Description of a different quantification method for amyloid burden (DPDload) and validation of SPECT/CT in cardiac amyloidosis

Abstract

Background: Bone tracers such as ^99mTc-DPD have shown high sensitivity and specificity in the non-invasive diagnosis of transthyretin cardiac amyloidosis (ATTR-CA). This study aims to validate SPECT/CT and assess the usefulness of uptake quantification (DPDload) in the myocardial tissue as potential information on the amyloid burden.

Methods: In a retrospective analysis of 46 patients with suspected CA, 23 cases with ATTR-CA had two quantification methods conducted to estimate amyloid burden (DPDload) through planar scintigraphic scans and a SPECT/CT.

Results: SPECT/CT significantly provided an added value in the patient's diagnosis with CA (P<.05). The estimation of the amyloid burden substantiated that the most affected wall of the LV is the interventricular septum in most cases and the existence of a significant relationship between the Perugini score uptake and the DPDload.

Conclusions: We validate the need for SPECT/CT to complement planar imaging in diagnosing ATTR-CA. For its part, quantifying the amyloid load continues to be a complex area of research. It requires further studies with a larger number of patients to validate a standardized method of amyloid load quantification, both for diagnosis and treatment monitoring.

Keywords: Amiloidosis cardiaca; Amyloid burden quantification; Cardiac amyloidosis; Cuantificación de la carga amiloide; DPDload; Light chain protein; Proteína de cadena ligera; Transthyretin; Transtirretina.