Variant Angina is Associated with Myocarditis

Vasospastic angina (VSA) is caused by severe diffuse or segmental coronary artery spasms. Patients with variant angina have poor clinical outcomes, although nitrates and calcium blockers help improve patient symptoms because there is no understanding of the etiology and causal treatment. The present study investigated whether VSA is associated with inflammation of the heart.

A total of 109 patients with VSA diagnosed by the presence of recurrent angina pectoris, typical electrocardiography, and coronary angiography were recruited, and 61 normal participants and 61 patients with acute myocardial infarction (AMI) and coronary artery stenosis were recruited as controls. The plasma levels of 24 cytokines were measured using a magnetic Luminex assay, and endothelin-1 and histamine levels tested using enzyme-linked immunosorbent assay and mass-spectrometry, respectively, for all participants. Furthermore, four patients with VSA underwent 18-fluorine fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT).

The plasma levels of interleukin (IL)-12p70, IL-13, PDL-1, IL-10, IL-6, IL-15, macrophage inflammatory protein (MIP)-1α, and MIP-1β in patients with VSA were significantly higher than those in both normal controls and patients with AMI (p<0.001) but did not differ between normal controls and patients with AMI. ¹⁸F-FDG PET/CT showed that the left ventricle, coronary perivascular tissue volume, and coronary perivascular FDG uptake were significantly increased in all four patients.

Our findings demonstrate that VSA patients have significantly elevated plasma cytokine levels and myocardial and pericoronary inflammation, suggesting that VSA is associated with myocarditis. This study provides novel insights into the etiology and treatment of VSA.