The relationship between serum bilirubin concentration and coronary slow flow

The pathophysiology of coronary slow flow (CSF) has not been clearly identified, although multiple abnormalities including arteritis, endothelial dysfunction, and atherothrombosis have been reported. Several studies have demonstrated that higher serum bilirubin inhibits the inflammation and proliferation of vascular smooth muscle cells; in addition, there is a relationship between serum bilirubin and cardiovascular disease. However, the relationship between bilirubin and CSF is still unknown. In our study, we compared serum bilirubin concentrations between CSF patients and controls.

The study included 50 CSF patients (19 male, mean age 65.6 ± 13.7 years) and 30 controls (10 male, mean age 57.86 ± 11.6 years). Concurrent routine biochemical tests and leukocyte count, hemoglobin, hematocrit, and platelet count on whole blood count were performed in patients that underwent a coronary angiogram. These parameters were compared between groups.

No statistically significant difference was found between the two groups in terms of basic characteristics. Total, direct, and indirect serum bilirubin levels were significantly lower among CSF patients than controls (14.0 ± 12.0 versus 6.15 ± 6.8, 5.6 ± 3.4 versus 2.6 ± 1.7, and 8.4 ± 8.5 versus 3.6 ± 3.4 µmol/l; all p < 0.001, respectively).

The study revealed a relationship between serum bilirubin and CSF.