title: Evaluation of assays for troponin I in healthy horses and horses with cardiac disease.
abstract: Cardiac troponin I (cTnI) is a marker for detection of myocardial damage in horses. Many cTnI assays exist and medical studies have shown that the clinical performance of assays differs. The aim of this study was to compare two different cTnI assays in horses. Serum samples were taken from 23 healthy horses (group 1) and 72 horses with cardiac disease (group 2). Cardiac troponin I was determined using assay 1 in laboratory A (limit of detection, LOD, 0.03 ng/mL) and assay 2 in laboratories B and C (LOD 0.01 ng/mL). In group 1, a median cTnI concentration of <0.03 (<0.03-0.04) ng/mL and <0.01 (<0.01-0.15) ng/mL was found with assays 1 and 2, respectively. A higher median value was demonstrated in group 2 for both assays (assay 1: 0.11 ng/mL, range 0.03-58.27 ng/mL, P < 0.001; assay 2: 0.02 ng/mL, range 0.01-22.87 ng/mL, P = 0.044). Although a significant correlation between assays existed, large mean differences that could be important for clinical interpretation of test results were found. A small mean difference was found between laboratories B and C. A significant optimal (P < 0.001) cut-off value for detection of cardiac disease could only be determined for assay 1 (0.035 ng/mL, sensitivity 70%, specificity 91%). Assay 1 performed better for detection of cardiac disease in horses in this study.
authors.affiliation: Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium. Electronic address: nicky.vandervekens@ugent.be.
authors.forename: N
authors.initials: N
authors.lastname: Van Der Vekens
authors.affiliation: Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Decloedt
authors.affiliation: Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Sys
authors.affiliation: Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Ven
authors.affiliation: Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: De Clercq
authors.affiliation: Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke B-9820, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: van Loon
mesh_terms: D000818:Animals; D015415:Biomarkers; D016022:Case-Control Studies; D004452:Echocardiography / Q000662:veterinary; D004562:Electrocardiography / Q000662:veterinary; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D006734:Horse Diseases / Q000097:blood* / Q000378:metabolism; D006736:Horses; D008297:Male; D019210:Troponin I / Q000097:blood* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D019210:Troponin I
keywords: Atypical myopathy; Cardiac biomarker; Equine; Troponin T; Valvular regurgitation