Abstract: AIM To assess the value of symptom-onset serum aldosterone levels in predicting short-term heart failure in patients with STEMI. METHODS The study included 117 consecutive patients in our hospital from January, 2007 to October, 2007, who underwent PCI within 12 hours of the symptom onset. Blood samples were drawn through the femoral arterial sheath before cardiac catheterization with the patients in the supine position (5.7±2.5) hours. Serum aldosterone levels were measured with a commercially available radioimmunoassay kit. The 30-day and a 3-month follow-ups of heart failure （acute attack or NYHA Ⅲ-Ⅳgrade）were recorded. RESULTS According to the aldosterone levels, we devided the patients into 3 groups (Aldo<100 μg/L, 100 μg/L≤Aldo≤200 μg/L and Aldo>200 μg/L). The rates of heart failure increased with the increase of serum aldosterone. Logistic analysis showed that independent of other prognostic factors such as age, gender, family heredity, hypercholesterolemia, diabetes, hypertension and smoking, the serum aldosterone level was a strong predictor of 30-day（r=0.54， OR 3.3795%CI 1.19 to 9.60, P<0.05）and 3-month （r=0.48，OR 2.9895%CI 1.31 to 6.80, P<0.01） incidence of heart failure. CONCLUSION The serum aldosterone level is associated with the increase of the rates of heart failure. Independent of other prognostic factors, the serum aldosterone level is a strong predictor of 30-day and 3-month incidence of heart failure.