Iodine-123-metaiodobenzylguanidine imaging can predict future cardiac events in heart failure patients with preserved ejection fraction.

Objective: Iodine-123-metaiodobenzylguanidine (I-MIBG) has been used to assess the function of the cardiac sympathetic nervous system in patients with chronic heart failure (HF). The usefulness of I-MIBG imaging for evaluating patients with heart failure with preserved ejection fraction (HFPEF) has not been established. Methods: We performed I-MIBG scintigraphy and echocardiography and measured the plasma brain natriuretic peptide (BNP) levels of 117 consecutive HF patients (64 men, mean age 66 ± 14 years) with a left ventricular ejection fraction (LVEF) of ≥50% who were admitted to our hospital. Patients were divided into 2 groups according to the New York Heart Association (NYHA) functional class. Results: The I-MIBG delayed heart-to-mediastinum ( H/ M) ratio was significantly lower, and the washout rate (WR) was higher in patients with HFPEF with advanced NYHA functional class (NYHA functional class I and II vs. III: 1.90 ± 0.34 vs. 1.49 ± 0.32, p < 0.0001; 25.9 ± 13.4 vs. 46.9 ± 16.3%, p < 0.0001, respectively). On the other hand, the I-MIBG WR was not correlated with LVEF and had a weak correlation with plasma BNP levels ( R = 0.207, p = 0.0346). Moreover, patients with a high I-MIBG WR showed a poor clinical outcome ( p = 0.0033). Conclusions: I-MIBG imaging provides independent prognostic information in patients with HFPEF. [ABSTRACT FROM AUTHOR]