0082: Multimodality imaging in cardiac amyloidosis: respective contributions of echocardiography, MRI and scintigraphy

Amyloidosis(A) prognosis is determined by cardiac involvement.The main types of A are immunoglobulin light chain(AL) and transthyretin-related(TTR), which can be mutated(TTRm) or senile(TTRwt). Specific treatments can’t be administrated unless A has been typed histologically.Literature suggests echocardiography, 99m Tc DPD scintigraphy and cardiac MRI could help typing A. We described these imaging modalities to assess these potential tools for an uninvasive typing. We analysed these imaging modalities in patients examined at Cardiomyopathies Competence Center(CCC) of La Timone Hospital in Marseille, with an histologically proven diagnosis of cardiac A(CA). We included 75patients examined between September 2006 and March 2014 at CCC, with a strongly suspected diagnosis of CA.CA could be histologically confirmed and typed in 45 patients(10 TTRm, 4 TTRwt, 6 TTR undeterminated; 19 AL;6 of other type).In 11 patients, CA was confirmed but untyped.No statistically significant difference was found between TTR and AL patients for the various imaging modalities.We observed 71% of men, aged 66, NYHA stage 2,4 on average.In all patients, cardiac biomarkers rates were increased. Myocardic mass and interventricular septal thickness were increased (199g/m² and 19mm), restrictive filling pattern was observed in 83% of patients.Despite a relatively preserved left ventricular ejection fraction, Global Longitudinal Strain was impaired at – 11%, with an apical sparing. Scintigraphy showed a frequent myocardic fixation (69%), slightly more intense in TTR patients.Cardiac MRI showed a constant late gadolinium enhancement, more extended in AL patients. We didn’t observe the differences described between CA types, probably because of a lack of statistical power.This encouraged us to develop a protocol for multidisciplinary evaluation of CA, to improve the management of this disease, and to keep on evaluating the diagnostic accuracy of these imaging modalities.