Abstract 738: Iodine-123-Metaiodobenzyl Guanidine Imaging Can Predict Future Cardiac Events in Patients With Preserved Heart Failure
Background: Iodine-123-metaiodobenzylguanidine (123I-MIBG) has been used to assess function of the cardiac sympathetic nervous system in patients with chronic heart failure. Although, it is well known that the washout rate of 123I-MIBG close correlates with left ventricular ejection fraction in patients with chronic heart failure, the usefulness of 123I-MIBG imaging for evaluating patients with preserved heart failure has not been established. In the present study, we examined whether 123I-MIBG imaging represented a prognostic marker in preserved heart failure patients.
Methods and Results: We performed 123I-MIBG scintigraphy, echocardiography and measured plasma BNP level of consecutive 94 heart failure patients with left ventricular ejection fraction ≥45% (54 men, mean age 64±15 years) who admitted to the our hospital. Patients were divided into 2 groups by New York Heart Association (NYHA) functional Class. 123I-MIBG washout rate was significantly higher, and delayed H/M ratio was lower in patients with preserved heart failure in increased with advancing NYHA functional Class (NYHA functional Class I and II vs. NYHA functional Class III: 25.5 ± 11.8% vs. 44.5 ± 18.8%, p < .0001. 1.91 < 0.3 vs. 1.57 < 0.38, p < .0001. respectively ). On the other hand, 123I-MIBG washout rate was not correlated with left ventricular ejection fraction, and plasma BNP level. Moreover, patients with high 123I-MIBG washout rate show poor clinical outcome (p = .0095).
Conclusion: 123I-MIBG imaging can predict future cardiac events in patients with preserved heart failure.