Diagnostic value of myocardial blood flow quantitative imaging with CZT SPECT in patients with high-risk coronary artery disease

Objectives: To investigate CZT SPECT myocardial blood flow quantitative imaging's diagnostic value in patients with high-risk coronary artery disease(CAD).

Methods: A total of 148 patients(82 males,66 females,age:42-85(63.8±8.2)years) who successfully completed CZT SPECT dynamic acquisition and routine SPECT myocardial perfusion imaging(MPI) in TEDA International Cardiovascular Hospital from November 2018 to October 2020 were analyzed retrospectively. According to the results of coronary angiography(CAG),the patients were divided into two groups:high-risk CAD group and low-to-medium-risk CAD group. At the case level,the quantitative parameters [stress/rest myocardial blood flow(sMBF/rMBF) and myocardial flow reserve(MFR)],semi-quantitative parameters [summed stress score(SSS),summed rest score(SRS),summed difference score(SDS) and transient ischemic dilation(TID)] and left ventricular function parameters [end-diastolic volume(EDV),end-systolic volume(ESV),left ventricular ejection fraction(LVEF) and difference between EDV/ESV under stress and rest state(ΔEDV/ΔESV)] of the two groups were compared,and the diagnostic accuracy was evaluated by the subject working characteristic(ROC) curve,the area under the curve (AUC) and its 95% confidence interval (CI). At the vascular level,the correlation between the degree of coronary artery stenosis and some parameters was analyzed. Independent sample t test,Mann-Whitney U test,Chi square test,Spearman correlation test and Z test were used for statistical analysis.

Results: Case level analysis showed that MFR and sMBF in high-risk CAD group were significantly lower than those in low-to-medium-risk CAD group[1.36(0.87,1.64) and 2.74(2.30,3.33),1.06(0.69,1.48) and 2.50(1.73,2.95)mL·g-1·min-1;P<0.05]. MFR and SDS are independent predictors of high-risk coronary CAD patients[OR(95%CI)=0.251(0.136-0.464) and 1.188(1.026-1.375);P<0.05],and MFR is more capable of predicting high-risk CAD. MFR and sMBF had the highest accuracy in diagnosing high-risk CAD(AUC:0.885 and 0.844;P <0.05),followed by SSS,SRS and SDS(AUC:0.823,0.757 and 0.816;P<0.05). The difference between MFR and other parameters AUC was statistically significant(Z:1.989~5.654;P<0.05),and the best diagnostic cut-off value was ≤1.83(sensitivity:85.90%;specificity:85.71%). Vascular level analysis showed that MFR and sMBF(r²:0.394 and 0.349;P<0.05) were negatively correlated with the degree of coronary stenosis,while semi-quantitative parameters SSS,SRS and SDS(r²:0215,0.121 and 0.136;P<0.05) were positively correlated with the degree of coronary stenosis.

Conclusions: Compared with conventional SPECT MPI,CZT SPECT myocardial blood flow quantitative imaging has better diagnostic efficacy and clinical value in patients with high-risk CAD.