ABSTRACT
OBJECTIVE: To compare the efficacy of modified simplex method and DUD method using SAS software for nonlinear regression analysis of cardiac enzyme kinetic model. METHOD: By using cardiac enzyme kinetic one-compartment mathematical model, nonlinear regression results obtained from DUD methods using SAS software and modified simplex method were compared with the same starting values to fit the creatine kinase curves in 22 patients with acute myocardial infarction. RESULTS: The parameters calculated by DUD method and modified simplex method were the same in 4 cases, and smaller least square was resulted from DUD method in 4 cases. In the other 14 cases, modified simplex method yielded smaller least square. The mean value of the least square calculated by modified simplex method was less than that by DUD method (867 747 vs 6 712 989, P=0.013). CONCLUSION: Modified simplex method appears to be more adequate than DUD method in estimating circulatory parameters of the one-compartment model.
