Study On The Predictive Value Of Lp-PLA2 Combined With VE/VCO₂@AT In Patients With Decreased Anaerobic Threshold For Coronary Heart Disease

Purpose:To compare the levels of serum lipoprotein-associated phospholipase A2（Lp-PLA2）and the gas parameters at anaerobic threshold between patients with coronary heart disease and non-coronary heart disease in cardiopulmonary exercise test（CPET）,to explore the role of Lp-PLA2combined with VE/VCO₂@AT in the diagnosis and prediction of coronary heart disease in patients with decreased anaerobic threshold,and to analyze the relationship between Lp-PLA2 and parameters related to anaerobic threshold in CPET.Methods:Methods:Lp-PLA2 and coronary angiography were performed in 136patients who had undergone cardiopulmonary exercise test in the fourth affiliated Hospital of Ji Shou University from November 2019 to December2020.According to the results of coronary angiography,all patients were divided into coronary heart disease group（n=82）and non-coronary heart disease group（n=54）.（1）the demographic data of the two groups were collected:age,sex,BMI,smoking history,drinking history,hypertension history,diabetes history and so on.（2）Laboratory examination data:C-reactive protein（CRP）,homocysteine（HCY）,blood lipid index[including total cholesterol（TC）triglyceride（TG）,apolipoprotein A1（Apo A1）,apolipoprotein B（Apo B）,high density lipoprotein（HDL-C）,low density lipoprotein（LDL-C）],Serum lipoprotein-associated phospholipase A2（Lp-PLA2）（3）parameters related to CPET anaerobic threshold:oxygen uptake per kilogram at anaerobic threshold（VO₂/kg@AT/kg）,percentage of maximum oxygen consumption at anaerobic threshold（AT%pred）,slope of oxygen uptake efficiency at anaerobic threshold（VE/VO₂@AT）,equivalent slope of carbon dioxide ventilation at anaerobic threshold（VE/VCO₂@AT）,power at anaerobic threshold（Watt@AT）,Heart rate at anaerobic threshold（HR@AT）.Statistical methods were used to compare the differences of clinical data,laboratory examination and CPET anaerobic threshold between the two groups.The related parameters of Lp-PLA2 and CPET anaerobic threshold and the predictive value of the combination of Lp-PLA2 and CPET in patients with coronary heart disease with decreased anaerobic threshold were evaluated by drawing ROC curve.It was verified by Kappa test.Results:（1）The number of patients with hypertension and diabetes,C-reactive protein（CRP）,triglyceride（TG）,low density lipoprotein（LDL-C）,homocysteine（HCY）,serum lipoprotein-associated phospholipase A2（Lp-PLA2）at anaerobic threshold carbon dioxide ventilation equivalent slope（VE/VCO₂@AT）in coronary heart disease group were higher than those in non-coronary heart disease group.The kilogram oxygen uptake at anaerobic threshold（VO₂/kg@AT/kg）,the percentage of maximum oxygen consumption at anaerobic threshold（AT%pred）and the power at anaerobic threshold（Watt@AT）were significantly lower than those in non-CHD group.（p<0.05）There was no significant difference in other indexes（p>0.05）.（2）Lp-PLA2 was negatively correlated with oxygen uptake per kilogram（VO₂/kg@AT/kg）at anaerobic threshold（r=-0.303,p=0.001）,and positively correlated with equivalent slope of carbon dioxide ventilation at anaerobic threshold（VE/VCO₂@AT）（r=0.244,p=0.004）.There is no remarkable connected with other parameters.After multivariate Logistic regression analysis,Lp-PLA2 and VE/VCO₂@AT were independent risk factors for coronary heart disease in patients with decreased anaerobic threshold.（3）When VE/VCO₂@AT>26.5,Lp-PLA2>141.34ng/m L,and Lp-PLA2combined with VE/VCO₂@AT were used to predict coronary heart disease,the area under the curve（AUC）was 0.619,0.685,0.718,the sensitivity was 96.30%,78.00%,72.00%,the specificity was 24.10%,59.30%,66.70%,and the missed diagnosis rate was 3.70%,22.00%,28.00%.The misdiagnosis rate was 75.90%,40.70%,33.30%,the positive predictive value was 65.80%,76.30%,76.62%,and the negative predictive value was81.25%,74.41%,61.01%,the positive likelihood ratio was 1.26,1.91,2.16,and the negative likelihood ratio was 0.15,0.37,0.49.The kappa value was 0.527（p<0.05）Conclusion:（1）Impaired cardiopulmonary function and motor function in patients with coronary heart disease.（2）VE/VCO₂@AT and Lp-PLA2 can predict coronary heart disease in people with decreased anaerobic threshold.VE/VCO₂@AT combined with Lp-PLA2 mabe has better correlation or predictive value with coronary heart disease than single index.（3）Lp-PLA2 was negatively correlated with oxygen uptake per kilogram（VO₂/kg@AT/kg）at anaerobic threshold,and positively correlated with wentilation equivalent slope of carbon dioxide ventilation（VE/VCO₂@AT）at anaerobic threshold.