Revisiting type 2 myocardial infarction: Unmet clinical needs

Cardiovascular disease is the most common cause of mortality and morbidity worldwide and acute coronary syndrome (ACS) is often the first clinical manifestation. Currently, the diagnosis of acute myocardial infarction (AMI) is based on the fourth universal definition of myocardial infarction (MI), with different subtypes based on their pathophysiological background. While type 1 myocardial infarction (T1MI) is defined by an acute coronary event with plaque disruption and consequent athero-thrombosis, type 2 myocardial infarction (T2MI) is defined as an event due to oxygen demand and supply imbalance, unrelated to acute coronary athero-thrombosis. The differentiation between these two entities is crucial since T1MI benefits from an early invasive approach aimed at myocardial reperfusion, while in T2MI it is critical to focus on the cause of the ischemia mismatch. Furthermore, T2MI is often associated with a poorer prognosis. The presence and severity of coronary artery disease (CAD) may significantly influence the ischemic threshold and the risk of T2MI, as it has been identified as an independent predictor of cardiovascular death and recurrent MI. The key point of contention is determining the presence of CAD in T2MI to identify patients eligible for a reperfusion strategy and to tailor therapy as well as secondary prevention strategies. In this narrative review, we aim to highlight the differences in clinical features, imaging, and biomarkers between T1MI and T2MI, emphasizing the role of CAD, in refining the diagnostic-therapeutic algorithm in T2MI.