Cardiology Coding Alert

Retrain your brain to avoid an easy hypertensive heart disease mistake.

Nearly one in three US adults has hypertension, so understanding how to code for this condition can benefit a large proportion of your claims. Fortunately, if you’ve taken time to master the rules of ICD-9 coding, you should find the transition to ICD-10 a smooth one. You’ll even find at least one easier step along the way.

Primary/Essential Hypertension: Swap 401.xx for I10

Most hypertension is considered primary or essential hypertension, and in ICD-9, it’s coded with a 401.x

(Essential hypertension) category code. To code for primary hypertension in ICD-9, you first need to determine whether the hypertension is malignant, benign, or unspecified.

The fourth digit for 401.x codes indicates whether the hypertension is malignant, benign, or unspecified:

• 401.0, Essential hypertension, malignant
• 401.1, Essential hypertension, benign
• 401.9, Essential hypertension, unspecified.

ICD-10 easier step: In ICD-10, you no longer need to specify whether primary hypertension is malignant, benign, or unspecified, says coding expert Brandi Whitemyer, RN, COS-C, HCS-D, HCS-O, AHIMA Approved ICD-10 Trainer/Ambassador in Weslaco, Texas. As a result, the hypertension table, found in the Alphabetic Index in ICD-9-CM, isn’t included in ICD-10. You’ll report all primary hypertension with the same code: I10 (Essential [primary] hypertension).

This change will be a positive one for coders whose providers fail to specify malignant or benign in their documentation, leaving them to report the unspecified code under ICD-9.

Remember to Watch for Organ Involvement

You also can categorize primary hypertension according to end organ involvement. When hypertension causes heart disease, chronic kidney disease, or both heart and chronic kidney disease, both ICD-9 and ICD-10 refer you to separate code categories.

Hypertensive Heart Disease: Replace 402.xx With I11

When you are selecting a diagnosis code for a patient diagnosed with hypertensive heart disease in ICD-9, you look to the 402.xx (Hypertensive heart disease) category.

These codes are further specified with a fourth digit to indicate whether the hypertension is malignant, benign, or unspecified, and a fifth digit that indicates whether the patient also has a heart failure diagnosis.

In ICD-10, your code selection for patients with hypertensive heart disease is streamlined. You have two codes from which to choose:

• I11.0, Hypertensive heart disease with heart failure
• I11.9, Hypertensive heart disease without heart failure.

Additional code: For those patients who have a diagnosis that includes heart failure, ICD-9 and ICD-10 ask you to also list a code to specify the type of heart failure. In ICD-9, look to the 428.0-428.43 range. For ICD-10, you’ll need to list a code from the I50.- (Heart failure) category.

Caution: One thing that’s a little confusing about the hypertensive heart disease ICD-10 codes is that “0” in the fifth digit on the ICD-9 code means that the patient does not have heart failure. But in ICD-10 the “0” on the end of the code means the patient does have heart failure, says Lisa Selman-Holman, JD, BSN, RN, COS-C, HCS-D, HCS-O, AHIMA Approved ICD-10-CM Trainer/Ambassador of Selman-Holman & Associates, LLC, CoDR—Coding Done Right and Code Pro University in Denton, Texas.

Lesson: “Don’t get caught by habit and assume the other digits/characters are going to match up between ICD-9 and ICD-10 like they do with some codes,” Selman-Holman warns.

Cause matters, too: You must have documentation to support a causal relationship between the patient’s hypertension and his heart disease to list a 402.xx or I11.- code, Whitemyer says. If there is no documentation that the two conditions are linked, you must report them separately.

The relationship, documented by the physician, may be implied or stated, Selman-Holman says. An example of implied, is “hypertensive heart disease.” An example of stated is “heart failure due to hypertension.”

Hypertensive CKD: 403.xx Makes Room for I12.-

When you are selecting a diagnosis code for a patient diagnosed with hypertensive chronic kidney disease (CKD) in ICD-9, you look to the 403.xx (Hypertensive chronic kidney disease) category. These codes require a fourth digit to indicate whether the hypertension is malignant, benign, or unspecified, and a fifth digit that indicates the stage of chronic kidney disease.

Coding for hypertensive chronic kidney disease in ICD-10 is simplified, with two codes to choose from based on the stage of the chronic kidney disease:

• I12.0, Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease
• I12.9, Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease.

Additional code: When you report a code from the 

403.xx or I12.- categories, you’ll need to list an additional code to indicate the stage of chronic kidney disease. For ICD-9, that’s a 585.x (Chronic kidney disease) code. In ICD-10, list a code from the N18.- (Chronic kidney disease) category.

Again, just keep in mind that “0” on the end of the code in ICD-10 means stage 5 or end stage renal disease is present, but in ICD-9 “0” on the end of the code means stage 1-4 or unspecified chronic kidney disease stage, Selman Holman says. And remember that the choice that includes unspecified ends with fourth digit “9.”

Cause and effect: Both ICD-9 and ICD-10 assume a causal relationship between hypertension and chronic kidney disease, Whitemyer says. So, when your patient has both diagnoses, it’s appropriate to code for them with a code from the 403.xx or I12.- category.

Hypertensive Heart and CKD: 404.xx Bows Out for I13.-

When you are selecting a diagnosis code for a patient diagnosed with both chronic kidney disease and hypertensive heart disease in ICD-9, you’ll look to the 404.xx (Hypertensive heart and renal disease) category. These codes are further specified with a fourth digit to indicate whether the hypertension is malignant, benign, or unspecified, and a fifth digit that indicates whether or not the patient has heart failure and the stage of chronic kidney disease.

You’ll choose from four I13.- (Hypertensive heart and chronic kidney disease) codes to report hypertensive heart and chronic kidney disease in ICD-10:

• I13.0, Hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease 
• I13.10, Hypertensive heart and chronic kidney disease without heart failure, with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease 
• I13.11, Hypertensive heart and chronic kidney disease without heart failure, with stage 5 chronic kidney disease, or end stage renal disease
• I13.2, Hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal disease. 

Additional code: For those patients who have a diagnosis that includes heart failure, ICD-9 asks you to also list a code from the 428.0-428.43 range to specify the type of heart failure. You’ll also need to list a code from the 585.x

(Chronic kidney disease) category to indicate the stage of chronic kidney disease.

In ICD-10, you’ll list a code from the I50.- category to identify the type of heart failure and the N18.- (Chronic kidney disease) category to indicate the stage of CKD. If your patient also has acute renal failure, you will also need to list the appropriate code from the N17.- (Acute kidney failure) category.

Cause and effect: Both ICD-9 and ICD-10 assume a causal relationship between hypertension and chronic kidney disease, but not between heart disease and hypertension. So, to list a hypertensive heart and chronic kidney disease code, you must have documentation that links the hypertension and the heart disease.