Q&A: Coronary stent

Q: The 2016 CDI Pocket Guide states that four or more stents or vessels is equivalent to an MCC and changes the DRG. I understand that Coding Clinic, Second Quarter 2015 defines the number of individual sites instead rather than anatomical vessels. The DRG Expert states four vessels or four plus stents changes the DRG. It was my understanding that when four stents are used in three vessels or sites, the DRG would not change. Could you please clarify if it is the number of stents or the number of sites that changes the DRG?

A: The coronary stent question has plagued the entire coding and CDI community since Oct. 1, 2015. There is much self-contradiction in the DRG titles, which includes vessels and stents, and the meaning of “sites” (implying stent locations) in the ICD-10-PCS Official Guidelines for Coding and Reporting. The Coding Clinic advice published in Second Quarter 2015 helped some, and I believe intended to clarify that the number of coronary arteries treated determines the code assigned, which then drives the DRG.

Because of the confusion and contradictions, the 2017 ICD-10-PCS Official Guidelines for Coding and Reporting sections B3.6, B3.7, B4.4 have been modified to indicate that procedures performed on coronary arteries are classified by the number of arteries treated, not the number of coronary artery sites.  The number of stents does impact code assignment or DRG classification, but the code titles for DRGs 246 and 248 still perplexingly retain “4+ vessels/stents.”

Editor’s note: Richard D. Pinson, MD, FACP, CCS, principal of Pinson & Tang LLC, and author of the CDI Pocket Guide answered this question. Contact him at info@pinsonandtang.com.