Echocardiographic Epicardial Fat Thickness is a Predictor for Target Vessel Revascularization in Patients with ST-elevation Myocardial Infarction

Background: The amount of epicardial adipose tissue (EAT) has been demonstrated to correlate with the severity of coronary artery disease (CAD) and the CAD activity. The aim of this study is to assess the impact of EAT on long term clinical outcomes in patients with ST elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI).

Methods: We analyzed the data and clinical outcomes of 761 patients (614 males, 57 ± 12 year-old) with STEMI who underwent successful primary PCI from 2003 to 2009. All patients were divided into two groups: thick EAT group, EAT ≥ 3.5 mm and thin EAT group, EAT < 3.5 mm. The primary end points were all-cause death, recurrent MI, target vessel revascularization (TVR) and major cardiac adverse events (MACEs), composite of all-cause death, recurrent MI and TVR, within 5 years.

Results: Median and mean EAT of 761 patients were 3.3 mm and 3.6 ± 1.7 mm, respectively. Mean follow up period was 46 ± 18 months. MACE-free survival rate in the thick EAT group was significantly lower than in the thin EAT group (log-rank P = 0.001). The event-free survival rate of all-cause death of the thick EAT group was significantly lower than that of the thin EAT group (log-rank P = 0.005). The TVR-free survival rate in the thick EAT group was significantly lower than in the thin EAT group (log-rank P = 0.007). The event-free survival rate of recurrent MI were not significantly different between the groups (log-rank P = 0.206). In the Cox's proportional hazard model, the adjusted hazard ratio of thick EAT thickness for TVR was 1.868 (95% confidence interval 1.181-2.953, P = 0.008).

Conclusion: This study demonstrates that the EAT thickness is related with long term clinical outcome in patients with STEMI. The EAT thickness might provide additional information for future clinical outcome, especially TVR.