Long-term mortality in patients with myocardial infarction with non-obstructive coronary arteries: cardiac magnetic resonance imaging results in comparison to population-based controls

Background Myocardial infarction with non-obstructive coronary arteries (MINOCA) is defined as a myocardial infarction with less than <50% stenosis in a major epicardial artery, based on coronary angiography. MINOCA is also defined as having an ischemic etiology, compared to non-ischemic causes such as myocarditis and takotsubo. Cardiac magnetic resonance (CMR) imaging has become an important diagnostic tool used in patients with MINOCA, although its prognostic value is not completely determined. Purpose The aim was to study the long-term mortality in patients with MINOCA depending on CMR findings in comparison to population-based controls. Methods Patients with the working diagnosis MINOCA were investigated with CMR between 2007 and 2018. A registered-based follow-up was made using the National Patient Register and Cause of Death Register until 2022, comparing patients with and without late gadolinium enhancement (LGE) with population-based controls. The Kaplan-Meier estimator and the log rank test were used to assess crude survival. Results In 282 patients, the mean age was 57 years and 68% were women. Patients with MINOCA had a higher income and education as well as a higher prevalence of hypertension, angina pectoris and thromboembolic events compared to controls (Table). A total of 34% patients had LGE due to ischemic myocardial injury or myocarditis and 66% had no LGE. There was no difference in mortality between MINOCA patients with and without LGE in comparison to population-based controls (Figure). Conclusion Patients with the working diagnosis MINOCA did neither have a significant difference in mortality after a 15-year follow-up depending on CMR findings, nor in comparison to population-based controls.