Myocardial Infarction (MI) Clinical Documentation and Medical Coding Accurate documentation of myocardial infarction (MI) involves assigning specific ICD-10 codes that provide additional information about the condition
www.outsourcestrategies.com OUTSOURCE STRATEGIES INTERNATIONAL 8596 E. 101st Street, Suite H Tulsa, OK 74133
1-800-670-2809
A myocardial infarction or heart attack occurs when one or more coronary arteries that carry blood to the heart are blocked. Blockage of a coronary artery deprives the heart muscle of blood and oxygen, causing injury to it. Cardiology medical billing involves documenting this disorder with suitable medical codes. While documenting acute MI, it is recommended to include the timeframe, which is now considered “acute” for 4 weeks from the time of the incident, subsequent AMI, and the exact site. Acute MI is mainly of two types - ST elevation myocardial infarctions (STEMI) and non-ST elevation myocardial infarctions (NSTEMI). STEMI or Transmural infarcts are associated with a buildup of plaque in a major coronary artery. They generally extend through the whole thickness of the heart muscle. NSTEMI or Subendocardial infarcts involve the wall of the left ventricle, the ventricular septum, or the papillary muscles. They are thought to be caused by a narrowing of the coronary arteries. ICD-10 Coding for Myocardial Infarction (MI) ICD-10 coding provides more specificity for the conditions and treatment offered. ICD-10 allows coding of a new MI that occurs during the 4 week “acute period” of the original AMI. ICD-10 codes list for myocardial infarction include ❖ I21 ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction • • • • •
I21.0 I21.1 I21.2 I21.3 I21.4
ST elevation (STEMI) myocardial infarction of anterior wall ST elevation (STEMI) myocardial infarction of inferior wall ST elevation (STEMI) myocardial infarction of other sites ST elevation (STEMI) myocardial infarction of unspecified site Non-ST elevation (NSTEMI) myocardial infarction
❖ I22 Subsequent ST myocardial infarction • • • • •
I22.0 I22.1 I22.2 I22.8 I22.9
Subsequent Subsequent Subsequent Subsequent Subsequent
elevation
(STEMI)
and
non-ST
elevation
(NSTEMI)
ST elevation (STEMI) myocardial infarction of anterior wall ST elevation (STEMI) myocardial infarction of inferior wall non-ST elevation (NSTEMI) myocardial infarction ST elevation (STEMI) myocardial infarction of other sites ST elevation (STEMI) myocardial infarction of unspecified site
❖ I23 Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period) • • • •
I23.0 Hemopericardium as current complication following acute myocardial infarction I23.1 Atrial septal defect as current complication following acute myocardial infarction I23.2 Ventricular septal defect as current complication following acute myocardial infarction I23.3 Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction
www.outsourcestrategies.com
1-800-670-2809
• • • • •
I23.4 Rupture of chordae tendineae as current complication following acute myocardial infarction I23.5 Rupture of papillary muscle as current complication following acute myocardial infarction I23.6 Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction I23.7 Postinfarction angina I23.8 Other current complications following acute myocardial infarction
Final ICD-10-CM code list for 2018 also adds new codes for Myocardial infarction (MI). New codes for myocardial infarction type 2 (I21.A1) and other myocardial infarction type (I21.A9) mean you will need to take into consideration the type of MI the patient is having. A type 2 MI describes a myocardial infarction due to demand ischemia. In addition, notes added under ST-elevation MI codes (I21.0-I21.4) clarify that the condition is a type 1 MI. ICD-10 Coding Guidelines ❖ Use the I21- codes for (initial) acute MIs and use I22- codes for subsequent MIs occurring within 28 days (four weeks) of the initial MI. ❖ Always submit an I22- code with a I21- coded MI. The I21- code identifies the site of the initial MI and indicates that the patient is still within the four-week time frame of healing from the initial MI. ❖ Code I22 must be followed by the I21- code if a patient has a subsequent acute MI after discharge for care of the initial acute MI. ❖ Before assigning a code from category I22, coders must confirm that the patient suffered two MIs within four weeks ❖ Code I21 must be followed by a I22- code if the patient has a subsequent acute MI while still in the hospital or under care for the initial acute MI. ❖ ICD-10-CM diagnosis coding for AMI (category I21) requires a fourth digit to identify the site of the MI. Category I21 requires a fifth digit to specify the “artery” (Main, LAD, RCA, LC, Other Coronary Artery). ❖ Diagnosis coding for a Subsequent AMI (category I22) requires a fourth digit to identify the “site” of the AMI. There is no fifth digit for category I22, Subsequent STEMI and NSTEMI. The sequencing of the I22 and I21 codes depends on the circumstances of the encounter. ❖ If an AMI is documented as nontransmural or subendocardial, but the site is provided, it is still coded as a subendocardial AMI. ❖ If STEMI converts to NSTEMI due to thrombolytic therapy, it is still coded as STEMI. ❖ AMI must be identified as initial or subsequent (occurring within the 4 week (28 day) acute phase of the initial MI ❖ STEMI of an unspecified site (I21.3) is the default code that is equivalent to the unspecified term AMI
www.outsourcestrategies.com
1-800-670-2809
ICD-10-CM guidelines are clear-cut and specifically state to identify the location of the MI (e.g., left main coronary, left anterior descending, right coronary artery) and to code to the highest level of specificity. If the condition is documented without the site, medical coders can query the physician before coding “other�. Medical billing and coding companies with relevant experience in the industry provide services of skilled medical coding specialists who can ensure accurate coding.
www.outsourcestrategies.com
1-800-670-2809