Gated Myocardial Perfusion Imaging Research Articles

The application of mass defect percentage in the evaluation of acute coronary syndrome.

White blood cells, neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio (NLR) distribution patterns in patients with anatomic coronary disease have previously been associated with cardiac events such as myocardial infarct size, complications, and prognosis. However, it remains unknown whether myocardial perfusion mass defect percentage (MDP) obtained from gated myocardial perfusion imaging (G-MPI) correlates with these hematological parameters. Therefore, our research aimed to investigate the application of MDP in the evaluation of acute coronary syndrome (ACS). Thirty-six patients with ACS underwent single-photon emission computed tomography/computed tomography using retrospective electrocardiography gating during the resting state. The primary outcome was the percentage of left ventricular mass with abnormal myocardial perfusion (i.e. MDP) in G-MPI. Furthermore, the correlation between myocardial perfusion MDP and lymphocyte count, neutrophil count, white blood cell count, and NLR was calculated. In addition, we explored the relationship of myocardial perfusion MDP with other cardiac function parameters obtained from G-MPI, such as summed rest score, left ventricular ejection fraction, end-systolic volume, and end-diastolic volume. Myocardial perfusion MDP significantly correlated with white blood cell count, neutrophil count, and NLR (P < 0.01). Furthermore, these hematological parameters were significantly different between low and high MDP groups. Additionally, myocardial perfusion MDP negatively correlated with end-systolic volume (r = -0.615) and left ventricular ejection fraction (r = -0.657). Myocardial perfusion MDP has a high correlation with inflammatory cell counts and cardiac function parameters obtained from G-MPI in ACS; this may be of help in the evaluation and treatment of these patients.

Radiomics Nomogram Derived from Gated Myocardial Perfusion SPECT for Identifying Ischemic Cardiomyopathy.

Personalized management involving heart failure (HF) etiology is crucial for better prognoses. We aim to evaluate the utility of a radiomics nomogram based on gated myocardial perfusion imaging (GMPI) in distinguishing ischemic from non-ischemic origins of HF. A total of 172 heart failure patients with reduced left ventricular ejection fraction (HFrEF) who underwent GMPI scan were divided into training (n = 122) and validation sets (n = 50) based on chronological order of scans. Radiomics features were extracted from the resting GMPI. Four machine learning algorithms were used to construct radiomics models, and the model with the best performances were selected to calculate the Radscore. A radiomics nomogram was constructed based on the Radscore and independent clinical factors. Finally, the model performance was validated using operating characteristic curves, calibration curve, decision curve analysis, integrated discrimination improvement values (IDI), and the net reclassification index (NRI). Three optimal radiomics features were used to build a radiomics model. Total perfusion deficit (TPD) was identified as the independent factors of conventional GMPI metrics for building the GMPI model. In the validation set, the radiomics nomogram integrating the Radscore, age, systolic blood pressure, and TPD significantly outperformed the GMPI model in distinguishing ischemic cardiomyopathy (ICM) from non-ischemic cardiomyopathy (NICM) (AUC 0.853 vs. 0.707, p = 0.038). IDI analysis indicated that the nomogram improved diagnostic accuracy by 28.3% compared to the GMPI model in the validation set. By combining radiomics signatures with clinical indicators, we developed a GMPI-based radiomics nomogram that helps to identify the ischemic etiology of HFrEF.

The diagnostic role of resting myocardial blood flow in STEMI patients after revascularization.

The value of semiquantitative resting myocardial perfusion imaging (MPI) in coronary artery disease (CAD) is limited. At present, quantitative MPI can be performed by a new cadmium zinc tellurium single-photon emission computed tomography (CZT-SPECT) scan. The quantitative index of resting myocardial blood flow (MBF) has received little attention, and its manifestations and clinical value in the presence of unstable coronary blood flow have not been clarified. In patients with ST-segment elevation myocardial infarction (STEMI), whether resting MBF can provide additional value of blood flow than semi-quantitative resting MPI is not sure. We also explored the influencing factors of resting MBF. This was a retrospective clinical study. We included 75 patients with STEMI in the subacute phase who underwent resting MPI and dynamic scans after reperfusion therapy. General patient information, STEMI-related data, MPI, gated MPI (G-MPI), and resting MBF data were collected and recorded. According to the clinically provided culprit vessels, the resting MBF was divided into ischemic MBF and non-ischemic MBF. The paired Wilcoxon signed-rank test was used for resting MBF. The receiver operating characteristic (ROC) curves were used to determine the optimal threshold for ischemia, and multiple linear regression analysis was used to analyze the influencing factors of resting MBF. There was a statistically significant difference between the ischemic MBF and non-ischemic MBF [0.59 (0.47-0.72) vs. 0.76 (0.64-0.93), p < 0.0001]. The ROC curve analysis revealed that resting MBF could identify ischemia to a certain extent, with a cutoff value of 0.5975, area under the curve (AUC) = 0.666, sensitivity = 55.8%, and specificity = 68.7%. Male sex and summed rest score (SRS) were influencing factors for resting MBF. To a certain extent, resting MBF can suggest residual ischemia after reperfusion therapy in patients with STEMI. There was a negative correlation between male sex, SRS, and ischemic MBF. A lower resting MBF may be associated with more severe myocardial ischemia.

The influence of arm positions on mechanical dyssynchrony measured by gated myocardial perfusion imaging.

In routine procedures, patient's arms are positioned above their heads to avoid potential attenuation artifacts and reduced image quality during gated myocardial perfusion imaging (G-MPI). However, it is difficult to achieve this action in the acute period following pacemaker implantation. This study aimed to explore the influence of arm positioning on myocardial perfusion imaging (MPI) in different types of heart disease. This study was conducted retrospectively. A total of 123 patients were enrolled and underwent resting G-MPI using a standard protocol with arms positioned above their heads and again with their arms at their sides. All individuals were divided into 3 groups: the normal group, the obstructive coronary artery disease (O-CAD) group, and the dilated cardiomyopathy (DCM) group. The G-MPI data were measured by QGS software and Emory Reconstruction Toolbox, including left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), extent, total perfusion deficit (TPD), summed rest score (SRS), scar burden, phase standard deviation (SD), and phase histogram bandwidth (BW). In total, extent, TPD, EDV, ESV, LVEF, systolic SD, systolic BW, diastolic SD, and diastolic BW were all significantly different between the 2 arm positions (all P<0.01). On the Bland-Altman analysis, both EDV and ESV with the arm-down position were significantly underestimated (P<0.001). Meanwhile, TPD, extent, and LVEF with the arm-down position were significantly overestimated (P<0.05). Systolic SD, systolic BW, diastolic SD, and diastolic BW were systematically overestimated (P<0.001). In the DCM group (n=52), EDV, ESV, systolic SD, systolic BW, diastolic SD, and diastolic BW were identified as significantly different by the paired t-test between the 2 arm positions (P<0.05). In the O-CAD group (n=32), scar burden, ESV, LVEF, and diastolic BW were significantly different between the 2 arm positions (P<0.05). Systolic and diastolic dyssynchrony parameters and most left ventricular (LV) functional parameters were significantly influenced by arm position in both normal individuals and patients with heart failure (HF) with different pathophysiologies. More attention should be given to LV dyssynchrony data during clinical evaluation of cardiac resynchronization therapy (CRT) implantation procedure.

Left ventricular systolic dyssynchrony: a novel imaging marker for early assessment of myocardial damage in Chinese type 2 diabetes mellitus patients with normal left ventricular ejection fraction and normal myocardial perfusion

ObjectivesMyocardial damage is the important cause of heart failure (HF) in type 2 diabetes mellitus (T2DM), which is difficult to early diagnose, especially in T2DM with normal left ventricular ejection fraction (LVEF) and normal myocardial perfusion. The goal was to evaluate myocardial damage in T2DM with normal LVEF and normal myocardial perfusion by detecting left ventricular systolic dyssynchrony (LVSD), and find out the risk factors associated with LVSD. MethodsThis study included 95 T2DM with normal LVEF, normal myocardial perfusion. 69 consecutive individuals without T2DM and CAD were enrolled as the control group with age-, sex- and BMI-matched. All participants underwent stress/rest 99mtechnetium-sestamibi (99mTc-MIBI) gated myocardial perfusion imaging (GMPI) and two-dimensional echocardiography within 1 week. Clinical data including age, gender, BMI, duration of diabetes, chronic diabetic complications, glycated haemoglobin A1c (HbA1c), fast blood glucose (FBG) and Brain Natriuretic Peptide (BNP) were collected from medical records. Left ventricular synchrony parameters were acquired, including phase standard deviation (PSD) and phase histogram bandwidth (PBW) by rest GMPI. ResultsPSD and PBW in T2DM group were significantly higher than control group (P < .05). LVSD was detected in 20 (21%) T2DM patients. Compared to non-LVSD T2DM group, LVSD T2DM group had higher BMI, higher prevalence of BNP ≥ 35 pg/mL and chronic diabetic complications (P < .05). BNP ≥ 35 pg/mL had mild positive association with LVSD (r = 0.318, P = .004). In multivariate logistic regression, chronic diabetic complications and high BMI (> 23.4 kg/m2) were independent risk factors of LVSD (OR 5.64, 95% CI 1.58-20.16, P = .008; OR 6.77, 95% CI 1.59-28.89, P = .010). ConclusionsLVSD existed in T2DM patients with normal LVEF and normal myocardial perfusion. Chronic diabetic complications and high BMI (> 23.4 kg/m2) were the independent risk factors of LVSD. LVSD based on GMPI can be the novel imaging marker to early assess myocardial damage in T2DM patients.

Assessing Myocardial Involvement in Systemic Lupus Erythematosus Patients without Cardiovascular Symptoms by Technetium-99m-sestamibi Myocardial Perfusion Imaging: A Correlation Study on NT-proBNP.

In patients with systemic lupus erythematosus (SLE), myocardial involvement is the third leading course of death after lupus nephropathy (LN) and infections. Previous autopsy studies have demonstrated a high incidence of cardiovascular abnormalities in the myocardium. However, the patients with typical symptoms are far much fewer than expected from post-mortem examinations. The current study aimed to evaluate the technetium-99m-sestamibi (99mTc-MIBI) gated myocardial perfusion imaging (GMPI) characteristics of lupus patients without cardiovascular symptoms, and the relationships between GMPI characteristics and biochemical markers of myocardial injury, and to explore the role of GMPI in assessing myocardial involvement. Thirty patients were studied with rest myocardial perfusion imaging, and summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were calculated automatically. Biomarkers, including N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and creatine-kinase-MB (CK-MB), were detected simultaneously. GMPI parameters, LV functions and biomarkers were compared between two NT-proBNP groups. The relationships between these parameters were studied by correlation analysis. SMS, STS, and glomerular filtration rate (eGFR) were the main influencing factors of NTproBNP level (p = 0.001, <0.001, 0.042, respectively). Thirteen patients with an evaluated concentration of NT-proBNP had the lower left ventricular ejection fraction (LVEF), peak filling rate (PFR), eGFR and higher levels of CK-MB (in all comparisons, p < 0.05), and SRS was the only influencing factor of NT-proBNP (p = 0.007). Within thirteen patients with SRS≥2, there was a significant correlation between SRS and NT-proBNP (p < 0.001). 99mTc-MIBI GMPI could evaluate the left ventricular function and prompt the cardiomyocyte function at the cellular level. SMS and STS were the main influencers for plasma NT-proBNP, and SRS was the independent factor for elevated NT-proBNP. This radionuclide imaging method could provide additional diagnostic information on myocardial involvement in patients with SLE.

CMR validation of left ventricular volumes and ejection fraction measured by the IQ-SPECT system in patients with small heart size

BackgroundThe IQ-SPECT system is equipped with multifocal collimators and uses ordered-subset conjugate gradient minimization (OSCGM) as its reconstruction algorithm, achieving a shorter acquisition time than conventional SPECT. Left ventricular ejection fraction (LVEF) is overestimated by conventional SPECT in patients with small heart size. In this study, we compared IQ-SPECT with conventional SPECT and cardiovascular magnetic resonance (CMR) for the estimation of LVEF in patients with small hearts (males: EDV ≤ 60 ml, ESV ≤ 25 ml; females: EDV ≤ 45 ml, ESV ≤ 20 ml).MethodsThe study consisted of 49 consecutive patients (20 normal and 29 with small heart size) undergoing gated myocardial perfusion imaging (GMPI) with a 99mTc-labelled agent during stress or rest to assess the risk of coronary artery disease (CAD). The data were reconstructed using filtered back-projection (FBP) for conventional SPECT and OSCGM for IQ-SPECT. ESV, EDV, and LVEF were calculated using quantitative gated SPECT (QGS). To determine the optimal ordered-subset reconstruction parameters, we compared the LVEF from SPECT to the corresponding measurement from CMR.ResultsEDV, ESV, and LVEF values obtained from IQ-SPECT and conventional SPECT showed that the results of these two forms of SPECT were significantly correlated, although the EDV and ESV obtained by IQ-SPECT were higher than those obtained by conventional SPECT. IQ-SPECT yielded lower LVEF measurements than conventional SPECT (normal heart size: 50.6 ± 4.3% vs. 73.4 ± 8.4%, P = 0.002; small heart size: 62.1 ± 7.8% vs. 75.0 ± 11.4%, P < 0.001). There were no significant differences in LVEF measurements made by IQ-SPECT and CMR (normal heart size: 50.6 ± 4.3% vs. 53.2 ± 5.8%, P > 0.05; small heart size: 62.1 ± 7.8% vs. 64.6 ± 8.8%, P > 0.05). Five subsets (S) and 12 iterations (I) did not differ significantly in LVEF between CMR and IQ-SPECT for patients with small hearts (64.6 ± 8.8% vs. 62.1 ± 7.8%, P = 0.120), while 3 S and 10 I were the best parameters for patients with normal heart size (50.6 ± 4.3% vs. 53.1 ± 5.8%, P = 0.117).ConclusionWith CMR as the standard, IQ-SPECT yields more reliable LVEF values than conventional SPECT for populations with small heart size. The best reconstruction parameters from IQ-SPECT were 5 S and 12 I for patients with small hearts.

A preliminary study of dobutamine myocardial flow reserve on 99mTc-Sestamibi CZT-SPECT

With improved resolution and sensitivity, the cadmium zinc telluride (CZT) detector measures myocardial blood flow (MBF) and myocardial flow reserve (MFR) via single photon emission computed tomography (SPECT). Recently, many studies have used vasodilator stress to obtain quantitative indexes. However, dobutamine used as a pharmaceutical stress has been rarely used to quantify myocardial perfusion using CZT-SPECT. Our study retrospectively analyzed the blood flow performance of 99mTc-Sestamibi (99mTc -MIBI) CZT-SPECT comparing dobutamine to adenosine. The study aims to explore whether dobutamine stress can be used for the myocardial perfusion quantitative analysis via CZT-SPECT as well as compare dobutamine MBF and MFR to adenosine. It was a retrospective study. A total of 68 patients with suspected or known coronary artery disease (CAD) were consecutively enrolled in this study. Thirty-four patients underwent dobutamine stress 99mTc-MIBI CZT-SPECT. Another thirty-four patients underwent adenosine stress 99mTc-MIBI CZT-SPECT. Patient characteristics, myocardial perfusion imaging (MPI) results, gated-myocardial perfusion imaging (G-MPI) results and quantitative analysis of MBF and MFR were collected. In dobutamine stress group, stress MBF was significantly higher than rest MBF (median [interquartile range], 1.63 [1.46-1.94] vs. 0.89 [0.73-1.06], P < 0.001). In adenosine stress group, similar results were observed (median [interquartile range], 2.01 [1.34-2.20] vs. 0.88 [0.75-1.01], P < 0.001). When comparing the dobutamine and adenosine stress group, global MFR showed significant differences (median [interquartile range], the dobutamine group: 1.88 [1.67-2.38] vs. the adenosine group: 2.19 [1.87-2.64], P = 0.037). MBF and MFR can be measured using dobutamine 99mTc -MIBI CZT-SPECT. In small sample single-center study, there was a difference in MFR produced by adenosine and dobutamine within the suspected or the known CAD population.

Relationship between left ventricular mechanical synchrony and left ventricular systolic function: a CZT-SPECT analysis

BackgroundCZT-SPECT has good agreement in the evaluation of mechanical synchronization compared with conventional SPECT. The aim of this study was to evaluate the correlation between left ventricular mechanical contraction synchrony and left ventricular systolic function by gated myocardial perfusion imaging (GMPI) using cadmium–zine–telluride (CZT) single photon emission computed tomography (SPECT).MethodsThis retrospective study involved 371 patients (239 males and 132 females, mean age 61.06 ± 11.78 years old) who underwent GMPI at the Nuclear Medicine Department of Shanxi Cardiovascular Hospital from January 2020 to August 2020. Systolic synchrony parameters and left ventricular systolic function parameters were calculated via Emory Cardiac Toolbox, including PP, PSD, PHB, HS, HK, EDV, ESV, and LVEF. Based on LVEF value, patients were divided into the severe reduction group (group 1, 127 cases, EF < 35%), moderate reduction group (group 2, 47 cases, 35% ≤ EF < 45%), mild reduction group (group 3, 50 cases, 45% ≤ EF < 50%) and normal group (group 4, 147 cases, EF ≥ 50%). Differences in PP, PSD, PHB, HS and HK among the four groups were compared using one-way ANOVA. Differences between two groups were compared using LSD-t test. The correlation among functional and mechanical contraction synchrony factors were analyzed using Pearson test.ResultsPP, PSD, PHB, HS and HK were significantly different among the four groups (F = 5.20, 188.72, 202.88, 171.05, 101.36, P < 0.001). Pairwise comparison tests showed significant differences in PSD and PHB in each two groups, and HS and HK in each two groups except for group 2 and 3 (t = 0.28 and 0.39, both P > 0.001). PP was significantly higher in group 1, relative to group 3 (t = 2.43, P < 0.001) and group 4 (t = 3.67, P < 0.001). Pearson correlation analysis revealed that LVEF negatively correlates with PP, PSD, PHB (r = 0.194, − 0.790, − 0.799, all P < 0.001). HS and HK showed positive correlation for LVEF (r = 0.778 and 0.795, P < 0.001), PSD, PHB and ESV were had good positive correlation (r = 0.778, 0.795, P < 0.001), PSD, PHB and EDV had good positive correlation (r = 0.722, 0.732, P < 0.001). However, PP had poor correlation with EDV (r = 0.095, P > 0.001). HS and HK were negatively correlated with EDV and ESV (r = − 0.700 to − 0.594, P < 0.001).ConclusionCZT SPECT GMPI provided left ventricular mechanical contraction synchrony parameters that correlated well with left ventricular systolic function. Worse left ventricular mechanical contraction synchrony lead to decreased LVEF, making the systolic synchrony parameters valuable in the prediction of left ventricular systolic function.

Longitudinal evaluation of diastolic dyssynchrony by SPECT gated myocardial perfusion imaging early after acute myocardial infarction and the relationship with left ventricular remodeling progression in a swine model

BackgroundLeft ventricular diastolic dyssynchrony (LVDD), a dyssynchronous relaxation pattern, has been known to develop after myocardial damage. We aimed to evaluate the dynamic changes in LVDD in the early stage of acute myocardial infarction (AMI) by phase analysis of 99mtechnetium methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography (SPECT) gated myocardial perfusion imaging (GMPI) and explore its relationship with the progression of left ventricular remodeling (LVR). MethodsThe left anterior descending coronary arteries of 16 Bama miniature swine were occluded with a balloon to build AMI models. Animals were imaged by SPECT GMPI before AMI and at 1 day, 1 week and 4 weeks after AMI, and quantitative analysis was performed to determine the extent of left ventricle (LV) perfusion defects, left ventricular systolic dyssynchrony (LVSD) and the LVDD parameters: phase histogram bandwidth (PBW) and phase standard deviation (PSD). Echocardiography was simultaneously applied to evaluate left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and the LVDD parameters: Te-12-diff and Te-12-SD. Myocardial injury markers were measured, and 12-lead ECGs were performed. The degree of LVR progression was defined as ΔLVESV (%) = (LVESVAMI4weeks − LVESVAMI1day)/LVESVAMI1day. ResultsThirteen swine completed the study. LVDD parameters changed dynamically at different time points after AMI. LVDD occurred as early as 1 day after AMI, peaked at 1 week, and trended toward a partial recovery at 4 weeks. Phase analysis on SPECT GMPI showed a significant correlation with tissue Doppler imaging for the assessment of LVDD during the longitudinal evaluation (r = 0.569 to 0.787, both P <0.05). During the univariate and multivariate regression analyses, the LVDD parameters PBW and PSD as of 1 day after AMI were significantly associated with the progression of LVR, respectively (PBW, β = 0.004, 95% CI 0.001 to 0.007, P = 0.024; PSD, β = 0.008, 95% CI 0.000 to 0.017, P = 0.049). Adjusted smooth curve fitting and threshold effect analysis indicated PBW and PSD break-point values of 142° and 60.4°, respectively, to predict the progression of LVR after AMI. ConclusionsPhase analysis of SPECT GMPI can accurately and reliably characterize LVDD. LVDD occurred on the first day after AMI, reached its peak at 1 week, and partially recovered at 4 weeks after AMI. LVDD as evaluated by phase analysis of SPECT GMPI early after AMI was significantly associated with the progression of LVR. The early assessment of LVDD after AMI may provide helpful information for predicting the progression of LVR in the future.

Summed rest score in gated myocardial perfusion imaging is a good predicator for treatment-related cardiotoxicity after anthracycline chemotherapy in patients with diffuse large B-cell lymphoma.

Anthracycline chemotherapy is commonly used in the treatment of diffuse large B-cell lymphoma (DLBCL). Treatment-related cardiotoxicity (TRC) is defined as when the patient is identified to have one of the following clinical manifestations: Symptomatic heart failure, cardiac death, arrhythmia, infarction, a decrease in left ventricular ejection fraction (LVEF) of >15% from baseline or a decrease in LVEF of >10 to <50%. TRC may induce severe cardiac failure or cardiac arrhythmia as the main cause of death. The present study aimed to investigate the prognostic value of the summed rest score (SRS) in gated myocardial perfusion imaging (G-MPI) for the early detection of TRC caused by anthracycline chemotherapy in patients with DLBCL. A total of 36 DLBCL patients were enrolled in the present study, and a series of parameters were compared at baseline and after chemotherapy. According to the occurrence of TRC during the observation period, the patients were divided into two groups, and parameters associated with cardiac function were compared. The SRS in G-MPI and the corrected QT interval in the electrocardiogram were significantly different before and after chemotherapy (P=0.012 and P=0.015, respectively). By comparing parameters associated with cardiac function between the TRC group (n=22) and the no-TRC group (n=14), it was found that only SRS was significantly different (P=0.012). Multivariate logistic regression analysis showed that the SRS level was the only independent predicator for TRC (P=0.018; HR, 6.053; 95% CI, 1.364-26.869). Receiver operating characteristic curve analysis identified an optimal SRS cutoff of >1 for predicting TRC after anthracycline chemotherapy (P<0.001). Overall, the G-MPI SRS level was an early indicator for TRC surveillance in patients with DLBCL after anthracycline chemotherapy. The application of G-MPI SRS in clinical practice may contribute to early treatment and a subsequent decrease in mortality caused by such cardiovascular complications.

Value of circulating miRNA-21 in the diagnosis of subclinical diabetic cardiomyopathy

BackgroundDiabetic cardiomyopathy (DCM) is a type of cardiac dysfunction that affects approximately 12% of diabetic patients, ultimately leading to heart failure or even death. However, there is currently no efficient or specific biomarker for DCM diagnosis. MethodsA total of 266 subjects with type II diabetes (T2DM) were enrolled in this study and were divided into the T2DM with cardiac dysfunction (DCM) group and T2DM without cardiac dysfunction (non-DCM) group. The diagnostic efficacy of miR-21 was determined and compared with that of serum hemoglobin A1c% (HbA1c%). Db/db mice and H9c2 cells stimulated with high glucose (HG)/high fatty acid (PA) were used as in vivo and in vitro models of DCM, respectively. ResultsThrough echocardiography and gated-myocardial perfusion imaging (gated-MPI), 49 patients were selected to be enrolled in the DCM group, with 49 matched controls in the non-DCM group. The circulating miR-21 levels were significantly decreased in the DCM group compared to the non-DCM group (P < 0.001). The diagnostic efficiency of miR-21 (area under the curve AUC = 0.899) was higher than that of other parameters, including HbA1c%. Moreover, when miR-21 was combined with the duration of diabetes, HbA1c%, and lipid profiles, the AUC was the highest (AUC = 0.939) and had the highest diagnostic efficiency. Furthermore, overexpression of miR-21 improved the impaired mitochondrial biogenesis and decreased the cardiomyocyte apoptosis induced by HG/PA, while inhibition of miR-21 exerted the opposite effects. ConclusionsOur findings identify circulating miR-21 as a novel biomarker in the diagnosis of DCM and provide an underlying mechanism for miRNA-based therapy for the treatment of DCM. Trial registrationThe study was approved by the Ethics Committee of the Third Affiliated Hospital of Soochow University and has been registered in the Chinese Clinical Trial Registry (ChiCTR1900027080).

Predictive value of phase analysis of gated myocardial perfusion imaging for major adverse cardiac events in patients with coronary artery disease

Objective To evaluate the value of phase analysis of gated myocardial perfusion imaging (GMPI) in predicting major adverse cardiac events (MACE) in patients with coronary atherosclerotic heart disease. Methods Patients who underwent two-day rest-stress GMPI in the Department of Nuclear Medicine of Beijing Hospital from September 2012 to January 2014 were selected as observed subjects and analyzed retrospectively. The general clinical information, GMPI images and related parameters including phase standard deviation (PSD), phase histogram bandwidth (PBW), entropy, left ventricular ejection fraction (LVEF), summed stress score (SSS), peak ejection rate (PER), peak filling rate (PFR) were noted. Patients were followed up until the onset of MACE (cardiac death, nonfatal myocardial infarction, and late revascularization within 60 d after GMPI). χ2 test, independent-sample t test or Wilcoxon rank sum test were used to compare data between different groups. The independent risk factors of MACE were obtained by Cox proportional risk regression model. Kaplan-Meier survival curve analysis was used to analyze the cumulative survival rate without MACE. Results A total of 505 patients (235 males, 270 females, median age: 73 years) were followed up successfully, with a median follow-up period of 55.6(52.0, 60.5) months. There were 54 cases (10.7%) with MACE: 6 patients with cardiac death, 27 patients with non-fatal myocardial infarction, and 21 patients with late revascularization. The incidence of hypertension and hyperlipidemia in patients with MACE was significantly higher than that in patients without MACE (χ2 values: 4.126, 6.021, both P 80°), abnormal entropy(>58 J·mol-1·K-1) and SSS≥12 were independent risk factors for MACE (odds ratio(OR) values: 2.795(95% CI: 1.259-6.201), 3.213(95% CI: 1.468-7.029), 3.640 (95% CI: 1.999-6.628), all P 26.7°), abnormal PBW group and abnormal entropy group were 51.2%, 63.2% and 46.7%, which were significantly lower than those of normal PSD group (92.3%; χ2=77.768, P<0.05), normal PBW group (94.2%; χ2=77.741, P<0.05) and normal entropy group (92.8%; χ2=117.437, P<0.05). The 5-year cumulative MACE-free survival rate (31.7%) of patients with abnormal PBW and SSS≥12 was significantly lower than that of patients with normal PBW or patients with abnormal PBW and SSS<12 (80.1%-94.4%; χ2=185.4, P<0.01). The combination analysis of entropy and SSS showed similar results. Conclusions PBW and entropy obtained by GMPI phase analysis are independent risk factors for predicting MACE in coronary artery disease. GMPI phase analysis is useful for coronary artery disease risk stratification. Key words: Coronary artery disease; Prognosis; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Technetium Tc 99m sestamibi

Phase analysis of gated myocardial perfusion imaging for early diagnosis of cardiotoxicity caused by anthracyclines in patients with diffuse large B-cell lymphoma

Objective To evaluate the left ventricular systolic synchrony and investigate the early diagnostic value of left ventricular systolic dyssynchrony on cardiotoxicity caused by anthracyclines in patients with diffuse large B-cell lymphoma (DLBCL). Methods Thirty-two patients (22 males, 10 females, age: 22-73(54.4±14.2) years) from June 2016 to January 2019 with confirmed DLBCL and normal gated myocardial perfusion imaging (GMPI) before anthracyclines chemotherapy were enrolled prospectively. GMPI was performed after 6 cycles or more of chemotherapy. Changes of myocardial markers, electrocardiogram (ECG) indicators, left ventricular function indicators including left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), peak filling rate (PFR), summed motion score (SMS) and summed thickening score (STS) as well as left ventricular systolic synchrony indicators including phase bandwidth (BW), phase standard deviation (SD) and entropy before and after anthracyclines chemotherapy were analyzed. Paired t test, Wilcoxon signed rank test and χ2 test were used for data analysis. Results Compared with pre-chemotherapy, the left ventricular systolic synchrony indicators were significantly higher than those before chemotherapy (BW: (42.81±11.37)° vs (29.28±8.68)°; SD: (11.65±4.64)° vs (8.79±3.14)°; entropy: (39.84±5.51)% vs (36.19±5.94)%; t values: -9.132 to -3.173, all P 0.05). Of 32 patients, 13 patients (40.62%) had left ventricular systolic dyssynchrony, and the rate of chemotherapy-induced left ventricular systolic dyssynchrony was significantly higher than that of left ventricular dysfunction (15.62%, 5/32; χ2=4.947, P=0.025). All 5 patients with left ventricular dysfunction caused by chemotherapy had left ventricular systolic dyssynchrony. The LVEF of the chemotherapy-induced left ventricular systolic dyssynchrony group was significantly lower than that of the left ventricular systolic synchronization group ((54.54±9.25)% vs (66.79±7.65)%; t=4.087, P<0.01). Conclusion Left ventricular systolic dyssynchrony can be appeared in DLBCL patients after chemotherapy and is significantly earlier than left ventricular dysfunction, which can be an early indicator of cardiotoxicity caused by anthracycline chemotherapy. Key words: Lymphoma, large B cell, diffuse; Drug therapy, combination; Anthracyclines; Ventricular function, left; Myocardial perfusion imaging

Clinical value of 99Tcm-MIBI gated myocardial perfusion imaging in evaluating sarcoglycanopathy.

The purpose of this study was to analyse the diagnostic value of gated myocardial perfusion imaging (G-MPI) in the evaluation of myocardial injury in sarcoglycanopathy. Twenty-eight patients diagnosed with sarcoglycanopathy were evaluated using 99m- -methoxyisobutylisonitrile(99Tcm-MIBI) G-MPI. The data was processed into tomographic images, and the left ventricular function was analysed using quantitative gated SPECT (QGS) to assess the degree of impairment in myocardial and cardiac function. The images of 23 of the patients (82.1%) were positive. Two hundred and twenty-nine sub-segments with abnormal lesions were detected out of 391 cardiac sub-segments of these 23 positive cases. According to the segmental abnormalities, the cases were divided into two cases (8.7%) with single abnormal wall segment, six cases (26.1%) with two abnormal wall segments, and 15 cases (65.2%) with three or more abnormal wall segments or scattered lesions. 99Tcm-MIBI G-MPI can objectively show impaired myocardium in patients with sarcoglycanopathy. Therefore, this method is helpful for early diagnosis and follow-up of myocardial damage.

Mechanical contraction to guide CRT left-ventricular lead placement instead of electrical activation in myocardial infarction with left ventricular dysfunction: An experimental study based on non-invasive gated myocardial perfusion imaging and invasive electroanatomic mapping

BackgroundWhether the region of the latest electrical activation (LEA) corresponds with the segment of the latest mechanical contraction (LMC) in ischemic cardiomyopathy (ICM) is uncertain. We aimed to investigate the relationship between the left-ventricular (LV) viable segments with LEA and with LMC after myocardial infarction (MI) and analyze the acute hemodynamic responses (dP/dtmax) after cardiac resynchronization therapy (CRT) pacing at different LV sites. Methods and resultsBama suckling pigs (n = 6) were subjected to create MI models. Both gated myocardial perfusion imaging (GMPI) and electroanatomic mapping (EAM) were performed successfully before MI and 4 weeks after MI. LMC was assessed by phase analysis of GMPI, while LEA was evaluated by EAM. The dP/dtmax was measured before CRT and when the CRT LV electrode was implanted in viable segments of LMC, viable segments of lateral wall and scar, respectively. The viable segments of LEA were consistent with the sites of LMC for five in six cases. The dP/dtmax increased significantly compared with that before CRT when the CRT LV electrode was implanted in viable segments of LMC (1103.33 ± 195.76 vs 717.83 ± 80.74 mmHg·s−1, P = .001), which was also significantly higher than in viable segments of lateral wall (751.17 ± 105.62 mmHg·s−1, P = .000) and scar (679.50 ± 60.87 mmHg·s−1, P = .001). ConclusionsNon-invasive GMPI may be a better option than invasive EAM for guiding LV electrode implantation for CRT in ICM.

Gated single-photon emission computed tomography myocardial perfusion imaging is superior to computed tomography attenuation correction in discriminating myocardial infarction from attenuation artifacts in men and right coronary artery disease.

In single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) studies, attenuation artifacts frequently cause false positives, which can be partially overcome by computed tomography attenuation correction (CT-AC) or gated acquisition [gated myocardial perfusion imaging (GMPI)]. The purpose of this study is to evaluate their relative diagnostic performances for coronary artery disease (CAD). We enrolled 181 patients who underwent gated SPECT with CT-AC in this study. Two observers who were blinded to the clinical data interpreted the GMPI and CT-AC images. Coronary angiography was considered as the reference standard. The diagnostic efficacy was evaluated based on sex, BMI, and individual coronary arteries. The diagnostic accuracy of GMPI was higher than that of nonattenuation correction overall, as well as for men, overweight individuals, and right CAD (P<0.05). Compared with CT-AC, GMPI overall had a higher specificity (96.3 vs. 86.9%, P=0.014) but the same sensitivity, achieving an increased accuracy and area under the curve (AUC, P>0.05). For diagnosing right CAD, GMPI had a higher diagnostic efficacy (AUC: 0.733 vs. 0.596, P<0.001) because of its higher sensitivity (52.0 vs. 26.0%, P=0.008); for men, the diagnostic efficacy of GMPI was significantly higher than that of CT-AC (AUC: 0.754 vs. 0.681, P=0.038). Both CT-AC and GMPI led to an increased diagnostic efficacy compared with nonattenuation correction in differentiating attenuation artifacts from fixed perfusion defects. These improvements were, however, more obvious for GMPI than for CT-AC, especially in men and right CAD.

Myocardial perfusion imaging detects mechanical dyssynchrony in left ventricular infarcted and noninfarcted areas early after acute myocardial infarction in a porcine model.

Left ventricular mechanical dyssynchrony (LVMD) is closely associated with left ventricular dysfunction and poor prognosis in patients with acute myocardial infarction (AMI). However, whether mechanical dyssynchrony is present in the noninfarcted areas remains controversial. This research aimed to quantitatively evaluate the global and regional mechanical dyssynchrony early after AMI by phase analysis of single-photon emission computed tomography (SPECT) gated myocardial perfusion imaging (GMPI) and to further explore the related influencing factors. Of 11 Bama suckling pigs, eight animals were successfully subjected to left anterior descending artery occlusion by balloon to generate porcine AMI models and completed the study. SPECT GMPI was performed before AMI and at 1 day, 1 week, and 4 weeks after AMI. The global bandwidth (BW), SD, entropy, total perfusion deficit, summed rest score, regional BW, regional summed motion score, and regional summed thickening score were measured by SPECT GMPI. The global BW, SD, and entropy values significantly increased after AMI and showed no significant change among the three time points after AMI. The BW in the infarcted area (left anterior descending artery-dominated area) at 1 day, 1 week, and 4 weeks after AMI was significantly higher than that before AMI, as was the BW in the noninfarcted areas (left circumflex artery-dominated and right coronary artery-dominated areas), which revealed that there was less dyssynchrony in the noninfarcted areas than in the infarcted area at the three time points after AMI. The global BW was positively correlated with the scar burden measured by summed rest score (r=0.709-0.832, all P<0.05), whereas the regional BW in the noninfarcted areas after AMI showed moderate to good correlation with regional summed motion score (r=0.733-0.875, all P<0.05) and regional summed thickening score (r=0.713-0.889, all P<0.05). LVMD occurs early on the first day after AMI, with no significant worsening over the next 4 weeks. Mechanical dyssynchrony was present in both the infarcted and noninfarcted areas. The global LVMD is mainly influenced by the scar burden, and the regional mechanical dyssynchrony in the noninfarcted areas is closely associated with the abnormal regional wall thickening and motion, which are indicative of reduced myocardial contractility.

Role of Gated Myocardial Glucose Metabolic Imaging in Assessing Left Ventricular Systolic Dyssynchrony after Myocardial Infarction and the Influential Factors

In this study, we investigated the role of gated myocardial glucose metabolic imaging in assessing left ventricular (LV) systolic dyssynchrony after myocardial infarction (MI) and explored the influencing factors. Bama mini-pigs were divided into normal group and MI group and subjected to gated myocardial metabolic imaging (GMMI) and gated myocardial perfusion imaging (GMPI). The phase bandwidth (BW), standard deviation (SD) and the latest activation site of left ventricle were obtained using program Cedars QGS. The results showed that (1) BW and SD obtained in GMMI and GMPI showed significant correlation in pigs with MI, but not in the normal pigs, (2) BW and SD obtained in GMMI and GMPI had good consistency in both normal pigs and MI pigs, (3) GMMI and GMPI had a 66.7% identity in determining the latest activation site of left ventricle in the normal pigs and 77.8% identity in determining the latest activation site of left ventricle in pigs with MI. Multivariate stepwise regression analysis showed that total perfusion deficit and summed motion score were independent factors affecting BW and SD in GMMI. In conclusion, phase analysis of GMMI images could objectively reflect LV systolic dyssynchrony resulted from interactions of multiple factors.

Myocardial perfusion imaging evaluation of left ventricular volume and ejection fraction using a novel semi-conductor SPECT: comparison to conventional SPECT and cardiac MRI

Objective To prospectively compare cadmium-zinc-telluride (CZT) SPECT gated myocardial perfusion imaging (GMPI), conventional SPECT MPI and cardiac MRI for the assessment of left ventricular volume and ejection fraction in patients with heart failure. Methods From July 2016 to October 2016, a total of 35 patients (27 males, 8 females, average age: (52.7±14.9) years) with heart failure were consecutively included. All patients underwent CZT SPECT GMPI, conventional SPECT GMPI and cardiac MRI within 7 d. LVEDV, LVESV and LVEF of three imaging modalities were calculated. One-way analysis of variance, Pearson correlation analysis and Bland-Altman analysis were used. Results CZT SPECT showed excellent correlation with conventional SPECT for LVEDV, LVESV and LVEF (r values: 0.983, 0.986 and 0.910, respectively; all P<0.001). Bland-Altman analysis revealed good agreement between CZT SPECT and conventional SPECT for LVEDV, LVESV and LVEF. The correlation between CZT SPECT and cardiac MRI for LVEDV, LVESV and LVEF were all significant (r values: 0.864, 0.896 and 0.836, respectively; all P<0.001). Compared with cardiac MRI, CZT SPECT showed systemic underestimation of LVEDV and LVESV and good agreement of LVEF by Bland-Altman analysis. Conclusions CZT SPECT has high clinical value for patients with heart failure. Despite underestimating LVEDV and LVESV, it correlated well with cardiac MRI. It also has a good agreement with conventional SPECT on left ventricular volume and LVEF. Key words: Heart failure; Cardiac volume; Stroke volume; Semiconductors; Tomography, emission-computed, single-photon; Magnetic resonance imaging; Technetium Tc 99m sestamibi