OBJECTIVETo investigate the correlations among persistent viral infection, heart function and Chinese medicine (CM) difined-syndromes in patients with dilated cardiomyopathy (DCM).

METHODSFifty patients with DCM in the First Affiliated Hospital of Zhejiang Chinese Medical University from October 2009 to December 2011 were selected as the research subjects, and 30 healthy people were simultaneously selected as the normal control group to detect persistent viral infections after admission. The CM syndrome type and grade of heart function were then evaluated. The expression level of Coxsackie adenovirus receptor (CAR) was detected using the flow cytometry (FCM) technique, coxsackie virus RNA (CVB-RNA) using reverse transcription polymerase chain reaction (RTPCR), and the plasma brain natriuretic peptide (BNP) level with a Triage meter plus diagnosis instrument. Finally, the parameters such as left ventricular end diastolic diameter (LVEDd) and left ventricular ejection fraction (LVEF) were measured by ultrasonic cardiogram. Person correlation analysis was used for measured data, Spearman correlation analysis for rating data, and the Chi-square test for numerical data.

RESULTSCVB-RNA was positive in 22 patients (44%) with DCM, while only 6 cases (20%) were CVB-RNA-positive in the normal control group, with a significant difference between the two groups (P<0.01). The expression level of CAR was significantly elevated in the DCM group compared with the normal control group (P<0.01). In CVB-RNA-positive patients (22 cases), the expression level of CAR was significantly higher than in CVB-RNA-negative patients (28 cases; P<0.01). In the DCM patients, there was a positive correlation between the CAR expression and the BNP level (r=0.34, P<0.05), while no significant difference was found between the CAR expression and the LVEF and LVEDd (r=-0.32, 0.30, P>0.05). There was no clear correlation between virus infection and the CM syndrome types in DCM patients (r=-0.22, P>0.05). According to the sequence of syndrome types: phlegm → qi deficiency → blood stasis → hydroretention with asthenic yang (from low to high), a positive correlation was existed between the BNP levels and CM syndrome types (r=0.139, P<0.05).

CONCLUSIONThe expression of CAR on the surface of white cells could be used to detect persistent viral infection. The expression level of CAR and heart function in DCM patients were highly correlated. The expression level of BNP may serve as an objective index for differentiating CM syndromes for patients with DCM.