Cardiology Coding Alert

Hint: Two codes are required when you report secondary hypertension.

With 11 types of hypertension classified in the 2018 ICD-10-CM Official Guidelines, it's no wonder that remembering all of the rules for hypertension coding can become quite tricky.

Heed the following seven tips to keep your hypertension coding on the right track this upcoming year.

Editor's note: The 2018 ICD-10 Guidelines Errata corrected an error that recently appeared in the hypertension section of the guidelines. Hypertensive crisis and pulmonary hypertension were both mistakenly numbered as the tenth kind of hypertension. For the correction, hypertensive crisis is now number 10 and pulmonary hypertension is number 11.

Tip 1: Report 2 Codes for Hypertensive Retinopathy

The American Heart Association (AHA) defines hypertensive retinopathy as damage to the retinal blood vessels attributed to hypertension.

To report hypertensive retinopathy, you will first choose a code from subcategory H35.0- (Background retinopathy and retinal vascular changes), according to the guidelines.

For the second code, you will choose the appropriate code from categories I10- (Essential primary hypertension) through I15- (Secondary hypertension) to indicate the patient's type of hypertension.

Remember: The sequencing of these two codes is based upon the reason for the encounter.

Tip 2: Follow These Rules for Transient Hypertension

For transient hypertension, you will report R03.0 (Elevated blood-pressure reading without diagnosis of hypertension), unless the patient has an established diagnosis of hypertension, per the guidelines.

Caution: If the patient has transient hypertension of pregnancy, you will look to O13-(Gestational (pregnancy-induced) hypertension without significant proteinuria) or O14.- (Pre-eclampsia) instead of R03.0.

Tip 3: Patient has Secondary Hypertension? Do This

If something like an endocrine disorder, a vascular problem, a disorder of the central nervous system, or a medication causes the patient's hypertension, then it is considered secondary hypertension.

Two codes are required when you report secondary hypertension, the guidelines state. The first code identifies the underlying etiology. For the second code, you will choose an option from category I15- to identify the specific type of hypertension.

Caution: The reason for the encounter determines the sequencing of these codes. Always make sure you're following ICD-10 coding direction. When "use additional code to identify ..." is stated, the hypertensive disease code (I11-I16) is coded first with the "use additional code" to follow.

Tip 4: For Hypertensive Crisis, Rely on a Code From Category I16-

To report a documented hypertensive urgency, hypertensive emergency, or unspecified hypertensive crisis, turn to the appropriate code from category I16- (Hypertensive crisis).

You should also code any identified hypertensive disease from categories I10- through I15-, per the guidelines. The sequencing of these codes is based on the reason for the encounter unless the ICD-10 coding direction states differently.

Expert definition: Hypertensive crisis involves a blood pressure increase so severe that it may result in a stroke, says Kelly D. Dennis, MBA, ACS-AN, CANPC, CHCA, CPC, CPC-I,  owner of Perfect Office Solutions in Leesburg, Florida. Hypertensive crisis can be classified as either urgent or emergency.

Citing information from the Mayo Clinic, Dennis explains that a patient experiencing urgent hypertensive crisis has extremely high blood pressure, but the patient's condition doesn't indicate organ damage. In contrast, emergency hypertensive crisis involves extremely high blood pressure that has resulted in internal organ damage that may lead to life-threatening complications.

Tip 5: Know This Controlled Hypertension Definition

For controlled hypertension, you will report the correct code from categories I10- through I15-.

Official definition: Controlled hypertension is defined as "an existing state of hypertension under control by therapy," per the guidelines.

Tip 6: Rely on this Advice for Uncontrolled Hypertension

The guidelines define uncontrolled hypertension in two ways:

• Untreated, or
• Not responding to a current therapeutic regimen.

To report uncontrolled hypertension, you will report the appropriate code from categories I10- through I15-.

Tip 7: Look to These Directions if Patient has Hypertension With Heart Disease

If the patient has hypertension with a heart condition that is classified under the category I50.- (Heart failure) or I51.4 (Myocarditis, unspecified) through I51.9 (Heart disease, unspecified), you should report a code from category I11- (Hypertensive heart disease). You should also report an additional code(s) from category I50- to identify the specific type(s) of heart failure.

However, according to the guidelines, you should separately code the same heart conditions (I50.- and I51.4 through I51.9) with hypertension if the cardiologist has specifically documented a different cause. The sequence of the codes will depend upon the circumstances of the encounter.

Look at this example for clarity: The cardiologist documents a diagnosis of left ventricular failure caused by hypertension. Since hypertension is the cause of the heart failure, you would report I11.0 (Hypertensive heart disease with heart failure). However, the note for I11.0 indicates you must report an additional code from the I50 series "to identify the type of heart failure," which, in this scenario, would be I50.1 (Left ventricular failure, unspecified). And all the I50 codes come with a code first note that states I50.1 must always be reported after I11.0, when appropriate.

Donelle Holle, RN, President of Peds Coding Inc., and a healthcare, coding, and reimbursement consultant in Fort Wayne, Indiana, offers the reminder that "code first notes indicate the primary reason for the diagnosis; they indicate the main cause for this other diagnosis."

The code first note, then, says that this disease or illness has caused this other disease or illness. So, you would report I11.0 before I50.1 if hypertension was the cause of the heart failure.

Reminder: There is a presumed causal relationship between hypertension and heart involvement (I50.- and I51.4-I51.9) and between hypertension and kidney involvement, as the two conditions are linked by the term "with" in the ICD-10 Alphabetic Index, according to Christina Neighbors, MA, CPC, CCC, Coding Quality Auditor for Conifer Health Solutions, Coding Quality & Education Department, and member of AAPC's Certified Cardiology Coder steering committee.

These conditions should be coded as related even in the absence of provider documentation explicitly linking them, unless the documentation clearly states that the conditions are unrelated, Neighbors adds.