Prediction of sudden death in patients with mild-to-moderate chronic heart failure by using cardiac iodine-123 metaiodobenzylguanidine imaging

Objective: To evaluate the usefulness of cardiac iodine-123 (I-123) metaiodobenzylguanidine ( MIBG) imaging as a predictor of sudden death in patients with chronic heart failure (CHF). Design and setting: Prospective cohort study in a tertiary referral centre. Patients: 97 outpatients with CHF with a radionuclide left ventricular ejection fraction < 40% ( mean (SD) 29% (7.5%)). Interventions: At study entry, cardiac I-123 MIBG imaging was performed. The cardiac MIBG heart-tomediastinum ratio (H/M) and washout rate (WR) were obtained from MIBG imaging. Main outcome measures: Patients were assigned to two groups based upon 27% of WR, which was the mean (2SD) control WR. 48 of 97 patients with CHF had abnormal WR (>= 27%), whereas the remaining 49 patients had normal WR (< 27%). All the study patients were then followed up. Results: During the mean ( SD) follow-up period of 65 ( 29) months, 12 (25%) patients in the abnormal WR group and 2 (4%) patients in the normal WR group died suddenly. Kaplan-Meier analysis revealed that sudden death was more often observed in patients with abnormal WR than those with normal WR ( p = 0.001). On Cox regression analysis, MIBG WR, H/M on the delayed image and H/ M on the early image were significantly associated with sudden death. Conclusion: Cardiac MIBG imaging would be useful for predicting sudden death in patients with CHF.