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

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.
Competing Interests: The authors declare no conflict of interest. While this study received funding from the Faculty of Veterinary Science Mahidol University (Thailand), Scarecrow Inc (Japan), T.J. Animal Health Co., Ltd. (Thailand), and Pharmalink International Ltd. (Hong Kong), these entities had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.