Type 2 Myocardial Infarction Phenotype

human heart
A heart attack (myocardial infarction) is usually caused by a blood clot, which stops the blood flowing to a part of your heart muscle.
Type 2 myocardial infarction (MI) has a unique cardiovascular phenotype, distinct from that of type 1 MI.

Type 2 myocardial infarction (MI) has a unique cardiovascular phenotype, distinct from that of type 1 MI, according to a study published in the Journal of the American College of Cardiology.

In this study, deidentified patient data from the 2017 Nationwide Readmissions Database was used to identify patients with type 1 MI (n=216,657), type 2 MI (n=37,765), and both type 1 and 2 MI (n=1525). MI classification was based on International Classification of Diseases-10th Revision codes for types 1 and 2 MI.

Patients with type 2 vs type 1 MI were found to be older (71 vs 69 years, respectively; P <.001), to have a greater percentage of women (47.3% vs 40%, respectively; P <.001),greater prevalence of heart failure (27.9% vs 10.9%, respectively; P <.001), kidney disease (35.7% vs 25.7%, respectively; P <.001), and atrial fibrillation (31% vs 21%, respectively; P <.001).

A smaller percentage of patients with type 2 vs type 1 MI underwent coronary angiography (10.9% vs 57.3%, respectively; P <.001), percutaneous coronary intervention (1.7% vs 38.5%, respectively; P <.001), and coronary artery bypass grafting (0.4% vs 7.8%, respectively; P <.001).

In addition, patients classified as having type 2 vs type 1 MI had lower risk for in-hospital mortality (adjusted odds ratio [aOR], 0.57; 95% CI, 0.54-0.60) and 30-day readmission for MI (aOR, 0.46; 95% CI, 0.35-0.59). No difference was found between patients with type 1 and type 2 MI with regard to the risk for 30-day all-cause mortality (aOR, 1.05; 95% CI, 0.99-1.11) or readmission for heart failure (aOR, 0.75; 95% CI, 0.52-1.07) in a multivariable regression analysis.

Study limitation include the lack of an independent adjudication to confirm administrative codes for type 1 and type 2 MI.

 “Clinical trials are needed to determine optimal management strategies for patients with type 3 MI,” concluded the study authors.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


McCarthy CP, Kolte D, Kennedy KF, Vaduganathan M, Wasfy JH, Januzzi JL Jr. Patient characteristics and clinical outcomes of type 1 versus type 2 myocardial infarction. J Am Coll Cardiol. 2021;77(7):848-857. doi:10.1016/j.jacc.2020.12.034