Part 3: Top 5 ICD-10-CM Chapters 2019

In 2019, HIA reviewed over 725,600 ICD-10-CM codes from many different facilities including review on our own coders. Yesterday we looked at the ICD-10-CM Chapter 1 and today we will focus on the third area with the most coding opportunities found during HIA reviews.

1. Z00-Z99—Factors influencing health status and contact with health services
2. A00-B99—Certain Infectious and Parasitic Diseases
3. I00-I99—Disease of the Circulatory System
4. J00-J99—Diseases of the Respiratory System
5. E00-E89—Endocrine, Nutritional, and Metabolic Diseases

For Part 3 of this 5 part series, we will look at Chapter 9 within ICD-10-CM—I00-I99—Diseases of the Circulatory System. This chapter contains so many of the everyday diagnoses that we code such as hypertension, heart disease and stroke. Some of the most common recommendations made by HIA in 2019 for this Chapter was:

• Sequencing of the PDX
• Not reporting combination codes correctly
• Failing to follow the “with” guideline in ICD-10-CM
• Not following the timeframe for acute myocardial infarctions
• Reporting type 2 AMI as the PDX instead of the underlying cause
• Missed complications and major complications
• Missed ICD-10-PCS codes
• Coding cardiac catheterization without pressure measurements documented
• Clarifying the validity of documented diagnoses such as acute heart failure without aggressive treatment

In addition to the Official Coding Guidelines for ICD-10-CM for FY 2020, Pages 46-52 that address specific chapter 9 guidelines to follow for reporting diseases of the cardiovascular system, there are multiple AHA Coding Clinics that discuss some of these in detail. Here are a few of these:

• ICD-10-CM/PCS Coding Clinic, Second Quarter 2019 Pages: 5, 22-23, 32-33
• ICD-10-CM/PCS Coding Clinic, First Quarter 2017 Pages: 44-47
• ICD-10-CM/PCS Coding Clinic, Second Quarter 2018 Pages: 9-10
• ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2016 Pages: 26-28, 84-86, 140
• ICD-10-CM/PCS Coding Clinic, First Quarter 2013 Pages: 24-26
• ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2017 Pages: 12-16, 84-86
• ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2012 Pages: 90-98, 102-103
• ICD-10-CM/PCS Coding Clinic, Second Quarter 2017 Pages: 11-12
• ICD-10-CM/PCS Coding Clinic, Second Quarter 2015 Pages: 16-17
• ICD-10-CM/PCS Coding Clinic, Third Quarter 2018 Pages: 5-6
• ICD-10-CM/PCS Coding Clinic, Third Quarter 2016 Pages: 22-23
• ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2018 Pages: 88-89
• ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2019 Pages: 6-7
• ICD-10-CM/PCS Coding Clinic, Second Quarter 2019 Pages: 3-6, 8
• ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2014 Pages: 21-22
• ICD-10-CM/PCS Coding Clinic, First Quarter 2019 Pages: 16, 33-34
• ICD-10-CM/PCS Coding Clinic, First Quarter 2016 Pages: 39-40

Coding Tips for Chapter 9: I00-I99—Disease of the Circulatory System

• Read and follow all instructional notes within ICD-10-CM Tabular
• ICD-10-CM presumes a causal relationship between hypertension and heart and/or kidney involvement unless the provider documents that the conditions are unrelated
• ICD-10-CM assumes rheumatic origin when valve disease affects multiple valves and the valvular heart disease is not described as non-rheumatic
• Follow the “with” in the Alphabetic Index
• ICD-10-CM presumes a causal relationship when a patient has both atherosclerosis and angina pectoris (unless other cause is identified)
• When a patient presents with acute myocardial infarction (AMI) and coronary artery disease, the AMI is sequenced first
• The documentation of “intraoperative” or “postprocedural” may be only specifying a timeframe of when a condition occurred and a query may be needed to clarify if this is a true complication
• If a type 1  non-ST elevation myocardial infarction (NSTEMI) evolves to Type 1 ST elevation myocardial infarction (STEMI), assign the STEMI code
• If a type 1 STEMI converts to NSTEMI due to thrombolytic therapy, it is still coded as STEMI
• Timeframe for AMI’s in ICD-10-CM is 4 weeks (this was 8 weeks in ICD-9)
• Type 2 myocardial infarctions are coded with the underlying cause sequenced first
• Non-traumatic myocardial injury is coded to I51.89 (other ill-defined heart disease)
• The provider must link the diagnoses of heart failure  and diastolic/systolic dysfunction
• The term “decompensated” indicates that there has been a flare up of a chronic condition
• Assign only one code if more than one type of atrial fibrillation is documented
• Verify the number of stents used when patient is undergoing percutaneous coronary artery stenting

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

The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.