Value of combining electrocardiogram and clinical examination indexes to diagnose coronary heart disease

AIM To investigate the sensitivity and specificity of combining electrocardiogram, high-sensitivity C-reactive protein and apolipoprotein A-1 to diagnose coronary heart disease. METHODS In this case-control study, 818 individuals with suspicion of CAD underwent coronary angiography in Zhongnan Hospital during 2010 to 2011. Based on the results of angiography, 565 subjects were diagnosed as coronary heart disease (CHD) and classified into experimental group, whereas 253 were normal and classified as control group. Meanwhile, low-density lipoprotein cholesterol (LDL-C), hs-CRP (high-sensitivity C-reactive protein), ApoA1 (apolipoprotein A1) and ECG (electrocardiogram) were analyzed. Data were entered into the SPSS v.18.0 statistical software for analysis. For those indicators that have significant correlation with CHD, receiver operating characteristic curve analysis was carried out looking for the cut-off point and crossed statistical analysis was classified to calculate the index and joint index diagnostic sensitivity and specificity. RESULTS Compared with the control group, plasma hs-CRP level is significantly higher, whereas ApoA1 is lower in the experimental group. ECG with ST-T change is common in the experimental group. The sensitivity of hs-CRP, ApoA1, and ECG is 73.8%, 43.5%, 77.3%, respectively. Specificity is 51.4%, 77.1%, 20.9%, respectively. Series of joint diagnosis: sensitivity of ECG+ApoA1, ECG+hs-CRP, hs-CRP+ApoA1 and ECG+ApoA1+hs CRP is 35.8%, 58.5%, 34.9%, 28.7%, respectively, and the specificity is 85.4%, 71.5%, 87.7%, 92.1%, respectively. Parallel to the joint diagnosis: sensitivity of ECG+hs-CRP, ApoA1+ECG, ApoA1+hs-CRP and ECG+ApoA1+hs-CRP is 92.7%, 85.1%, 82.7% and 94.3%, respectively. Specificity is 72.7%, 39.1%, 40.9% and 23.3%, respectively. CONCLUSION The combination of ECG, hs-CRP and ApoA1 can improve the sensitivity or specificity of early clinical diagnosis of CHD.