RÉSUMÉ
OBJECTIVES: This study aimed to identify indicators of the risk of progression of preclinical hypertrophic cardiomyopathy (HCM). METHODS: This was a prospective cohort study following a population of cats with preclinical HCM. Cats serially underwent physical examination, blood pressure measurement, blood sampling and echocardiography. Development of congestive heart failure (CHF), arterial thromboembolism (ATE) or sudden death (SD) were considered cardiac-related events. Associations between factors recorded at baseline, and on revisit examinations, and the development of a cardiac-related event were explored using receiver operator characteristic (ROC) analysis. RESULTS: Forty-seven cats were recruited to the study and were followed for a median period of 1135 days. Fifteen cats (31.9%) experienced at least one cardiac-related event; six CHF, five ATE and five SD. One cat experienced a cardiac-related event per 10.3 years of patient follow-up. Cats with increased left atrial (LA) size and higher concentrations of N-terminal pro B-type natriuretic peptide (NTproBNP) at baseline were more likely to experience an event. Cats with a greater rate of enlargement of LA size between examinations were also more likely to experience an event. CONCLUSIONS AND RELEVANCE: Factors easily measured, either once or serially, in cats with preclinical HCM can help to identify those at greater risk of going on to develop clinical signs.