Indicators for pulmonary hypertension in dogs with degenerative mitral valve disease

Pulmonary hypertension (PH) is a common complication of degenerative mitral valve disease (DMVD) in dogs. This study aimed to determine PH indicators in dogs with stage C DMVD through thoracic radiography and M-mode and 2-dimensional echocardiography.

A retrospective study of 133 dogs with DMVD stage C was conducted. The patients were divided into two groups: DMVD and DMVD with PH. Characteristics, thoracic radiographic findings, and echocardiographic variables were recorded for analysis.

Pulmonary hypertension was diagnosed in 56 dogs, with a prevalence of 42.1%. Univariable logistic regression analysis revealed associations among PH and right-sided heart enlargement, pulmonary artery enlargement, left ventricular size, and percent fractional shortening. Multivariable logistic regression analysis demonstrated that pulmonary artery enlargement (odds ratio [OR]: 5.96; 95% confidence interval [CI]: 1.45-24.54; p = 0.014) and decreased left ventricular size (OR: 0.02; 95%CI: 0.003-0.13; p = 0.001) were significantly associated with PH. The accuracy of predicting PH in dogs at DMVD stage C using pulmonary artery enlargement combined with decreased left ventricular size was moderate (area under the curve [AUC] 0.77; 95%CI: 0.68-0.86).

Pulmonary hypertension is common in dogs with DMVD stage C. The presence of pulmonary artery enlargement assessed by radiography and decreased left ventricular size assessed by echocardiography, were associated with PH and may serve as predictors of PH in DMVD stage C.