Use MI Age to Select Correct Code(s)
Question: I just got a job with a cardiologist’s practice and have learned that the “age” of a myocardial infarction (MI) is crucial to reporting the appropriate diagnosis code. Why does the age of the MI matter? Texas Subscriber Answer: ICD-10-CM guidelines organize myocardial infarction diagnoses into categories based on age; specifically, whether the age of the MI is equal to or less than four weeks old. Guidelines 9.e.1 say: “For encounters occurring while the myocardial infarction is equal to, or less than, four weeks old, including transfers to another acute setting or postacute setting, and the myocardial infarction meets the definition for ‘other diagnoses’ … codes from category I21 [Acute myocardial infarction] may continue to be reported. For encounters after the 4 week time frame and the patient is still receiving care related to the myocardial infarction, the appropriate aftercare code should be assigned, rather than a code from category I21.” Age of an MI also comes into play when a patient has a second MI within four weeks of the first. In such a situation, a coder should assign the appropriate codes from category I21 to identify each type, rather than I22 (Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction). “Codes from category I22 should only be assigned if both the initial and subsequent myocardial infarctions are type 1 or unspecified,” the guidelines say. Rachel Dorrell, MA, MS, CPC-A, CPPM, Development Editor, AAPC
