Athscl autologous vein CABG w unstable angina pectoris

This code signifies the development of atherosclerosis within a coronary artery bypass graft that was created using the patient's own vein (autologous). This atherosclerotic process is specifically complicated by the presence of unstable angina pectoris, indicating acute coronary ischemia.

Apply this code when documentation confirms a patient with a history of coronary artery bypass grafting using an autologous vein graft presents with new or worsening angina symptoms consistent with unstable angina, and diagnostic studies (e.g., angiography) reveal atherosclerotic changes within that specific vein graft. This code requires explicit documentation of both the graft type and the unstable angina.

• Do not use this code if the unstable angina is not attributed to atherosclerosis of an autologous vein graft; refer to the Excludes1 note.
• Ensure documentation clearly specifies "autologous vein" graft; other graft types (e.g., arterial) would require a different code.
• This code inherently includes the unstable angina; do not code I20.0 separately.