Background: High sensitivity Troponin T (hsTnT) was approved by the FDA to aid in the diagnosis of myocardial infarction. Anecdotal experience suggests hsTnT is frequently elevated in patients with renal dysfunction. We examined patients with chief complaints of potential acute coronary syndrome (ACS) or heart failure (HF) symptoms with intermediate and high hsTnT values and correlated to estimated glomerular filtration rates (eGFR).
Methods: In the retrospective cohort study, consecutive adult patients presenting with ACS or HF symptoms were collected from July 1st, 2017 to May 24th, 2018 at large academic and community Emergency Departments, each with 65,000 visits, during which patients received 2 hsTnT and an N-terminal pro b-type natriuretic peptide (NT-proBNP) blood tests. Only one encounter selected at random per patient was included. Patients with missing data and elevated NT-proBNP (≥125 pg/mL for ages ≤74 years and ≥450 pg/mL for ages ≥75 years per hospital guidelines) were excluded. Data was analyzed using an ANOVA analysis via a Tukey-Kramer test to compare eGFR values among patients who had low (≤12 ng/L), intermediate (≥12 and < 52ng/L), and high ( ≥ 52 ng/L) hsTnT values. A Chi-squared test was done to evaluate the role of eGFR on hsTnT.
Results: 1,327 patient encounters were evaluated. Exclusion criteria included multiple visits (81), missing data (38), elevated NT-proBNP (771), or the lack of a chief complaint indicative of ACS or HF (75). This remaining cohort of 362 individuals had a mean age of 59, were 56% female, and 49% Caucasian. The mean eGFR was 82 mL/min/1.73 m². In patients with a low (67%) hsTnT, the mean eGFR was 87 (SD=22). In the intermediate (31%) and high (2%) hsTnT groups, the mean eGFR was 72 (SD=21) and 73 (SD=31), respectively. We detected a statistically significant difference between the low and intermediate groups at a level of p<0.0001, but not between the intermediate and high hsTnT groups. 27% of individuals with an eGFR ≥60 had an elevated hsTnT compared to 58% of those individuals with an eGFR < 60 (Chi-square, p < 0.0001).
Conclusion: Patients with intermediate and high hsTnTs were found to have significantly decreased eGFR. Further studies are needed to determine algorithms for the rapid rule out of myocardial infarction in patients with renal dysfunction.