Novel mutation leading to splice donor loss in a conserved site of DMD gene causes Duchenne muscular dystrophy with cryptorchidism.

BACKGROUND: As one of the most common congenital abnormalities in male births, cryptorchidism has been found to have a polygenic aetiology according to previous studies of common variants. However, little is known about genetic predisposition of rare variants for cryptorchidism, since rare variants have larger effective size on diseases than common variants. METHODS: In this study, a cohort of 115 Chinese probands with cryptorchidism was analysed using whole-genome sequencing, alongside 19 parental controls and 2136 unaffected men. Additionally, CRISPR-Cas9 editing of a conserved variant was performed in a mouse model, with MRI screening used to observe the phenotype. RESULTS: In 30 of 115 patients (26.1%), we identified four novel genes (ARSH, DMD, MAGEA4 and SHROOM2) affecting at least five unrelated patients and four known genes (USP9Y, UBA1, BCORL1 and KDM6A) with the candidate rare pathogenic variants affecting at least two cases. Burden tests of rare variants revealed the genome-wide significances for newly identified genes (p<2.5×10-6) under the Bonferroni correction. Surprisingly, novel and known genes were mainly found on X chromosome (seven on X and one on Y) and all rare X-chromosomal segregating variants exhibited a maternal inheritance rather than de novo origin. CRISPR-Cas9 mouse modelling of a splice donor loss variant in DMD (NC_000023.11:g.32454661C>G), which resides in a conserved site across vertebrates, replicated bilateral cryptorchidism phenotypes, confirmed by MRI at 4 and 10 weeks. The movement tests further revealed symptoms of Duchenne muscular dystrophy (DMD) in transgenic mice. CONCLUSION: Our results revealed the role of the DMD gene mutation in causing cryptorchidism. The results also suggest that maternal-X inheritance of pathogenic defects could have a predominant role in the development of cryptorchidism.

Glycemic control and clinical outcomes in diabetic patients with heart failure and reduced ejection fraction: insight from ventricular remodeling using cardiac MRI.

BACKGROUND: Glycemic control, as measured by glycosylated hemoglobin (HbA1c), is an important biomarker to evaluate diabetes severity and is believed to be associated with heart failure development. Type 2 diabetes mellitus (T2DM) and heart failure with reduced ejection fraction (HFrEF) commonly coexist, and the combination of these two diseases indicates a considerably poorer outcome than either disease alone. Therefore, glycemic control should be carefully managed. The present study aimed to explore the association between glycemic control and clinical outcomes, and to determine the optimal glycemic target in this specific population. METHODS: A total of 262 patients who underwent cardiac MRI were included and were split by HbA1c levels [HbA1c < 6.5% (intensive control), HbA1c 6.5-7.5% (modest control), and HbA1c > 7.5% (poor control)]. The biventricular volume and function, as well as left ventricular (LV) systolic strains in patients in different HbA1c categories, were measured and compared. The primary and secondary outcomes were recorded. The association of different HbA1c levels with adverse outcomes was assessed. RESULTS: Despite similar biventricular ejection fractions, both patients with intensive and poor glycemic control exhibited prominent deterioration of LV systolic strain in the longitudinal component (P = 0.004). After a median follow-up of 35.0 months, 55 patients (21.0%) experienced at least one confirmed endpoint event. Cox multivariable analysis indicated that both patients in the lowest and highest HbA1c categories exhibited a more than 2-fold increase in the risk for primary outcomes [HbA1c < 6.5%: hazard ratio (HR) = 2.42, 95% confidence interval (CI) = 1.07-5.45; P = 0.033; HbA1c > 7.5%: HR = 2.24, 95% CI = 1.01-4.99; P = 0.038] and secondary outcomes (HbA1c < 6.5%: HR = 2.84, 95% CI = 1.16-6.96; P = 0.022; HbA1c > 7.5%: HR = 2.65, 95% CI = 1.08-6.50; P = 0.038) compared with those in the middle HbA1c category. CONCLUSIONS: We showed a U-shaped association of glycemic control with clinical outcomes in patients with T2DM and HFrEF, with the lowest risk of adverse outcomes among patients with modest glycemic control. HbA1c between 6.5% and 7.5% may be served as the optimal hypoglycemic target in this specific population.

Early left ventricular microvascular dysfunction in diabetic pigs: a longitudinal quantitative myocardial perfusion CMR study.

BACKGROUND: Microvascular pathology is one of the main characteristics of diabetic cardiomyopathy; however, the early longitudinal course of diabetic microvascular dysfunction remains uncertain. This study aimed to investigate the early dynamic changes in left ventricular (LV) microvascular function in diabetic pig model using the cardiac magnetic resonance (CMR)-derived quantitative perfusion technique. METHODS: Twelve pigs with streptozotocin-induced diabetes mellitus (DM) were included in this study, and longitudinal CMR scanning was performed before and 2, 6, 10, and 16 months after diabetic modeling. CMR-derived semiquantitative parameters (upslope, maximal signal intensity, perfusion index, and myocardial perfusion reserve index [MPRI]) and fully quantitative perfusion parameters (myocardial blood flow [MBF] and myocardial perfusion reserve [MPR]) were analyzed to evaluate longitudinal changes in LV myocardial microvascular function. Pearson correlation was used to analyze the relationship between LV structure and function and myocardial perfusion function. RESULTS: With the progression of DM duration, the upslope at rest showed a gradually increasing trend (P = 0.029); however, the upslope at stress and MBF did not change significantly (P > 0.05). Regarding perfusion reserve function, both MPRI and MPR showed a decreasing trend with the progression of disease duration (MPRI, P = 0.001; MPR, P = 0.042), with high consistency (r = 0.551, P < 0.001). Furthermore, LV MPR is moderately associated with LV longitudinal strain (r = - 0.353, P = 0.022), LV remodeling index (r = - 0.312, P = 0.033), fasting blood glucose (r = - 0.313, P = 0.043), and HbA1c (r = - 0.309, P = 0.046). Microscopically, pathological results showed that collagen volume fraction increased gradually, whereas no significant decrease in microvascular density was observed with the progression of DM duration. CONCLUSIONS: Myocardial microvascular reserve function decreased gradually in the early stage of DM, which is related to both structural (but not reduced microvascular density) and functional abnormalities of microvessels, and is associated with increased blood glucose, reduced LV deformation, and myocardial remodeling.

Reduced thoracic skeletal muscle size is associated with adverse outcomes in diabetes patients with heart failure and reduced ejection fraction: quantitative analysis of sarcopenia by using cardiac MRI.

BACKGROUND: Sarcopenia is frequently found in patients with heart failure with reduced ejection fraction (HFrEF) and is associated with reduced exercise capacity, poor quality of life and adverse outcomes. Recent evidence suggests that axial thoracic skeletal muscle size could be used as a surrogate to assess sarcopenia in HFrEF. Since diabetes mellitus (DM) is one of the most common comorbidities with HFrEF, we aimed to explore the potential association of axial thoracic skeletal muscle size with left ventricular (LV) remodeling and determine its prognostic significance in this condition. METHODS: A total of 243 diabetes patients with HFrEF were included in this study. Bilateral axial thoracic skeletal muscle size was obtained using cardiac MRI. Patients were stratified by the tertiles of axial thoracic skeletal muscle index (SMI). LV structural and functional indices, as well as amino-terminal pro-B-type natriuretic peptide (NT-proBNP), were measured. The determinants of elevated NT-proBNP were assessed using linear regression analysis. The associations between thoracic SMI and clinical outcomes were assessed using a multivariable Cox proportional hazards model. RESULTS: Patients in the lowest tertile of thoracic SMI displayed a deterioration in LV systolic strain in three components, together with an increase in LV mass and a heavier burden of myocardial fibrosis (all P < 0.05). Moreover, thoracic SMI (ß = -0.25; P < 0.001), rather than body mass index (ß = -0.04; P = 0.55), was independently associated with the level of NT-proBNP. The median follow-up duration was 33.6 months (IQR, 20.4-52.8 months). Patients with adverse outcomes showed a lower thoracic SMI (40.1 [34.3, 47.9] cm2/m2 vs. 45.3 [37.3, 55.0] cm2/m2; P < 0.05) but a similar BMI (P = 0.76) compared with those without adverse outcomes. A higher thoracic SMI indicated a lower risk of adverse outcomes (hazard ratio: 0.96; 95% confidence interval: 0.92-0.99; P = 0.01). CONCLUSIONS: With respect to diabetes patients with HFrEF, thoracic SMI is a novel alternative for evaluating muscle wasting in sarcopenia that can be obtained by a readily available routine cardiac MRI protocol. A reduction in thoracic skeletal muscle size predicts poor outcomes in the context of DM with HFrEF.

Different bone health progression patterns and early-stage risk marker in glucocorticoid-treated ambulatory Duchenne muscular dystrophy.

Fractures often cause irreversible harm in Duchenne muscular dystrophy (DMD). This study investigated the trajectory of bone mineral density (BMD) using group-based trajectory modeling and identified that BMD acts as an early-stage indicator of clinically significant bone fragility. The greater the early-stage BMD, the better the 4-year bone health outcome. PURPOSE: Most Duchenne muscular dystrophy (DMD) children suffer bone loss after long-term glucocorticoid (GC) exposure, which induces scoliosis and fragility fractures. To assess the BMD progression pattern and individual medical risk markers for these phenotypes in young ambulatory boys with DMD, and provide evidence-based suggestions for clinical management of bone health. METHODS: A retrospective longitudinal cohort study of 153 boys with DMD in West China Second University Hospital (2016-2023) was performed. Group-based trajectory modeling was used to study the BMD progression pattern, and potential predictors were further analyzed by logistic regression and survival analysis. RESULTS: One hundred and fifty-three participants were included, 71 of which had more than 3 BMD records. Three BMD trajectories were identified. Baseline BMD and age-started GC and were independent predictors of trajectory attribution. The median survival time of the first observation of low BMD in GC-treated DMD boys was 5.32 (95% CI 4.05-6.59) years, and a significant difference was tested (P < 0.001) among the three trajectory groups. CONCLUSION: BMD may serve as a novel early indicating marker for monitoring bone fragility for DMD. We proposed a bone health risk stratification through BMD progression trajectory that allows us to adapt the osteoporosis warning sign in DMD from a fixed threshold approach to a more individualized strategy, where baseline BMD and age of glucocorticoid initiation can provide an earlier prediction of bone loss. Better management of primary BMD may be able to delay or avoid the onset of adverse bone health outcomes in the fifth year in children with DMD.

Free-Breathing Compressed Sensing Cine Cardiac MRI for Assessment of Left Ventricular Strain by Feature Tracking in Children.

BACKGROUND: Cardiac MRI feature-tracking (FT) with breath-holding (BH) cine balanced steady state free precession (bSSFP) imaging is well established. It is unclear whether FT-strain measurements can be reliably derived from free-breathing (FB) compressed sensing (CS) bSSFP imaging. PURPOSE: To compare left ventricular (LV) strain analysis and image quality of an FB CS bSSFP cine sequence with that of a conventional BH bSSFP sequence in children. STUDY TYPE: Prospective. SUBJECTS: 40 children able to perform BHs (cohort 1 [12.1 ± 2.2 years]) and 17 children unable to perform BHs (cohort 2 [5.2 ± 1.8 years]). FIELD STRENGTH/SEQUENCE: 3T, bSSFP sequence with and without CS. ASSESSMENT: Acquisition times and image quality were assessed. LV myocardial deformation parameters were compared between BH cine and FB CS cine studies in cohort 1. Strain indices and image quality of FB CS cine studies were also assessed in cohort 2. Intraobserver and interobserver variability of strain parameters was determined. STATISTICAL TESTS: Paired t-test, Wilcoxon signed-rank test, intraclass correlation coefficient (ICC), and Bland-Altman analysis. A P-value <0.05 was considered statistically significant. RESULTS: In cohort 1, the mean acquisition time of the FB CS cine study was significantly lower than for conventional BH cine study (15.6 s vs. 209.4 s). No significant difference were found in global circumferential strain rate (P = 0.089), global longitudinal strain rate (P = 0.366) and EuroCMR image quality scores (P = 0.128) between BH and FB sequences in cohort 1. The overall image quality score of FB CS cine in cohort 2 was 3.5 ± 0.5 with acquisition time of 14.7 ± 2.1 s. Interobserver and intraobserver variabilities were good to excellent (ICC = 0.810 to 0.943). DATA CONCLUSION: FB CS cine imaging may be a promising alternative technique for strain assessment in pediatric patients with poor BH ability. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 1.

Association of Pulmonary Transit Time and Pulmonary Blood Volume From First-Pass Perfusion Cardiac MRI With Diastolic Dysfunction and Left Ventricle Deformation in Restrictive Cardiomyopathy.

BACKGROUND: Patients with restrictive cardiomyopathy (RCM) have impaired diastolic filling and hemodynamic congestion. Pulmonary transit time (PTT) and pulmonary blood volume index (PBVi) reflect the hemodynamic status, but the relationship with left ventricle (LV) dysfunction remains unclear. PURPOSE: To evaluate the PTT and PBVi in RCM patients, the association with diastolic dysfunction and LV deformation, and the effects on the occurrence of major adverse cardiac events (MACE) in RCM patients. STUDY TYPE: Retrospective. POPULATION: 137 RCM patients (88 men, age 58.80 ± 10.83 years) and 68 age- and sex-matched controls (46 men, age 57.00 ± 8.59 years). FIELD STRENGTH/SEQUENCE: 3.0T/Balanced steady-state free precession sequence, recovery prepared echo-planar imaging sequence, and phase-sensitive inversion recovery sequence. ASSESSMENT: The LV function and peak strain (PS) parameters were measured. The PTT was calculated and corrected by heart rate (PTTc). The PBVi was calculated as the product of PTTc and RV stroke volume index. STATISTICAL TESTS: Chi-squared test, student's t-test, Mann-Whitney U test, Pearson's or Spearman's correlation, multivariate linear regression, Kaplan-Meier survival analysis, and Cox regression models analysis. A P-value <0.05 was considered statistically significant. RESULTS: The PTTc showed a significant correlation with the E/A ratio (r = 0.282), and PBVi showed a significant correlation with the E/e' ratio, E/A ratio, and diastolic dysfunction stage (r = 0.222, 0.320, and 0.270). PTTc showed an independent association with LVEF, LV circumferential PS, and LV longitudinal PS (ß = 0.472, 0.299, and 0.328). In Kaplan-Meier analysis, higher PTTc and PBVi were significantly associated with MACE. In multivariable Cox regression analysis, PTTc was a significantly independent predictor of the MACE in combination with both cardiac MRI functional and tissue parameters (hazard ratio: 1.23/1.32, 95% confidence interval: 1.10-1.42/1.20-1.46). DATA CONCLUSION: PTTc and PBVi are associated with diastolic dysfunction and deteriorated LV deformation, and PTTc independently predicts MACE in patients with RCM. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Association Between Myocardial Oxygenation and Fibrosis in Duchenne Muscular Dystrophy: Analysis by Rest Oxygenation-Sensitive Magnetic Resonance Imaging.

BACKGROUND: Myocardial hypoxia has been demonstrated in many cardiomyopathies and is related to development of myocardial fibrosis. However, myocardial hypoxia and its association with myocardial fibrosis are understudied in Duchenne muscular dystrophy (DMD)-associated cardiomyopathy. PURPOSE: To evaluate myocardial hypoxia by oxygenation-sensitive (OS) cardiac magnetic resonance imaging, and further explore its association with fibrosis. STUDY TYPE: Prospective. SUBJECTS: Ninety-one DMD boys (8.78 ± 2.32) and 30 healthy boys (9.07 ± 2.30). FIELD STRENGTH/SEQUENCE: 3 T, Balanced steady-state free procession, Modified Look-Locker inversion recovery sequence and Single-shot phase-sensitive inversion recovery sequence. ASSESSMENT: Cardiac MRI data, including left ventricular functional, segmental native T1, and oxygenation signal-intensity (SI) according to AHA 17-segment model, were acquired. Patients were divided into LGE+ and LGE- groups. In patients with LGE, all segments were further classified as positive or negative segments by segmentally presence/absence of LGE. STATISTICAL TESTS: Variables were compared using Student's t, Wilcoxon, Kruskal-Wallis test and one-way analysis of variance. Bivariate Pearson or Spearman correlation were calculated to determine association between oxygenation SI and native T1. Variables with P < 0.10 in the univariable analysis were included in multivariable model. Receiver operating characteristic analysis was used to assess the performance of OS in diagnosing myocardial hypoxia. RESULTS: The myocardial oxygenation SI of DMD was significantly decreased in all segments compared with normal controls, and more obvious in the LGE+ segments (0.46 ± 0.03 vs. 0.52 ± 0.03). For patients with and without LGE, myocardial oxygenation SI were significantly negatively correlated with native T1 in all segments (r = -0.23 to -0.42). The inferolateral oxygenation SI was a significant independent associator of LGE presence (adjusted OR = 0.900). DATA CONCLUSION: Myocardial hypoxia evaluated by the OS-Cardiac-MRI indeed occurs in DMD and associate with myocardial fibrosis, which might be used as a biomarker in assessing myocardial damage in DMD. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Connectomic disturbances in Duchenne muscular dystrophy with mild cognitive impairment.

Duchenne muscular dystrophy (DMD) is frequently associated with mild cognitive deficits. However, the underlying disrupted brain connectome and the neural basis remain unclear. In our current study, 38 first-episode, treatment-naive patients with DMD and 22 matched healthy controls (HC) were enrolled and received resting-sate functional magnetic resonance imaging scans. Voxel-based degree centrality (DC), seed-based functional connectivity (FC), and clinical correlation were performed. Relative to HC, DMD patients had lower height, full Intellectual Quotients (IQ), and IQ-verbal comprehension. Significant increment of DC of DMD patients were found in the left dorsolateral prefrontal cortex (DLPFC.L) and right dorsomedial prefrontal cortex (DMPFC.R), while decreased DC were found in right cerebellum posterior lobe (CPL.R), right precentral/postcentral gyrus (Pre/Postcentral G.R). DMD patients had stronger FC in CPL.R-bilateral lingual gyrus, Pre/Postcentral G.R-Insular, and DMPFC.R-Precuneus.R, had attenuated FC in DLPFC.L-Insular. These abnormally functional couplings were closely associated with the extent of cognitive impairment, suggested an over-activation of default mode network and executive control network, and a suppression of primary sensorimotor cortex and cerebellum-visual circuit. The findings collectively suggest the distributed brain connectome disturbances maybe a neuroimaging biomarker in DMD patients with mild cognitive impairment.

Left ventricular concentric hypertrophy with cardiac magnetic resonance imaging improves risk stratification in patients with Duchenne muscular dystrophy: a prospective cohort study.

BACKGROUND: The development of left ventricular (LV) remodeling has been associated with an increased cardiovascular risk and cardiogenic death, and different patterns of remodeling result in varying levels of prognosis. OBJECTIVE: To investigate the association between different patterns of LV remodeling and clinical outcomes in the preclinical stage of patients with Duchenne muscular dystrophy (DMD). MATERIALS AND METHODS: A total of 148 patients with DMD and 43 sex- and age-matched healthy participants were enrolled. We used the four-quadrant analysis method to investigate LV remodeling based on cardiac magnetic resonance (MR) imaging. Kaplan-Meier curves were generated to illustrate the event-free survival probability stratified by the LV remodeling pattern. Cox regression models were constructed and compared to evaluate the incremental predictive value of the LV remodeling pattern. RESULTS: During the median follow-up period of 2.2 years, all-cause death, cardiomyopathy, and ventricular arrhythmia occurred in 5, 35, and 7 patients, respectively. LV concentric hypertrophy (hazard ratio 2.91, 95% confidence interval 1.47-5.75, P=0.002) was an independent predictor of composite endpoint events. Compared to the model without LV concentric hypertrophy, the model with LV concentric hypertrophy had significant incremental predictive value (chi-square value 33.5 vs. 25.2, P=0.004). CONCLUSION: Age and late gadolinium enhancement positivity were positively correlated with clinical outcomes according to the prediction models. LV concentric hypertrophy was also an independent predictor for risk stratification and provided incremental value for predicting clinical outcomes in the preclinical stage of patients with DMD.

Evaluation of coronary microvascular dysfunction and risk factors in children and youth with Turner syndrome by magnetic resonance myocardial perfusion imaging.

OBJECTIVE: Turner syndrome (TS) has an increased predisposition to ischaemic heart disease and the status of coronary microcirculation in TS is largely unknown. This study aims to evaluate myocardial microvascular function in TS using first-pass magnetic resonance perfusion imaging and determine significant risk factors contributing to microvascular dysfunction in the early stage. DESIGN: Perspective cohort study. PATIENTS: The study cohort consisted of 67 children and youth with TS and 32 age- and gender-matched controls. Measurements Clinical characteristics, left ventricle (LV) volume and function and cardiovascular magnetic resonance-derived myocardial perfusion parameters were assessed. Univariable and multivariable linear regression analyses were performed to assess the potential risk factors for microvascular dysfunction. RESULT: Microvascular perfusion decreased in TS in global and segmented myocardium as reflected in the lower upslopecor and maximum signal intensity (MaxSI) of LV myocardium compared to controls. Multivariable linear regression analysis indicated that age (ß = -0.107, 95% confidence interval [CI] = -0.201 to -0.013, p = .026) and being overweight/obese (ß = -1.155, CI = -2.134 to -0.176, p = .021) were independent impact factors of microvascular dysfunction. Subgroup analysis showed the upslopecor of older patients with TS decreased more significantly compared with that of normal controls. Upslopecor and MaxSI were lower in overweight/obese patients with TS than in patients with normal body mass index (BMI) and controls. CONCLUSION: Myocardial microvascular dysfunction can occur in children and youth patients with TS. Age and overweight/obesity were the independent risk factors of microvascular dysfunction, which imply the importance of lowering BMI for the prevention of coronary heart disease in young TS population.

Association of diabetes mellitus and glycemic control with left ventricular function and deformation in patients after acute myocardial infarction: a 3 T cardiac magnetic resonance study.

BACKGROUND: Diabetes mellitus (DM) is considered a major risk factor for myocardial infarction (MI), and MI patients with DM have a poor prognosis. Accordingly, we aimed to investigate the additive effects of DM on LV deformation in patients after acute MI. MATERIALS AND METHODS: One hundred thirteen MI patients without DM [MI (DM-)], 95 with DM [MI (DM+)] and 71 control subjects who underwent CMRscanning were included. LV function, infarct size and LV global peak strains in the radial, circumferential and longitudinal directions were measured. MI (DM+) patients were divided into two subgroups based on the HbA1c level (< 7.0% and ≥ 7.0%). The determinants of reduced LV global myocardial strain for all MI patients and MI (DM+) patients were assessed using multivariable linear regression analyses. RESULTS: Compared with control subjects, both MI (DM-) and MI (DM+) patients presented higher LV end-diastolic and end-systolic volume index and lower LV ejection fraction. LV global peak strains progressively declined from the control group to the MI(DM-) group to the MI(DM+) group (all p < 0.05). Subgroup analysis showed that LV global radial PS and longitudinal PS were worse in MI(MD+) patients with poor glycemic control than in those with good glycemic control (all p < 0.05). DM was an independent determinant of impaired LV global peak strain in radial, circumferential and longitudinal directions in patients after acute MI (ß = - 0.166, 0.164 and 0.262, both p < 0.05). The HbA1c level was independently associated with a decreased LV global radial PS (ß = - 0.209, p = 0.025) and longitudinal PS (ß = 0.221, p = 0.010) in MI (DM+) patients. CONCLUSIONS: DM has an additive deleterious effect on LV function and deformation in patients after acute MI, and HbA1c was independently associated with impaired LV myocardial strain.

Early longitudinal changes in left ventricular function and morphology in diabetic pigs: evaluation by 3.0T magnetic resonance imaging.

BACKGROUND: Previous researches on large animal models of diabetic cardiomyopathy were insufficient. The aim of this study was to evaluate early changes in left ventricular (LV) function and morphology in diabetic pigs using a cardiac magnetic resonance (CMR) time-volume curve and feature tracking technique. METHODS: Streptozotocin (STZ) was used to induce diabetic in sixteen pigs. 3.0T MRI scanned the pig's heart before and 2, 6, 10 and 16 months after modelling. CMR biomarkers, including time-volume curve and myocardial strain, were compared to analyse the longitudinal changes in LV function and morphology. Pearson correlation was used to evaluate the relationship between LV strain and remodelling. Cardiac specimens were obtained at 6, 10, and 16 months after modelling to observe the myocardial ultrastructural and microstructure at different courses of diabetes. RESULTS: Twelve pigs developed diabetes. The 80% diastolic volume recovery rate (DVR) at 6 months after modelling was significantly higher than that before modelling (0.78 ± 0.08vs. 0.67 ± 0.15). The LV global longitudinal peak strain (GLPS) (- 10.21 ± 3.15 vs. - 9.74 ± 2.78 vs. - 9.38 ± 3.71 vs. - 8.71 ± 2.68 vs. - 6.59 ± 2.90%) altered gradually from the baseline data to 2, 6, 10 and 16 months after modelling. After 16 months of modelling, the LV remodelling index (LVRI) of pigs increased compared with that before modelling (2.19 ± 0.97 vs. 1.36 ± 0.45 g/ml). The LVRI and myocardial peak strain were correlated in diabetic pigs (r= - 0.40 to - 0.54), with GLPS being the most significant. Electron microscopy and Masson staining showed that myocardial damage and fibrosis gradually increased with the progression of the disease. CONCLUSION: Intravenous injection of STZ can induce a porcine diabetic cardiomyopathy model, mainly characterized by decreased LV diastolic function and strain changes accompanied by myocardial remodelling. The changes in CMR biomarkers could reflect the early myocardial injury of diabetic cardiomyopathy.

The right ventricular dysfunction and ventricular interdependence in patients with DM: assessment using cardiac MR feature tracking.

BACKGROUND: To investigate the difference of right ventricular (RV) structural and functional alteration in patients with diabetes mellitus (DM) with preserved left ventricular ejection fraction (LVEF), and the ventricular interdependence in these patients, using cardiac MR (CMR) feature tracking. METHODS: From December 2016 to February 2022, 148 clinically diagnosed patients with DM who underwent cardiac MR (CMR) in our hospital were consecutively recruited. Fifty-four healthy individuals were included as normal controls. Biventricular strains, including left/right ventricular global longitudinal strain (LV-/RVGLS), left/right ventricular global circumferential strain (LV-/RVGCS), left/right ventricular global radial strain (LV-/RVGRS) were evaluated, and compared between patients with DM and healthy controls. Multiple linear regression and mediation analyses were used to evaluate DM's direct and indirect effects on RV strains. RESULTS: No differences were found in age (56.98 ± 10.98 vs. 57.37 ± 8.41, p = 0.985), sex (53.4% vs. 48.1%, p = 0.715), and body surface area (BSA) (1.70 ± 0.21 vs. 1.69 ± 0.17, p = 0.472) between DM and normal controls. Patients with DM had decreased RVGLS (- 21.86 ± 4.14 vs. - 24.49 ± 4.47, p = 0.001), RVGCS (- 13.16 ± 3.86 vs. - 14.92 ± 3.08, p = 0.011), and no decrease was found in RVGRS (22.62 ± 8.11 vs. 23.15 ± 9.05, p = 0.743) in patients with DM compared with normal controls. The difference in RVGLS between normal controls and patients with DM was totally mediated by LVGLS (indirect effecting: 0.655, bootstrapped 95%CI 0.138-0.265). The difference in RVGCS between normal controls and DM was partly mediated by the LVGLS (indirect effecting: 0.336, bootstrapped 95%CI 0.002-0.820) and LVGCS (indirect effecting: 0.368, bootstrapped 95%CI 0.028-0.855). CONCLUSIONS: In the patients with DM and preserved LVEF, the difference in RVGLS between DM and normal controls was totally mediated by LVGLS. Although there were partly mediating effects of LVGLS and LVGCS, the decrease in RVGCS might be directly affected by the DM.

Effects of diabetes mellitus on left ventricular function and deformation in patients with restrictive cardiomyopathies: a 3.0T CMR feature tracking study.

BACKGROUND: Diabetes mellitus (DM) is the most common metabolic disease worldwide and a major risk factor for adverse cardiovascular events, while the additive effects of DM on left ventricular (LV) deformation in the restrictive cardiomyopathy (RCM) cohort remain unclear. Accordingly, we aimed to investigate the additive effects of DM on LV deformation in patients with RCM. MATERIALS AND METHODS: One hundred thirty-six RCM patients without DM [RCM(DM-)], 46 with DM [RCM (DM+)], and 66 age- and sex-matched control subjects who underwent cardiac magnetic resonance (CMR) scanning were included. LV function, late gadolinium enhancement (LGE) type, and LV global peak strains (including radial, circumferential, and longitudinal directions) were measured. The determinant of reduced LV global myocardial strain for all RCM patients was assessed using multivariable linear regression analyses. The receiver operating characteristic curve (ROC) was performed to illustrate the relationship between DM and decreased LV deformation. RESULTS: Compared with the control group, RCM (DM-) and RCM(DM+) patients presented increased LV end-diastolic index and end-systolic volume index and decreased LV ejection fraction. LV GPS in all three directions and longitudinal PDSR progressively declined from the control group to the RCM(DM-) group to the RCM(DM+) group (all p < 0.05). DM was an independent determinant of impaired LV GPS in the radial, circumferential, and longitudinal directions and longitudinal PDSR (ß = - 0.217, 0.176, 0.253, and - 0.263, all p < 0.05) in RCM patients. The multiparameter combination, including DM, showed an AUC of 0.81(95% CI 0.75-0.87) to predict decreased LV GLPS and an AUC of 0.69 (95% CI 0.62-0.76) to predict decreased LV longitudinal PDSR. CONCLUSIONS: DM may have an additive deleterious effect on LV dysfunction in patients with RCM, especially diastolic dysfunction in RCM patients, indicating the importance of early identification and initiation of treatment of DM in patients with RCM.

Association of insulin use with LV remodeling and clinical outcomes in diabetic patients with heart failure and reduced ejection fraction: assessed by cardiac MRI.

BACKGROUND: Insulin is commonly used in type 2 diabetes mellitus (T2DM) to achieve glycemic control. However, recent evidence showed that insulin use is associated with poor outcomes in the context of heart failure (HF). Since heart failure with reduced ejection fraction (HFrEF) accounts for approximately 50% of cases in the general HF population, we aimed to evaluate the effect of insulin treatment on left ventricular (LV) remodeling and contractility abnormalities in a HFrEF cohort and assess whether insulin was a predictor of adverse outcomes in this entity. METHODS: A total of 377 HFrEF patients who underwent cardiac MRI were included and divided according to diabetes status and the need for insulin treatment. LV structural and functional indices, as well as systolic strains, were measured. The determinants of impaired myocardial strains were assessed using linear regression analysis. The associated endpoints were determined using a multivariable Cox proportional hazards model. RESULTS: T2DM patients on insulin displayed a higher indexed LV end-diastolic volume and LV mass than those with T2DM not on insulin or those without T2DM, despite similar LV ejection fractions, accompanied by a higher three-dimensional spherical index (P < 0.01). Worse longitudinal and circumferential peak systolic strain was shown to occur in T2DM patients on insulin (P < 0.01). Insulin treatment was independently associated with impaired magnitudes of systolic strain. The median follow-up duration was 32.4 months (IQR, 15.6-43.2 months). Insulin treatment remained consistently associated with poor outcomes after adjustment for established confounders, with an adjusted hazard ratio of 3.11; (95% CI, 1.45-6.87; P = 0.009) in the overall cohort and 2.16 (95% CI, 1.08-4.59; P = 0.030) in the diabetes cohort. CONCLUSIONS: Insulin may further lead to adverse LV remodeling and contractile dysfunction in the context of HFrEF with T2DM. Considerable care should be taken when treating HFrEF patients with insulin.

Effect of Obesity on Left Ventricular Remodeling and Clinical Outcome in Chinese Patients With Hypertrophic Cardiomyopathy: Assessed by Cardiac MRI.

BACKGROUND: Obesity is highly prevalent in patients with hypertrophic cardiomyopathy (HCM) and believed to influence its phenotype. PURPOSE: To explore the effects of obesity on left ventricular (LV) remodeling and long-term clinical course in Chinese patients with HCM. STUDY TYPE: Longitudinal. POPULATION: A total of 247 patients with HCM classified according to body mass index (BMI) (normal weight: BMI = 18.0-22.9 kg/m2 [N = 90]; overweight: BMI = 23.0-24.9 kg/m2 [N = 58]; and obese: BMI ≥ 25 kg/m2 [N = 99]). FIELD STRENGTH/SEQUENCE: 3.0 T/Balanced steady-state free precession sequence and phase-sensitive inversion recovery late gadolinium enhancement (LGE) sequence. ASSESSMENT: LV function and geometry were measured. LV peak strain analysis was performed. The presence and percentage of LGE in the LV were recorded. The endpoints including heart failure, sudden cardiac death, and overall composite outcome were assessed during a median follow-up of 4.1 years (interquartile range, 3.0-6.2 years). STATISTICAL TESTS: One-way analysis of variance, Kruskal-Wallis test, or chi-square test; Pearson correlation coefficient (r); multivariable linear regression analysis; Kaplan-Meier survival analysis; and Cox proportional hazards model analysis were conducted. A two-tailed P-value < 0.05 was considered statistically significant. RESULTS: Obese patients exhibited a significant progressive increase in LV mass compared with normal-weight patients. The magnitude of all LV strain indices gradually and significantly decreased as BMI increased, whereas LV ejection fraction was not significantly different among BMI groups (P = 0.364). Multivariable linear regression analysis showed that obesity had a significant association with impaired strain indices as well as with indexed LV mass. Multivariable Cox model analysis retained obesity as an independent marker for future endpoints, and conveyed a > 3-fold increase in risk compared with patients with normal weight (hazard ratio, 3.04; 95% confidence interval, 1.07-6.57). DATA CONCLUSION: Obesity is an important environmental modifier that is associated with adverse LV remodeling and is independently associated with future clinical outcomes in Chinese patients with HCM. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

High-Speed T2 -Corrected Multiecho Magnetic Resonance Spectroscopy for Quantitatively Detecting Skeletal Muscle Fatty Infiltration and Predicting the Loss of Ambulation in Patients With Duchenne Muscular Dystrophy.

BACKGROUND: High-speed T2 -corrected multiecho MRS (HISTO-MRS) is emerging as a quantitative modality for detecting muscle fat infiltration (MFF). However, the predictive value of HISTO-MRS for the loss of ambulation (LoA) in Duchenne muscular dystrophy (DMD) is unknown. PURPOSE: To determine the feasibility of HISTO-MRS for assessing MFF in DMD and further identify the predictive value of HISTO-MRS for the LoA. STUDY TYPE: Prospective. SUBJECTS: A total of 134 DMD boys (9.20 ± 2.43 years old) and 21 healthy boys (9.25 ± 2.10 years old). FIELD STRENGTH/SEQUENCE: A 3 T, fast spin echo T1 -weighted imaging (T1 WI), two-point-Dixon gradient echo sequence (2-pt-Dixon) and HISTO-MRS. ASSESSMENT: Subjective T1 WI fat grades by three radiologists, ROI analysis for MFF on 2 pt-Dixon (Dixon MFF) and MFF on HISTO-MRS (HISTO MFF) by two radiologists. Clinical motor function: North Star Ambulatory Assessment, 10-m run/walk time, Gowers maneuver, and time to four-stairs climb and descend. STATISTICAL TESTS: Spearman rank correlation was used to assess the relation of fat filtration assessments and motor ability. Bland-Altman plots was performed to determine the agreement of HISTO MFF and Dixon MFF. Receiver operating characteristic (ROC) curves were analyzed to determine the discriminating ability of above MRI modalities for ambulatory and nonambulatory DMD. Logistic regression was used to identify the predictor of LoA. Variables with P < 0.05 in univariate logistic regression analysis were entered into the multivariate logistic regression model. RESULTS: HISTO MFF was significantly correlated with Dixon MFF. Bland-Altman plots show good agreement of HISTO MFF and Dixon MFF. ROC curves indicated that HISTO MFF show similar discrimination of LoA for DMD with Dixon MFF but better value than T1WI fat grades. Logistic regression showed that HISTO MFF was an independent predictor for LoA. DATA CONCLUSION: HISTO-MRS is a potential quantitative method for assessing fat infiltration and shows predictive value for LoA in DMD patients. TECHNICAL EFFICACY: Stage 5.

Incremental prognostic value of myocardial strain over ventricular volume in patients with repaired tetralogy of Fallot.

OBJECTIVES: The relative incremental predictive value of myocardial deformation over ventricular volume for future adverse events in patients with repaired tetralogy of Fallot (rTOF) remains unknown. We aimed to determine the incremental prognostic value of myocardial deformation over ventricular volume to predict adverse events in patients with rToF. METHODS: We retrospectively included patients with rTOF who completed cardiac magnetic resonance (CMR) and follow-up in our hospital from January 2014 to October 2020, and stratified according to the presence or absence of adverse events during follow-up. The strain parameters of the right ventricular (RV) and left ventricular (LV) were obtained from CMR-derived feature tracking. Multivariable Cox proportional hazard models and net reclassification improvement analysis were used to analyze the prognostic information of biventricular strain and volume parameters in rTOF patients. RESULTS: Among 98 patients with rTOF, 54 (55.1%) experienced primary and/or secondary events during a median follow-up period of 27.0 months. Univariable analysis indicated that RV volume and strain were significantly associated with both primary events and all adverse events (all p < .01). Multivariable Cox regression and net reclassification improvement analyses achieved incremental global χ2 (all p < .001), C index (all p < .001), and overall correct reclassification by sequentially adding CMR-derived RV volume, RV strain and LV strain parameters to preexisting clinical factors in adverse events model analyses. CONCLUSIONS: RV and LV myocardial deformation provided incremental prognostic information and significant improvement for risk stratification over RV size and clinical variables and therefore can be combined to further enhance prognostication. KEY POINTS: • RV volume and strain were significantly associated with both primary events and all adverse events, whereas LV volume and strain were associated with primary events. • Ventricular myocardial deformation is a strong predictor of adverse outcomes of patients with repaired tetralogy of Fallot, providing increased prognostic information and significantly improved risk stratification over ventricular size.

Novel terpestacin derivatives with l-amino acid residue as anticancer agents against U87MG-derived glioblastoma stem cells.

Based on the natural product terpestacin, seventeen derivatives (1-17) with various l-amino acid side chains were designed and synthesized. Their anticancer activities against U87MG-derived glioblastoma stem cells (GSCs) were evaluated, and compounds 5, 11, 13 and 15 showed strong abilities to inhibit the proliferation (IC50 = 2.8-6.9 µM) and tumorsphere formation of GSCs. Besides, compounds 13 and 15 could effectively induce apoptosis and significantly inhibit the invasion of GSCs (95 and 97 % inhibition, respectively, at 2.5 µM). The levels of CD133 marker in GSCs also decreased in dose-dependent manners after the treatment of these active compounds. Compared to terpestacin and the positive control A1938, our derivatives showed stronger activities and compounds 13 and 15 are promising candidates for further development as anticancer agents by targeting GSCs.