A preliminary study on radiographic measurements and blood parameters for diagnosing myxomatous mitral valve disease in dogs

The present preliminary study aimed to investigate the diagnostic ability of several methods which may be applied in the absence of echocardiography in clinical decision-making for myxomatous mitral valve disease (MMVD) – one of the most common acquired cardiac conditions and leading cause of congestive heart failure in small-breed adult dogs. Five radiographic measurements (VHS, VLAS, M-VLAS, RLAD and LAWIDTH) and four blood parameters (NT-proBNP, cTnI, NLR and MLR) were measured in nineteen client-owned dogs ≤ 20 kg body weight who were free of comorbidities. Each animal underwent physical examination, electrocardiography, echocardiography, radiography and blood analysis and was assigned into one of two groups based on disease stage: group 1 (A+B1) or group 2 (B2+C). The results demonstrated that all five radiographic measurements had an excellent diagnostic accuracy (AUC=0.915–0.972; P<0.05), with RLAD and M-VLAS achieving the best overall performance (94.7% accuracy; 87.5% sensitivity; 100% specificity; κ 0.89; P<0.001). Of the four blood parameters, only NT-proBNP could distinguish between the groups and performed comparably to RLAD and M-VLAS. These findings indicate that radiographic measurements and NT-proBNP can be reliable tools for diagnosis of generalised MMVD when echocardiography is unavailable.