Chronic coronary microvascular dysfunction

This code represents a chronic condition where the small blood vessels of the heart (microvasculature) are dysfunctional, leading to inadequate blood flow to the myocardium despite the absence of significant obstructive epicardial coronary artery disease. Patients typically experience angina-like chest pain and evidence of myocardial ischemia.

Use this code when documentation confirms chronic coronary microvascular dysfunction, often diagnosed after ruling out obstructive coronary artery disease through angiography. This diagnosis is supported by findings such as abnormal coronary flow reserve, microvascular spasm, or endothelial dysfunction.

• Ensure documentation explicitly states "chronic" and "microvascular dysfunction" to support this specific code.
• Differentiate from other forms of angina or ischemic heart disease where obstructive epicardial disease is present.
• Consider sequencing with codes for angina pectoris (e.g., I20.9) if present, as microvascular dysfunction is a cause of angina.