Incremental Prognostic Value of Cardiac Metaiodobenzylguanidine Imaging Over the Co-Morbid Burden in Acute Decompensated Heart Failure

AIMS: Co-morbidities are associated with poor clinical outcomes in patients with chronic heart failure, while cardiac iodine-123 (I-123) metaiodobenzylguanidine (MIBG) imaging provides prognostic information in such patients. We sought to prospectively investigate the incremental prognostic value of cardiac MIBG imaging over the co-morbid burden, in patients admitted for acute decompensated heart failure (ADHF). METHODS AND RESULTS: In 433 consecutive ADHF patients with survival to discharge, we measured the co-morbidity using age-adjusted Charlson co-morbidity index (ACCI), commonly employed to evaluate a weighted and scored co-morbid condition, adding additional points for age. In cardiac MIBG imaging, the cardiac MIBG heart-to-mediastinum ratio (late HMR) was measured on the delayed image. Over a follow-up period of 2.9 ± 1.5 years, 160 patients had a cardiac event (a composite of cardiac death and unplanned hospitalization for worsening heart failure). Patients with high ACCI (≥6: median value) had a significantly greater risk of a cardiac event. In multivariate Cox analysis, the ACCI and late HMR were significantly and independently associated with a cardiac event. In both high and low ACCI subgroups (ACCI ≥ 6 and <6, respectively), patients with low late HMR had a significantly greater risk of a cardiac event (high ACCI: 51% vs. 34% P = 0.0026, adjusted HR 1.74 [1.21-2.51]; low ACCI: 34% vs. 17%, P = 0.0228, adjusted HR 2.19 [1.10-4.37]). CONCLUSIONS: Cardiac MIBG imaging could provide additional prognostic information over ACCI, which was also promoted to be a useful risk model, in patients admitted for ADHF.