Background and Aim: Myxomatous mitral valve disease (MMVD) is the most common cardiac disorder in dogs and is frequently associated with progressive cardiac remodeling and pulmonary hypertension (PH). Increasing evidence suggests that systemic inflammation contributes to disease progression; however, the clinical relevance of inflammatory biomarkers in relation to cardiac structural changes and outcomes remains incompletely understood. This study aimed to evaluate the associations between C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), cardiac remodeling indices, PH, and survival outcomes in dogs with MMVD. Materials and Methods: A retrospective cohort study was conducted using medical records of 94 client-owned dogs diagnosed with MMVD between 2023 and 2025. Dogs were classified according to the American College of Veterinary Internal Medicine (ACVIM) stages (B1–D). Echocardiographic parameters, including left atrial (LA) volume, LA/Ao ratio, and left ventricular internal diameter, were assessed alongside PH status determined by tricuspid regurgitation velocity. Hematologic parameters and serum CRP concentrations were analyzed. Correlation, regression, receiver operating characteristic (ROC), and survival analyses were performed to determine associations and prognostic value. Results: LA enlargement was observed in 84.0% of dogs and increased with disease severity. CRP and NLR showed weak but statistically significant positive correlations with indexed LA volume (CRP: r = 0.31, p < 0.01; NLR: r = 0.29, p < 0.05). Neither biomarker demonstrated a significant association with PH. Indexed LA volume, rather than inflammatory biomarkers, was more strongly associated with echocardiographic indicators of PH risk. CRP exhibited moderate diagnostic performance for PH (area under the curve = 0.7517, p < 0.001), whereas NLR showed poor discrimination. Survival analysis revealed that dogs with elevated CRP levels and concurrent PH had significantly reduced survival probabilities. Although NLR increased with disease progression, its prognostic utility remained limited. Conclusion: Systemic inflammatory biomarkers, particularly CRP, are modestly associated with cardiac remodeling and survival in dogs with MMVD but are not reliable predictors of PH. Echocardiographic indices, especially LA remodeling, remain superior indicators of disease severity and PH risk. While CRP may provide adjunctive prognostic value, its clinical application should be interpreted cautiously alongside established imaging parameters. Keywords: cardiac remodeling, c-reactive protein, dog, myxomatous mitral valve disease, neutrophil-to-lymphocyte ratio, pulmonary hypertension, survival analysis, veterinary cardiology.

Transcatheter edge-to-edge repair (TEER) is a recent minimally invasive method of managing mitral regurgitation (MR) in dogs with myxomatous mitral valve disease (MMVD). The goal of interventions is to minimize MR severity. The objective of this study was to determine the association between reduced MR and changes in myocardial work indices after TEER in dogs. Client-owned dogs with moderate-to-severe MR were enrolled in the study. TEER performance was completed with multimodal imaging guidance in all 10 dogs. Before and after the procedure, myocardial work was analyzed. MR severity, transmitral pressure gradients, left atrial and ventricular measurements, and index of myocardial work (GWI, GCW, GWW, and GWE) were calculated. TEER significantly reduced MR severity in the majority of dogs. MR decrease was associated with a greater efficiency of myocardial work, more constructive work, and less wasted energy. No significant negative associations of moderate post-procedure gradients with short-term clinical outcomes emerged. TEER-mediated reduction of MR improves myocardial function in dogs. However, long-term studies are also needed to examine the effects of residual MR and transmitral gradients on cardiac function and clinical outcome.

Transcatheter edge-to-edge repair (TEER) is a recent minimally invasive method of managing mitral regurgitation (MR) in dogs with myxomatous mitral valve disease (MMVD). As the goal of intervention is to minimize MR severity, this study aimed to determine the association between reduced MR and changes in myocardial work indices after TEER in dogs. Ten client-owned dogs with moderate-to-severe MR were enrolled in the study, and all underwent TEER with multimodal imaging guidance. Myocardial work was analyzed before and after the procedure, and the MR severity, transmitral pressure gradients, left atrial and ventricular measurements, and index of myocardial work (GWI: the total myocardial work during systole; GCW: work contributing to LV ejection; GWW: ineffective work that contributes to no forward displacement; and GWE: ratio of constructive work to total work) were calculated. TEER significantly reduced MR severity in the majority of dogs, and this MR decrease was associated with a greater efficiency of myocardial work, more constructive work, and less wasted energy. No significant negative associations of moderate post-procedure gradients with short-term clinical outcomes emerged. TEER-mediated reduction in MR improves myocardial function in dogs. However, long-term studies are also needed to examine the effects of residual MR and transmitral gradients on cardiac function and clinical outcome.

Mitral valve regurgitation (MR) remains a common health problem in dogs. The typical pathophysiological consequences of mitral valve diseases, regardless of the etiology, are left atrial (LA) dilatation and pulmonary hypertension (PH). Medical records of dogs diagnosed with mitral valve disease between June 2023 and June 2025 were retrospectively reviewed. Mitral valve cases were evaluated for signalment, blood profiles, echocardiographic parameters, and survival. Client-owned dogs (n = 94) had a mean age of 11.18 ± 2.9 years; 46.8% were males with MMVD stages B to D, as assessed using the ACVIM consensus guidelines (2019). LA volume was evaluated using the Simpson biplane method. PH was defined on the basis of transthoracic echocardiography. Dogs were followed monthly and underwent a physical examination, blood work, and echocardiogram assessment. Ninety-four dogs had a history of left atrial dilation, which was present in 84.0% of cases. Left ventricular (LV) fractional shortening was 33.37 ± 8.41%. The LA volume and MR SV were 5.87 ± 4.21 ml and 1.28 ± 2.09 mm², respectively. Age, body weight, left ventricular end-diastolic volume, left atrial volume, and mitral valve stroke volume were univariately associated with both the CRP level and the NLR. The CRP level and NLR were related to LA volume according to correlation analyses using Pearson’s r (P < 0.01), yet the NLR was not predictive of pulmonary hypertension according to univariate models. In this population of dogs at high risk for developing pulmonary hypertension, the CRP level and NLR were associated with left atrial (LA) volume and were not predictive of pulmonary hypertension. In contrast, the indexed LA volume was related to clinical risk factors for predicting the development of pulmonary hypertension. CRP demonstrated good diagnostic performance with a statistically significant discriminatory ability, whereas the NLR showed limited diagnostic value with no statistical significance. Higher CRP levels and NLRs were associated with a decreased survival probability, and canine patients without pulmonary hypertension had significantly better outcomes at lower biomarker levels. CRP levels and the NLR may serve as valuable prognostic markers, particularly in non-PH populations.