Hereditary transthyretin amyloid cardiomyopathy

Cardiac amyloidosis develops when abnormal proteins become unstable, misfold and build up as amyloid deposits within the heart muscle. These deposits make the heart walls thicker and stiffer, reducing the heart's ability to relax and pump blood effectively. The two main forms are light-chain (AL) amyloidosis, caused by abnormal antibody proteins produced by bone marrow cells, and transthyretin (ATTR) amyloidosis, caused by deposits of transthyretin protein that may be inherited or develop with ageing. Over time, this protein build-up can lead to heart failure and rhythm problems³⁻⁴.

Symptoms of cardiac amyloidosis often develop gradually and can resemble other heart conditions, which may delay diagnosis. Common symptoms include breathlessness, tiredness, swelling of the ankles or legs, dizziness or fainting, and palpitations or irregular heartbeats. Some people may also experience symptoms affecting other parts of the body, such as carpal tunnel syndrome, numbness or tingling in the hands or feet, low blood pressure when standing, digestive problems or spinal stenosis. These wider symptoms can provide important clues to the diagnosis³⁻⁴.

Diagnosing cardiac amyloidosis requires a combination of clinical assessment and specialist investigations. Doctors may suspect the condition in people with unexplained heart failure, increased heart wall thickness or associated symptoms such as carpal tunnel syndrome. Investigations can include electrocardiography (ECG), echocardiography, cardiac MRI and nuclear imaging scans, together with blood and urine tests to identify or exclude light-chain disease. In some cases, a tissue biopsy may be needed to confirm amyloid deposits and identify the specific amyloid type, which is essential because treatment depends on the underlying cause³⁻⁴.

Treatment for cardiac amyloidosis aims to manage heart symptoms and slow or stop further amyloid build-up. Supportive treatment may include medicines to relieve fluid build-up and heart failure symptoms, although some standard heart failure medicines may be less effective or poorly tolerated. Disease-specific treatment depends on the amyloid type. AL amyloidosis is typically treated with therapies that target the abnormal bone marrow cells producing light chains, while ATTR amyloidosis may be treated with transthyretin stabilising or gene-silencing medicines designed to slow disease progression. Early diagnosis is important because treatment is generally more effective before significant heart damage develops³⁻⁴.