New ICD-10-CM Codes for Reporting Coronary Microvascular Dysfunction

by  Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT
Nov 28th, 2023

In the ICD-10-CM annual updates, implemented on October 1, 2023, several new codes were added to describe coronary microvascular dysfunction, a vascular disease that affects the small vessels (microvessels) that come off of the larger coronary arteries of the heart. 

The coronary arteries deliver oxygen-rich blood from the lungs to heart tissue and the veins return the oxygen-depleted blood back to the lungs for reoxygenation. When these microvessels constrict, they do not allow the needed oxygen-rich blood to nourish heart tissue, resulting in damage or death of heart tissue. While heart disease is considered damage to blood vessels from plaque buildup, microvascular dysfunction is damage caused by malfunction of the vessel mechanism and not from plaque buildup. 

Risk Factors, Symptoms, Diagnosis, and Treatment Options

Coronary microvascular dysfunction is more likely to affect women than men, and has been diagnosed in women with low estrogen levels, which normally occur before and after menopause. Other risk factors include: 

• Autoimmune disease, including vasculitis
• Obesity
• Diabetes
• A diet that is high in salt, saturated fats, and processed foods
• Sedentary lifestyle
• Hypertension
• Hypercholesterolemia
• Lupus or rheumatoid arthritis
• Nicotine dependence

Symptoms commonly include chest pain, chest tightness, and shortness of breath, especially with stress or exertion, and fatigue. 

Diagnosis is a challenge, because the size of these microvessels is on par with a single strand of hair and will not accommodate the catheter used in the standard cardiac catheterization. Instead, cardiac catheterization using coronary flow reserve (CFR) is used, in which these microvessels are tested to see how quickly they can expand to accommodate increased blood flow based on the body’s immediate need during testing. 

Additional testing used may include a nuclear cardiac stress test (PET scan) or a cardiac MRI with perfusion study. It is estimated that approximately 50% of patients with chest pain (angina/angina pectoris) also have coronary microvascular disease. 

Documentation

When determining which codes to report, be aware that the medical record may reflect coronary microvascular dysfunction by other names, such as: 

• Small artery disease
• Small vessel disease
• Cardiac X syndrome
• Microvessel disease
• Nonobstructive coronary artery disease

The following new codes are reportable for this condition when the provider documents a definitive diagnosis of coronary microvascular dysfunction that is either acute or chronic, associated with angina, or linked to a myocardial infarction, as follows: 

About Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT

Aimee L. Wilcox is a medical coding, billing, and auditing consultant, author, and educator with more than 30 years of clinical and administrative experience in healthcare, coding, billing, and auditing. Medicine, including coding and billing, is a constantly changing field full of challenges and learning and she loves both. Aimee believes there are talented medical professionals who, with proper training and excellent information, can continue to practice the art of healing while feeling secure in their billing and reimbursement for such care.