First Description of Hypertrophic Cardiomyopathy Phenotype in Apparently Healthy Cats in Morocco: An Echocardiographic Prevalence Study

Hypertrophic Cardiomyopathy Phenotype (HCM-Ph) is the most common group of myocardial disorders in cats. It has been the subject of research worldwide with prevalence rates ranging from 8% to 34%. However, there is no data available on its occurrence in Morocco. This study aimed to investigate the prevalence of HCM-Ph in apparently healthy cats in Morocco, describe the epidemiological and echocardiographic findings of affected cats and to compare patients in ACVIM stages B1 and B2. A total of 81 apparently healthy cats underwent echocardiographic screening. The overall prevalence of HCM-Ph was 9.88% (95% CI: 4.36–18.54%). The median age was four years (IQR 3.5–5.5) and a male overrepresentation (75%) was noted. Affected cats exhibited various echocardiographic patterns of left ventricular hypertrophy, normal left ventricular diameters, preserved fractional shortening and different degrees of left atrial enlargement. Cats in B2 stage were older and had more myocardial hypertrophy compared to cats in B1 stage, highlighting the potential role of wall thickness in clinical staging and risk assessment. Subclinical HCM-Ph is relatively common in apparently healthy cats in Morocco. Veterinarians should be aware of its clinical importance, as despite the fact that it presents no clinical signs, it can have fatal cardiovascular outcomes.