How accurate are NT-proBNP, ANP, and cTnI levels in diagnosing dogs with myxomatous mitral valve disease?

Abstract

Background: Myxomatous mitral valve disease (MMVD) is prevalent in dogs. Specialized diagnostics (radiography and echocardiography) may be unavailable in some veterinary settings. Cardiac biomarkers offer potential alternatives. Aim: This study evaluated the diagnostic value of N-terminal fragments of pro-brain natriuretic peptides (NT-proBNPs), atrial natriuretic peptides (ANPs), and cardiac troponin I (cTnI) levels in dogs with MMVD. Methods: 69 dogs with MMVD (asymptomatic and symptomatic) and 19 healthy controls were assessed. Biomarker levels were measured using commercial kit rapid tests. Results: Our results showed that the median NT-proBNP level in the symptomatic group was higher than those in the asymptomatic (p < 0.001) and control (p < 0.001) groups. Moreover, the median NT-proBNP level in the asymptomatic group was higher than that in the control group (p < 0.001). The cTnI level in the control group was lower than those in the asymptomatic (p = 0.039) and symptomatic (p = 0.001) groups. No statistically significant difference in the cTnI level was noted between the asymptomatic and symptomatic groups. The best cutoff value of the NT-proBNP level to differentiate the normal controls from dogs with MMVD with or without congestive heart failure was > 505.65 pmol/l [sensitivity, 76.8%; specificity, 89.5%; and area under the curve (AUC), 0.862]. The suggested cutoff value of the NT-proBNP level to differentiate symptomatic MMVD from asymptomatic MMVD was >787.65 pmol/l (sensitivity, 78.38%; specificity, 72.55%; and AUC, 0.792). Conclusion: NT-proBNP and cTnI may serve as point-of-care tests for dyspneic dogs, aiding MMVD assessment where specialized diagnostics are limited.