¹²³I-MIBG Imaging for Prediction of Mortality and Potentially Fatal Events in Heart Failure: The ADMIRE-HFX Study

UNLABELLED: ADMIRE-HF (AdreView Myocardial Imaging for Risk Evaluation in Heart Failure) established the prognostic significance of (123)I-metaiodobenzylguanidine ((123)I-MIBG) imaging in heart failure subjects (median follow-up, 17 mo) using a composite endpoint dominated by heart failure progression. The ADMIRE-HF extension (ADMIRE-HFX) extended follow-up to a median of 24 mo and used mortality as the primary endpoint. The objective of these analyses was to use multiple multivariate risk modeling techniques to determine the independent predictive ability of (123)I-MIBG imaging for mortality outcomes. METHODS: Data from 964 New York Heart Association class II-III subjects in ADMIRE-HFX were included. All-cause mortality and a composite endpoint of death or death-equivalent events (resuscitated arrest, successful defibrillation for ventricular tachycardia or ventricular fibrillation) were analyzed with multivariate Cox proportional hazards and logistic regression techniques using demographic and clinical variables and the (123)I-MIBG heart-to-mediastinum ratio (H/M). The incremental value of H/M was also examined for the logistic regression models using receiver-operating-characteristic curve methods and for the proportional hazards models using net reclassification improvement. RESULTS: There were 101 deaths, and 136 subjects had a composite event during follow-up. H/M was significant in all multivariate proportional hazards and logistic regression models for the 2 mortality endpoints, both models developed with only clinical variables and those including left ventricular ejection fraction and b-type natriuretic peptide (BNP). For baseline models including BNP, the addition of H/M did not significantly increase receiver-operating-characteristic curve area. However, there was significant net reclassification improvement with the addition of H/M to a proportional hazards model containing BNP and left ventricular ejection fraction. CONCLUSION: The multivariate Cox proportional hazards and logistic regression analyses demonstrated consistent significance for H/M when added to the baseline risk models for mortality and mortality-equivalent events.