Transthoracic echocardiographic Doppler metrics in evaluating bioprosthetic tricuspid valve dysfunction.

PURPOSE: There is currently limited information on the utility of transthoracic echocardiography (TTE)-derived Doppler parameters for assessing bioprosthetic tricuspid valve (BTV) dysfunction. Our study aimed to establish the precision and appropriate reference ranges for routinely collected transthoracic Doppler parameters in the assessment of BTV dysfunction. METHODS: We retrospectively evaluated 100 BTV patients who underwent TTE. Based on redo surgical confirmation or more than 2 repeat TTE or transesophageal echocardiography (TEE) examinations, patients were allocated to normal (n = 61), regurgitant (n = 24), or stenotic (n = 15) BTV group. Univariate and multivariate binary logistic regression were performed to identify TTE Doppler parameters that detected BTV dysfunction. RESULTS: The VTI ratio (VTITV/VTILVOT) was the most accurate Doppler parameter for detecting BTV dysfunction, with a ratio of >2.8 showing 84.6% sensitivity and 90.2% specificity. VTI ratio > 3.2, mean gradient (MGTV) > 6.2 mmHg and pressure half-time > 218 ms detected significant BTV stenosis, with sensitivities of 100%, 93.3% and 93.3% and specificities of 82.4%, 75.3% and 87.1%, respectively. After multivariate analysis, the VTI ratio > 2.8 (OR = 9.00, 95% CI = 2.13-41.61, p = .003) and MGTV > 5.1 mmHg (OR = 6.50, 95% CI = 1.69-27.78, p = .008) were the independent associations of BTV dysfunction. With these cutoff values, 75.0%-92.2% of normal and 62.5%-96.0% of dysfunctional BTV were identified. CONCLUSIONS: Doppler parameters from TTE can accurately identify BTV dysfunction, particularly with VTI ratio > 2.8 and MGTV > 5.1 mmHg, to assess the need for additional testing with TEE.

Feasibility and prognostic value of tissue motion annular displacement in patients with heart transplantation.

BACKGROUND: Tissue motion of mitral annular displacement (TMAD) assessment has proved to be an effective method for several cardiovascular diseases including hypertrophic cardiomyopathy, heart failure, non-ST-elevation myocardial infarction, etc. However, there are no studies exploring the feasibility of TMAD in heart transplantation (HT) recipients, and the predictive value of this parameter for adverse outcomes in these patients remains unknown. Consequently, this study aimed to evaluate the feasibility of TMAD in the evaluation of left ventricular (LV) systolic function in clinically well adult HT patients, and further investigate the prognostic value of TMAD. METHODS: Echocardiography was performed in 155 adult HT patients and 49 healthy subjects. All the subjects were examined by conventional transthoracic two-dimensional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE) with evaluation of the LV end-diastolic diameter, LV end-diastolic volume index, LV end-systolic volume index, interventricular septal thickness, left atrial diameter, mitral annular plane systolic excursion (MAPSE), LV ejection fraction (LVEF), TMAD and LV global longitudinal strain (LVGLS). The end point was defined as all-causes mortality or posttransplant related hospitalization during follow up. Cox proportional hazards regression was performed to evaluate the prognostic value of the parameters for predicting poor outcomes in HT patients. RESULTS: A significant positive correlation was found between the measurements of TMAD and LVGLS (r = .714, p < .001). TMAD obtained by 2D-STE had good reproducibility. The LVGLS and TMAD were significantly lower in HT group than in control group (both p < .001). In HT patients, compared with event free group, adverse outcome group displayed reduced TMAD and LVGLS, and elevated age (p < .001, < .001, = .017, respectively). Patients with higher TMAD (> 9.1 mm) had comparatively better survival when stratified by cutoff value (log-rank p < .001). LVGLS and TMAD were independently associated with adverse outcomes in multivariable analysis (both p < .001). CONCLUSION: Assessment of TMAD is effective for evaluating LV longitudinal systolic function and predicting adverse outcomes in clinically well adult HT patients.

Prognostic Implications of Left Atrial Strain in Bicuspid Aortic Valve With Chronic Aortic Regurgitation.

BACKGROUND: Left atrial reservoir strain (LARS) is a novel imaging biomarker of left ventricular diastolic dysfunction. This study aimed to examine the prognostic implications of LARS in patients with bicuspid aortic valve and significant (moderate-severe to severe) aortic regurgitation. METHODS AND RESULTS: A total of 220 patients with bicuspid aortic valve and significant aortic regurgitation were prospectively enrolled in our study. LARS and left ventricular global longitudinal strain were derived from speckle-tracking echocardiography. The end point was a composite of all-cause mortality, heart failure hospitalization, and aortic valve repair or replacement. The threshold value of LARS <24% was used to identify impaired left atrial mechanics based on prior results. During a median follow-up of 364 (interquartile range, 294-752) days, 46 patients (20.9%) reached the composite end points. On multivariable Cox analysis, impaired LARS (adjusted hazard ratio, 2.08 [95% CI, 1.05-4.11]; P=0.036) was a statistically significant predictor of composite end points after adjustment for other statistically significant predictors. Finally, adding impaired LARS to other statistically significant predictors (New York Heart Association functional class and left ventricular global longitudinal strain) significantly improved the global χ2 (from 32.19 to 36.56; P=0.037) and reclassification (continuous net reclassification index=0.55; P<0.001) of the prediction model. CONCLUSIONS: In patients with bicuspid aortic valve and significant aortic regurgitation, the impairment of LARS is a strong independent prognostic predictor and confers incremental prognostic utility over clinical and other echocardiographic parameters. These findings suggest that LARS could be considered in risk stratification for such populations.

Effects of the combination of Epimedii Folium and Ligustri Lucidi Fructus on apoptosis and autophagy in SOP rats and osteoblasts via PI3K/AKT/mTOR pathway.

BACKGROUND: This study aimed to investigate the effects of the combination of Epimedii Folium (EF) and Ligustri Lucidi Fructus (LLF) on regulating apoptosis and autophagy in senile osteoporosis (SOP) rats. METHODS: Firstly, we identified the components in the decoction and drug-containing serum of EL (EF&LLF) by Ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS). Secondly, SOP rats were treated with EF, LLF, EL and caltrate to evaluate the advantages of EL. Finally, H2O2-, chloroquine-, and MHY1485-induced osteoblasts were treated with different doses of EL to reveal the molecular mechanism of EL. We detected bone microstructure, oxidative stress levels, ALP activity and the expressions of Bax, Bcl-2, caspase3, P53, Beclin-1, p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and LC3 in vivo and in vitro. RESULTS: 36 compounds in EL decoction and 23 in EL-containing serum were identified, including flavonoids, iridoid terpenoids, phenylethanoid glycosides, polyols and triterpenoids. EL could inhibit apoptosis activity and increase ALP activity. In SOP rats and chloroquine-inhibited osteoblasts, EL could improve bone tissue microstructure and osteoblasts functions by upregulating Bcl-2, Beclin1, and LC3-II/LC3-I, while downregulating p53 in all treatment groups. In H2O2-induced osteoblasts, EL could upregulate the protein and mRNA expressions of Bcl-2 while downregulate LC3-II/LC3-I, p53 and Beclin1. Besides, EL was able to down-regulate PI3K/AKT/mTOR pathway which activated in SOP rats and MHY1485-induced osteoblasts. CONCLUSIONS: These findings demonstrate that EL with bone protective effects on SOP rats by regulating autophagy and apoptosis via PI3K/Akt/mTOR signaling pathway, which might be an alternative medicine for the treatment of SOP.

Echocardiographic assessment of pediatric heart transplantation: A single-center experience in China.

BACKGROUND: Pediatric heart transplant (HT) has become the standard of care for end-stage heart failure in children worldwide. Serial echocardiographic evaluations of graft anatomy and function during follow-up are crucial for post-HT management. However, evolution of cardiac structure and function after pediatric HT has not been well described, especially during first year post-HT. This study aimed to characterize the evolution of cardiac structure and function after pediatric HT and investigate the correlation between biventricular function with adverse clinical outcomes. METHODS: A single-center retrospective study of echocardiographic data obtained among 99 pediatric HT patients was conducted. Comprehensive echocardiographic examination was performed in all patients at 1-, 3-, 6-, 9- and 12-months post-HT. We obtained structural, functional and hemodynamic parameters from both left- and right-side heart, such as left ventricular stroke volume (LVSV), left ventricular ejection fraction (LVEF), right ventricular fractional area change (RVFAC), etc. The cardiac evolution of pediatric HT patients during first post-HT year was described and compared between different time points. We also explored the correlation between cardiac function and major adverse transplant events (MATEs). RESULTS: 1) Evolution of left heart parameters: left atrial length, mitral E velocity, E/A ratio, LVSV and LVEF significantly increased while mitral A velocity significantly decreased over the first year after HT (P < .05). Compared with 1 month after HT, interventricular septum (IVS) and left ventricular posterior wall (LVPW) decreased at 3 months but increased afterwards. (2) Evolution of right heart parameters: right ventricular base diameter and mid-diameter; right ventricular length diameter, tricuspid E velocity, E/A ratio, tricuspid annular velocity e' at free wall, and RVFAC increased, while tricuspid A velocity decreased over the first year after HT (P < .05). (3) Univariate logistic regression model suggests that biventricular function parameters at 1-year post-HT (LVEF, RVFAC, tricuspid annular plane systolic excursion and tricuspid lateral annular systolic velocity) were associated with MATEs. CONCLUSION: Gradual improvement of LV and RV function was seen in pediatric HT patients within the first year. Biventricular function parameters associated with MATEs. The results of this study pave way for designing larger and longer follow-up of this population, potentially aiming at using multiparameter echocardiographic prediction of adverse events.

Early left ventricular systolic function is a more sensitive predictor of adverse events after heart transplant.

BACKGROUND: First-phase ejection fraction (EF1) is a novel measure of early changes in left ventricular systolic function. This study was to investigate the prognostic value of EF1 in heart transplant recipients. METHODS: Heart transplant recipients were prospectively recruited at the Union Hospital, Wuhan, China between January 2015 and December 2019. All patients underwent clinical examination, biochemistry measures [brain natriuretic peptide (BNP) and creatinine] and transthoracic echocardiography. The primary endpoint was a combined event of all-cause mortality and graft rejection. RESULTS: In 277 patients (aged 48.6 ± 12.5 years) followed for a median of 38.7 [26.8-45.0] months, there were 35 (12.6%) patients had adverse events including 20 deaths and 15 rejections. EF1 was negatively associated with BNP (ß = -0.220, p < 0.001) and was significantly lower in patients with events compared to those without. EF1 had the largest area under the curve in ROC analysis compared to other measures. An optimal cut-off value of 25.8% for EF1 had a sensitivity of 96.3% and a specificity of 97.1% for prediction of events. EF1 was the most powerful predictor of events with hazard ratio per 1% change in EF1: 0.628 (95%CI: 0.555-0.710, p < 0.001) after adjustment for left ventricular ejection fraction and global longitudinal strain. CONCLUSIONS: Early left ventricular systolic function as measured by EF1 is a powerful predictor of adverse outcomes after heart transplant. EF1 may be useful in risk stratification and management of heart transplant recipients.

Ultrasound-targeted microbubble destruction promotes PDGF-primed bone mesenchymal stem cell transplantation for myocardial protection in acute Myocardial Infarction in rats.

BACKGROUND: Ultrasound-targeted microbubble destruction (UTMD) has emerged as a promising strategy for the targeted delivery of bone marrow mesenchymal stem cells (MSCs) to the ischemic myocardium. However, the limited migration capacity and poor survival of MSCs remains a major therapeutic barrier. The present study was performed to investigate the synergistic effect of UTMD with platelet-derived growth factor BB (PDGF-BB) on the homing of MSCs for acute myocardial infarction (AMI). METHODS: MSCs from male donor rats were treated with PDGF-BB, and a novel microbubble formulation was prepared using a thin-film hydration method. In vivo, MSCs with or without PDGF-BB pretreatment were transplanted by UTMD after inducing AMI in experimental rats. The therapeutic efficacy of PDGF-BB-primed MSCs on myocardial apoptosis, angiogenesis, cardiac function and scar repair was estimated. The effects and molecular mechanisms of PDGF-BB on MSC migration and survival were explored in vitro. RESULTS: The results showed that the biological effects of UTMD increased the local levels of stromal-derived factor-1 (SDF-1), which promoted the migration of transplanted MSCs to the ischemic region. Compared with UTMD alone, UTMD combined with PDGF-BB pretreatment significantly increased the cardiac homing of MSCs, which subsequently reduced myocardial apoptosis, promoted neovascularization and tissue repair, and increased cardiac function 30 days after MI. The vitro results demonstrated that PDGF-BB enhanced MSC migration and protected these cells from H2O2-induced apoptosis. Mechanistically, PDGF-BB pretreatment promoted MSC migration and inhibited H2O2-induced MSC apoptosis via activation of the phosphatidylinositol 3-kinase/serine-threonine kinase (PI3K/Akt) pathway. Furthermore, crosstalk between PDGF-BB and stromal-derived factor-1/chemokine receptor 4 (SDF-1/CXCR4) is involved in the PI3K/AKT signaling pathway. CONCLUSION: The present study demonstrated that UTMD combined with PDGF-BB treatment could enhance the homing ability of MSCs, thus alleviating AMI in rats. Therefore, UTMD combined with PDGF-BB pretreatment may offer exciting therapeutic opportunities for strengthening MSC therapy in ischemic diseases.

Noninvasive left ventricular pressure-strain myocardial work in patients with well-functioning bicuspid aortic valves and aortic dilation: a preliminary study.

Background: Noninvasive left ventricular pressure-strain myocardial work (MW) is a novel method for evaluating left ventricular function that integrates myocardial deformation and afterload and has certain advantages over global longitudinal strain (GLS). The study aimed to analyze MW in patients with well-functioning bicuspid aortic valve (BAV) and explore the influences of aortic dilation and arterial stiffness on left ventricular function. Methods: A total of 104 patients with well-functioning BAVs and 50 controls were enrolled in our study. Global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE), GLS, and aortic stiffness index were measured. Based on the ascending aortic diameter, patients with BAV were divided into 3 subgroups (nondilated, mildly dilated, and moderately dilated). Results: GWI, GCW, GWW, and aortic stiffness index were significantly increased (P<0.001, P=0.023, P<0.001, and P<0.001, respectively), while GWE and GLS were significantly decreased among patients with BAV compared with controls (all P values <0.001). Patients with BAV and mildly and moderately dilated aortas had an increased GWW and aortic stiffness index but a decreased GWE compared with patients with BAV and nondilated aortas (all P values <0.05); meanwhile, GCW and GLS did not differ among the BAV subgroups (all P values >0.05). GWI was elevated in patients with BAV and moderately dilated aortas compared with patients with BAV and nondilated aortas (P<0.05). On multivariable analysis, the aortic stiffness index was an independent influencer of GWI, GCW, GWW, and GWE (P=0.025, P=0.049, P<0.001, and P=0.001, respectively). The aortic diameter was highly correlated with the aortic stiffness index (r=0.863; P<0.001). Conclusions: MW could assess early myocardial impairment in patients with well-functioning BAV. MW may help to differentiate the detrimental effect of aortic dilation on left ventricular function, whereas GLS may not.

Left atrial strain brings new insights for evaluating early diastolic dysfunction in patients with well-functioning bicuspid aortic valve.

BACKGROUND: Left atrial reservoir strain (LARS) is an early sensor of left ventricular (LV) diastolic dysfunction. Still, the clinical implications of LARS in patients with well-functioning bicuspid aortic valve (BAV) remain unknown. MATERIALS: The study recruited 103 patients with well-functioning BAV and 50 controls with tricuspid aortic valves. LARS, LV global longitudinal strain (LVGLS) and aortic elasticity indices (aortic strain, aortic distensibility and stiffness index) were acquired. This study aimed to analyze the changes of LARS and further explore the influential factors of LARS in patients with well-functioning BAV. RESULTS: Patients with BAV had lower LARS (34.17 ± 4.85 vs. 44.72 ± 6.06 %, P < .001) and LVGLS (20.53 ± 1.28 vs. 22.30 ± .62 %, P < .001), and abnormal aortic elasticity indices (aortic strain:7.14 ± 1.57 vs. 10.99 ± 1.03 %, aortic distensibility: 5.82 ± 1.50 vs. 8.98 ± 2.42 (10-6 cm2 dyne-1 ), and stiffness index: 6.30 ± 2.30 vs. 3.92 ± .98, all P < .05) compared with controls. LARS was associated with LVGLS (r = .799), interventricular septum index (r = -.232), lateral e' (r = .290), septal e' (r = .308), E/e' ratio (r = -.392), aortic strain (r = .829), aortic distensibility (r = .361), and stiffness index (r = -.724) (all P < .05). LVGLS, aortic strain and E/e' ratio were independent influencers of LARS in the multifactorial analysis model (all P < .05). CONCLUSION: In patients with well-functioning BAV, decreased LARS may provide evidence of subclinical LV diastolic function impairment. LARS may be helpful for clinical risk stratification in such a population.

Soil and vegetation characteristics during the formation of typical Ligularia virgaurea degraded grassland.

To understand the formation process of typical poisonous plant degraded grassland, we studied the cha-racteristics of vegetation and soil during the gradual expansion of Ligularia virgaurea into the native grassland of Qinghai-Tibet Plateau. The results showed that population density, plant height, coverage, and biomass of L. virgaurea increased during the formation of L. virgaurea degraded grassland. In comparison with native grassland, the degraded grassland had higher total aboveground biomass (113.9%), soil total nitrogen concentration (61.0%), NH4+-N (77.9%), organic carbon concentration (45.3%), available phosphorus concentration (78.8%) as well as soil microbial biomass carbon (42.1%) and nitrogen (47.4%), but lower NO3--N (40.1%) and species richness (28.5%) and aboveground biomass (45.7%) of other species beyond L. virgaurea. The extremely strong abilities of interspecific inhibition and morphological plasticity of L. virgaurea, as well as efficient nutrient accumulation and utilization were the keys to its successful expansion, which facilitated the formation of typical L. virgaurea degraded grassland.

Clinical Usefulness of Speckle-Tracking Echocardiography in Patients with Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is defined as HF with left ventricular ejection fraction (LVEF) not less than 50%. HFpEF accounts for more than 50% of all HF patients, and its prevalence is increasing year to year with the aging population, with its prognosis worsening. The clinical assessment of cardiac function and prognosis in patients with HFpEF remains challenging due to the normal range of LVEF and the nonspecific symptoms and signs. In recent years, new echocardiographic techniques have been continuously developed, particularly speckle-tracking echocardiography (STE), which provides a sensitive and accurate method for the comprehensive assessment of cardiac function and prognosis in patients with HFpEF. Therefore, this article reviewed the clinical utility of STE in patients with HFpEF.

Soil Bacterial Communities Across Seven Rhizoma Peanut Cultivars (Arachis glabrata Benth.) Respond to Seasonal Variation.

Soil microorganisms play key roles in soil nutrient transformations and have a notable effect on plant growth and health. Different plant genotypes can shape soil microbial patterns via the secretion of root exudates and volatiles, but it is uncertain how a difference in soil microorganisms induced by crop cultivars will respond to short-term seasonal variations. A field experiment was conducted to assess the changes in soil bacterial communities of seven rhizoma peanut (Arachis glabrata Benth, RP) cultivars across two growing seasons, April (Spring season) and October (Fall season). Soils' bacterial communities were targeted using 16S rRNA gene amplicon sequencing. Bacterial community diversity and taxonomic composition among rhizoma peanut cultivars were significantly affected by seasons, cultivars, and their interactions (p < 0.05). Alpha diversity, as estimated by the OTU richness and Simpson index, was around onefold decrease in October than in April across most of the RP cultivars, while the soils from Arblick and Latitude had around one time higher alpha diversity in both seasons compared with other cultivars. Beta diversity differed significantly in April (R = 0.073, p < 0.01) and October (R = 0.084, p < 0.01) across seven cultivars. Bacterial dominant taxa (at phylum and genus level) were strongly affected by seasons and varied towards more dominant groups that have functional potentials involved in nutrient cycling from April to October. A large shift in water availability induced by season variations in addition to host cultivar's effects can explain the observed patterns in diversity, composition, and co-occurrence of bacterial taxa. Overall, our results demonstrate an overriding effect of short-term seasonal variations on soil bacterial communities associated with different crop cultivars. The findings suggest that season-induced shifts in environmental conditions could exert stronger impacts on soil microorganisms than the finer-scale rhizosphere effect from crop cultivars, and consequently influence largely microbe-mediated soil processes and crop health in agricultural ecosystems.