Ruaux C, Scollan K, Suchodolski JS, Steiner JM, Sisson DD. Biologic variability in NT-proBNP and cardiac troponin-I in healthy dogs and dogs with mitral valve degeneration.
Vet Clin Pathol 2015;
44:420-30. [PMID:
26108974 DOI:
10.1111/vcp.12268]
[Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND
The N-terminal fragment of the prohormone B-type natriuretic peptide (NT-proBNP) and cardiac troponin-I are candidate biomarkers for cardiac disease in dogs. The degree of biologic variation in these biomarkers has not previously been reported in healthy dogs or dogs with mitral regurgitation.
OBJECTIVES
The purpose of the study was to derive estimates of intrinsic biologic variability and reference change values for NT-proBNP and cardiac troponin-I in healthy dogs and dogs with mitral regurgitation grade IB and II according to the International Small Animal Cardiac Health Council (ISACHC) grading system.
METHODS
Plasma and sera were collected weekly for up to 7 weeks from 12 control dogs and 9 dogs with mitral regurgitation. NT-proBNP and troponin-I (C-TnI) concentrations were determined. Indices of biologic variation such as reciprocal index of individuality (r-IoI) and reference change values (RCV) were calculated in both the groups.
RESULTS
Individuality was high in control dogs and dogs with grade IB and II mitral valve regurgitation for both C-TnI (r-IoI 1.6 and 2) and NT-proBNP (1.5 and 2.7), while the 2-sided RCV for NT-proBNP was significantly lower in dogs with mitral regurgitation (52.5% vs 99.4%, P<0.01.).
CONCLUSIONS
High individuality of these cardiac biomarkers suggests that, following diagnosis, these assays are best interpreted by serial determination in individual canine patients rather than by comparison to a population-based reference interval. The smaller RCV values for dogs with mitral regurgitation suggest that smaller relative changes in NT-proBNP are clinically meaningful in these patients.
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