High sensitivity troponin I and newly/recently diagnosed coronavirus-19 disease patients presenting to the emergency department: values above and below the 99th percentile predict 28 day mortality
Authors: Nowak R M , Jacobsen G , Cook B , Linoj S , Moyer M , Lanfear D 
Published: October 2022

Abstract

Background
Studies indicate that the presence of cardiac injury [troponin level &gt; the 99th percentile upper reference limit (99th % URL) using mostly contemporary assays] is predictive of death within 30 days during hospitalization of coronavirus disease 2019 (COVID-19) patients. Troponin measurements in these reports were ordered and/or resulted in the Emergency Department (ED) or during various times after hospital admission and not all patients were followed for 30 days.

Purpose
Our objective was to determine the 28 day survival prognostic value of Emergency Department (ED) resulted high sensitivity cardiac troponin I (hs-cTnI) measurements in all COVID-19 patients including those discharged after their ED visit or hospitalization.

Methods
An ED centric electronic database of COVID-19 patients (nasopharyngeal swab testing within 1 week prior to or during the ED visit) having at least 1 hs-cTnI (Beckman Coulter, Brea, CA; level of quantitation (LoQ) 4ng/L, non sex specific 99th % URL 18 ng/L) value reported during a visit to an urban, academic ED in the United States was constructed. All patients were followed for 28 days and Kaplan Meir survival curves constructed amongst predetermined initial hs-cTnI value intervals.

Results
From March 16-November 2, 2020 1476 consecutive ED COVID-19 patients were identified with 1044 (70.7%) having at least 1 hs-cTnI value resulted in the ED. Patients' mean age and body mass index were 60.8±16.1 years and 32.4±11.3 kg/m2 respectively. 531 (50.9%) were male, 804 (77.0%) self-identified as African American and 615 (58.9%) had 2 or more comorbidities with hypertension (42.5%), diabetes (37.4%) and hyperlipidemia (27.23%) commonest. Frequent primary presenting complaints were shortness of breath (37.7%), fever/chills (14.5%) and cough (11.9%). Hs-cTnI interval values were: 147 (14.1%) &lt;4 (LoQ), 359 (34.4%) 4–10 and 151 (14.5%) 11–18 ng/L. Hs-cTnI values were &gt;99th % URL in 387 (37.1%) patients with 230 (22.0%) 19–54, 63 (6.0%) 54–99 and 94 (9.0%) ≥100 (laboratory reported critical value) ng/L. 145 (13.9%) patients were discharged directly home and 2 (0.2%) died in the ED. 147 (14.1%) were admitted to an ICU with 104 (70.7%) dying. Each of the interval initial ED hs-cTnI values was associated with a different (p&lt;0.001) 28 day survival curve.

Conclusions
Most COVID-19 patients had a hs-cTnI value obtained with 85.9% of these &gt;4 ng/L. No one with an initial hs-cTnI &lt;4 ng/L died within 28 days while increasing presenting hs-cTnI values &gt;4 ng/L were associated with decreased 28 day survival. Our findings indicate that in COVID-19 patients detectable initial ED hs-cTnI values, whether reaching thresholds for cardiac injury or not, are highly prognostic of 28 day survival. Studies are needed to better define how hs-cTnI values could alter early management of COVID-19 disease to improve outcomes for these patients.

Funding Acknowledgement
Type of funding sources: Private hospital(s). Main funding source(s): Henry Ford Health System Department of Emergency Medicine