Tests of kidney function were performed at the beginning of the study. The participants were then randomly assigned to treatment with either ramipril or an inactive placebo pill and were followed for 3.5 to 5.5 years. Because high blood pressure and diabetes can cause heart disease by themselves, patients with those disorders were analyzed separately. The primary outcomes studied were cardiac death, heart attack, or stroke. Outcomes of secondary interest were the total number of deaths, hospitalizations for heart failure, and performance of surgical procedures to increase blood flow to the heart.