Abstract 13456: Screening for Transthyretin Cardiac Amyloidosis Using 99mTc-Pyrophosphate Scintigraphy in Patients Undergoing Transcatheter Aortic Valve Replacement

Background: Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure with preserved ejection fraction (EF). Bone scintigraphy has emerged as a non-invasive imaging approach that is highly sensitive and specific for identifying ATTR-CA. We conducted a prospective cohort study using 99mTc-pyrophosphate scintigraphy (99mTc-PYP) to determine the prevalence of ATTR-CA and other clinical associations with 99mTc-PYP positivity in older patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). Methods: A total of 40 patients (53% men) with severe AS underwent 99mTc-PYP planar cardiac imaging within 30 days of TAVR. Myocardial uptake was assessed with both a semi-quantitative visual score (range 0: no uptake to 3: uptake greater than bone) and by quantitative analysis by drawing a region of interest over the heart, mirroring it to the contralateral chest, and calculating a heart-to-contralateral ratio (HCL). Semi-quantitative score ≥...