- Stable angina or unstable angina (Clinical event equal to or greater than 30 days and confirmatory test equal to or greater than 7 days prior to ApneaLinkTM assessment) defined as either ≥70% diameter stenosis of at least one major epicardial artery segment, or ≥50% diameter stenosis of the left main coronary artery, or >50% stenosis in at least two major epicardial arteries.; or positive stress test (ST depression equal to or greater than 2 mm or a positive nuclear perfusion scintigram)