Assessment of Platelet Function in Dogs with Myxomatous Mitral Valve Disease

Chronic degenerative atrioventricular valve disease, particularly myxomatous mitral valve disease (MMVD), is the leading cause of heart failure in dogs. It significantly affects platelet function, especially under high shear stress, as well as potentially alters platelet activation and reactivity. Platelets are vital for coagulation and inflammation, and their function can be assessed using the Platelet Function Analyzer-200 (PFA-200), which simulates in vivo conditions. This study aimed to investigate the differences in closure time—measured using the PFA200—in dogs with MMVD, with a focus on the impact of cardiac remodeling. The dogs were classified into the control, stage B1, stage B2, and stage C groups according to the American College of Veterinary Internal Medicine (ACVIM) guidelines. They were further categorized into the non-cardiac remodeling (normal, MMVD stage B1) and cardiac remodeling groups (MMVD stages B2 and C) based on cardiac remodeling status. Significant differences were found in the closure times of collagen-adenosine diphosphate (C/ADP) and collagen-epinephrine (C/EPI) between the non-cardiac and cardiac remodeling groups. Additionally, both closure times demonstrated a moderate positive correlation with the left atrial to aortic root ratio. Thus, assessing the closure times of C/ADP and C/EPI may provide valuable information for monitoring and staging MMVD in dogs.