researchers used a multivariable logistic regression model to evaluate the link between testing strategies and clinical outcomes.

Results

Overall, there were 27,918 encounters with a mean age of 58.7 years old included in the study. For the patients with an initial troponin measurement below the level of detection, 51.8% (n = 14,459) were discharged after a single troponin measurement, while 48.2% (n = 13,459) underwent serial troponin tests.

When the researchers adjusted for cardiac risk factors and comorbidities they found no statistically significant difference in the primary outcome of acute myocardial infarction or cardiac mortality within 30 days between the 2 groups (single troponin, n = 56; 0.4%; serial troponin, n = 52; 0.4%; aOR, 1.41; 95% CI, 0.96-2.07).

They also found patients discharged following a single troponin test had lower rates of coronary artery bypass graft (aOR, 0.24; 95% CI, 0.11-0.48) and invasive coronary angiography (aOR, 0.46; 95% CI, 0.38-0.56).

“This study suggests that patients are routinely discharged from the ED after a single negative troponin test result, and when compared with serial troponin testing, a single troponin test appears safe based on current physician decision-making, with no difference in rates of 30-day cardiac mortality and acute myocardial infarction, which are low in both groups,” the authors wrote.

The study, “Single vs Serial Measurements of Cardiac Troponin Level in the Evaluation of Patients in the Emergency Department With Suspected Acute Myocardial Infarction,” was published online in JAMA Network Open.