Interpreting cardiac troponin results from high-sensitivity assays in chronic kidney disease without acute coronary syndrome.
BACKGROUND
Quantification and comparison of high-sensitivity (hs) cardiac troponin I (cTnI) and cTnT concentrations in chronic kidney disease (CKD) have not been reported. We examined the associations between hs cTnI and cTnT, cardiovascular disease, and renal function in outpatients with stable CKD.


METHODS
Outpatients (n = 148; 16.9% with prior myocardial infarction or coronary revascularization) with an estimated glomerular filtration rate (eGFR) of <60 mL · min⁻¹ · (1.73 m²)⁻¹ had serum cTnI (99th percentile of a healthy population = 9.0 ng/L), and cTnT (99th percentile = 14 ng/L) measured with hs assays. Left ventricular ejection fraction (LVEF) and mass were assessed by echocardiography, and coronary artery calcification (CAC) was determined by computed tomography. Renal function was estimated by eGFR and urine albumin/creatinine ratio (UACR).


RESULTS
The median (interquartile range) concentrations of cTnI and cTnT were 6.3 (3.4-14.4) ng/L and 17.0 (11.2-31.4) ng/L, respectively; 38% and 68% of patients had a cTnI and cTnT above the 99th percentile, respectively. The median CAC score was 80.8 (0.7-308.6), LV mass index was 85 (73-99) g/m², and LVEF was 58% (57%-61%). The prevalences of prior coronary disease events, CAC score, and LV mass index were higher with increasing concentrations from both hs cardiac troponin assays (P < 0.05 for all). After adjustment for demographics and risk factors, neither cardiac troponin assay was associated with CAC, but both remained associated with LV mass index as well as eGFR and UACR.


CONCLUSIONS
Increased hs cTnI and cTnT concentrations are common in outpatients with stable CKD and are influenced by both underlying cardiac and renal disease.
Division of Cardiology, Department of Medicine, University of Maryland School of Medicine, 22 S. Greene St., Baltimore, MD 21201, USA. cdefilip@medicine.umaryland.edu
Christopher
C
deFilippi
Stephen L
SL
Seliger
Walter
W
Kelley
Show-Hong
SH
Duh
Michael
M
Hise
Robert H
RH
Christenson
Myles
M
Wolf
Hanna
H
Gaggin
James
J
Januzzi
D054058:Acute Coronary Syndrome / Q000150:complications; D000368:Aged; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*; D020107:Troponin T / Q000097:blood*
D019210:Troponin I; D020107:Troponin T