To the Editor We read with great interest the article by Castano et al1 and commend the authors on their continuous excellent work in this field. Technetium pyrophosphate scintigraphy has become a cornerstone of the noninvasive diagnostic algorithm in cardiac amyloidosis, and the authors used a retrospective cohort from 3 respected centers to conclude that a heart-to-contralateral (H/CL) ratio greater than 1.6 was associated with worse survival among patients with transthyretin amyloidosis (ATTR). However, there are some points to discuss before this particular number becomes widely used as a prognostic marker.
Sperry BW, Brunken R, Jaber WA. Prognosis Using Planar Imaging in Cardiac Amyloidosis. JAMA Cardiol. 2017;2(6):704. doi:10.1001/jamacardio.2016.5885