Abstract 741: Cardiac I-123 Metaiodobenzylguanidine Imaging Lacks the Power to Predict the Risk of Sudden Death in Chronic Heart Failure Patients With Diabetes Mellitus
Background: Cardiac I-123 metaiodobenzylguanidine (MIBG) imaging provides prognostic information in patients with chronic heart failure (CHF). Diabetes mellitus (DM) has been reported as a predictor for mortality in CHF patients, and a reduction in MIBG uptake has been reported in DM patients. Thus, we tried to prospectively evaluate the prognostic value of cardiac MIBG imaging in CHF patients, relating to DM.
Methods: In 106 CHF outpatients (including 29 DM patients) with radionuclide LVEF<40% (29.5±7.6%), the cardiac MIBG washout rate (WR) was calculated from the chest anterior view images obtained at 20 and 200 min after isotope injection. Abnormal WR was defined as >27% as reported previously. The primary endpoint was sudden death.
Results: During the follow up period of 6.2±3.2 years, sudden death was observed in 5 of 23 DM patients and in 14 of 83 non DM patients. Kaplan-Meier analysis revealed that there was no significant difference of the probability of sudden death between abnormal WR and normal WR in CHF patients with DM (21% vs 22%, p=0.995, RR: 0.96, 95% CI 0.20 – 4.7), while patients with abnormal WR had a significantly higher risk of cardiac death than those with normal WR in CHF patients without DM (29% vs 7%, p=0.0027, RR: 4.3, 95% CI 1.3–14).
Conclusion: Cardiac MIBG imaging would lack the power to predict the risk of sudden death in CHF patients with DM. However, cardiac MIBG imaging would be useful to predict the risk of sudden death in CHF patients without DM.