Myocardial infarction without obstructive coronary artery disease (MINOCA) - prevalence and prognosis

Introduction: There are conflicting data on the prevalence and prognosis of AMI patients with non-obstructive coronary artery disease (MINOCA). Aim: We studied the prevalence and prognosis of MINOCA patients. Method: In the Hungarian Myocardial Infarction Registry (HUMIR) 45,223 patients (pts) with acute myocardial infarction (AMI) were found who were treated between Jan 1, 2014, and June 30, 2018, and coronary arteriography was performed. ST-elevation myocardial infarction was diagnosed in 22,469 pts (49.7%). Patients without obstructive coronary artery disease who had no previous myocardial infarction, heart failure, PCI and CABG procedure were selected to the MINOCA group (n = 2003). Patients with obstructive coronary artery disease belonged to the MICAD group (n = 43,220). We investigated clinical characteristics of the patients, overall survival and reinfarction. Survival curves were estimated with the Kaplan-Meier method and were modeled with the Cox proportional hazards model. Results: The proportion of MINOCA pts among all myocardial infarction was by 4.4% higher in the STEMI pts compared to the NSTEMI group (2.0% vs. 6.8%). The MINOCA pts were younger (age 64.0 +/- 14.4 vs. 65.5 +/- 12.2 years), and the proportion of women was higher (55.7% vs. 36.5%). Hypertension, diabetes mellitus and peripheral artery disease were more common in the MICAD group (79.1% vs. 73.7%, 33.0% vs. 21.2%, and 12% vs. 8%). The mortality was higher among the MICAD pts. In the MINOCA group, the mortality of men did not differ between STEMI and NSTEMI, as opposed to women: women with STEMI had higher mortality than women with NSTEMI. The risk of reinfarction was higher in the MICAD group, especially in NSTEMI, the risk in the MINOCA group was lower, and there was no substantial difference between types. Conclusion: In this real word, retrospective, observational study, we found a significant difference in the prevalence of MINOCA pts according to different types of myocardial infarction. In the MINOCA group, the mortality of women with STEMI was substantially higher.