We would like to thank Segovia Cubero and Segovia Moreno for their interesting comment on our published cardiology image.1
First, we should clarify that intense uptake of the amyloid tracer 18F-florbetapir was detected by positron emission computed tomography in our patient. This was accompanied by a typical late gadolinium uptake pattern in the cardiac magnetic resonance imaging and an abdominal fat biopsy positive for Congo red.
As previous articles have indicated, there are no noninvasive tests that can be considered the gold standard for diagnosis.218F-florbetapir can, however, be useful in different aspects of cardiac amyloidosis. In patients with a strong suspicion of heart disease and intense 18F-florbetapir uptake, a negative endomyocardial biopsy could be interpreted as a false negative and a repeat biopsy could be considered. On the other hand, positron emission computed tomography with 18F-florbetapir enables early detection of heart involvement, for which chemotherapy is indicated to reduce amyloid deposition and its irreversible consequences. The article by Dorbala et al.3 even indicates that the deposition of the radiotracer may reflect not only the presence of amyloid but could differentiate between light chain and transthyretin amyloid deposition.
In conclusion, we believe that positron emission computed tomography with 18F-florbetapir can allow assessment of cardiac and extracardiac amyloid deposition4 and improve the diagnosis and management of patients with amyloidosis. As mentioned by the authors, definitive diagnosis of amyloidosis currently requires a histological demonstration of amyloid deposition, whether in the heart or other tissues. Perhaps in the future, after further study, multimodal imaging diagnosis will render biopsy unnecessary.
FUNDINGThis study was supported by a grant to Mariano Linares from the 2014 Program of the Fundación Grupo ERESA.