Persistence of 123I-mIBG Prognostic Capability in Relation to Medical Therapy in Heart Failure (from the ADMIRE-HF Trial)

Abstract

123I-mIBG imaging has been evaluated to assess sympathetic function and prognosis in heart failure (HF). However, the effect of combined HF medical therapies on 123I-mIBG uptake and its prognostic significance has not been previously examined. This analysis examined the relation between the intensity of guideline-directed HF medical therapy and global 123I-mIBG cardiac uptake in the AdreView Myocardial Imaging for Risk Evaluation in Heart Failure (ADMIRE-HF) database. A second objective was to investigate whether this guideline-based therapy, measured by total medication doses, had the expected effect on outcome, that is, that patients with higher 123I-mIBG cardiac uptake and more intensive medical therapy had the fewest outcome events. Three HF cardiologists developed an HF Medication Score (HFMS) to quantify adequacy of dosages of β blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers and mineralocorticoid receptor antagonists. A Cox model was used to investigate the predictive ability of the HFMS for mortality events during median 17months follow-up. Multiple regression and Cox models assessed the usefulness of the HFMS relative to the planar heart/mediastinum ratio (H/Mp) from 123I-mIBG imaging in prediction of an event and to characterize the interaction of HFMS and H/M in predicting an event. HFMS was not a significant predictor of all-cause or cardiac death in either univariate or multivariate Cox models; H/Mp was highly significant for both event categories (p <0.0001). Mean H/Mp did not differ among HFMS ranges 0 to 3, 4 to 6, and 7 to 9. However, within each category, the mean H/Mp for subjects with events was significantly lower than that of subjects without events, with the exception of cardiac mortality in those with highest scores. In conclusion, intensity of medical therapy is not predictive of short-term mortality in HF patients. H/Mp is a good predictor for both cardiac and overall mortality regardless of medical therapy levels.