New indicator of cellular ischemia in coronary slow-flow phenomenon: Cell-free DNA

OBJECTIVE
Coronary slow-flow phenomenon (CSFP) is defined as the delayed arrival of coronary blood flow to the distal vascular bed in at least 1 major epicardial coronary artery. Cell-free DNA (cfDNA) is a type of DNA that circulates freely in the blood once released from nucleated cells. The aim of this study was to determine if the level of cfDNA, which is an indicator of ischemia at the cellular level, was increased in CSFP.

METHODS
The study included 46 patients in total: 23 patients with CSFP and 23 with a normal coronary angiogram (NCA). The level of cfDNA, and clinical, biochemical, and angiographic features of the groups were compared.

RESULTS
The mean age was 53.8±10.3 years for the CSFP patient group and 56.6±9.4 years for the NCA patient group. There was no statistically significant difference between the groups in terms of basal clinical characteristics or laboratory data. The plasma cfDNA level was 5.04±2.37 ng/µL in the CSFP patients and 2.28±1.09 ng/µL in the NCA group (p<0.001).

CONCLUSION
Several invasive and noninvasive studies conducted on patients with CSFP have revealed myocardial ischemia. The results of this study demonstrated that the level of cfDNA was significantly increased in patients with CSFP as a result of ischemia at the cellular level caused by microvascular disruption.