Practice recommendation for measuring washout rates in 123I-BMIPP fatty acid images

Abstract

The purpose of this practice recommendation is to specifically identify the critical steps involved in performing and interpreting 123I-β-methyl-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) and measurement of washout rate (WR) from the heart. This document will cover backgrounds, patient preparation, testing procedure, visual image interpretation, quantitation methods using planar and SPECT studies, and reporting of WR. The pitfall and some tips for the calculation of 123I-BMIPP WR are also included. The targets of global and regional WR calculation include ischemic heart disease, cardiomyopathy, heart failure, and triglyceride deposit cardiomyovasculopathy, an emerging rare heart disease.

Distinct myocardial triglyceride lipolysis pathways in primary and idiopathic triglyceride deposit cardiomyovasculopathy

“…Then, TG-BMIPP is hydrolysed by intracellular lipases including ATGL, and eventually, its catabolites are washed out from cardiomyocytes. [2][3][4] Thus, BMIPP-WR, defined as a % count reduction between early and delayed images in myocardial scintigraphy, 5 reflects lipolysis of TG in the heart. 2,3 We developed the diagnostic criteria for TGCV in which low BMIPP-WR was included as an essential item and have identified ~200 patients by December 2021.…”

“… 3 In both types, defective TG lipolysis can be evaluated using scintigraphy by calculating the washout rates (WR) of 123 I‐β‐methyl‐p‐iodophenyl‐pentadecanoic acid (BMIPP), 2 , 3 an established radiopharmaceutical of LCFA analogue. 4 , 5 After intravenous administration, BMIPP is taken up by cell surface transporters including CD36. Approximately 90% of cellular BMIPP form TG‐BMIPP and are incorporated into TG pool.…”

“…Then, TG‐BMIPP is hydrolysed by intracellular lipases including ATGL, and eventually, its catabolites are washed out from cardiomyocytes. 2 , 3 , 4 Thus, BMIPP‐WR, defined as a % count reduction between early and delayed images in myocardial scintigraphy, 5 reflects lipolysis of TG in the heart. 2 , 3 …”

“…BMIPP scintigraphy and measurement of BMIPP‐WR were performed according to the recommendation by the Japan Society of Nuclear Cardiology. 5 The P‐TGCV patient was a 34‐year‐old man with HF, homozygous for a large deletion of PNPLA2 (Gene ID: LC508023). The patient's BMIPP‐WR was −4.5% (<10% BMIPP‐WR, the cutoff for TGCV diagnosis 5 ).…”

“… 5 The P‐TGCV patient was a 34‐year‐old man with HF, homozygous for a large deletion of PNPLA2 (Gene ID: LC508023). The patient's BMIPP‐WR was −4.5% (<10% BMIPP‐WR, the cutoff for TGCV diagnosis 5 ). The 17 I‐TGCV patients included 15 men and 2 women (mean age: 66.1 ± 12.7 years).…”