Angiotensin-converting enzyme inhibition improves cardiac fatty acid metabolism in patients with congestive heart failure.
This study aimed to examine whether angiotensin-converting enzyme (ACE) inhibition improved cardiac fatty acid metabolism in patients with congestive heart failure (CHF). Myocardial 123I-beta-methyl-iodophenylpentadecanoic acid (123I-BMIPP) imaging was performed in 25 patients with CHF and in 10 control subjects. Myocardial 123I-BMIPP images were obtained 30 min and 4 h after tracer injection. The heart-to-mediastinum (H/M) ratio of 123I-BMIPP uptake and the washout rate of 123I-BMIPP from the myocardium were calculated. Patients were given enalapril for 6 months, and 123I-BMIPP imaging was repeated. H/M ratios on early and delayed images were lower in CHF patients than in normal controls (P<0.01). The washout rate of 123I-BMIPP from the myocardium was faster in CHF patients than in controls (P<0.01). As the severity of the New York Heart Association (NYHA) functional class increased, the H/M ratio decreased and the washout rate increased. The washout rate of 123I-BMIPP was inversely correlated with left ventricular fractional shortening (R=-0.62, P<0.01). ACE inhibition with enalapril increased the H/M ratio on delayed images (P<0.05) and reduced the washout rate of 123I-BMIPP (P<0.05) in CHF patients. These data suggest that: (1) angiotensin II-mediated intracellular signalling activation may be a possible mechanism for the decreased myocardial uptake and enhanced washout of 123I-BMIPP in heart failure patients; and (2) the improvement in fatty acid metabolism by ACE inhibition may represent a new mechanism for the beneficial effect of this therapy in heart failure.
Yamauchi
S
S
First Department of Internal Medicine, Yamagata University School of Medicine, Yamagata, Japan. takeishi@med.id.yamagata-u.ac.jp
Takeishi
Y
Y
Minamihaba
O
O
Arimoto
T
T
Hirono
O
O
Takahashi
H
H
Miyamoto
T
T
Nitobe
J
J
Nozaki
N
N
Tachibana
H
H
Watanabe
T
T
Fukui
A
A
Kubota
I
I
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D004656:Enalapril / Q000008:administration & dosage*; D005227:Fatty Acids / Q000378:metabolism* / Q000493:pharmacokinetics; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000187:drug effects*; D006333:Heart Failure / Q000188:drug therapy / Q000378:metabolism*; D006801:Humans; D007462:Iodobenzenes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics
D000806:Angiotensin-Converting Enzyme Inhibitors; D005227:Fatty Acids; D007462:Iodobenzenes; D019275:Radiopharmaceuticals; C049338:iodofiltic acid; D004656:Enalapril