Cardiology Coding Alert

Question: I have been told that it is OK to report the use of ambulatory blood pressure monitoring (ABPM) for a diagnosis of white coat hypertension. I cannot find this diagnosis in the ICD-9 manual. Should I use 796.2 (Elevated blood pressure reading without diagnosis of hypertension) instead? California Subscriber Answer: Yes. Effective April 1, 2002, Medicare will cover ABPM for patients with suspected white coat hypertension, also known as isolated office (IO) hypertension, which is characterized by consistently elevated office blood pressure concurrent with normal daytime blood pressure. Medicare transmittal AB-01-18, which announced the new coverage, did not list any diagnoses or diagnosis codes that should be used for this condition. In fact, the correct ICD-9 code is 796.2.

The transmittal defined white coat hypertension as: Office blood pressure greater than 140/90 mmHg on at least three separate clinic/office visits with two separate measurements made at each visit. At least two documented separate blood pressure measurements taken outside the office that are less than 140/90 mmHg. No evidence of end-organ damage. According to the transmittal, "ABPM is not covered for any other uses. In the rare circumstance that ABPM needs to be performed more than once in a beneficiary, the qualifying criteria described above must be met for each subsequent ABPM test."

ABPM services may be reported using one of the following codes: 93784 Ambulatory blood pressure monitoring, utilizing a system such as magnetic tape and/or computer disk, for 24 hours or longer; including recording, scanning analysis, interpretation and report
93786 recording only
93790 physician review with interpretation and report
93788 scanning analysis with report [explicitly noncovered].
ABPM measures the patient's blood pressure over time (usually 24 hours) and is to a single, isolated blood pressure test what a 24-hour Holter monitor is to an ECG. It is used for much the same reason that a patient receives a Holter monitor to obtain data (in this case, a blood pressure sample) over time because in some cases a normal blood pressure test, which provides a "snapshot," may not be accurate.