Carvedilol improves left ventricular function in heart failure patients with idiopathic dilated cardiomyopathy and a wide range of sympathetic nervous system function as measured by iodine 123 metaiodobenzylguanidine.
BACKGROUND
Carvedilol treatment reduces the mortality rate in patients with congestive heart failure. It is not known whether carvedilol treatment is effective in heart failure patients with substantial cardiac sympathetic nerve dysfunction. The goal of this study was to determine the effect of chronic carvedilol treatment in patients with cardiac sympathetic nerve dysfunction of varying severity.


RESULTS
In 22 congestive heart failure patients with idiopathic cardiomyopathy, sympathetic nerve function was assessed before and after 7.2 +/- 2.7 months of carvedilol treatment with the use of iodine 123 metaiodobenzylguanidine (MIBG) imaging, radionuclide ventriculography, and transmyocardial norepinephrine sampling. Patients with relatively advanced impairment of cardiac sympathetic nerve function, as manifested by a baseline I-123 MIBG ratio lower than 1.40, had a statistically significant improvement in I-123 heart-mediastinum ratio with carvedilol treatment, from 1.26 +/- 0.12 to 1.39 +/- 0.20 (P =.004). Of 10 patients with a baseline I-123 MIBG ratio lower than 1.40, 9 had an increase in the heart-mediastinum ratio with carvedilol treatment. Left ventricular ejection fraction increased from 25.4% +/- 7.8% to 37.3% +/- 14.7% (P <.001), with no difference between patients with relatively advanced versus relatively preserved cardiac sympathetic nerve function.


CONCLUSIONS
Most patients with congestive heart failure show a favorable response in left ventricular function to carvedilol treatment, regardless of the baseline level of cardiac sympathetic nervous system function, as assessed by neuronal imaging with I-123 MIBG. Patients with relatively advanced impairment of baseline I-123 MIBG uptake are most likely to show evidence of improved cardiac sympathetic nervous system function in response to carvedilol therapy.
Gerson
Myron C
MC
Division of Cardiology, Department of Internal Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio 45267, USA. myron.gerson@uc.edu
Craft
Laura L
LL
McGuire
Nancy
N
Suresh
Damodhar P
DP
Abraham
William T
WT
Wagoner
Lynne E
LE
D019797:3-Iodobenzylguanidine; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D002227:Carbazoles / Q000008:administration & dosage*; D002311:Cardiomyopathy, Dilated / Q000150:complications; D000077261:Carvedilol; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects / Q000294:innervation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011412:Propanolamines / Q000008:administration & dosage*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging* / Q000187:drug effects; D016896:Treatment Outcome; D014666:Vasomotor System / Q000000981:diagnostic imaging / Q000187:drug effects; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology
D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D019275:Radiopharmaceuticals; D000077261:Carvedilol; D019797:3-Iodobenzylguanidine; D009638:Norepinephrine