Affiliations: Division of Dyslipidemia, State Key Laboratory of
Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular
Disease, Chinese Academy of Medical Sciences and Peking Union Medical College,
Beijing, China | Department of Cardiology, Fifth Hospital of Wuhan
City, Wuhan, Hubei, China
Note: [] Corresponding author: Jian-Jun Li, Division of Dyslipidemia,
State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National
Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and
Peking Union Medical College, Beijing 100037, China. Tel.: +86 10 88396077;
Fax: +86 10 68331730; E-mail: lijnjn@yahoo.com.cn
Abstract: BACKGROUND: Cardiac syndrome X (CSX) is a condition characterized by
chest pain with normal coronary arteries. However, its pathogenesis has not
fully been understood yet. Red blood cell distribution width (RDW) has recently
been suggested as a marker of acute and chronic cardiovascular diseases, while
no data is available in patients with CSX. METHODS: One hundred and twenty consecutive patients with CSX and
102 normal controls were prospectively enrolled in this study. Blood samples
were drawn from all individuals for measuring RDW and high-sensitivity
C-reactive protein (CRP). The baseline data were compared between patients with
CSX and normal controls. RESULTS: The RDW levels were significantly higher in patients with
CSX than that in those with normal controls (13.1 ± 2.1 versus 12.3
± 1.8, p=0.011). Moreover, the data showed that the levels of plasma CRP
were marked higher in patients with CSX than those that were observed in normal
controls (CRP: 2.8 ± 2.2 mg/L versus 2.0 ± 1.7 mg/dl, p=0.014).
In addition, the multivariate analysis indicated that peripheral monocyte cell,
CRP and RDW were the independent variables most strongly associated with CSX.
In a receiver operating characteristic (ROC) curve analysis, we found that an
RDW value of 12.8% was used as an effective cut-point in the segregation of the
presence or absence of cardiac syndrome X, a sensitivity of 52.0% and a
specificity of 65.4% were obtained. Finally, correlation analysis suggested
that there was positive correlation between plasma levels of CRP and RDW levels
(n=120, γ =0.381, P=0.013). CONCLUSIONS: The present study, for the first time, demonstrated
that elevated RDW and CRP levels were independently associated with the
presence of CSX.
Keywords: Cardiac syndrome X, Red cell distribution width, C-reactive protein, complete blood count
