Objective:To investigate the prognostic value of myocardial flow reserve (MFR) measured by SPECT myocardial blood flow (MBF) quantitative technique in patients with intermediate stenoses of coronary arteries.Methods:From September 2019 to May 2021, patients with intermediate stenoses (50% to 80%) identified by invasive coronary angiography in Fuwai Hospital, Chinese Academy of Medical Sciences, Fuwai Center China Cardiovascular Hospital, and TEDA International Cardiovascular Hospital were prospectively included. All patients underwent a one-day rest/stress SPECT myocardial perfusion imaging (MPI) and SPECT MBF quantification. The radioactivity distribution of each segment of the MPI bullseye polar maps were obtained according to the standard 5-point method to obtain the summed stress score (SSS) and the summed difference score (SDS) to determine the existence of abnormality. ROC curve analysis was used to obtain the optimal prognostic cut-off value for MFR. The primary endpoint was defined as cardiovascular endpoint events. Survival and prognostic analyses were conducted by Kaplan-Meier method and Cox proportional hazard models. The difference of AUCs was analyzed by Delong test.Results:A total of 314 patients (194 males, 120 females; age (59.4±8.6) years) were enrolled. Over a median follow-up duration of 754 (range: 628-914) d, 54 patients had endpoint events. ROC curve showed that the prediction ability of MFR was significantly better than that of conventional MPI (AUCs: 0.713 and 0.512; z=3.76, P<0.001). The optimal prognostic cut-off value for MFR to predict endpoint events in patients with intermediate stenoses was 2.04. Cox multivariate analysis showed that MFR (hazard ratio ( HR)=0.434, 95% CI: 0.282-0.669, P<0.001) was an independent predictor of endpoint events in patients with intermediate stenoses. Kaplan-Meier survival analysis showed that the prevalence of endpoint events in patients with MFR≤2.04 was significantly higher than that in patients with MFR>2.04 (25.4%(43/169) vs 7.6%(11/145); χ2=21.27, P<0.001). Conclusion:The MFR measured by SPECT MBF quantitative technique has an independent predictive value for cardiovascular endpoint events in patients with intermediate stenoses.

Objective:To investigate the diagnostic value of myocardial blood flow quantitative imaging with cadmium zinc telluride (CZT) SPECT in patients with high-risk coronary artery disease (CAD).Methods:A total of 148 patients (82 males, 66 females, age: (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), patients were divided into two groups: high-risk CAD group and low-to-medium-risk CAD group. At the case level, quantitative parameters (stress myocardial blood flow (sMBF), rest myocardial blood flow (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 of two groups were compared. Diagnostic accuracy was evaluated by ROC curve analysis. At the vascular level, the correlation between the degree of coronary artery stenosis and some parameters was analyzed. Mann-Whitney U test, logistic regression, Spearman rank correlation analysis and DeLong 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) vs 2.74(2.30, 3.33), 1.06(0.69, 1.48) vs 2.50(1.73, 2.95) ml·g -1·min -1; U values: 628.0 and 853.5, both P<0.001). MFR and SDS were independent predictors of high-risk CAD patients (odds ratio ( OR)=0.251(95% CI: 0.136-0.464), P<0.001; OR=1.188(95% CI: 1.026-1.375), P=0.021), and MFR was more capable of predicting high-risk CAD. MFR and sMBF had the highest accuracy in diagnosing high-risk CAD (AUCs: 0.885 and 0.844). Differences of AUCs between MFR and other parameters were statistically significant ( z values: 1.99-6.77, all 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 values: 0.39 and 0.35, both P<0.001) were negatively correlated with the degree of coronary stenosis, while SSS, SRS and SDS ( R2 values: 0.22, 0.12 and 0.14, all P<0.001) were positively correlated with the degree of coronary stenosis. Conclusion: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.

Objective:To investigate the effect of motion correction (MC) on the calculated values of myocardial blood flow (MBF) and myocardial flow reserve (MFR) based on cadmium-zinc-telluride SPECT (CZT SPECT) images.Methods:Twenty-eight consecutive patients (10 males, 18 females, age: (60.75±11.62) years) with suspected or known coronary artery disease who underwent myocardial perfusion imaging (MPI) with dynamic CZT SPECT between June 2019 and August 2019 in TEDA International Cardiovascular Hospital were retrospectively analyzed. The MBF and MFR during rest imaging and stress imaging were quantitatively analyzed. Corridor 4DM software was used to calculate the stress MBF (sMBF) and MFR of the coronary artery branches and left ventricular (LV) before and after MC. The paired t test and Pearson correlation were used for data analysis. Results:The sMBF and MFR of LV before MC were (0.82±0.49) ml·min -1·g -1 and 1.69±0.68 respectively. After MC the two parameters increased to (1.05±0.64) ml·min -1·g -1 and 2.12±0.77 respectively ( t values: -4.87, -6.01, both P<0.001). The sMBF and MFR in left anterior descending (LAD), left circumflex (LCX), right coronary artery (RCA) and LV before MC were correlated with those after MC ( r values: 0.69-0.96, all P<0.001). If MFR <2.0 was used as the reference of impaired MFR, data before MC showed 19 patients (67.9%, 19/28) had impaired MFR, while 13 patients (46.4%, 13/28) had impaired MFR based on MFR values after MC. Conclusion:For MPI quantitative imaging with CZT SPECT, the calculated values of sMBF and MFR after MC is higher than those before MC, suggesting that MC is helpful to reduce the false positive results which may be caused by the " creep" effect of the heart.