Q&A: Proper sequencing of heart failure with hypertensive heart/kidney disease

January 19, 2012

Q: I have a question regarding sequencing. I would usually have sequenced 428.21 (heart failure) as principal diagnosis, but I was advised by my inpatient coder that she would sequence 404.91 (Unspecified hypertensive heart and renal disease with heart failure) as the principal diagnosis in keeping with the Official ICD-9-CM Guidelines for Coding and Reporting.

Is this a compliant practice?

I’ve turned it over in my head, reasoning that acute heart failure is a manifestation of the chronic condition of hypertensive heart and chronic kidney disease, but that the heart failure was really mostly mediated by cardiomyopathy.

A: Report hypertensive heart disease as the principal diagnosis and acute congestive heart failure (CHF) as secondary. The Tabular ICD-9-CM Manual guidance trumps all other advice and the ‘code also’ notes include the acute forms of CHF. This note states to code all forms of CHF as secondary codes in conjunction with hypertensive heart disease.

If you should deal with this issue again in the future, you may wish to refer all to the entry in the Tabular list of ICD-9 clearly instructing one to: “Code first heart failure due to hypertension.” This is found at the tabular at the 3 digit category for 428 Heart Failure. This is a clear directive that the particular form of specific CHF is to be used as a secondary code.

Note that the sequencing has implications for MS-DRG assignment if ‘hypertensive heart failure’ is properly sequenced as the principal diagnosis. Sequencing the codes correctly, as follows:

404.91: Hypertensive Heart/Kidney Disease, not otherwise specified (NOS)
428.21: Acute Systolic Heart Failure
585.4: Chronic Kidney Disease, Stage IV (severe)

Results in a DRG assignment of 291 (Heart Failure with Shock with MCC) with a relative weight of 1.5010.

Sequencing 428.21 incorrectly as principal, as in the following example:

428.21: Acute Systolic Heart Failure
404.91: Hypertensive Heart/Kidney Disease NOS
585.4: Chronic Kidney Disease, Stage IV (severe)

Results in a DRG assignment of 292 (Heart Failure and Shock with CC) with a relative weight of 1.0214.

Related also is the following statement from the ICD-9-CM Official Guidelines for Coding and Reporting:

“These guidelines are a set of rules that have been developed to accompany and complement the official conventions and instructions provided within the ICD-9-CM itself. The instructions and conventions of the classification take precedence over guidelines. These guidelines are based on the coding and sequencing instructions in Volumes I, II and III of ICD-9-CM, but provide additional instruction. Adherence to these guidelines when assigning ICD-9-CM diagnosis and procedure codes is required under the Health Insurance Portability and Accountability Act (HIPAA).”

The relationship between CRF, HTN, and CHF is complex and the coding rules are easily misunderstood, in my opinion.

Editor’s Note: This question was discussed on the August 2011 ACDIS Quarterly Conference Call. Thanks to ACDIS member Paul Evans, RHIA, CCS, CCS-P, Supervisor of Clinical Documentation Integrity and the Quality Department for the California Pacific Medical Center in San Francisco for providing the answer and related research.

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