Q&A: MI coding FAQs, part 3

Q: Recently, the patient had a two-day length of stay (LOS) on telemetry, no cardiac related symptoms or complaints, no EKG, no troponins, no cardiology consult or cardiac work-up. The patient was continued on his home medications, which included Atorvastatin and Ticagrelor. I’ve read the Official Guidelines for Coding and Reporting, but I’m still unsure if this meets the definition of a secondary diagnosis. Would telemetry and the continuation of home medications be considered continued care for the MI or treatment, making it a valid MCC?

A: When we talk about secondary diagnoses, we have to look at the Uniform Hospital Discharge Data Set (UHDDS) guidelines which state that one of the following must apply in order for the diagnosis to be eligible for code assignment:

• Clinically evaluated/monitored
• Therapeutically treated
• Diagnostics were performed
• Increase in nursing care or monitoring
• Increase in length of stay

If a condition meets one of the above criteria, then it is eligible for code assignment. As long as the prior MI within the 28 days meets any one of the above, then it is reported along with the I22 code for the subsequent MI.

If the prior MI was 30 days (four weeks, plus two days), then there would not be a subsequent MI by definition and the acute type 1 MI would be reported with the I21 codes for the new MI. If the initial MI is still requiring care after the 28-day timeframe, then an aftercare code from the I25 code series would be applied as stated in my answer to the prior question.

I think the main takeaways are to remember that:

1. Subsequent MI codes are only used for type 1 or unspecified MIs and always have to be used in conjunction with the I21 code series. This is the first step to determine.
2. If the initial MI is still being treated, evaluated, monitored, etc., then the appropriate code from the I21 code series is applied.
3. If the initial MI is older than the 28-day timeframe and is still being treated, then the I25 aftercare code will apply.
4. You can only use an I22 code when there’s an I21 code to apply.

I know this is a lot of information and I hope this helps you sort out the details as this is a confusing subject for a lot of people. If you can step the process out, it becomes much easier.

Editor’s Note: Dawn Valdez, RN, LNC, CDIP, CCDS, CDI education specialist and CDI Boot Camp instructor for HCPro in Middleton, Massachusetts, answered this question. For information, contact her at dvaldez@hcpro.com. For information regarding CDI Boot Camps, click here. To read the first part of this Q&A, click here. To read the second part of this Q&A, click here.