Longitudinal profile of N-terminal pro-atrial natriuretic peptide and N-terminal pro B-type natriuretic peptide in dogs undergoing mitral valve repair.

INTRODUCTION/

OBJECTIVES

N-terminal pro-atrial natriuretic peptide (NT-proANP) and N-terminal pro B-type natriuretic peptide (NT-proBNP) are established biomarkers in veterinary cardiology, but their postoperative dynamics in dogs remain unclear. The aims of this study were to describe longitudinal profiles of these biomarkers and to explore associated factors in dogs undergoing mitral valve repair (MVR).

ANIMALS, MATERIALS, AND

METHODS

This single-center, prospective observational cohort study enrolled 109 dogs with myxomatous mitral valve disease that underwent MVR. N-terminal pro-atrial natriuretic peptide, NT-proBNP, renal parameters, echocardiography, and radiography were assessed repeatedly up to six months postoperatively. Serial data were analyzed using multivariable linear mixed-effect regression.

RESULTS

Cardiac reverse remodeling occurred shortly after MVR, whereas the natriuretic peptides (NPs) declined gradually with high variability. In multivariable analysis, log2-NT-proANP was associated with older age (0.12 [95% confidence interval, 0.05 to 0.20] standard deviation [SD]), lower body weight (-0.11 [-0.18 to -0.03] SD), and higher serum creatinine (0.18 [0.12 to 0.23] SD). Log2-N-terminal pro B-type natriuretic peptide was associated with older age (0.11 [0.03 to 0.20] SD), lower body weight (-0.09 [-0.18 to -0.00] SD), higher serum creatinine (0.07 [0.01 to 0.14] SD), and right ventricular pressure overload (0.35 [0.12 to 0.57] SD). While single-point NP measurements did not reflect postoperative cardiac size, relative NT-proBNP changes were associated with subsequent cardiac size alterations.

STUDY LIMITATIONS: Single-center design limits generalizability. Interobserver variability in imaging could introduce measurement error.

CONCLUSIONS

Natriuretic peptide reductions following MVR were gradual and variable. Age, body weight, renal function, and right ventricular pressure overload may influence NP concentrations. Interpreting single postoperative NP measurements may be challenging.