Patients were eligible to participate if they had at least 1 of the following: a history of myocardial infarction, angiographic evidence of at least 50% stenosis in 1 or more coronary vessels, prior evidence of exercise-induced ischemia by treadmill or nuclear testing, a history of coronary revascularization, or a diagnosis of coronary artery disease documented by an internist or cardiologist. Between September 11, 2000, and December 20, 2002, a total of 1024 participants were enrolled: 240 from the public health clinics, 346 from the university medical center, and 438 from the VA medical centers.
All participants completed a baseline examination that included an interview, fasting blood draw, psychiatric interview, questionnaire, echocardiogram, exercise treadmill test, 24-hour ambulatory electrocardiogram, and 24-hour urine collection. Of the 1024 participants who completed the baseline examination, we were not able to contact 7 (<1%) during the follow-up period, leaving 1017 for this analysis. Our protocol was approved by the appropriate institutional review boards, and all participants provided written informed consent.