Eosinophilic inflammation in spontaneous coronary artery dissection: A potential therapeutic target?

Spontaneous coronary artery dissection (SCAD), defined as non-traumatic, non-iatrogenic dissociation of coronary vessel wall resulting from intimal disruption or intramural hemorrhage, represents an important cause of sudden death and myocardial infarction among young or middle-aged women without conventional risk factors for atherosclerosis. On histopathological examination, SCAD is featured by prominent eosinophilic infiltration of the adventitia or periadventitial layer of coronary artery. It has been estimated that approximately 15-30% of SCAD patients experience recurrent episodes of dissection despite medical therapy. Preliminary evidence suggests that injury to the vascular endothelium and myocytes in the arterial wall may be explained by cytotoxic products released from eosinophils in response to inflammatory mediators. In addition, neovascularization of vasa vasorum and dilatation of intimal capillaries may be stimulated by localized eosinophils. Newly formed fragile vasa vasorum may disrupt due to high intraluminal pressure from the interconnected capillary network, leading to the expansion of intramural hemorrhage. It is hypothesized that anti-inflammatory therapy targeting eosinophilic coronary periarteritis would be effective in preventing the recurrence of SCAD by promoting the healing of dissection. The article delineates the biological plausibility, empirical data, and future perspective regarding eosinophilic inflammation as a potential therapeutic target for SCAD.