N-terminal pro–B-type natriuretic peptide levels in normotensive and hypertensive dogs with myxomatous mitral valve disease stage B

Abstract

Abstract Background Systemic hypertension affects the heart, and to the best of our knowledge, no study has investigated the effects of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in dogs with myxomatous mitral valve disease (MMVD) stage B and systemic hypertension. This study aimed to investigate the blood level of NT-proBNP and assess the selected echocardiographic variables in dogs with MMVD stage B according to the presence of systemic hypertension or normal blood pressure and in dogs without MMVD. Results The study group comprised 37 dogs with stage B MMVD (normotensive group, n = 30; systemic hypertension group, n = 7) and 13 dogs without MMVD. We evaluated NT-proBNP, blood pressure, complete blood count (CBC), and serum chemistry in all 50 dogs. We performed electrocardiography, radiography, and echocardiography on 44 dogs (37 dogs with MMVD and 7 dogs without MMVD). The NT-proBNP concentrations showed significant intergroup differences (p < 0.001). Normotensive dogs with MMVD stage B (median [interquartile range]: 1083.5 [574.8–1912.8] pmol/L) and hypertensive dogs with MMVD stage B (2345.0 [1812.5–2533.0] pmol/L) showed significantly higher NT-proBNP concentrations than dogs without MMVD (504 [430–774] pmol/L, p = 0.009 and p < 0.001, respectively), and dogs in the systemic hypertension group showed significantly higher NT-proBNP concentrations than those in the normotensive group (p = 0.046). Mitral valve regurgitation velocity was significantly higher in dogs in the systemic hypertension group (6.11 [6.07–6.24] m/s) than in those in the normotensive group (5.53 [5.17–5.95] m/s, p = 0.006). The left atrial to aortic root ratio (LA/Ao), E-peak velocity, and left ventricular end‐diastolic internal diameter corrected for body weight (LVIDDN) were significantly lower in dogs without MMVD than in dogs with MMVD stage B. Conclusions These findings suggest that NT-proBNP concentrations are higher in dogs with MMVD stage B with systemic hypertension than in normotensive dogs with MMVD stage B. Therefore, clinicians should be aware that NT-proBNP could be elevated in the presence of systemic hypertension.