The biomarkers Nitric Oxide Responsiveness, platelet aggregation and Asymmetric dimethylarginine (ADMA) and clinical variables were measured in a study from The Queen Elizabeth Hospital Department of Cardiology, South Australia.

The effectiveness of enalapril (ACE inhibitor) was measured in the Study of Left Ventricular Dysfunction Randomised Clinical Trial (SOLVD). Nitric Oxide Tolerance levels were predicted using common variables between SOLVD and the South Australian study.

The figure above shows the increasing effectiveness of enalapril as the patient’s NO tolerance increases. Prediction tables are multilayered and given below.