Elevated serum troponin clearly does not equal myocar-dial infarction (MI). This was the strong message in the

2018 publication of the Fourth Universal Definition of Myocardial Infarction1 (4UDMI), the first update to the international consensus document since 2012. Most clinicians have learned how to accurately diagnose the classic Type 1 MI (T1MI) due to atherosclerotic plaque rupture; however, elevated troponin in the absence of T1MI is increasingly common due to more frequent and less discriminate troponin testing. 2 Patients with elevated troponin in the absence of T1MI have traditionally created confusion and variability in diagnosis, management, and documentation. Interpretation and management of elevated troponin in the absence of T1MI has become difficult.

In this clinical practice update, we aim to review the updated definition of Type 2 MI (T2MI) and nonischemic myocardial injury (NIMI), since these are the two predominant diagnoses among patients with elevated troponin in the absence of T1MI. We also provide a clinical framework for clinicians to think through elevated serum cardiac troponin levels and identify opportunities for quality improvement around this critical issue.