Coronary Artery “Sites” Coding

There were a lot of changes to ICD-10-PCS for FY2017 involving the cardiovascular system. The biggest change was how coronary arteries are coded. With the implementation of ICD-10-PCS, these were classified by the number of distinct “sites” treated and not the number of coronary arteries treated (by distinct name). This was a big change for coders as these cases were coded to the number of coronary arteries treated in ICD-9-CM. The descriptor “sites” was removed for FY2017. The new guideline applies to the number of coronary arteries treated and not the number of sites treated. This is going back to the way coronary artery procedures were coded in ICD-9-CM.

 

When coding procedures on coronary arteries, the question of what arteries are considered coronary arteries when branches are bypassed/stented may come to mind. What branches are considered “distinct” coronary arteries?

Coronary circulation consists of two main arteries, right and left, each with several branches:

Right coronary artery (RCA)

• Right marginal
• Right posterior descending

Left main coronary artery (LMCA)

• Left anterior descending branch (LAD)
  • Diagonal
  • Septal
• Left circumflex (LCX)
  • Obtuse marginal (OM)
  • Posterior descending
  • Posterolateral

If procedures such as coronary bypass or PTCA/stent are performed on any of these arteries and branches they would be counted as coronary arteries in ICD-10-PCS coding as of October 1, 2016.

Here is the excerpt from the ICD-10-PCS Official Guidelines for Coding and Reporting:

Coronary arteries – B4.4

The coronary arteries are classified as a single body part that is further specified by number of arteries treated. One procedure code specifying multiple arteries is used when the same procedure is performed, including the same device and qualifier values.

Examples:

• Angioplasty of two distinct coronary arteries with placement of two stents is coded as Dilation of Coronary Artery, Two Arteries with Two Intraluminal Devices.
• Angioplasty of two distinct coronary arteries, one with stent placed and one without, is coded separately as Dilation of Coronary Artery, One Artery with Intraluminal Device, and Dilation of Coronary Artery, One Artery with no device.

Coding scenario examples:

• Patient has PTC angioplasty of RCA and OM with drug eluting stents placed. This would be coded as Dilation of Coronary Artery, Two Arteries with Two Intraluminal Devices.
• Patient has aortocoronary bypass graft of the LAD and RCA this would be coded as Bypass of Two coronary arteries.

Authored by Kim Boy, RHIT, CDIP, CCS, CCS-P

References:
AHA Coding Clinic, Fourth Quarter 2016, Page: 82-86
ICD-10-PCS Official Guidelines for Coding and Reporting 2017 (original revision year)
AHA Coding Clinic, First Quarter 1991 Page: 7 to 9

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