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 (123I) 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-to-mediastinum 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 (> or =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.