Incremental utility of iodine-123 meta-iodobenzylguanidine imaging beyond established heart failure risk models.

Abstract

BACKGROUND:

Nuclear myocardial imaging with iodine-123 meta-iodobenzylguanidine ((123)I-mIBG) is approved for risk stratification of patients with systolic heart failure (HF). Whether (123)I-mIBG imaging provides incremental prognostic utility beyond established risk models remains unclear.

METHODS AND RESULTS:

In a multicenter study, 961 patients with moderate systolic HF underwent (123)I-mIBG imaging and were followed for cardiac death, progressive HF, or life-threatening arrhythmias over 2 years. We constructed 4 multivariable models, using variables from each of 4 published HF risk models, and patient-level scores were calculated both before and after adding the heart-to-mediastinum ratio (H/M) from (123)I-mIBG imaging. Incremental utility was evaluated by calculating integrated discrimination improvement (IDI), which quantifies the increase in probability of experiencing the primary end point after adding H/M to each model. The composite end point occurred in 25% of patients. After adding H/M, absolute IDI ranged from 2.1% to 3.0%, representing 33%-59% relative improvements in risk stratification. Of note, hazard ratios for H/M were remarkably similar between risk models (0.40-0.44 for predicting the composite end point, 0.10-0.18 for mortality; all P < .001).

CONCLUSIONS:

Despite notable differences in predictor variables, patient populations, and analytic techniques from which each model was initially derived, adding (123)I-mIBG data to HF risk models consistently identified patients at lower risk of experiencing adverse events.

• Authors: Kaushik K Jain, Paul J Hauptman, John A Spertus, Kevin F Kennedy, Timothy M Bateman, Arnold F Jacobson, Joshua M Stolker
• Journal: Journal of cardiac failure (J Card Fail) Vol. 20 Issue 8 Pg. 577-83 (Aug 2014) ISSN: 1532-8414 [Electronic] United States
• PMID: 24951931 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Iodine Radioisotopes
• N-methyl-4-iododexetimide
• Dexetimide

Topics

• Aged
• Dexetimide (analogs & derivatives)
• Diagnostic Imaging (methods, statistics & numerical data)
• Female
• Follow-Up Studies
• Heart Failure (diagnostic imaging, epidemiology)
• Humans
• Incidence
• Iodine Radioisotopes
• Male
• Middle Aged
• Prognosis
• Radionuclide Imaging
• Retrospective Studies
• Risk Assessment (methods)
• Risk Factors
• United States