Myocardial ischemia in nonobstructive coronary arteries: A review of diagnostic dilemmas, current perspectives, and emerging therapeutic innovations

Table 5 Biomarkers in spontaneous coronary artery dissection

Biomarker	Description	Clinical significance
TGF-β	TGF-β is an angiogenic factor involved in vascular remodeling, fibrosis, and smooth muscle cell proliferation. Dysregulation of TGF-β can cause abnormal composition of the arterial wall leading to SCAD	Impaired levels of TGF-β contribute to vascular remodeling and fibrosis, promoting the formation of dissection and impaired vessel function. A study found that miRNAs belonging to the TGF-β family were found to be expressed in high levels in patients with SCAD implicating the role of TGF-β in this disease pathology suggesting the potential of the miRNAs to be biomarkers of SCAD
Fibrillin 1 protein	Fibrillin 1 is a structural component of the extracellular matrix, important for vascular integrity. Deficiency or mutation may lead to SCAD and MINOCA	Impaired fibrillin 1 leads to compromised vascular integrity, making arteries prone to dissection and subsequent myocardial ischemia
Eosinophils	High levels of circulating eosinophils were found in patients with SCAD. Eosinophil activation and infiltration in the adventitial layer of the coronary artery causes lytic substances degranulation resulting in vascular damage in SCAD and MINOCA	Eosinophil infiltration promotes vascular inflammation and damage, which may contribute to SCAD development and microvascular dysfunction

TGF-β: Transforming growth factor beta; SCAD: Spontaneous coronary artery dissection; MINOCA: Myocardial infarction with nonobstructive coronary arteries; miRNAs: MicroRNAs.