Arterial thromboembolism: risks, realities and a rational first-line approach

Area of Science:

• Veterinary Cardiology
• Thrombosis Research
• Feline Medicine

Background:

• Feline arterial thromboembolism (ATE) is a critical complication of myocardial disease, frequently leading to euthanasia.
• It arises from endothelial dysfunction and blood stasis, causing platelet activation and thrombus formation in the left atrium.
• Thrombus embolisation results in severe ischemia, with diagnosis often aided by the classic 'saddle thrombus' in the aorta.

Observation:

• Cats with left atrial enlargement due to cardiomyopathy are primarily at risk.
• Other predisposing conditions include hyperthyroidism, pulmonary neoplasia, and supravalvular mitral stenosis.
• Pain management is critical, with methadone or fentanyl infusions for severe pain; furosemide treats congestive heart failure, but tachypnea can be misleading.

Findings:

• Thrombolytic therapy is not advised for feline arterial thromboembolism.
• Antithrombotic treatment should commence promptly, with aspirin and clopidogrel demonstrating good tolerability.
• While observational studies exist, randomized controlled trials on ATE prevention or treatment in cats are limited, though one comparing aspirin and clopidogrel is ongoing.

Implications:

• Prompt initiation of antithrombotic therapy is crucial for improving outcomes in cats with ATE.
• Accurate diagnosis and differentiation of pain-induced tachypnea from congestive heart failure are vital for appropriate management.
• Further research, particularly randomized controlled trials, is needed to establish definitive treatment and prevention strategies for feline arterial thromboembolism.