Systematic Review of Patients Presenting with Suspected Myocardial Infarction and Non-Obstructive Coronary Arteries (MINOCA)
Background—Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a puzzling clinical entity with no previous evaluation of the literature. This systematic review aims to: (A) quantify the prevalence, risk factors, and 12-month prognosis in patients with MINOCA, and (B) evaluate potential pathophysiological mechanisms underlying this disorder.
Methods and Results—Quantitative assessment of 28 publications using a meta-analytic approach evaluated the prevalence, clinical features, and prognosis of MINOCA. The prevalence of MINOCA was 6% [95%CI: 5, 7%] with a median patient age of 55 years (95%CI: 51, 59 years) and 40% women. However, in comparison to those with myocardial infarction associated with obstructive coronary artery disease (MI-CAD), the patients with MINOCA were more likely to be younger and female but less likely to have hyperlipidemia, although other cardiovascular risk factors were similar. All-cause mortality at 12-month was lower in MINOCA (4.7% [95%CI: 2.6, 6.9%]) compared to MI-CAD (6.7% [95%CI: 4.3, 9.0%]). Qualitative assessment of 46 publications evaluating the underlying pathophysiology responsible for MINOCA, revealed the presence of a typical myocardial infarct on cardiac magnetic resonance imaging in only 24% of patients, with myocarditis occurring in 33% and no significant abnormality in 26%. Coronary artery spasm was inducible in 27% of MINOCA patients and thrombophilia disorders were detected in 14%.
Conclusions—MINOCA should be considered as a 'working diagnosis' with multiple potential causes that require evaluation so that directed therapies may improve its guarded prognosis.
- coronary artery abnormality
- magnetic resonance
- myocardial infarction
- coronary artery disease
- coronary spasm
- cardiac magnetic resonance imaging
- Received May 16, 2014.
- Revision received December 8, 2014.
- Accepted December 29, 2014.