Cardiovascular and non-cardiovascular mortality at 5 years in patients with type 1 and type 2 myocardial infarction

Type 2 myocardial infarction (MI) occurs due to myocardial oxygen supply or demand imbalance, often during another acute illness, in the absence of coronary atherothrombosis. In patients aged over 70 years, it is responsible for over one in three in-hospital MI events, yet, we have no accepted standards for investigation nor clinical trials to support decisions for treatment. It is recognized that short and long-term outcomes are poor, with just one in three patients are alive at 5 years.1 Despite a significant competing risk of non-cardiovascular death in patients with Type 2 MI, there is high risk of recurrent MI, equivalent to those who have MI due to atherothrombosis (Type 1 MI).2 In studies which apply systematic cardiac imaging, coronary artery disease is identified in at least two-thirds of patients with Type 2 MI, with obstructive disease identified in over a third.3,4 These observations suggest some patients with Type 2 MI could benefit from antiplatelet or lipid-lowering therapy or coronary revascularisation. Clinical trials exploring the optimal approach to investigation and treatment are urgently required. TARGET-Type 2 recently demonstrated it is feasible to recruit and randomize patients with Type 2 MI to a complex intervention to identify and treat coronary artery disease and left ventricular impairment.5 However, the optimal primary outcome for a clinical trial in this setting is unclear, and the likelihood of cardiovascular therapies having a meaningful impact on all-cause mortality is uncertain.