Type 2 myocardial infarction: incidence, presentation, treatment and outcome in routine clinical practice.

AIMS: The clinical definition and optimal treatment for myocardial infarction (MI) type 2 (T2MI) are not well established. We assessed differences in presentation, treatment and outcomes of patients with MI type 1 (T1MI) and T2MI.

METHODS: The data of MI patients enrolled in the AMIS Plus cohort with T2MI were compared with T1MI using propensity score matching.

RESULTS: A total of 13 829 patients had T1MI and 1091 (7.3%) T2MI. Patients with T2MI were older, often female, with more risk factors and comorbidities, and less ST segment elevation. After matching for these differences (1091 per group), T2MI patients less often presented with typical chest pain but more frequently with atrial fibrillation (15.6 vs. 4.9%; P < 0.001) and anemia (33.5 vs. 23.3%; P < 0.001) than patients with T1MI. They less frequently received percutaneous coronary interventions (51.1 vs. 76.4%; P < 0.001) and antiplatelet treatment. No differences were found for in-hospital (5.8 vs. 5.6%; OR 1.04; 95% confidence interval 0.72-1.49) and 1-year mortality (11.2 vs. 7.2%; P = 0.38) between matched T2MI and T1MI patients.

CONCLUSION: Patients who suffered a T2MI had less typical symptoms, were less aggressively treated with anticoagulants, platelet inhibitors or percutaneous coronary intervention, but had similar complications and mortality to those with T1MI. Patients with T2MI are a heterogeneous group that requires further investigation to better define optimal therapeutic approaches.