Assessment of the relationship between red cell distribution width and cardiac syndrome X

Background: Cardiac syndrome X (CSX) is characterised by angina-like chest pain, a positive stress test, and normal coronary arteries. Increased red cell distribution width (RDW) level may be indicative of an underlying inflammatory state. Aim: To investigate RDW level in patients with CSX and compare patients having coronary artery disease (CAD) and normal subjects. Methods: 245 subjects (79 patients with CSX, 81 patients with CAD, and 85 controls) were enrolled in the study. The CSX group consisted of patients with anginal chest pain, ischaemia on noninvasive stress test and a normal coronary angiogram. CAD was defined as >= 50% stenosis in at least one coronary artery. The control group was selected from the patients with anginal symptoms but a normal stress test and a normal coronary angiogram. RDW measurements among the three groups were compared. Results: Baseline clinical and biochemical characteristics were not different among the three groups. There were no statistically significant differences in RDW levels between the CSX and CAD groups (p = 0.17). RDW measurements in both the CSX and CAD groups were found to be significantly higher than the control group (p < 0.01). Conclusions: We discovered that patients with CSX and CAD have significantly higher RDW measurements compared to controls. The relationship between CSX and higher RDW level suggests that endothelial dysfunction may also contribute to the etiopathogenesis of the CSX phenomenon as it does with CAD.