I20.1

HCC Category Mapping

What This Code Means

Chest pain caused by temporary narrowing of heart blood vessels due to spasm, confirmed by cardiac testing or clinical documentation.

Coding Tips

• •Ensure documentation explicitly mentions coronary vasospasm or Prinzmetal's angina
• •This type of angina often occurs at rest or during sleep and may respond to calcium channel blockers

Clinical Significance

Angina pectoris with documented spasm, also known as Prinzmetal angina or variant angina, is caused by transient coronary artery vasospasm that temporarily reduces blood flow. This occurs typically at rest, often in the early morning hours, and is distinguished from classic atherosclerotic angina by its mechanism. Treatment focuses on calcium channel blockers and nitrates rather than typical antiplatelet strategies.

Documentation Requirements

• ✓Provider documentation of angina due to coronary artery vasospasm
• ✓ECG evidence of transient ST-segment elevation during episodes (characteristic finding)
• ✓Documentation of symptom pattern (rest angina, nocturnal, cyclic)
• ✓Provocative testing results if performed (ergonovine or acetylcholine challenge)
• ✓Coronary angiography results showing spasm or normal/near-normal coronaries
• ✓Current treatment plan (calcium channel blockers, nitrates)
• ✓Documentation distinguishing from fixed obstructive coronary disease

Commonly Confused Codes