Abstract Body: Background:
A recent prospective study reported that myocardial infarction (MI) was present in nearly half of ischemic stroke patients with substantially elevated troponin, with 1 in 5 having a type 1 MI. The proportion of stroke patients in whom cardiac troponin, a key component of diagnosing MI, is checked at Emergency Department (ED) presentation is unknown. We therefore used population-level data to report the frequency of cardiac troponin assessments among U.S. patients presenting emergently with stroke symptoms and to identify factors associated with cardiac troponin testing.

Methods:
Using the National Hospital Ambulatory Medical Care Survey (NHAMCS), which provides data from a nationally representative sample of EDs in the U.S., we analyzed patients presenting from 2016 to 2021 with an initial diagnosis of stroke, defined by ICD-10 codes in any diagnostic position as abstracted from free text responses by ED staff. The study exposure was cardiac troponin testing, which is a collected variable in NHAMCS. We applied survey weights to calculate national estimates and 95% confidence intervals (CI). Survey-weighted tests of comparison were used to compare demographics and clinical features between visits in which troponin was tested versus not. We constructed a multivariable conditional logistic regression model to evaluate potential associations between demographic and clinical factors and troponin testing in the ED.

Results:
An estimated 5.8 ([95% CI, 4.8-5.7) million patients or 0.69% (95% CI, 0.58-0.80%) of all ED visits during the study period were for suspected stroke. Mean age was 67.8 (95% CI, 66.5-69.2) years and 53.1% (95% CI, 48.2-57.9) were women. In suspected stroke patients, 26.1% (95% CI, 20.9-32.2%) had troponin tested in the ED. In unadjusted analysis, factors significantly associated with troponin testing were a triage complaint of chest pain, older age, higher mean systolic BP, hypertension, diabetes, obesity, stroke or TIA, congestive heart failure, or coronary disease. In a multivariable model, only elevated systolic blood pressure was significantly associated with having cardiac troponin tested in the ED (p= 0.02).

Conclusion:
Using population-level data, we found that only 1 in 4 patients with a suspected stroke had troponin tested in the ED. There appears to be an opportunity to improve MI detection among stroke patients in the U.S.