Cardiology Coding Alert

You’ll be able to hold on to your old rule about hypertensive heart disease, too.

ICD-9 and ICD-10 offer identical code definitions for myocardial degeneration, so your biggest challenge for the transition to code I51.5 may be distinguishing the letter “I” from the digit “1” in this alphanumeric code.

The diagnosis: Myocardial degeneration involves a decline from the normal structure or function of the middle layer of the heart wall, the myocardium.

ICD-9-CM Code

• 429.1, Myocardial degeneration

ICD-10-CM Code

• I51.5, Myocardial degeneration

ICD-9 coding rules: ICD-9 instructs you to use 429.1 for fatty, mural, or muscular degeneration of the heart or myocardium. Myocardial disease also falls under 429.1. The code applies regardless of whether the documentation mentions arteriosclerosis. If the patient does have arteriosclerosis, you should code that diagnosis, as well. However, myocardial degeneration due to hypertension should be coded to 402.x (Malignant hypertensive heart disease).

ICD-10 changes: Code 429.1 crosses directly to I51.5. Like ICD-9, ICD-10 excludes myocardial degeneration due to hypertension (see I11.-, Hypertensive heart disease). Code I51.5 specifically includes fatty or senile degeneration of the heart or myocardium. Other diagnoses indexed to I51.5 include cardiomalacia, cardiomyoliposis, myocytolysis, myocardial stricture, and Beau’s syndrome.

Documentation: Your physician’s documentation shouldn’t need to change for this diagnosis. As long as your current documentation for myocardial degeneration is adequate, you should be fine when it’s time to switch to ICD-10. Still, be sure to check both the index and tabular list to match the documentation to the proper code.

Coder tips: Includes and excludes lists are crucial for finding the proper diagnosis code. If your practice uses tools or aids, be sure coders can quickly see that myocardial degeneration due to hypertension does not belong under I51.5. Also, “Signs and symptoms that are associated routinely with a disease process should not be assigned as additional codes, unless otherwise instructed by the classification,” the ICD-10 official guidelines state. So understanding how a disease evolves, the signs and symptoms that occur, and clear documentation of the relationship between signs/symptoms and a diagnosed condition are extremely important to proper coding.

Remember: ICD-9 codes will no longer be accepted for dates of service on or after October 1, 2014. And “ICD-10 codes will not be recognized or accepted on claims prior to October 1, 2014. Claims cannot contain both ICD-9 codes and ICD-10 codes,” explained Sarah Shirey-Losso from the Provider Billing Group of the Center for Medicare in the “Begin Transitioning to ICD-10 in 2013” National Provider Call on April 18, 2013. Learn more at www.cms.gov/ICD10/ and www.cdc.gov/nchs/icd/icd10cm.htm#10update .