Echocardiography is the gold standard for feline HCM screening, but a multimodal approach combining physical examination, cardiac biomarkers, and imaging is recommended given the highly variable presentation of the disease. Veterinary Clin…+1

Echocardiography remains the definitive diagnostic test for feline cardiomyopathy. Mild to moderate left ventricular (LV) wall thickening is a diagnosis of exclusion — hyperthyroidism, systemic hypertension, acromegaly, and dehydration must be ruled out before attributing LV hypertrophy to HCM. Journal of Feli… Prevalence estimates using a ≥6 mm LV wall thickness cutoff range from 8.3% to 14.7% in general cat populations; studies using a ≥5.5 mm cutoff report 8.5% to 25% depending on breed. Journal of Vete… Focused cardiac ultrasound by non-specialist practitioners is a recognized option for screening asymptomatic cats when specialist echocardiography is unavailable, though echocardiograms performed by board-certified cardiologists remain the clinical reference standard. Journal of Vete…

Cardiac troponin I (cTnI) is the most sensitive and specific blood-based screening test currently available. Using the Siemens ADVIA Centaur TnI-Ultra assay, a cutoff of >0.06 ng/mL distinguishes healthy cats from cats with HCM with 91.7% sensitivity and 95.4% specificity. For asymptomatic cats with HCM specifically, the same cutoff yields 87.8% sensitivity and 95.4% specificity. Journal of Vete… A separate assay using a cutoff of 0.163 ng/mL achieves 100% specificity but only 62.0% sensitivity for distinguishing healthy cats from asymptomatic HCM cats without left atrial enlargement (LAE), limiting its utility as a screening tool. Journal of Vete… A cutoff of 0.234 ng/mL on that same assay identifies cats in heart failure with 95.0% sensitivity and 77.8% specificity. Journal of Vete… Elevated cTnI is not cardiac-specific — hyperthyroidism, hypertension, renal disease, and critical illness can all increase cTnI concentrations, and echocardiography is required to confirm the diagnosis. Journal of Feli…+1

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is the only point-of-care screening test currently available for occult HCM, but its sensitivity is limited. The rapid point-of-care assay correctly identifies approximately half of cats with moderate-to-severe occult HCM; false negatives occur in cats with mild disease, and false positives occur with chronic kidney disease or non-cardiac respiratory disease. Journal of the…+1 Given the low prevalence of HCM in the general cat population, the clinical value of NT-proBNP screening in every cat must be weighed against the rate of needless echocardiographic follow-up in false-positive cats. Journal of the…

Biomarkers alone are insufficient to diagnose HCM — they should not be relied upon as the sole diagnostic tool, and echocardiographic confirmation is required for any positive screening result. Journal of Feli…+1

Genetic testing is available for breed-specific variants. In Sphynx cats, the ALMS1 variant (g.92439157G>C) is associated with HCM and is highly prevalent in Italian Sphynx populations (allele frequency >0.50); genetic counselling and accurate genotyping are recommended to guide breeding decisions. Animal Genetics Genetic screening is one component of the recommended multimodal approach alongside physical examination, biomarkers, and imaging. Veterinary Clin…

ECG markers including QT interval and QRS duration show potential as ancillary screening tools. Cats with HCM demonstrate prolongation of QTa, QTac, and QRSd, as well as increased short-term instability (STI) of the QT interval compared with healthy cats. Journal of Feli… These ECG markers are not yet established as primary screening tools and are best used as adjuncts to echocardiography. Journal of Feli…

No consensus screening interval has been established in the veterinary literature. The REVEAL study data indicate that the increment of risk for cardiovascular events increases substantially at 2.5 and 5 years after initial evaluation, suggesting these time points are clinically meaningful for re-screening decisions in cats with preclinical HCM. Journal of Vete… Arrhythmias are detected at study entry in approximately 13% of cats with preclinical HCM compared with 4% of apparently healthy cats, supporting the value of periodic cardiac re-evaluation in known preclinical cases. Journal of Vete…

Would you like guidance on how to interpret an equivocal echocardiogram — specifically the workup for mild LV wall thickening that doesn't clearly meet HCM criteria?