Atrial Natriuretic Peptide in cardiac horses

peer reviewedBackground: Natriuretic peptides are cardiac biomarkers that have been shown to have high potential for diagnosis, prognosis, and guidance of treatment in human and small animal cardiology. However, their diagnostic and prognosis value in the equine species has only been studied in a limited number of cases. Objective: To investigate the plasma atrial natriuretic peptide concentration (ANPPl) in a large group of horses with various degrees of valvular regurgitation (VR) and heart failure (HF). Animals: Ninety-one horses, admitted at the equine teaching hospital of the University of Liege, and with no, mild, moderate or severe VR and presenting various stages of HF, according to human and canine grading system (A: no VR, B1: asymptomatic VR without cardiac remodelling, B2: asymptomatic VR with cardiac remodelling, C: symptomatic VR). Methods: All horses underwent clinical and Doppler echocardiographic examination, which allowed determining the presence, nature, and severity of VR, and the HF stage. The ANPPl was measured using a commercially available human RIA test. The mean values of body weight, age, ANPPl and each echocardiographic parameter were compared between horses in stage A, B1, B2 or C of HF and between horses with no, mild, moderate or severe VR, using a one-way ANOVA test. Then, correlations between ANPPl and each echocardiographic parameter were assessed using a Pearson’s product-moment analysis. Results: Horses with severe and moderate VR had significantly higher ANPPl than horses with mild or no VR. ANPPl was significantly higher in horses at stage B2 and C of HF than horses at stage A and B1. Moreover, ANPPl was significantly correlated with most of the measured echocardiographic variables. This correlation was especially strong with the left atrial diameter and its percentage of dilation. Conclusions and Clinical Importance: Those results suggest that ANPPl in horses suffering from VR could have a high diagnostic value of HF, especially in horses with tricuspid or mitral insufficiency and with enlargement or dysfunction of the atria