Prognostic value of left ventricular trabeculae fractal analysis in patients with dilated cardiomyopathy.

BACKGROUND: The prognostic value of left ventricular (LV) myocardial trabecular complexity on cardiovascular magnetic resonance (CMR) in dilated cardiomyopathy (DCM) remains unknown. This study aimed to evaluate the prognostic value of LV myocardial trabecular complexity using fractal analysis in patients with DCM. METHODS: Consecutive patients with DCM who underwent CMR between March 2017 and November 2021 at two hospitals were prospectively enrolled. The primary endpoints were defined as the combination of all-cause death and heart failure hospitalization. The events of cardiac death alone were defined as the secondary endpoints.LV trabeculae complexity was quantified by measuring the fractal dimension (FD) of the endocardial border based on fractal geometry on CMR. Cox proportional hazards regression and Kaplan-Meier survival analysis were used to examine the association between variables and outcomes. The incremental prognostic value of FD was assessed in nested models. RESULTS: A total of 403 patients with DCM (49.31 ± 14.68 years, 69% male) were recruited. After a median follow-up of 43 months (interquartile range, 28-55 months), 87 and 24 patients reached the primary and secondary endpoints, respectively. Age, heart rate, New York Heart Association functional class >II, N-terminal pro-B-type natriuretic peptide, LV ejection fraction, LV end-diastolic volume index, LV end-systolic volume index, LV mass index, presence of late gadolinium enhancement, global FD, LV mean apical FD, and LV maximal apical FD were univariably associated with the outcomes (all P < 0.05). After multivariate adjustment, LV maximal apical FD remained a significant independent predictor of outcome [hazard ratio = 1.179 (1.116, 1.246), P < 0.001]. The addition of LV maximal apical FD in the nested models added incremental prognostic value to other common clinical and imaging risk factors (all <0.001; C-statistic: 0.84-0.88, P < 0.001). CONCLUSION: LV maximal apical FD was an independent predictor of the adverse clinical outcomes in patients with DCM and provided incremental prognostic value over conventional clinical and imaging risk factors.

Feasibility of Cardiac Computed Tomography for the Evaluation of Ventricular Function in Postoperative Children With Congenital Heart Disease: Comparison With Cardiac Magnetic Resonance Imaging.

OBJECTIVE: We explored the feasibility of cardiac computed tomography (CCT) to evaluate postoperative ventricular function in children with congenital heart disease (CHD) and evaluated the accuracy and reproducibility of CCT using cardiac magnetic resonance (CMR) as a reference. METHODS: Thirty-two postoperative children with CHD (20 boys and 12 girls) who underwent CMR and CCT were enrolled. Left and right ventricular ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, and cardiac index were measured using cardiac function analysis software. Cardiac function data were compared between CMR and CCT. The agreement between the 2 modalities was assessed using a Bland-Altman analysis. Intraclass correlation coefficients were used to assess intraobserver and interobserver reproducibility in CCT functional measurements. RESULTS: All functional parameters showed no significant difference (P > 0.05) and were well-correlated (r > 0.5, P < 0.05) between CMR and CCT. The mean values of all ventricular function parameters in CCT were higher compared with CMR. As indicated by 95% limits of agreement, left ventricular function parameters showed a better level of agreement compared with right ventricular function parameters between the 2 modalities. Intraobserver and interobserver reproducibility were excellent in CCT measurements for all functional parameters (intraclass correlation coefficient > 0.9). CONCLUSIONS: Compared with the criterion standard of CMR, CCT is feasible for assessing postoperative ventricular function with sufficient diagnostic accuracy and reproducibility in children with CHD. In addition to its important role regarding anatomical characterization, CCT is a suitable alternative and convenient follow-up tool that can be used to functional evaluation in children who are intolerant with CMR or have contraindications to CMR.

Right and left ventricular function and flow quantification in pediatric patients with repaired tetralogy of Fallot using four-dimensional flow magnetic resonance imaging.

BACKGROUND: To assess the accuracy and reproducibility of right ventricular (RV) and left ventricular (LV) function and flow measurements in children with repaired tetralogy of Fallot (rTOF) using four-dimensional (4D) flow, compared with conventional two-dimensional (2D) magnetic resonance imaging (MRI) sequences. METHODS: Thirty pediatric patients with rTOF were retrospectively enrolled to undergo 2D balanced steady-state free precession cine (2D b-SSFP cine), 2D phase contrast (PC), and 4D flow cardiac MRI. LV and RV volumes and flow in the ascending aorta (AAO) and main pulmonary artery (MPA) were quantified. Pearson's or Spearman's correlation tests, paired t-tests, the Wilcoxon signed-rank test, Bland-Altman analysis, and intraclass correlation coefficients (ICC) were performed. RESULTS: The 4D flow scan time was shorter compared with 2D sequences (P < 0.001). The biventricular volumes between 4D flow and 2D b-SSFP cine had no significant differences (P > 0.05), and showed strong correlations (r > 0.90, P < 0.001) and good consistency. The flow measurements of the AAO and MPA between 4D flow and 2D PC showed moderate to good correlations (r > 0.60, P < 0.001). There was good internal consistency in cardiac output. There was good intraobserver and interobserver biventricular function agreement (ICC > 0.85). CONCLUSIONS: RV and LV function and flow quantification in pediatric patients with rTOF using 4D flow MRI can be measured accurately and reproducibly compared to those with conventional 2D sequences.

Right and left ventricular interactions, strain, and remodeling in repaired pulmonary stenosis patients with preserved right ventricular ejection fraction: A cardiac magnetic resonance study.

BACKGROUND: Right ventricular dilation and dysfunction is a common long-term complication in patients with repaired pulmonary stenosis (rPS). Additionally, abnormal right and left ventricular interactions have been reported in right-sided heart defect after intervention, including in pulmonary stenosis. PURPOSE: To analyze ventricular strain, remodeling, and left and right ventricular interactions in rPS patients with preserved right ventricular ejection fraction (RVEF) compared with healthy children using cardiac magnetic resonance. STUDY TYPE: A cross-sectional study. POPULATION: In all, 34 rPS patients and 10 healthy children volunteers (controls). FIELD STRENGTH/SEQUENCE: 3.0T/2D balanced steady-state free precession (2D b-SSFP) cine, late gadolinium enhancement (LGE), and 2D phase contrast (2D-PC). ASSESSMENT: Pulmonary regurgitation (PR) fractions of the main pulmonary artery, biventricular volumes, masses, function, and cardiac strain. STATISTICAL TESTS: Mann-Whitney U-test, t-test, Pearson correlation coefficients, Spearman's correlation coefficients, and intraclass correlation coefficients analysis were performed. RESULTS: For group analysis, the right ventricular (RV) global circumferential strain and radial strain were significantly increased in patients when compared with controls (-13.57 ± 2.69 vs. -5.91 ± 3.16, P < 0.001; 25.31 ± 8.12 vs. 9.87 ± 5.32, P < 0.001, respectively). The fraction of PR displayed moderate correlation with right ventricular end-diastolic volume index (RVEDVi) (r = 0.452, P = 0.022). RVEDVi and mass index were larger in patients vs. control (104.92 ± 27.46 vs. 85.15 ± 11.98, P = 0.016; 18.28 ± 4.95g/m2 vs. 11.67 ± 2.14 g/m2 , P < 0.001, respectively). Patients presented with preserved left ventricular ejection function, but was lower than healthy controls (60.89% ± 4.89% vs. 65.95% ± 4.56%, P = 0.006). Regional circumferential strain of segment 3 of left ventricle (LV) were significantly decreased in patients (-7.79 ± 6.52 vs. -13.56 ± 3.22, P = 0.003). DATA CONCLUSION: Compensated increased RV strain, myocardial remodeling of RV, and adverse right and left ventricular interactions occur in rPS patients with preserved RVEF. The decreased interventricular septum strain may lead to impaired LV function due to RV dilation as a result of PR. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;52:129-138.

Vortex formation time as an index of left ventricular filling efficiency: comparison between children volunteers and patients with tetralogy of Fallot.

Background: Vortex formation time (VFT) had been considered a useful marker for assessing diastolic performance. the VFT assessment of diastolic function using four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has not been used in repair of tetralogy of Fallot (rTOF) patient. The aims of this study were as follows: (I) establish reference ranges for VFT measurements in healthy children and adolescents using 4D flow CMR imaging; and (II) analyze VFT parameters to assess diastole dysfunction in rTOF patients group. Methods: We acquired the CMR data was of 62 healthy participants (aged 6-18 years; male: 40, female: 22) and 20 patients with rTOF (aged 10-13 years; male: 15, female: 5) using 4D flow and cine sequence in routine chamber view. The VFT was calculated based on comparison of different algorithms from cine measurements (VFTvolume) and 4D flow measurements (VFTblood). Then, VFT measurements were compared to subject peak filling rate (PFR), age, and cardiac mass using simple linear regression and multiple regression analyses. Data were also categorized according to age for VFT and cardiac functional assessment comparisons between 3 age groups (Group 1: 6-9 years; Group 2: 10-13 years; Group 3: 14-18 years). The correlation of VFT and cardiac function parameters were analyzed in the rTOF group. Results: Normal mean value of VFTvolume and VFTblood were 4.25±0.92 and 3.77±1.11 in healthy children participants. The VFTvolume was correlated with VFTblood (r=0.61, P<0.001). There was a moderately significant correlation between VFTvolume and PFR (r=0.46, P<0.001) and between VFTblood and PFR (r=0.47, P<0.001), age (r=0.41, P=0.002) and left ventricular (LV) mass (r=0.48, P<0.001). Multiple regression analyses demonstrated that VFTvolume was independently associated with PFR (T=2.239; P<0.05) and VFTblood (T=4.361; P<0.001). There was a significant difference in VFTvolume between healthy controls and rTOF patients (5.44±1.93 vs. 4.27±0.88, P=0.018). Conclusions: The VFT measurements showed that the LV that had appropriate space to form the optimal vortex ring in normal children and adolescents aged 6-18 years old. The VFTvolume could potentially be helpful in improving our understanding of LV diastolic dysfunction in rTOF patients.

Cardiac Computed Tomography-Derived Left Atrial Strain and Volume in Pediatric Patients With Congenital Heart Disease: A Comparative Analysis With Transthoracic Echocardiography.

Purpose: This study aimed at exploring the feasibility and reproducibility of CCT for the measurement of Left Atrial (LA) strain and volume compared with transthoracic echocardiography (TTE) in pediatric patients with congenital heart disease (CHD). Materials and Methods: The present study included 43 postoperative patients with CHD (7.39 ± 3.64 years, 56% male) who underwent clinically indicated CCT, and all patients underwent additional TTE on the same day. LA strain and volume parameters were measured by dedicated software. The correlation and agreement of LA strain and volume parameters were assessed using Pearson's correlation coefficient and Bland-Altman analysis. Intra-class correlation coefficients (ICC) were used to assess CCT intra-observer and inter-observer reproducibility. Results: All strain parameters of CCT were lower compared to TTE (reservoir strain: 28.37 ± 6.92 vs. 32.15 ± 8.15, respectively; conduit strain: 21.33 ± 6.46 vs. 24.23 ± 7.75, respectively; booster strain: 7.04 ± 2.74 vs. 7.92 ± 3.56). While the volume parameters of CCT were higher compared to TTE (LAV: 29.60 ± 19.01 vs. 25.66 ± 17.60, respectively; LAVi: 30.36 ± 22.31 vs. 28.63 ± 19.25, respectively). Both LA strain and volume measurements showed good correlation and agreement between the two modalities (r = 0.63-0.87, p < 0.001). CT-derived LA strain and volume measurements showed good intra- and inter-observer reproducibility using prototype software (ICC = 0.78-0.96). Conclusions: CCT was feasible for measuring LA strain and volume with good correlation and high reproducibility as compared with TTE. As a complementary modality, CCT can regard as an accepted method in the evaluation of LA function in pediatric patients with CHD.

Impairment of left atrial function in pediatric patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance imaging study.

We aimed to assess left atrial (LA) strain before LA dilatation in patients with repaired tetralogy of Fallot (rTOF) compared with healthy controls. We also determined the effects of right atrial (RA) dilatation on LA performance using cardiovascular magnetic resonance-feature tracking (CMR-FT). Forty-nine pediatric patients with rTOF and 36 age- and sex-matched healthy controls were prospectively recruited between June 2017 and August 2019. Balanced steady-state free precession (2D b-SSFP) cine, 2D late gadolinium enhancement (LGE) and phase-contrast (PC) sequences were acquired on 1.5 and 3.0 Tesla scanners. Both ventricular and atrial volumes and ejection fraction were measured. Left ventricular (LV) strain and diastolic strain rates were evaluated between the rTOF patient and control groups. LA reservoir (Ɛs), conduit (Ɛe), and booster strain (Ɛa) were determined at LV end-systole, LV diastasis, and pre-LA systole, respectively. The first derivatives of the respective strains yielded corresponding peak strain rates. Statistical analysis was performed using the t-test and Mann-Whitney test for parametric and non-parametric variables, respectively. Correlations were assessed using Pearson's correlation coefficient for normally distributed variables and Spearman's correlation coefficient for non-parametric data. Intra-observer and inter-observer variabilities of LA strain and strain rate measurements were determined from ten randomly selected rTOF patients and ten control subjects. LA strain was significantly lower in patients with rTOF compared with controls (Ɛs, P < 0.001; Ɛe, P = 0.002; Ɛa, P < 0.001). The correlations between LA strain and RA stroke volume indices (SVi) and RA ejection fraction (EF) were moderate (Ɛs and SVi, r = 0.538, P < 0.001; Ɛs and RA EF, r = 0.493, P < 0.001; Ɛe and SVi, r = 0.532, P < 0.001; Ɛe and RA EF, r = 0.466, P < 0.001). LA strain and strain rates had good reproducibility in intra-observer and inter-observer analyses. LA strain and strain rates decreased in pediatric patients with rTOF compared with controls before LA enlargement. A dysfunction in LA performance might precede LV dysfunction in patients with rTOF, even in the early stages after repair.

Feasibility of using a non-sedation protocol for evaluation of neonatal congenital heart disease by using a 16-cm wide-detector computed tomography with a low radiation dose: preliminary experience from a single pediatric medical center.

The aim of this study is to explore the feasibility of using a non-sedation protocol for the evaluation of neonatal congenital heart disease by using 16-cm wide-detector CT with a low radiation dose. Thirty-four neonates (group 1) were enrolled to undergo cardiac CT without sedation between August 2018 and March 2019. The control group (group 2) comprising 20 inpatient neonates was sedated. Cardiac CT was performed using 16-cm area detector 320-row CT with free breathing and prospective ECG-triggering scan mode. The examination completion time, radiation dose, and image quality were compared between the groups. The results of cardiac CT for patients in group 1 who underwent surgery were compared with surgical findings. Intergroup differences in body weight, age, examination completion time, radiation dose, and image quality evaluation were not significant. There was no significant difference in oxygen saturation before and after the examination in group 1. In all, 98 separate cardiovascular abnormalities in 27 group 1 patients were confirmed using surgical reports. The overall sensitivity, specificity, positive predictive value, and negative predictive value of cardiac CT were 94.90%, 100.0%, 100.0%, and 98.53%. The non-sedation protocol can be applied in neonates with congenital heart disease by using 16-cm wide-detector CT with a low radiation dose. Based on the image quality obtained, non-sedative examination did not extend the examination completion time and helped avoid the possible side effects of sedative drugs.

Postoperative evaluation of left ventricular global strain using cardiac computed tomography in pediatric patients with congenital heart disease: A comparison with echocardiography.

PURPOSE: We explored the feasibility and reproducibility of cardiac computed tomography (CCT)-derived left ventricular (LV) global strain in postoperative childrenwith congenital heart disease (CHD) and compared its correlation and agreement with transthoracic echocardiography (TTE). METHODS: Fifty-one patients (28 males, 23 females) were included who underwent clinically indicated retrospective electrocardiography-triggered CCT. and all patients underwent additional TTE on the same day. LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were measured. Correlations of global strains between CCT and TTE were assessed using Pearson's correlation coefficient. Intra-class correlation coefficients (ICC) were used to assess CCT intra-observer and inter-observer reproducibility. RESULTS: GLS and GCS were not significantly different between CCT and TTE (GLS: -23.54 ± 3.24 vs. -23.85 ± 3.72, respectively, p = 0.415; GCS: -28.21 ± 3.55 vs. -28.79 ± 3.69, respectively, p = 0.155). GRS was significantly different between CCT and TTE (60.79 ± 15.11 vs. 41.73 ± 4.27, respectively, p < 0.001). There was good correlation between CCT- and TTE-derived GLS (r = 0.70, p < 0.001) and GCS (r = 0.68, p < 0.001), but GRS showed no correlation between CCT and TTE (r = 0.09, p = 0.54). CCT-derived global strain showed good intra- and inter-observer reproducibility (ICC = 0.86-0.92), except the inter-observer reproducibility for GRS (ICC = 0.77). CONCLUSIONS: CCT was feasible for postoperative evaluation of LV global strain in pediatric patients with CHD with sufficient reproducibility. CCT-derived global strain can provide additional information in selected CHD patients with poor acoustic windows and who are intolerant to or have contraindications for cardiac magnetic resonance.

Biodiesel derived glycerol hydrogenolysis to 1,2-propanediol on Cu/MgO catalysts.

Hydrogenolysis of biodiesel derived glycerol to 1,2-propanediol (1,2-PDO) has attracted much attention in recent years. In this work, glycerol hydrogenolysis to 1,2-PDO was performed over CuO/MgO catalysts prepared by impregnation and coprecipitation at 180 degrees C and 3.0 MPa H(2). It was found that the Cu(15)/MgO catalyst prepared by coprecipitation had the best activity. The conversion of glycerol and the selectivity of 1,2-PDO over Cu(15)/MgO reached 72.0% and 97.6%, respectively. And the conversion of glycerol was further increased to 82.0% when small amount of NaOH was added in the reaction mixture. Those highly active catalysts were characterized by X-ray diffraction, transmission electron microscopy, N(2)-adsorption and temperature-programmed reduction with H(2). Characterization results revealed that the activity of the prepared catalysts depended strongly on the particle sizes of both Cu and MgO. Catalysts that have smaller sized Cu and MgO particles are more active for glycerol hydrogenolysis.