Abstract

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 Prospective cohort study.

Setting Tertiary referral centre.

Patients Ninety-seven CHF outpatients with a radionuclide left ventricular ejection fraction < 40% ( 29±7.5% ).

Intervensions At the 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 We divided patients into two groups based upon 27% of WR, which was the mean control WR +2 SD. Forty-eight of 97 CHF patients had abnormal WR (≥27%), while the remaining 49 patients had normal WR (<27%). All the study patients were then followed up.

Results During the mean follow up period of 65±29 months, 12 patients (25%) died suddenly in abnormal WR group, while two patients (4%) died in normal WR group. Kaplan-Meier analysis revealed that sudden death was more frequently observed in patients with than without abnormal WR (p=0.0010). At 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 to predict sudden death in patients with CHF.