Published in:
01-02-2005 | Original Article
Cardiac metaiodobenzylguanidine activity can predict the long-term efficacy of angiotensin-converting enzyme inhibitors and/or beta-adrenoceptor blockers in patients with heart failure
Authors:
Tomoaki Nakata, Takeru Wakabayashi, Michifumi Kyuma, Toru Takahashi, Kazufumi Tsuchihashi, Kazuaki Shimamoto
Published in:
European Journal of Nuclear Medicine and Molecular Imaging
|
Issue 2/2005
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Abstract
Purpose
Although the benefits of treatment with angiotensin-converting enzyme (ACE) inhibitors and beta-blockers are well known, no method has as yet been established to predict the efficacy of drug therapy. This study tested whether cardiac 123I-metaiodobenzylguanidine (MIBG) activity is of prognostic value and can predict the improvement in heart failure patients resulting from treatment with ACE inhibitors and/or beta-blockers.
Methods
Following quantification of the heart-to-mediastinum ratio (HMR) of MIBG activity, 88 patients with heart failure who were treated with ACE inhibitors and/or beta-blockers (treated group) and 79 patients with heart failure who were treated conventionally without the aforementioned agents, and who served as controls, were followed up for 43 months with a primary endpoint of cardiac death.
Results
The treated group had a significantly lower prevalence of cardiac death and a significantly lower mortality at 5 years compared with the control group (15% vs 37% and 21% vs 42%, p<0.05, respectively). Multivariate analysis revealed that significant predictors were HMR, age, nitrate use and ventricular tachycardia for the treated group, and HMR, nitrate use and NYHA class for the control group. The drug treatment significantly reduced mortality from 36% to 12% when HMR was 1.53 or more and from 53% to 37% when HMR was less than 1.53. The reduction in risk of mortality within 5 years in patients without a severe MIBG defect (67%) was twice that in patients with such a defect (32%) (p<0.05).
Conclusion
The reduction in mortality risk achieved by using ACE inhibitors and/or beta-blockers is associated with the severity of impairment of cardiac MIBG uptake. Cardiac MIBG activity can consequently be of long-term prognostic value in predicting the effectiveness of such treatment in patients with heart failure.