C-Reactive Protein to Albumin Ratio May Be an Inflammatory Indicator for the Coronary Slow Flow Phenomenon

Introduction: Coronary slow flow phenomenon (CSFP) is defined by the low-speed filling of contrast material in the distal portion of one or more coronary arteries despite the absence of stenosis of the coronary arteries on coronary angiography (CAG). Although the pathophysiology of this phenomenon is not known, suggested mechanisms in-clude increased oxidative stress and inflammation, disturbed endothelial function, and microvascular dysfunction. The C-reactive protein (CRP)/albumin ratio (CAR) is a sensitive indicator of the severity and progression of the inflam-matory reaction. In our study, we planned to examine the relationship between CSFP and CAR.

Methods: In this prospective and single-center study, 45 patients with CSFP detected in CAG between June 2021 and June 2022 were included. In the control group, 49 people with normal coronary arteries matched for gender and age were included. We analyzed the relationship between CSFP and CAR according to laboratory findings and patient demographics.

Results: The mean age of the study group was 56.43±9.66 years. CRP (4.69±3.69 vs 2.93±1.93, p=0.006) and CAR (1.14±0.86 vs 0.66±0.41, p=0.002) were significantly higher in the CSFP group compared with controls. Albumin levels were significantly lower in CSFP (4.05±0.90 mg/dL vs 4.40±0.71 mg/dL, p=0.037). In addition, CAR showed a significant diagnostic value for CSFP in receiver operating characteristic curve analysis (area under the curve: 0.65±0.06, p=0.0130).

Discussion and Conclusion: CAR values, which are important indicators of inflammation, were higher in patients with CSFP. This finding may reveal that inflammation is also effective in the pathogenesis of CSFP, and we think CAR can be used for screening and predicting prognosis in this patient group.

Keywords: Coronary slow flow phenomenon; C-Reactive protein to albumin ratio; Inflammation; Coronary angiography