Clinical Investigations: Imaging and Diagnostic TestingEvaluation of β-blocker therapy in patients with dilated cardiomyopathy—Clinical meaning of iodine 123–metaiodobenzylguanidine myocardial single-photon emission computed tomography☆
Section snippets
Subjects
Subjects were 58 patients with DCM (51 male and 7 female, mean age 54 ± 11 years) whose diagnosis was confirmed by the handbook for diagnosis of the Japanese Ministry of Health and Welfare. Cardiac catheterization revealed no significant (50% or higher) coronary artery stenosis in any of the patients, and DCM was definitively diagnosed from myocardial biopsy specimens. The 58 cases complicated by acute heart failure were treated with digitalis, diuretics, or vasodilators. 123I-MIBG myocardial
Data acquisition by 123I-MIBG myocardial SPECT
With each patient resting, 111 MBq (3 mCi) of 123I-MIBG was intravenously administered, and 123I-MIBG myocardial SPECT images were obtained at 20 minutes (early image) and 4 hours (delayed image) after administration of 123I-MIBG. The images were taken by PRISM-3000 (Picker, Cleveland, Ohio/Shimadzu, Kyoto, Japan), a triple-head gamma camera equipped with a low-energy, general all-purpose collimator. Data were collected with a matrix size of 64 × 64 and a mode adjusted to step and sheet, 5
Comparison between LVEF and extent score/severity score of 123I-MIBG
There was a significant correlation between LVEF and extent score (r = –0.433, P <.001) or severity score (r = –0.405, P <.001) among the 143 early 123I-MIBG images (Figure 1).A significant correlation was also found between LVEF and extent score (r = –0.503, P <.001) or severity score (r = –0.494, P <.001)
Discussion
It has been reported that β-blocker therapy improves cardiac function and exercise tolerance and at the same time lowers mortality rates in patients with chronic heart failure.4, 5, 6, 7, 8, 9 In cases of severe cardiac failure, however, β-blocker administration aggravates cardiac function. It is also not the case that β-blocker will be effective for all cases, and there are still no established criteria for dosage and duration of dosage.15 Clinical symptoms, LVEF, pulmonary arterial wedge
References (29)
- et al.
Predicting survival for an individual with congestive heart failure using the plasma norepinephrine concentration
Am Heart J
(1987) - et al.
Prolongation of survival in congestive cardiomyopathy by beta-receptor blockade
Lancet
(1979) Benefit of beta-blockers for heart failure: proven in 1999
Lancet
(1999)Beta blocker treatment in heart failure
Prog Cardiovasc Dis
(1999)- et al.
Long-term β-blocker vasodilator therapy improves cardiac function in idiopathic dilated cardiomyopathy: a double-blind, randomized study of bucindolol versus placebo
Am J Med
(1990) - et al.
Etiology and response to drug treatment in heart failure
J Am Coll Cardiol
(1998) - et al.
Iodine-123 metaiodobenzylguanidine myocardial scintigraphy for prediction of response to β-blocker therapy in patients with dilated cardiomyopathy
Am Heart J
(1997) - et al.
Effects of carvedilol on left ventricular mass, chamber geometry, and mitral regurgitation in chronic heart failure
Am J Cardiol
(1999) - et al.
Increased β-receptor density and improved hemodynamic response to catecholamine stimulation during long-term metoprolol therapy in heart failure from dilated cardiomyopathy
Circulation
(1989) - et al.
Plasma norepinephrine as a guide to prognosis in patients with chronic congestive heart failure
N Engl J Med
(1984)
Effect of chronic beta-adrenergic receptor blockade in congestive cardiomyopathy
Br Heart J
Benefical effects of long-term beta-blockade in congestive cardiomyopathy
Br Heart J
Newer drug therapy for congestive heart failure
Arch Intern Med
Myocardial imaging with radioiodinated norepinephrine storage analog
J Nucl Med
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Reprint requests: Junichi Yamazaki, MD, First Department of Internal Medicine, Ohmori Hospital, Toho University School of Medicine, 6-11-1 Ohmori-Nishi, Ohta-ku, Tokyo, 143 Japan.