Clinical Study Of PET Quantitative Myocardial Blood Flow In Diagnosis Of Coronary Microvascular Disease

Objective: to make a quantitative analysis of myocardial blood flow(MBF)and coronary flow reserve(CFR)by 13N-NH3 PET myocardial perfusion imaging(MPI)in patients with suspected coronary microvascular disease(CMVD),and to make a definite diagnosis by evaluating coronary microcirculation according to myocardial perfusion.Methods: from December 2018 to December 2019,20 patients with myocardial ischemia symptoms who had no obstructive coronary artery disease after coronary angiography or coronary CTA were enrolled.The absolute quantitative indexes of PET(MBF and CFR)were calculated by the MBF program of Siemens.Combined with the information obtained,the patients were diagnosed according to the diagnostic criteria of microvascular angina pectoris related to coronary microvascular dysfunction established by COVADIS,and the patients were divided into CMVD group and non-CMVD group.CMVD group was classified according to different pathogenesis.At the same time,the general data and risk factors of the patients were statistically analyzed,and the levels of homocysteine(Hcy)and high sensitivity C-reactive protein(hs-CRP)were detected,and the correlation with resting MBF,hyperemic MBF and CFR was analyzed to explore the risk factors of coronary microvascular disease.SPSS20.0 software was used for statistical analysis,and Pearson correlation analysis was used for correlation analysis.Results: among the 20 patients,there were 16 patients in CMVD group(8 patients with type 1 CMVD,3 patients with type 2 CMVD,5 patients with type 3 CMVD)and 4 patients without CMVD.There was no significant difference in age,sex,smoking,hypertension,diabetes,total cholesterol(TC)level,triglyceride(TG)level,hs-CRP and Hcy level between CMVD group and non-CMVD group,and between CMVD group and each subtype.Quantitative blood flow data(average MBF of resting and hyperemic left ventricle,mean value of global CFR of left ventricle)were statistically significant between the CMVD group(mean resting MBF: 0.83 ±0.17;average hyperemic MBF: 1.67 ±0.38;CFR:2.06±0.17)andthe non-CMVD group(mean resting MBF: 1.10 ±0.15;average hyperemic MBF: 2.26 ±0.29;CFR:2.56±0.09);The quantitative data of blood flow in patients with type 1 CMVD(mean resting MBF:0.94 ±0.09;average hyperemic MBF: 1.94 ±0.20;CFR:2.16±0.17)were significantly higher than those in patients with type 2 CMVD(mean resting MBF: 0.67 ±0.15;average hyperemic MBF: 1.29 ±0.35;CFR:1.95±0.08)and patients with type 3 CMVD(mean resting MBF: 0.75 ±0.17;average hyperemic MBF: 1.49 ±0.35;CFR:1.96±0.11).There was no significant difference between patients with type 2 and type 3 CMVD(P>0.05).Correlation analysis results of quantitative blood flow data with hs-CRP and Hcy found that:in the CMVD group,resting MBF(r =-0.626,P = 0.010),hyperemic MBF(r =-0.566,P =0.022),CFR(r =-0.525,P = 0.037)is negatively correlated with hs-CRP,resting MBF(r =-0.660,P = 0.003),and hyperemic MBF(r =-0.556,P = 0.028)are negatively correlated with Hcy,In non-CMVD group,only resting MBF(r =-0.952,P = 0.048)was found to be negatively correlated with Hcy.Conclusion: PET MPI myocardial blood flow quantitative technique can evaluate coronary microvascular function,provide basis for the diagnosis of CMVD,and verify the feasibility,safety and accuracy of this technique in patients with CMVD.