Isidoro Matos, JorgeCaro Vadillo, AliciaFalcón-Cordón, YaizaGarcía-Rodríguez, Sara NievesCosta-Rodríguez, NoeliaCarretón, ElenaMontoya-Alonso, José Alberto2024-04-252024-04-252023-02-17Matos, J.I.; Caro-Vadillo, A.; Falcón-Cordón, Y.; García-Rodríguez, S.N.; Costa-Rodríguez, N.; Carretón, E.; Montoya-Alonso, J.A. Echocardiographic Assessment of the Pulmonary Vein to Pulmonary Artery Ratio in Canine Heartworm Disease. Animals 2023, 13, 703. https:// doi.org/10.3390/ani1304070310.3390/ani13040703https://hdl.handle.net/20.500.14352/103544Dirofilaria immitis produces proliferative pulmonary endarteritis and pulmonary thromboembolism in infected dogs. The pulmonary vascular lesions lead to irreversible and persistent structural damage and, as a consequence, sustained precapillary pulmonary hypertension (PH). The purpose of this study was to assess the diagnostic value of the pulmonary vein to pulmonary artery ratio (PV:PA ratio) to determine moderate or severe PH (>50 mmHg) in dogs with heartworm disease. Methods: A total of 151 naturally heartworm-infected and 66 healthy dogs were included in the study. The presence/absence of PH was based on the right pulmonary artery distensibility index (RPAD index < 29.5%), and the PV:PA ratio was echocardiographically measured by the time–motion mode (M mode) and two-dimensional mode (2D mode). Other echocardiographic parameters were also assessed (pulmonary trunk to aorta ratio, tricuspid regurgitation pressure gradient, and AT:ET ratio). Results: The results of the PV:PA ratio showed a highly positive correlation between the M and 2D modes (r = 0.928). The PV:PA ratio obtained by the M mode was identified as the strongest predictor for RPAD index (R2 0.628, p < 0.0001) with a good diagnostic accuracy (AUC = 0.99). The results of PV/PA by the 2D mode showed a similar prediction for the RPAD index (R2 0.606, p < 0.0001) with a good diagnostic accuracy (AUC = 0.98). Both of the 2D and M modes’ PV:PA ratios decreased significantly with the presence of PH. A cut-off value of ≤0.845 showed high sensitivity and specificity for the M mode (97% and 94%, respectively) and the 2D mode (96% and 93%, respectively). Conclusions: The PV:PA ratio may be useful as a complementary diagnostic method for the estimation of moderate or severe PH in dogs with heartworm.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article2076-2615https://doi.org/10.3390/ani1304070336830490open access636.7616.12Dirofilaria immitis;Heartworm diseasePulmonary veinPulmonary arteryPV:PA ratioRPAD indexPulmonary hypertensionAnimal diseasesVeterinaria3109 Ciencias Veterinarias