TECEOS (Butédronate) - Amylose cardiaque à transthyrétine

Key points

Favourable opinion for reimbursement in cardiac scintigraphy for the diagnosis of transthyretin cardiac amyloidosis (ATTR) (after ruling out light-chain cardiac amyloidosis (AL) by serum and urine immunofixation and serum free light chain assay).

What therapeutic improvement?

No clinical added value in the diagnostic management of transthyretin cardiac amyloidosis (ATTR) (after ruling out light-chain cardiac amyloidosis (AL) by serum and urine immunofixation and serum free light chain assay).

 Role in the diagnostic pathway?

Transthyretin amyloid cardiomyopathy (ATTR-CM) may be suspected in patients presenting heart failure with preserved ejection fraction, in particular. A diagnosis of cardiomyopathy is generally suggested following echocardiography and surface ECG, and confirmed by cardiac scintigraphy.

A diagnosis of ATTR-CM is usually suspected in the event of left ventricular parietal hypertrophy, which is considered to be significant if it is greater than 13 or 14 mm. The cardiovascular conditions described in the disease or related to the disease include, in particular:

• heart failure with preserved ejection fraction;
• atrial arrhythmias: very common in patients with wild-type ATTR;
• conduction disorders: first cardiac manifestation in 7% of patients;
• valve damage: in particular low-flow aortic stenosis, often presenting a specific clinical form (low-flow low-gradient form);
• stroke.

The 2022 European and North American guidelines for patients in whom there is a strong clinical suspicion of cardiac amyloidosis, following exclusion of the presence of serum or monoclonal light chains, recommend the performance of cardiac scintigraphy using metastable technetium-99-labelled radiotracers (^99mTc-DPD, ^99mTc-HDP, ^99mTc-PYP) to confirm the presence of transthyretin amyloidosis.

In adult patients with a family history of hereditary ATTR and symptoms suggestive of the disease, the identification of a mutation by genetic sequencing enables a diagnosis of hereditary ATTR. Genetic counselling may be requested by asymptomatic relatives liable to be carriers of a mutation based on their family history.

Role of the medicinal product in the care pathway:

TECEOS (butedronate) has a role in the diagnostic pathway, in the same way as the other metastable technetium-99-labelled phosphonates (^99mTc-HDP, ^99mTc-PYP) when the current guidelines schedule the performance of cardiac scintigraphy to investigate for the presence of ATTR following the performance of an echocardiogram and after ruling out light-chain cardiac amyloidosis (AL) (by serum and urine immunofixation and serum free light chain assay).

In comparison with endomyocardial biopsy, myocardial scintigraphy is non-invasive and painless for the patient and does not cause any adverse event. Endomyocardial biopsy, a definitive diagnostic test, is only offered in cases of doubt (Perugini grade 1).