The use of focused cardiac ultrasound to screen for occult heart disease in asymptomatic cats

Abstract

Background: Focused cardiac ultrasound (FCU) helps detect occult heart disease in human patients. Hypothesis: Focused cardiac ultrasound by a nonspecialist practitioner (NSP) will increase the detection of occult heart disease in asymptomatic cats compared with physical examination and ECG. Animals: Three hundred forty-three client-owned cats: 54 excluded and 289 analyzed. Methods: Multicenter prospective cohort study. Twenty-two NSPs were trained to perform FCU. Cats without clinical signs of heart disease were recruited, and NSPs performed the following in sequential order: physical examination, ECG, FCU, and point-of-care N-terminal pro-B-type natriuretic peptide assay (POC-BNP). After each step, NSPs indicated yes, no, or equivocal as to whether they believed heart disease was present. The level of agreement between the NSP diagnosis and a blinded cardiologist's diagnosis after echocardiogram was evaluated using Cohen's kappa test. Results: Cardiologist diagnoses included 148 normal cats, 102 with heart disease, and 39 equivocal ones. Agreement between NSP and cardiologist was slight after physical examination (kappa 0.253 [95% CI, 0.172-0.340]), did not increase after ECG (0.256 [0.161-0.345]; P =.96), increased after FCU (0.468 [0.376-0.558]; P =.002), and the level of agreement was similar after POC-BNP (0.498 [0.419-0.580]; P =.67). In cats with mild, moderate, and marked occult heart disease, the proportion of cats having a NSP diagnosis of heart disease after FCU was 45.6%, 93.1%, and 100%, respectively. Conclusions and Clinical Importance: Focused cardiac ultrasound performed by NSPs increased the detection of occult heart disease, especially in cats with moderate to marked disease. Focused cardiac ultrasound appears to be a feasible and useful tool to assist NSPs in the detection of heart disease in cats.