Prognostic indicators in cats with hypertrophic cardiomyopathy

Area of Science:

• Veterinary Cardiology
• Echocardiography
• Feline Medicine

Background:

• Hypertrophic cardiomyopathy (HCM) in cats is linked to reduced survival.
• Left atrial enlargement, congestive heart failure (CHF), and aortic thromboembolism (ATE) are known poor prognostic indicators.
• The prognostic value of specific echocardiographic variables in feline HCM remains incompletely understood.

Purpose of the Study:

• To investigate the prognostic value of left atrial (LA) echocardiographic variables.
• To assess the predictive capability of left ventricular (LV) diastolic and systolic function in cats with HCM.
• To identify echocardiographic predictors of cardiac survival in feline HCM.

Main Methods:

• Retrospective analysis of clinical and echocardiographic records from 282 cats diagnosed with HCM.
• Inclusion criteria: Echocardiographic confirmation of LV diastolic wall thickness ≥ 6 mm.
• Outcomes (cardiac death) were determined from clinical records and veterinarian/owner reports.

Main Results:

• Univariable analysis identified numerous predictors of cardiac death, including age, arrhythmias, CHF, ATE, extreme LV hypertrophy (≥ 9.0 mm), low LV fractional shortening (≤ 30%), regional wall hypokinesis, LA dysfunction, spontaneous echo-contrast/thrombus, and restrictive filling patterns.
• Cox's proportional hazard analysis revealed LA dysfunction, impaired LV systolic function, and extreme LV hypertrophy as independent predictors of decreased cardiac survival.
• LA dysfunction, low LV systolic function, and extreme LV hypertrophy independently predicted decreased cardiac survival time.

Conclusions:

• Echocardiographic assessment of LA function is crucial for feline HCM prognosis.
• Measurement of LV systolic function provides significant prognostic information in cats with HCM.
• Extreme LV hypertrophy is an independent predictor of survival in feline hypertrophic cardiomyopathy.