Development and evaluation of a composite echocardiographic score for predicting pulmonary hypertension severity in dogs

Abstract

Background: Tricuspid regurgitation peak velocity (pTRV) is commonly used to estimate pulmonary arterial systolic pressure in dogs but is not always obtainable. Echocardiographic changes may suggest p ulmonary hypertension (PH) probability, but not all of themequallyreflect severity. Hypothesis/Objectives: Develop a composite echocardiographic score predicting p TRV in dogs. Animals: Client-owned dogs (n = 118) undergoing echocardiography for various cardior espiratory reasons. Methods: Multicenter retrospective study of dogs with identifiable tricuspid regurgitation. Echocardiographic findings were categorized into 6 a priori variables consisting of structural and flow-related abnormalities. Variable weighting was explored using regression analysis and cut-off scores were established for predicting pTRV ≥ 3.4 and≥ 4.3 m/s using receiver operating characteristic(ROC)curves,andthepredictiveperformanceofthePHscorealsowasassessed.Correlat ionsbetweenPHscore andpTRVwereanalyzed,andintra-andinterratermeasurementreliability wasevaluated. Results: A final weighted PH score (25-point) incorporated semiquantification of right ventricular (RV) wall thickening (0/1/2 points), RV dilatation (0/2/4/6), right atrial (RA) enlargement (0/2/4/6), pulmonary artery enlargement (0/2/4/6), interventricular septal flattening (0/2/4), and midsystolic notching of RV outflow (0/1). In dogs without severe left atrial enlargement (LAE), 89% of cases were correctly stratified (area under the curve [AUC], 0.95), whereas performance was limited in dogs with postcapillary PH and marked LAE. Five-fold cross-validation identified final recommended thresholds of 3 (predicting pTRV ≥3.4 m/s) and 9(pTRV≥4.3 m/s). The PH score correlated with pTRV (rs = 0.88, P < .001) and showed excellent intraandinter-rater agreement (intraclass correlation coefficient [ICC] > 0.95). Conclusions and clinical importance: The PH score may serve as a complementary tool for evaluating PH i n dogs, particularly in those withoutsevere LAE.