Type 2 myocardial infarction tied to fewer invasive management, lower mortality

Type 2 myocardial infarction (MI) is responsible for about 40 percent of perioperative MIs, a study has found. Patients with type 2 perioperative MI are less likely to undergo invasive management and die compared to those with type 1 perioperative MI.

“Perioperative MI is frequently attributed to type 2 MI, a mismatch in myocardial oxygen supply-demand without unstable coronary artery disease,” the authors said.

In this study, the authors identified characteristics, management, and outcomes of perioperative type 1 vs type 2 MI among adults aged ≥45 years hospitalized for noncardiac surgery in the US. Perioperative MI was identified using the International Classification of Diseases, 10th revision (ICD-10) codes.

Of the 4,755,382 surgical hospitalizations, 38,975 (0.82 percent) were perioperative MIs, with type 2 MI in 42 percent. Patients with type 2 MI were older, more likely to be women, and less likely to have cardiovascular comorbidities than those with type 1 MI.

In addition, type 2 MI was associated with fewer invasive management (6.7 percent vs 28.8 percent; p<0.001) and lower mortality (12.1 percent vs 17.4 percent; p<0.001; adjusted odds ratio [aOR], 0.51, 95 percent confidence interval [CI], 0.45‒0.59) than type 1 MI. Of note, invasive management correlated with lower mortality in type 1 (aOR, 0.56, 95 percent CI, 0.49‒0.74) but not type 2 MI (aOR, 1.19, 95 percent CI, 0.77‒1.85).

No between-group difference was seen in 90-day hospital readmission among survivors (36.5 percent vs 36.1 percent; p=0.72).