Correlation Between Characteristics Of Coronary CT Angiography And Coronary Heart Disease Risk Factors And Prognosis Of Asymptomatic Non-Diabetic Population

Objectives: To investigate the characteristics of CT angiography (CTA) under risk factorsof coronary heart disease (CHD), such as gender, age, hypertension, hyperlipemia,smoking and hyperuricmia, in Chinese asymptomatic non-diabetic population, analyse thecorrelation between risk factor score system and cardiac events and CTA results, and assessthe value of CTA in predicting events.Material and Methods: One thousand and one hundred eighteen asymptomatic subjectswithout prior history of CHD and diabetes who underwent coronary CTA were enrolled.The status of coronary atherosclerosis was described. The differences of luminal stenosis,number of involved branch, lesion involved left main artery, segment involvement score(SIS) and segment stenosis score (SSS) by CT were analyzed between subjects with andwithout risk factors. The CTA results were compared between122subjects withhyperuricmia and172with normal uric acid. According to Framingham risk score (FRS)system and systematic coronary risk evaluation (SCORE) system, the correlation betweenrisk factor score and plaque score by CT was assessed in593subjects. In the follow-upstudy of357subjects, the prior CTA results were compared between subjects with andwithout cardiac events.Results:(1)56.3%subjects were diagnosis as coronary artery disease (CAD) by CT,10.4%as CHD (≥50%), and1.7%as severe CAD (≥70%). Gender, age, hypertension,hyperlipemia and smoking were associated with the progress of atherosclerotic plaque. Thenumber of risk factor was correlated with plaque score (SIS r=0.26, SSS r=0.23).(2)Both in univariate analysis and after correction for conventional risk factors, thedifference of CTA results was not significant between subjects with hyperuricmia andnormal uric acid.(3)FRS and SCORE were correlated with SIS and SSS (FRS: SIS r=0.20, SSS r=0.16; SCORE: SIS r=0.23, SSS r=0.23). The area under curve (AUC) was calculated according to the receiver operating characteristic curve. In discriminatingsubjects with and without CAD, the AUC were0.59for FRS and0.59for SCORE. Indiscriminating subjects with and without CHD, the AUC were0.59for FRS and0.58forSCORE.(4) The incidence of events was0.7%in subjects without coronary atherosclerosisby CT. The incidence of CAD, CHD and severe CAD, the proportion of lesion involvedleft main, the number of branch involved, SIS, SSS, noncalcified SIS and noncalcified SSSwere higher in subjects with events. In predicting events, the AUC was0.75and theoptimal cutoff point was1.5for SIS, with sensitivity77.8%, specificity64.9%, positivepredictive value (PPV)10.5%and negative predictive value (NPV)98.2%, while the AUCwas0.71and the optimal cutoff point was2.5for SSS, with sensitivity55.6%, specificity81.4%, PPV13.7%and NPV97.2%.Conclusion: CT angiography could provide important information about luminal stenosisand plaque burden in one scan noninvasively and accurately. In asymptomatic non-diabeticpopulation, the conventional risk factors except hyperuricmia and risk factor score systemare correlated with CT findings, but still limited in predicting luminal stenosis and plaqueburden. CTA has a ruling out ability in predicting cardiac events, and for subjects with anegative CTA result, the incidence of cardiac events is very low.