Prognostic significance of cardiac 123I-metaiodobenzylguanidine imaging in heart failure with preserved ejection fraction

Background Cardiac 123I-metaiodobenzylguanidine (123I-MIBG) imaging provides prognostic information in heart failure; however, evidence in heart failure with preserved ejection fraction (HFpEF) is limited. Objectives We evaluated the prognostic significance of cardiac 123I-MIBG imaging in HFpEF from a multicenter registry. Methods We analyzed the PURSUIT-HFpEF registry including patients hospitalized for acute decompensated HF with left ventricular ejection fraction ≥50%. Cardiac 123I-MIBG imaging was performed before discharge. The late heart-to-mediastinum ratio (HMR) was selected as the primary imaging metric. Primary outcome was a composite of all-cause death or heart failure readmission. Results Among 376 HFpEF patients who underwent cardiac 123I-MIBG imaging at discharge, spline analysis demonstrated a non-linear association between late HMR and the primary outcome. Patients were stratified by late HMR tertiles: low (≤1.90), middle (1.90–2.35), and high (≥2.35) groups. Patients in the low group had the poorest prognosis for the primary outcome, with intermediate risk in the high group and the most favorable prognosis in the middle group. In multivariable Cox proportional hazard analysis with the middle group as reference, both the low and high groups were associated with a higher risk of primary outcome, even after adjustment with the covariates (adjusted HR for the low group: 1.85, 95% CI: 1.25-2.74, P= 0.002; for the high group: 1.67, 95% CI: 1.14-2.73, P= 0.008). Conclusions In HFpEF, cardiac 123I-MIBG imaging provides clinically relevant prognostic information, with a U-shaped association between late HMR and outcomes, necessitating a refined, context-dependent interpretation of sympathetic imaging for risk stratification in HFpEF.FigureFigure