Assessment of underlying etiology and cardiac sympathetic innervation to identify patients at high risk of cardiac death

T. Wakabayashi, T. Nakata, A. Hashimoto, S. Yuda, K. Tsuchihashi, M. I. Travin, K. Shimamoto

Research output: Contribution to journalArticle

137 Scopus citations

Abstract

Cardiac 123-labeled metaiodobenzylguanidine (MIBG) activity has significant incremental prognostic value, but the difference between the long-term prognostic value of MIBG imaging for ischemic cardiomyopathies and the long-term prognostic value of MIBG imaging for idiopathic cardiomyopathies is not clear. This study aimed to determine whether assessment of cardiac 123-MIBG activities in ischemic and idiopathic cardiomyopathies have equally prognostic values and whether the kinetics are different because of the underlying etiologies. Methods: After quantitative 123-MIBG imaging, 76 ischemic and 56 idiopathic cardiomyopathy patients were prospectively followed up for 54 mo. In addition to conventional parameters, cardiac 123MIBG activity was quantified as a heart-to-mediastinum ratio (H/M) for early and late images and the washout kinetics were calculated using tomographic imaging. The data were compared with those obtained from 16 healthy volunteers. Results: During follow-up, 29 deaths from heart failure, 11 sudden cardiac deaths, 2 deaths from arrhythmia, and 5 deaths from acute myocardial infarction were documented. Multivariate discriminant analysis using the Cox proportional hazards model showed that, in comparison with other variables, late H/M was the most powerful independent predictor of a lethal clinical outcome in ischemic (Wald X2 18.6502; P = 0.0000) and idiopathic (Wald X2 = 5.3394; P = 0.0208) groups. When patients with left ventricular ejection fraction (LVEF) < 40% were considered, late H/M had the greatest statistical power in both groups. KaplanMeier analysis showed late H/M to have an identical threshold (1.82) for both groups for identifying patients at risk of cardiac death. Likewise, when analysis was restricted to patients with an LVEF < 40%, the upper cutoff value of late H/M was 1.50 (P = 0.0358; log rank = 4.41) for ischemic patients and 2.02 (P = 0.0050; log rank = 7.86) for idiopathic patients. For patients with an LVEF < 40% and a late H/M less than the identified threshold of late H/M, the annual rate of cardiac death was greatest, 18.2%/y for the ischemic group and 11.9%/y for the idiopathic group. Conclusion: Cardiac 1231MIBG activity has the most powerful independent long-term prognostic value for both ischemic cardiomyopathy patients and idiopathic cardiomyopathy patients, indicating that both disease processes have common pathophysiologic and prognostic implications of impaired cardiac sympathetic innervation. Although combined testing of cardiac function and 123-MIBG activity is most likely to identify patients at increased risk of cardiac death, the underlying etiology of cardiac dysfunction may affect the threshold of 123-MIBG activity for the differentiation of high-risk patients.

Original languageEnglish (US)
Pages (from-to)1757-1767
Number of pages11
JournalJournal of Nuclear Medicine
Volume42
Issue number12
StatePublished - Dec 1 2001
Externally publishedYes

Keywords

  • Cardiomyopathy
  • Heart failure
  • Nuclear medicine
  • Prognosis
  • Sympathetic nervous system

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'Assessment of underlying etiology and cardiac sympathetic innervation to identify patients at high risk of cardiac death'. Together they form a unique fingerprint.

  • Cite this

    Wakabayashi, T., Nakata, T., Hashimoto, A., Yuda, S., Tsuchihashi, K., Travin, M. I., & Shimamoto, K. (2001). Assessment of underlying etiology and cardiac sympathetic innervation to identify patients at high risk of cardiac death. Journal of Nuclear Medicine, 42(12), 1757-1767.