Cardiology Coding Alert

Deterred by Insufficient CAD Documentation? Read This First

Published on Thu Jan 27, 2005

Don't be lax in coding the highest level of specificity

If your cardiologist sees a patient with coronary artery disease (CAD) but doesn't identify the location of the disease, you should report 414.00 as the diagnosis, right? Wrong. Overuse of 414.00 is among the most common coding errors, according to the American Health Information Management Association (AHIMA). Avoid making this mistake by learning the difference between 414.00 and 414.01.

Common Cause of CAD Is Atherosclerosis

The most prevalent type of heart disease, CAD, occurs when the coronary arteries become narrowed or blocked, says Jerome Williams Jr., MD, FACC, a cardiologist with Mid Carolina Cardiology in Charlotte, N.C. The most common cause is atherosclerosis, a progressive buildup of plaque that allows less blood flow to the heart muscle, resulting in angina pectoris. Some of the many complications of obstructive CAD include angina pectoris, cardiomyopathy or weakened heart muscle, and possibly sudden death.

When you code for CAD, you'll look at the subcategory 414.0x and determine the fifth-digit classification by the location of the disease (e.g., native vessel, bypass graft, etc.) and by whether or not the CAD has occurred in a transplanted heart.

Keep in mind: You may assign more than one code from the subcategory 414.0x. "You might use more than one code from the 414.0x if the physician indicates that the patient has CAD involving more than one type of coronary artery and specify which types," says Greg Schnitzer, RN, CCS, CCS-P, CPC, CPC-H, RCC, CHC, product manager at CodeRyte Inc. In addition, make sure you specify which coronary artery is diseased.

Avoid 414.00 as a Catchall

You should only use 414.00 (Coronary atherosclerosis; of unspecified type of vessel, native or graft) if your documentation shows that the patient has obstructive CAD involving coronary artery bypass conduits but the cardiologist didn't specify the location of the obstruction.

Example 1: A patient presents to your cardiologist having had a CABG. The cardiologist documents the patient as having CAD but does not specify if the CAD is of a native vessel or bypass graft.

In this instance, "the physician really did fail to specify which type of artery has the CAD when he probably should have," Schnitzer says. "When the physician didn't specify and you have documentation that the patient has more than just native arteries, then you should use 414.00."

Example 2: Your cardiologist documents "Patient admitted with CAD and unstable angina" but does not include information about the location. In this situation, you should also code CAD first using 414.00, because this is the reason for the unstable angina (411.1), which could be reported as a secondary diagnosis.

Use 414.01 for Native Coronary Artery

If the cardiologist's documentation tells you that the CAD is of a native coronary artery and the patient is not a heart-transplant patient, you should choose 414.01 (Coronary atherosclerosis; of native coronary artery). You should also report this code in two other circumstances:

if the patient has CAD and the cardiologist documents that she has no history of a prior CABG and

if the patient had a prior percutaneous transluminal coronary angioplasty (PTCA) of a native artery and the cardiologist admits her with reocclusion of this lesion.

Example 1: A CAD patient's medical record clearly indicates that she has had no previous bypass surgery. You should code 414.01.

Example 2: The medical record specifies that the CAD exists in one of the named coronary arteries, such as the left anterior descending, and the patient is not a heart- transplant patient. In this case, you are also safe to report code 414.01.

Important: If the documentation is unclear concerning prior bypass surgery and the location of the CAD, you should check with your cardiologist. After pestering him enough times and explaining that this information is necessary for billing purposes, your cardiologist will probably start documenting the location of the CAD.

Example 3: Your cardiologist admits a CAD patient with angina. On a previous admission, the patient underwent PTCA to a branch of the right coronary artery. During this admission, the cardiologist performs a cardiac catheterization, which identifies that the same vessel has reoccluded.

In this situation, you should report 414.01 for the atherosclerosis of the coronary artery. You would also include the secondary diagnosis 413.9 (Angina pectoris; other and unspecified angina pectoris).

Don't Confuse With 411.81

If you think 414.xx and 411.81 (Acute coronary occlusion without myocardial infarction) are synonymous diagnosis codes, then think again.

You should use 411.81 if your documentation shows that some debris causes an acute blockage of a coronary artery. However, if your documentation shows that calcium and plaque have built up over time in the coronary artery (in other words, atherosclerosis), you can choose an appropriate code from the 414.xx series.

If you look at the notes under 411.81, you will see that this code excludes "obstruction without infarction due to atherosclerosis (414.00-414.07)," according to ICD-9. Therefore, 414.xx and 411.81 are not interchangeable.