Abstract: AIM:To evaluate the performance of Acute Physiology and Chronic Health Evaluation II(APACHE II) scores,Global Registry of Acute Coronary Events(GRACE) risk scores,free triiodothyronine(FT3) levels,and reverse T3(rT3) levels in patients with acute myocardial infarction(AMI).METHODS:A total of 240 patients with AMI were enrolled.Blood samples were obtained for serum levels of FT3 and rT3 measurements at the time of admission.APACHE II scores and GRACE risk scores were calculated for each patient.Mortality during hospitalization was evaluated.Information regarding survival was obtained by telephone inquiry 1 month after discharge.RESULTS:APACHE II scores and GRACE risk scores were higher in nonsurvivors in comparison with survivors(19.7±2.9 vs.14.4±3.0,260±51 vs.209±34,P<0.01).Significant differences in FT3 and rT3 levels were observed between nonsurvivors and survivors (3.6±1.2) vs.(4.9±1.5) pmol/L,P<0.01 and(1.4±0.3) vs.(1.2±0.4) nmol/L,P<0.05.In a multivariate Cox proportional hazards model,APACHE II scores,GRACE risk scores and FT3 levels were independent predictors of early mortality(HR=1.459,95%CI:1.227-1.734,P<0.01;HR=0.997,95% CI:0.987-1.008,P<0.01;HR=0.6,95% CI:0.418-0.862,P<0.01).Standard partial regression coefficient of APACHE II scores was higher than those of GRACE risk scores and FT3 levels(1.321,0.611,-0.573).Area under the curve for APACHE II scores was higher than that for GRACE risk scores and rT3 levels(0.893,95% CI:0.834-0.952;0.822,95% CI:0.757-0.866;0.681,95% CI:0.590-0.771,P<0.01).CONCLUSIONS:APACHE II scores are of the highest value for mortality prediction in patients with AMI.