As a reminder for us all, Type 2 myocardial infarction (MI) is defined by a rise and fall of cardiac biomarkers and evidence of ischemia without unstable coronary artery disease (CAD), due to a mismatch in myocardial oxygen supply and demand. Myocardial injury is similar but does not meet clinical criteria for MI. There is uncertainty regarding clinical characteristics, management and outcomes of type 2 MI and myocardial injury in comparison to type 1 MI. (Coron Artery Dis. 2018 Jan; 29(1): 46–52)
Basically, it helps to think of it this way: a type 2 MI is always a consequence of something unrelated to a clog in a coronary artery.
The important thing to remember: The Type II MI is always coded second, after the underlying cause.
“In the setting of a type II Myocardial Infarction, underlying etiology should be coded first, followed by the type 2 MI code.”
I21.A1 Myocardial Infarction Type 2
• the underlying cause, such as:
- anemia D50.0 D64.9
- chronic obstructive pulmonary disease J44
- paroxysmal tachycardia I47.0 I47.9
- shock R57.0 R57.9