The Clinical Evaluation Of ¹⁸F-fluoride PET/CT For Identification Of Unstable Atherosclerotic Plaques

Objective: At present,the identification of unstable AS plaque is still lack of noninvasive detection methods.Studies have shown that ¹⁸F-Na F PET-CT can early identified unstable AS plaque by located micro-calcification in plaque at histological level,but the efficiency of ¹⁸F-Na F PET-CT for identify the unstable plaque is still controversial,so the aim of this part is to assess the ability and clinical value of ¹⁸F-Na F PET-CT for identification of unstable AS plaques with using IVUS as the "gold standard".Methods: Our study screened unstable angina patients according to the established standards,and collected the clinical data of patients including diabetes history,hypertension history,smoking history,laboratory tests,etc.¹⁸F-Na F PET-CT,IVUS?part of them?,CAG,CAC were performed in the selected patients in 2 weeks.IVUS imaging results were used as the gold standard for the determination of unstable plaques,and then the unstable plaques were divided into ¹⁸F-Na F positive group and ¹⁸F-Na F negative group according to the results of ¹⁸F-Na F PET-CT imaging,and the differences of SUVmax and IVUS parameters were compared between the two groups,IVUS parameters included Lumen?Area,Max,Min?,Vessel?Area,Max,Min?,Burden,Plaque composition?Fibrotic,Lipidic,Necrotic,Calcified?.Results: a total of 31 patients?a total of 124 coronary arteries including LM,LAD,LCX,RCA?performed ¹⁸F-Na F PET/CT.The number of patients with positive results of ¹⁸F-Na F PET-CT imaging was 23 cases,the patient's positive rate of¹⁸F-Na F PET-CT imaging was74.19%,and the number of coronary artery with positive results of ¹⁸F-Na F PET-CTimaging was 35,the coronary positive rate of¹⁸F-Na F PET-CT imaging was 28.23%.The differences of clinical data between ¹⁸F-Na F positive groups and ¹⁸F-Na F negative groups are compared,the results showed that there were significant differences between the two groups in high sensitivity C reactive protein?P=0.011?,but the other clinical indicators between the two groups showed no statistically significant difference,P >0.05.In this study,a total of 21 patients including 62 AS plaques with 38 coronary arteries underwent IVUS imaging,41 unstable AS plaques were determined by IVUS imaging,¹⁸F-Na F positive plaques were 23,so the positive rate of ¹⁸F-Na F PET-CT was 56.1%.The sensitivity of¹⁸F-Na F PET-CT for detection of unstable AS plaques was 56.09%,the specificity was 90.47%,the positive predictive value was 92%,the negative predictive value was 48.64%,and the accuracy of this diagnostic test was 67.74%.The differences of IVUS parameters would be compared between¹⁸F-Na F positive group and negative group in unstable AS plaques.The results show that the minimum diameter of vascular,plaque burden,fibrosis and necrotic core in histological components of unstable AS plaques have discrepancy between the two groups P<0.05,but no significant differences in other indicators.Conclusion: ¹⁸F-Na F PET-CT imaging can identify part of unstable plaques with a higher positive predictive value,and the ¹⁸F-Na F PET-CT positive plaque is more unstable than the negative ones.These results suggest that ¹⁸F-Na F PET-CT has a better ability for identification of unstable AS plaques and also can be used to stratify the unstable plaque,that would meet the needs of precise treatment.However,negative results of that can not be ruled out the high risk of MACE in patients with UA.Objective: at present,the identification of unstable AS plaque is still lack of non-invasive detection methods.Studies have shown that¹⁸F-Na F PET-CT can early identified unstable AS plaque by located micro-calcification in plaque at histological level,However,the traditional methods to assess the risk of cardiovascular events,such as CAG and CAC,have been shown to be effective,but the relationship among ¹⁸F-Na F PET-CT,CAG,CAC is uncertain.This study selected clinical patients with unstable angina,and screened unstable plaques with IVUS as the gold standard,then the results of ¹⁸F-Na F PET-CT imaging were compared with those of CAG and CAC in order to clarify the relationship among them.Methods: Our study screened unstable angina patients according to the established standards,and collected the clinical data of patients including diabetes history,hypertension history,smoking history,laboratory tests,etc.The selected patients would be performed ¹⁸F-Na F PET-CT,IVUS?part of them?,CAG,CAC in 2 weeks,IVUS imaging results were used as the gold standard for the determination of unstable plaques.The selected patients were divided into ¹⁸F-Na F positive group and¹⁸F-Na F negative group with the results of ¹⁸F-Na F PET-CT;All involved coronary artery of selected patients were divided into 4 groups,namely no stenosis?stenosis =0%?,mild stenosis?stenosis < 50%?,moderate stenosis?stenosis =50-75%?and severe stenosis?stenosis >75%?with CAG results;the patients were divided into 5 groups according to the results of CACS imaging,namely CACS=0,CACS=1-10,CACS=11-100,CACS=101-400,CACS>400;Thedifferences of¹⁸F-NaF positive rates among the stenosis groups?CAG?and the CACS groups?CACS?were compared.Results: a total of 31 patients?a total of 124 coronary arteries including LM,LAD,LCX,RCA?performed¹⁸F-Na F PET/CT.The number of patients with positive results of¹⁸F-Na F PET-CT imaging was 23 cases,the patient's positive rate of ¹⁸F-Na F PET-CT imaging was74.19%,and the number of coronary artery with positive results of ¹⁸F-Na F PET-CT imaging was 35,the coronary positive rate of ¹⁸F-Na F PET-CT imaging was 28.23%.The differences of clinical data between ¹⁸F-Na F positive groups and ¹⁸F-Na F negative groups are compared,the results showed that there were significant differences between the two groups in high sensitivity C reactive protein?P=0.011?,but the other clinical indicators between the two groups showed no statistically significant difference,P >0.05.35 branches were included in none coronary stenosis group,¹⁸F-Na F positive rate was 2.86%;26branches were included in coronary artery stenosis <50% group,¹⁸F-Na F positive rate was23.08%;28 branches were included in coronary artery 50%-75% stenosis group,the positive rate of ¹⁸F-Na F was 51.43%,Total coronary positive rate of ¹⁸F-Na F was28.23%.Comparing the difference of the ¹⁸F-Na F positive rate among the groups with different degree of coronary artery stenosis,the results showed that there was a difference in ¹⁸F-Na F positive rate among the groups P<0.001.The statistical results of multiple comparisons showed no significant difference between normal group and stenosis less than50% group,stenosis is 50-75% group,and stenosis more than 75% group in¹⁸F-Na F positive rate?P<0.01?,but an significant difference between stenosis less than 50% group and stenosis more than 75% group in coronary artery ¹⁸F-Na F positive rate,P=0.025.However,there was no difference among the different CACS groups P>0.05.Conclusion: ¹⁸F-Na F PET-CT imaging can identify part of unstable plaques.To a certain extent,¹⁸F-Na F positive rate increased with the degree of coronary artery stenosis,but no significant differences have been shown in¹⁸F-Na F positive rate between different CACS groups,and the highest ¹⁸F-Na F positive rate of coronary artery was observed in CACS =101 400 group.These results suggest that there is a certain degree of consistency between ¹⁸F-Na F PET-CT and CAG in assessing the risk of MACE events,but themicroscopic calcification of CAC detected and the microscopic calcification of¹⁸F-Na F PET-CT detected represent different stages of unstable plaque,the two are not comparable.Objective: 10-Yr Framingham risk score and ICVD score were used to assess the risk of cardiovascular events in patients of our study,and then the results of ¹⁸F-Na F PET-CT were compared with that.To explore whether ¹⁸F-Na F PET-CT can be used as a reliable indicator of the risk of cardiovascular events.Methods: Our study screened unstable angina patients according to the established standards,and collected the clinical data of patients including diabetes history,hypertension history,smoking history,laboratory tests,etc.¹⁸F-Na F PET-CT,IVUS?part of them?,CAG,CAC were performed in the selected patients in 2 weeks.IVUS imaging results were used as the gold standard for the determination of unstable plaques,and then the unstable plaques were divided into ¹⁸F-Na F positive group and ¹⁸F-Na F negative group according to the results of ¹⁸F-Na F PET-CT imaging.The coronary heart disease?CHD?risk scores of two groups were calculated using the internationally recognized 10-Yr Framingham risk score scale,the ischemic cardiovascular disease?ICVD?risk scores of two groups were calculated using the nationally recognized ICVD risk score scale,and recorded the corresponding percentage of CHD risk and ICVD risk.According to the10-year CHD percentage and ICVD risk percentage,the patients were divided into three groups included <10% group,10 20% group,and > 20% group,respectively.The differences of CHD risk score and ICVD risk score and corresponding risk percentage between ¹⁸F-Na F positive group and ¹⁸F-Na F negative group were compared,and the differences of the¹⁸F-Na F positive rate between the different CHD risk groups and ICVDrisk groups were analyzed.Results: a total of 31 patients?a total of 124 coronary arteries including LM,LAD,LCX,RCA?performed ¹⁸F-Na F PET/CT.The number of patients with positive results of ¹⁸F-Na F PET-CT imaging was 23 cases,the patients' positive rate of¹⁸F-Na F PET-CT imaging was74.19%.The differences of clinical data between ¹⁸F-Na F positive groups and ¹⁸F-Na F negative groups are compared,the results showed that there were significant differences between the two groups in high sensitivity C reactive protein?P=0.011?,but the other clinical indicators between the two groups showed no statistically significant difference,P>0.05.The differences of 10-Yr Framingham risk score and ICVD risk score between¹⁸F-Na F positive group and ¹⁸F-Na F negative group were compared,the results showed that there was a significant difference in CHD risk score between the two groups?P =0.003?,but no significant difference in ICVD risk score,this result suggest that the CHD risk score of ¹⁸F-Na F positive group was higher than that of ¹⁸F-Na F negative group,whereas the ICVD risk score had no similar results.The ¹⁸F-Na F positive rate between the different CHD risk groups and ICVD risk groups were compared,the results showed that the ¹⁸F-Na F positive rate increased with the 10-Yr Framingham risk percentage,but the multiple comparisons results showed that there was no significant difference in¹⁸F-Na F positive rate among different risk groups?P> 0.05?.Conclusion: ¹⁸F-Na F PET-CT imaging can identify part of unstable plaques,and the CHD risk score of¹⁸F-Na F positive group was higher than that of¹⁸F-Na F negative group,whereas the ICVD risk score had no similar results.Suggesting that ¹⁸F-Na F PET-CT can be used as an indicator of the risk of cardiovascular events in clinical practices,and showed a certain degree of consistency with 10-Yr Framingham Score.