Scintigraphic evaluation of myocardial ischaemia using a new fatty acid analogue: iodine-123-labelled 15-( p -iodophenyl)-9-( R , S )-methylpentadecanoic acid (9MPA)

Abstract

Iodine-123-labelled 15-(p-iodophenyl)-9-(R,S)-methylpentadecanoic acid (9MPA) is a branched fatty acid analogue for myocardial imaging, which has been recently designed for medium washout rates from the myocardium. The purpose of this study was to assess the clinical feasibility of use of 9MPA for the evaluation of myocardial ischaemia. Twenty-one patients were injected with 9MPA at rest, and sequential single-photon emission tomography (SPET) acquisitions were performed 5, 45 and 240 min after administration to calculate washout rates from the myocardium. The findings of 9MPA images were analysed in comparison with those of perfusion images with thallium-201 or sestamibi, coronary angiography and left venticulography. In general, reduction of 9MPA uptake was more remarkable than that of perfusion tracers. The findings of 9MPA early images correlated better with those of exercise perfusion images than with the rest images. Measured washout rates of 9MPA from ischaemic myocardium were significantly slower than those from normal myocardium. The majority of areas with abnormal 9MPA distribution manifested wall motion abnormality, while all areas with normal tracer distribution presented normal wall motion. The detectability of myocardial ischaemia was improved by adding mid and delayed images in six cases. However, both washout and fill-in patterns were encountered in ischaemic lesions, rendering the interpretation of images difficult. In conclusion, the results of this study indicated that 9MPA has acceptable myocardial uptake, that its use is feasible for the detection of ischaemia and that the abnormal distribution of the tracer correlates well with wall motion abnormality reflecting metabolic disorders.

Ischemic preconditioning accelerates the fatty acid oxidation of rat hearts

“…Thus, alterations in fatty acid metabolism are considered a sensitive marker of ischemia. Branched-chain fatty acid analogs such as 123 I-BMIPP and 123 I-9MPA have been clinically applied to assess fatty acid metabolism in patients with coronary heart disease [11][12][13]15,16]. Slow recovery of the tracer uptake after ischemic insult has been found in clinical and experimental studies [18,21], a finding consistent with the present study which was performed 3 days after ischemia-reperfusion.…”

“…In contrast to a straight chain fatty acid, methyl-branched fatty acid analogs such as BMIPP are expected to interfere with β-oxidation because the metabolic process requires α-oxidation before β-oxidation [14]. Recently, a fatty acid tracer of 15-(piodophenyl)-9-methylpentadecanoic acid (9MPA) was developed for clinical use [15,16]. This tracer is converted to an intermediate metabolite of 3-methylnonanoic acid (3MNA) after 3 cycles of β-oxidation and then α-oxidation is required for further metabolic process.…”

Biodiversity of Jinggangshan Mountain: The Importance of Topography and Geographical Location in Supporting Higher Biodiversity

“…Topography is an important factor affecting vegetation structure and species diversity by providing (micro-) habitat heterogeneity [ 82 , 83 , 84 ]. The habitat-heterogeneity hypothesis states that more complex habitats contain more niches and therefore higher species richness [ 15 ].…”

Initial evaluation of 99m Tc-tricarbonyl-cyclopentadienyl fatty acids derivatives as SPECT tracers for myocardium

“…15‐(p‐[ 123 I]iodophenyl) 3‐methylpentadecanoic acid (BMIPP) is eliminated slowly from the myocardium by introducing a methyl branch in the β‐position of [ 123 I]‐IPPA. Another branched FA analogue is iodine‐123‐labeled‐15‐(p‐iodophenyl)‐9‐(R,S)‐methylpentadecanoic acid (9MPA), which inserted a methyl branch in the ninth carbon location of [ 123 I]‐IPPA. A methyl branch was introduced to hinder FAs metabolic and enhance myocardial retention.…”