National patterns in imaging utilization for diagnosis of cardiac amyloidosis: A focus on Tc99m-pyrophosphate scintigraphy

Tc99m-pyrophosphate (tc99m-pyp) scintigraphy has emerged as a diagnostic modality for transthyretin (ttr) cardiac amyloidosis (ca). we sought to examine the variability in test utilization across multiple centers in the us. an electronic, web-based survey addressing specifics on tc-99m pyp imaging was emailed to asnc members, totaling 2785 recipients. only one response per institution was allowed. responses were collected from 101 centers between 2 and 27, 2015. among the respondents, 24% performed tc-99m pyp specifically for ca diagnosis. the most commonly used dose was 20 mci (37%) and most centers (35%) imaged 1 hour after injection. scans were most often interpreted by cardiologists (60%). quantification of uptake was performed in 57% of institutions with almost half (43%) utilizing the heart-to-contralateral lung (h/cl) ratio. this national survey shows relatively low penetrance and high variability in tc99m-pyp scintigraphy for ca diagnosis highlighting the need for standardization.