Patients were excluded from participating for any of
the following reasons: a history of debilitating stroke or transient
ischemic attack, myocardial infarction during the preceding
6 weeks, surgically untreated left main coronary artery
lesion with 50% diameter narrowing, coronary revascularization
procedure during the preceding 6 months, current unstable
angina pectoris, abnormal lung uptake on previous scintigram
or positron emission tomogram, class IV congestive
heart failure, or ejection fraction 30% at time of study entry,
significant co-morbidity, current use of tobacco products, or
alcohol or drug abuse.