I21.A1

HCC Category Mapping

What This Code Means

A heart attack caused by a mismatch between the heart's oxygen supply and demand, rather than a blocked artery. This typically occurs when the heart is stressed by conditions like severe anemia, infection, or extreme blood pressure changes.

Coding Tips

• •Type 2 MI requires documentation of the underlying cause (such as sepsis, anemia, or tachycardia) to support medical necessity and accurate billing
• •Do not assign a Type 2 MI code if the documentation indicates atherosclerotic coronary artery disease with plaque rupture, as this would be Type 1 MI instead

Clinical Significance

Type 2 myocardial infarction results from oxygen supply-demand mismatch rather than atherosclerotic plaque rupture, making it pathophysiologically distinct from type 1 myocardial infarction. Common triggers include sepsis, severe anemia, respiratory failure, tachyarrhythmia, and hypertensive crisis. Accurate identification is essential because the treatment targets the underlying cause rather than coronary revascularization, and this distinction has important risk adjustment implications.

Documentation Requirements

• ✓Explicit documentation of 'type 2 myocardial infarction' or 'demand ischemia myocardial infarction'
• ✓Identification of the underlying cause creating supply-demand mismatch (sepsis, anemia, tachycardia, hypotension, respiratory failure)
• ✓Cardiac biomarker elevation with appropriate clinical context
• ✓Documentation that the myocardial infarction is not due to plaque rupture or coronary thrombosis
• ✓Treatment directed at the underlying cause
• ✓Code the underlying condition as an additional diagnosis

Commonly Confused Codes