Increased myocardial [123I]-metaiodobenzylguanidine uptake after enalapril treatment in patients with chronic heart failure.
OBJECTIVE
To assess non-invasively the effect of enalapril on cardiac sympathetic neuronal uptake function in patients with congestive heart failure, by using [123I]-metaiodobenzylguanidine (MIBG), which is a noradrenaline analogue. Cardiac MIBG uptake was visualised by single photon emission tomography (SPET). In addition, plasma noradrenaline concentration, indicating systemic sympathetic activity, was measured to see whether it was related to cardiac MIBG uptake.


METHODS
Consecutive patients were treated with enalapril and served as their own controls.


METHODS
Cardiac unit of a tertiary care centre.


METHODS
23 Patients with chronic, mild to moderate, stable congestive heart failure, and a left ventricular ejection fraction less than 40%. Heart failure was caused by ischaemic heart disease or was idiopathic.


METHODS
Cardiac MIBG SPET was performed and plasma noradrenaline concentration was measured before and after 6 weeks treatment with enalapril.


METHODS
Cardiac uptake of MIBG was measured by using the left ventricular cavity and a venous blood sample as a reference.


RESULTS
Cardiac uptake of MIBG increased significantly after enalapril treatment, indicating improved cardiac neuronal uptake function. Plasma noradrenaline concentration did not decrease significantly. Cardiac MIBG uptake was not related to plasma noradrenaline concentration.


CONCLUSIONS
Cardiac MIBG SPET can be used to assess changes in cardiac sympathetic neuronal uptake function caused by pharmacological intervention. Enalapril seemed to improve cardiac sympathetic neuronal uptake function but did not significantly affect plasma noradrenaline concentrations in a group of patients with predominantly moderate heart failure. These results accord with the hypothesis that restoration of cardiac neuronal uptake of noradrenaline is one of the beneficial effects of enalapril in such patients.
Somsen
G A
GA
Department of Cardiology, Academic Medical Centre, Amsterdam, Netherlands.
van Vlies
B
B
de Milliano
P A
PA
Borm
J J
JJ
van Royen
E A
EA
Endert
E
E
Lie
K I
KI
D019797:3-Iodobenzylguanidine; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D002908:Chronic Disease; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000187:drug effects; D006333:Heart Failure / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism; D007462:Iodobenzenes / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000097:blood; D011446:Prospective Studies; D013565:Sympatholytics / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon
D000806:Angiotensin-Converting Enzyme Inhibitors; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D013565:Sympatholytics; D019797:3-Iodobenzylguanidine; D004656:Enalapril; D009638:Norepinephrine