Cardiac amyloid imaging with ¹⁸F-florbetaben positron emission tomography: a pilot study

Abstract

Aim: Determine the feasibility of ¹⁸F-florbetaben positron emission tomography (PET) in diagnosing cardiac amyloidosis. Methods: ¹⁸F-florbetaben PET was performed in 14 subjects: 5 light chain (AL) amyloid, 5 transthyretin (ATTR) amyloid, and 4 control subjects with hypertensive heart disease. Qualitative and quantitative assessments of ¹⁸F-florbetaben activity were performed using mean standardized uptake value (SUV) of the left ventricular (LV) myocardium and blood pool, and calculation of target-to-background SUV ratio. Percentage myocardial ¹⁸F-forbetaben retention was also calculated as the percentage mean myocardial SUV change between 0–5mins and 15–20mins after radiotracer injection. Global LV longitudinal and right ventricular (RV) free wall longitudinal strain were calculated using 2D speckle tracking echocardiography. Results: Target-to-background SUV ratio and percentage myocardial ¹⁸F-forbetaben retention were higher in amyloid patients compared to hypertensive control subjects. A cut-off value of 40% was able to differentiate between cardiac amyloid patients and hypertensive control subjects. Percentage myocardial ¹⁸F-forbetaben retention was an independent determinant of both global LV longitudinal and RV free wall longitudinal strain via an inverse curve relationship. Conclusion: ¹⁸F-florbetaben PET imaging can accurately identify and differentiate between cardiac amyloidosis and hypertensive heart disease. Percentage myocardial ¹⁸F-florbetaben retention was an independent determinant of myocardial dysfunction in cardiac amyloidosis.