Diagnostic Principle with Washout Rate of 123I-β-methyl-p-iodophenyl pentadecanoic Acid for Triglyceride Deposit Cardiomyovasculopathy.

Triglyceride deposit cardiomyovasculopathy (TGCV) (Orphanet ORPHA code: 692305) is an emerging rare adult-onset cardiovascular disease, first identified in Japan. In TGCV, defective intracellular lipolysis of long-chain triglycerides results in cellular steatosis and energy failure, leading to intractable heart failure, diffuse coronary artery disease, and ventricular arrhythmia. A hallmark of TGCV diagnosis is the reduced washout rate (WR) of 123I-β-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a well-established radiopharmaceutical of long-chain fatty acid (LCFA). Recently, the working group of the Japanese Society of Nuclear Cardiology published the practical guideline for measuring 123I-BMIPP-WR. Here, we present the diagnostic principle of TGCV using 123I-BMIPP-WR based upon basic and clinical studies in nuclear cardiology as well as current biochemical insights into TG and LCFA metabolism.