Young adults with type 2 myocardial infarction at higher risk of death

Type 2 myocardial infarction (MI) in young patients is associated with higher long-term mortality than type 1 MI, with approximately one-half of patients with myocardial injury and more than one-third with type 2 MI succumbing to death within 10 years, reports a study.

The investigators identified 3,829 adults aged ≤50 years (median age, 44 years; 30 percent women) who presented with troponin >99th percentile or the International Classification of Diseases code for MI over a 17-year period. Patients were categorized as type 1 MI, type 2 MI or myocardial injury based on the Fourth Universal Definition of MI. Cox proportional hazards models were generated for survival free from all-cause and cardiovascular death.

Of the patients, 55 percent had type 1 MI, 32 percent had type 2 MI, and 13 percent had myocardial injury. Mortality was highest for myocardial injury (45.6 percent), followed by type 2 MI (34.2 percent) and type 1 MI (12 percent), over a median follow-up of 10.2 years (p<0.001).

In adjusted model, type 2 MI correlated with higher all-cause (hazard ratio [HR], 1.8, 95 percent confidence interval [CI], 1.2–2.7; p=0.004) and cardiovascular mortality (HR, 2.7, 95 percent CI, 1.4–5.1; p=0.003) compared with type 1 MI.

Patients with type 2 MI or myocardial injury tended to be younger and have fewer cardiovascular risk factors but have more noncardiovascular comorbidities. In addition, they were significantly less likely to receive cardiovascular medication prescription at discharge.

“These findings emphasize the need to provide more aggressive secondary prevention for patients who experience type 2 MI and myocardial injury,” the investigators said.