Background Many studies have shown that cardiac sympathetic nerve activity evaluated by [¹²³I]m-iodobenzylguanidine ([¹²³I]MIBG) scintigraphic study during a stable period is useful for determining the prognosis of patients with chronic heart failure.

Objective To examine whether results of this imaging method performed 3 weeks after the onset of ST-segment elevation myocardial infarction (STEMI) are a reliable prognostic marker for patients with STEMI.

Methods The study analysed findings for 213 consecutive patients with STEMI undergoing [¹²³I]MIBG scintigraphy. The left ventricular (LV) end-diastolic and end-systolic volume and LV ejection fraction (EF) were determined by left ventriculography or echocardiography 3 weeks after the onset of STEMI. The delayed total defect score, heart-to-mediastinum ratio and washout rate (WR) were also determined from [¹²³I]MIBG scintigraphy at the same time.

Results Of the 213 patients, 46 experienced major adverse cardiac events (MACE) during the study. The median follow-up period was 982 days. Patients were divided into an event-free group (n=167; 78.4%) and a MACE group (n=46; 21.6%). The LV and [¹²³I]MIBG scintigraphic parameters in the event-free group were better than those in the MACE group. Multivariate Cox regression analyses revealed that WR was a significant predictor of MACE along with oral nicorandil (ATP-sensitive potassium channel opener) treatment and undergoing percutaneous coronary intervention. On Kaplan–Meier analysis, the event-free rate of patients with a WR<40% was significantly higher than that in patients with a WR≥40% (p<0.001). Even when confined to patients with LVEF>45%, WR was a predictor of MACE, pump failure death, cardiac death and progression of heart failure in patients with STEMI.

Conclusion WR evaluated by [¹²³I]MIBG scintigraphy 3 weeks after the onset of STEMI is a significant predictor of MACE in patients with STEMI, independent of LVEF.