Before adjusted with using IPW, more patients taking aspirin than not taking one had smoking, diabetes, peripheral vascular disease, angina, hypertension, previous MI, required urgent surgery and underwent CABG, but less underwent CABG + valve surgery and took shorter time on bypass and cross-clamp; they were more with family history of CAD, more taking lipid lowering drugs, ACE inhibitors or beta blockers, but less with history of congestive heart failure, bypass time and cross clamp time. The gene discussed is ACE; the disease is congestive heart failure.