Risk Factors and Markers for Acute Myocardial Infarction With Angiographically Normal Coronary Arteries

Myocardial Infarction with normal coronary arteries (MINCA) is common with a prevalence of 1% to 12% of all myocardial infarctions. The pathogenic mechanisms of MINCA are still unknown, but endothelial dysfunction has been suggested as a possible cause. To investigate risk factors and markers for MINCA, we conducted a case-control study. Considering the reported low prevalence of classical risk factors for coronary heart disease (CHD) in some but not all studies, our hypothesis was that endothelial function and intima-media thickness (IMT) were better, respectively lower, than CHD controls. One hundred patients with MINCA fulfilling diagnostic criteria according to the European Society of Cardiology/American Collage of Cardiology/American Heart Association universal definition of myocardial infarction with myocarditis excluded by cardiac magnetic resonance imaging were investigated. Risk factors, endothelial function (EndoPAT), and IMT were compared to gender- and age-matched patients with myocardial infarction and CHD, respectively healthy controls. Smoking, hypertension, impaired glucose tolerance and diabetes mellitus, inflammatory disease, and psychiatric disorders were more common in patients with MINCA than in healthy controls. In contrast to patients with CHD, the lipid profile was antiatherogenic with low low-density lipoprotein and high high-density lipoprotein cholesterol. There were no major differences between the groups regarding endothelial function and IMT that were in the normal range. In conclusion, the present study showed that MINCA was associated with many established cardiovascular risk factors without major differences in atherosclerosis markers. MINCA patients recalled a high prevalence of emotional stress before admission that together with previous psychiatric vulnerability and female gender speaks strongly in favor of Takotsubo syndrome being an important cause of MINCA.