Retrospective evaluation of a right heart parameter score in the assessment of precapillary pulmonary hypertension in dogs (2017–2021): 135 cases

Objective

To determine if emergency and critical care residents can identify moderate to severe precapillary pulmonary hypertension on cardiologist-obtained cineloops using a pulmonary hypertension score (PHS) and report the interobserver variability of the PHS.

Design

Multicenter, retrospective, case–control study from 2017 to 2021.

Setting

Private referral center and veterinary teaching hospital.

Animals

One hundred and thirty-five client-owned dogs that underwent diagnostic echocardiography.

Interventions

None.

Measurements and Main Results

Medical records of dogs with stage B1 myxomatous mitral valve disease (MMVD) and dogs diagnosed with precapillary pulmonary hypertension (PCPH) via echocardiograms were reviewed. Dogs were categorized by a cardiologist into 5 groups (normal, B1 MMVD, mild, moderate, and severe PCPH) based on Doppler pulmonary pressure gradients and right heart morphology. Cineloops from each case were subjectively evaluated by emergency and critical care residents for the presence of right atrial and ventricular enlargement, right ventricular hypertrophy, interventricular septal flattening, and pulmonary artery and trunk enlargement to form a composite pulmonary hypertension score out of 8 (PHS8). When available, signs of peritoneal effusion and distention of the caudal vena cava were subjectively assessed to generate a pulmonary hypertension score out of 10 (PHS10). There was excellent discrimination of moderate to severe PCPH versus grouped absent to mild PCPH using PHS8 (area under the receiver operator curve [AUC] [95% confidence interval, CI] = 0.90 [0.84–0.95], P < 0.0001) and PHS10 (AUC [95% CI] = 0.89 [0.81–0.97], P < 0.0001). PHS8 ≥3 was 64% sensitive and 98% specific for moderate to severe PCPH (positive likelihood ratio [LR+] 32, negative likelihood ration [LR−] 0.37). PHS10 ≥ 3.3 was 64% sensitive and 92% specific for moderate to severe PCPH (LR+ 8, LR− 0.39). Interobserver agreement was good to excellent (intraclass correlation coefficient [ICC] = 0.74 [95% CI: 0.66–0.80], n = 135).

Conclusions

Residents identified moderate to severe PCPH in dogs using PHS on cineloops previously obtained by a cardiologist. The interrater agreement was good to excellent with limited training. Prospective studies to determine if residents can obtain diagnostic images for PHS are warranted.