Manipulating Identical Filter Redundancy for Efficient Pruning on Deep and Complicated CNN.

The existence of redundancy in convolutional neural networks (CNNs) enables us to remove some filters/channels with acceptable performance drops. However, the training objective of CNNs usually tends to minimize an accuracy-related loss function without any attention paid to the redundancy, making the redundancy distribute randomly on all the filters, such that removing any of them may trigger information loss and accuracy drop, necessitating a fine-tuning step for recovery. In this article, we propose to manipulate the redundancy during training to facilitate network pruning. To this end, we propose a novel centripetal SGD (C-SGD) to make some filters identical, resulting in ideal redundancy patterns, as such filters become purely redundant due to their duplicates, hence removing them does not harm the network. As shown on CIFAR and ImageNet, C-SGD delivers better performance because the redundancy is better organized, compared to the existing methods. The efficiency also characterizes C-SGD because it is as fast as regular SGD, requires no fine-tuning, and can be conducted simultaneously on all the layers even in very deep CNNs. Besides, C-SGD can improve the accuracy of CNNs by first training a model with the same architecture but wider layers and then squeezing it into the original width.

Tectorigenin targets PKACα to promote GLUT4 expression in skeletal muscle and improve insulin resistance in vitro and in vivo.

The decreased expression and dysfunction of glucose transporter 4 (GLUT4), the insulin-responsive glucose transporter, are closely related to the occurrence of insulin resistance (IR). To improve the expression of GLUT4 may represent a promising strategy to prevent and treat IR and type 2 diabetes (T2DM). Here, we demonstrate that the natural compound tectorigenin (TG) enhances GLUT4 expression, glucose uptake and insulin responsiveness via activating AMP-activated protein kinase (AMPK)/myocyte enhancer factor 2 (MEF2) signaling in both normal and IR skeletal muscle cells and tissues. Accordingly, prophylactic and therapeutic uses of TG can significantly ameliorate IR and hyperglycemia in T2DM mice. Mechanistically, we identify protein kinase A catalytic subunit α (PKACα) as the target of TG to increase GLUT4 expression and TG-PKACα binding promotes the dissociation of PKACα from the regulatory subunits, leading to the activation of PKA/AMPK signaling. PKACα knockdown in local quadriceps muscles almost completely abolished the therapeutic effects of TG on IR and T2DM, as well as the enhancement on AMPK signaling and GLUT4 expression in skeletal muscle. This study supports TG as a new drug candidate to treat IR and its related diseases, but also enriches our knowledge of PKA signaling in glucose metabolism in skeletal muscle.

Polarization clustering of biological structures with Mueller matrix parameters.

Mueller matrix imaging polarimetry (MMIP) is a promising technique for the characterization of biological tissues, including the classification of microstructures in pathological diagnosis. To expand the parameter space of Mueller matrix parameters, we propose new vector parameters (VPs) according to the Mueller matrix polar decomposition method. We measure invasive bladder cancer (IBC) with extensive necrosis and high-grade ductal carcinoma in situ (DCIS) with MMIP, and the regions of cancer cells and fibrotic stroma are classified with the VPs. Then the proposed and existing VPs are mapped on the Poincaré sphere with 3D visualization, and an indicator of spatial feature is defined based on the minimum enclosing sphere to evaluate the classification capability of the VPs. For both IBC and DCIS, the results show that the proposed VPs exhibit evident contrast between the regions of cancer cells and fibrotic stroma. This study broadens the fundamental Mueller matrix parameters and helps to improve the characterization ability of the MMIP technique.

Systemic Blood Predictors of Elevated Pulmonary Artery Pressure Assessed by Non-invasive Echocardiography After Acute Exposure to High Altitude: A Prospective Cohort Study.

Aim: Elevated pulmonary artery pressure (ePAP) in response to high-altitude hypoxia is a critical physiopathological factor in the hypoxic adaptation that may lead to high-altitude pulmonary edema in the acute phase or high-altitude pulmonary hypertension in the long term. However, the sea-level predictors of risk factors for altitude-induced ePAP have not been examined. Thus, we aimed to identify the baseline systemic blood predictors of ePAP after acute high-altitude exposure. Materials and Methods: A total of 154 participants were transported to a high altitude 3,700 m from sea level within 2 h. Echocardiography examinations were performed to assess the mean pulmonary artery pressure (mPAP) and hemodynamics at both altitudes. All the individuals underwent blood tests to determine the concentrations of vascular regulatory factors. Univariate and adjusted logistic regression analyses were performed to identify the independent predictors of ePAP and factors related to ePAP. Results: The mPAP increased significantly from sea level to high altitude (19.79 ± 6.53-27.16 ± 7.16 mmHg, p < 0.05). Increased levels of endothelin (ET-1), Ang (1-7), Ang II, and bradykinin were found after high-altitude exposure, while the levels of nitric oxide (NO), prostaglandin E2 (PEG2), and serotonin decreased sharply (all p-values < 0.05). At high altitude, 52.6% of the subjects exhibited ePAP, and the mPAP was closely correlated with the baseline Ang II level (r = 0.170, p = 0.036) and follow-up levels of NO (r = -0.209, p = 0.009), Ang II (r = 0.246, p = 0.002), and Ang (1-7) (r = -0.222, p = 0.006) and the left atrial inner diameter (LAD, r = 0.270, p < 0.001). Both the baseline and follow-up NO and Ang II levels were significantly different between the ePAP and non-ePAP groups. Finally, we identified the baseline Ang II and NO concentrations as two independent predictors of ePAP (p < 0.05). We also found that two vascular regulatory factors with inverse roles, namely, Ang (1-7) and Ang II, at high altitudes were independently associated with ePAP. Additionally, ET-1, NO, PEG2, and LAD were associated with ePAP. Conclusion: The baseline concentrations of Ang II and NO at sea level are two independent predictors of ePAP after acute high-altitude exposure. Furthermore, Ang (1-7) and Ang II combined with ET-1, NO, PEG2, and LAD at high altitudes may contribute to the development of ePAP.

A review on the removal of phthalate acid esters in wastewater treatment plants: from the conventional wastewater treatment to combined processes.

In the past decades, phthalate acid esters (PAEs), as a new class of recalcitrant environmental contaminant, have attracted increasing concern due to their potential hazards to reproductive system. wastewater treatment plants (WWTPs) are generally regarded as a crucial barrier to prevent a variety of contaminants from introducing into aquatic environment. This paper reviews the occurrence, fate, and removal efficacy of six widely appearing PAEs in conventional wastewater treatment. PAEs removal appears to be compound- and process-dependent. Advanced treatment processes, including activated carbon, advanced oxidation process (AOPs), membrane filtration, and membrane bioreactor, show good performance in PAEs elimination, but many methods have been commercially limited by toxic byproducts, high operation, and maintenance costs. Even though combined processes are qualified as a promising alternative, further studies are required to optimize these processes, especially the competitiveness between technique and economy.

Baseline Ratio of Soluble Fas/FasL Predicts Onset of Pulmonary Hypertension in Elder Patients Undergoing Maintenance Hemodialysis: A Prospective Cohort Study.

Background: Pulmonary hypertension (PH) is one of the most common complications associated with end-stage renal disease (ESRD). Though numerous risk factors have been founded, other risk factors remain unidentified, particularly in patients undergoing maintenance hemodialysis with elder age. Soluble Fas (sFas) and its ligand FasL (sFasL) have been reported in chronic renal disease patients; however, they have not been identified in the PH patients of elder hemodialysis patients. We aimed to determine the roles of sFas/sFasL in onset of PH in elder patients undergoing maintenance hemodialysis with ESRD. Methods: Altogether, 163 patients aged 68.00 ± 10.51 years with ESRD who undergoing maintenance hemodialysis in a prospective cohort and were followed-up for a median of 5.5 years. They underwent echocardiography examinations, liver function assessments, residual renal function, and serum ion examinations, before and after dialysis. Furthermore, levels of sFas and sFasL at baseline had also been measured. We compared demographic data, echocardiographic parameters, liver function, ions, and residual renal function as well as serum sFas and sFasL between the PH and non-PH groups. These parameters were correlated with systolic pulmonary artery pressure (sPAP) using Spearman's correlation. Moreover, univariate and adjusted logistic regression analyses have also been conducted. Results: The incidence of PH in the elder dialysis patients was 39.1%. PH populations were demonstrated with significantly higher end-diastolic internal diameters of the left atrium, left ventricle, right ventricle (RV), and pulmonary artery, as well as the left ventricular posterior wall thickness (LVWP; all p < 0.05). A higher baseline serum sFas and sFasL levels have also been identified ( p < 0.001). They also showed lower fractional shortening and left ventricular ejection fraction (LVEF; p < 0.05). Following dialysis, the post-dialysis serum potassium concentration (K+) was significantly higher in the PH group ( p = 0.013). Furthermore, the adjusted regression identified that ratio of sFas/FasL (OR: 1.587, p = 0.004), RV (OR: 1.184, p = 0.014), LVPW (OR: 1.517, p = 0.007), and post-dialysis K+ (OR: 2.717, p = 0.040) was the independent risk factors for PH while LVEF (OR: 0.875, p = 0.040) protects patients from PH. Conclusion: The baseline ratio of sFas/sFasL, RV, LVPW, and post-dialysis K+ was independent risk factors for PH onset, while LVEF was a protective factor for PH.

Prognostic significance of day-by-day in-hospital blood pressure variability in COVID-19 patients with hypertension.

Hypertension is the most common comorbidity in patients with coronavirus disease 2019 (COVID-19) and increases in-hospital mortality. Day-by-day blood pressure (BP) variability (BPV) is associated with clinical outcomes in hypertensive patients. However, little information is available on the association of BPV with the outcomes of COVID-19 patients with hypertension. This study aimed to demonstrate whether day-by-day in-hospital BPV had prognostic significance in these patients. The authors included 702 COVID-19 patients with hypertension from Huoshenshan Hospital (Wuhan, China), who underwent valid in-hospital BP measurements on at least seven consecutive days. Day-by-day BPV was assessed by standard deviation (SD), coefficient of variation (CV), and variation independent of mean (VIM). Overall, patients with severe COVID-19 and non-survivors had higher BPV than moderate cases and survivors, respectively. Additionally, higher BPV was correlated with greater age and higher levels of C-reactive protein, procalcitonin, high-sensitive cardiac troponin I, and B-type natriuretic peptide. In multivariable Cox regression, SD of systolic BP (SBP) was predictive of mortality [hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.05-1.30] as well as acute respiratory distress syndrome (ARDS) (HR 1.09, 95% CI 1.01-1.16). Similar trends were observed for CV and VIM of SBP, but not indices of diastolic BP variability. The authors demonstrated that day-by-day in-hospital SBP variability can independently predict mortality and ARDS in COVID-19 patients with hypertension. And high BPV might be correlated with severe inflammation and myocardial injury. Further studies are needed to clarify whether early reduction of BPV will improve the prognosis of these patients.

A novel echocardiographic parameter to identify individuals susceptible to acute mountain sickness.

BACKGROUND: Acute mountain sickness (AMS) may cause life-threatening conditions. This study aimed to screen echocardiographic parameters at sea level (SL) to identify predictors of AMS development. METHODS: Overall, 106 healthy men were recruited at SL and ascended to 4100 m within 7 days by bus. Basic characteristics, physiological data, and echocardiographic parameters were collected both at SL and 4100 m above SL. AMS was identified by 2018 Lake Louise Questionnaire Score. RESULTS: After acute high altitude exposure (AHAE), 33 subjects were diagnosed with AMS and exhibited lower lateral mitral valve tissue motion annular displacement (MV TMADlateral) at SL than AMS-free subjects (13.09 vs. 13.89 mm, p = 0.022). MV TMADlateral at SL was significantly correlated with AMS occurrence (OR = 0.717, 95% CI: 0.534-0.964, p = 0.028). The MV TMADlateral<13.30-mm group showed over 4-fold risk for AMS development versus the MV TMADlateral≥13.30-mm group. After AHAE, the MV TMADlateral<13.30-mm group had increased HR (64 vs. 74 bpm, p = 0.001) and right-ventricular myocardial performance index (0.54 vs. 0.69, p = 0.009) and decreased left ventricular global longitudinal strain (-21.50 vs. -20.23%, p = 0.002), tricuspid valve E/A ratio (2.11 vs. 1.89, p = 0.019), and MV E-wave deceleration time (169.60 vs. 156.90 ms, p = 0.035). CONCLUSION: MV TMADlateral at SL was a potential predictor of AMS occurrence and might be associated with differential alterations of ventricular systolic and diastolic functions in subjects with different MV TMADlateral levels at SL after AHAE.

The Association Between Notching of the Right Ventricular Outflow Tract Flow Velocity Doppler Envelope and Impaired Right Ventricular Function After Acute High-Altitude Exposure.

INTRODUCTION: Pulmonary artery pressure (PAP) is increased and right ventricular (RV) function is well preserved in healthy subjects upon exposure to high altitude (HA). An increase in PAP may trigger notching of the right ventricular outflow tract Doppler flow velocity envelope (RVOT notch), which is associated with impaired RV function in patients with pulmonary hypertension. However, whether HA exposure can induce RVOT notch formation and the subsequent impact on cardiac function in healthy subjects remains unclear. METHODS: A total of 99 subjects (69 males and 30 females) with a median age of 25 years were enrolled in this study; they traveled from 500 to 4100 m by bus over a 2-day period. All subjects underwent a comprehensive physiological and echocardiographic examination 1 day before ascension at low altitude and 15 ± 3 h after arrival at HA. The RVOT notch was determined by the presence of a notched shape in the RVOT Doppler flow velocity envelope. The systolic PAP (SPAP) was calculated as Bernoulli equation SPAP = 4 × (maximum tricuspid regurgitation velocity)2+5 and mean PAP (mPAP) = 0.61 × SPAP+2. Cardiac output was calculated as stroke volume × heart rate. Pulmonary capillary wedge pressure (PCWP) was calculated as 1.9+1.24 × mitral E/e'. Pulmonary vascular resistance (PVR) was calculated as (mPAP-PCWP)/CO. RESULTS: After HA exposure, 20 (20.2%) subjects had an RVOT notch [notch (+)], and 79 (79.8%) subjects did not have an RVOT notch [notch (-)]. In the multivariate logistic regression analysis, the SPAP, right ventricular global longitude strain (RV GLS), and tricuspid E/A were independently associated with the RVOT notch. The SPAP, mPAP, PVR, standard deviations of the times to peak systolic strain in the four mid-basal RV segments (RVSD4), peak velocity of the isovolumic contraction period (ICV), and the peak systolic velocity (s') at the mitral/tricuspid annulus were increased in all subjects. Conversely, the pulse oxygen saturation (SpO2), RV GLS, and tricuspid annulus plane systolic excursion (TAPSE)/SPAP were decreased. However, the increases of SPAP, mPAP, PVR, and RVSD4 and the decreases of SpO2, RV GLS, and TAPSE/SPAP were more pronounced in the notch (+) group than in the notch (-) group. Additionally, increased tricuspid ICV and mitral/tricuspid s' were found only in the notch (-) group. CONCLUSION: HA exposure-induced RVOT notch formation is associated with impaired RV function, including no increase in the tricuspid ICV or s', reduction of RV deformation, deterioration in RV-pulmonary artery coupling, and RV intraventricular synchrony.

Sex Differences in the Incidence and Risk Factors of Myocardial Injury in COVID-19 Patients: A Retrospective Cohort Study.

Male novel coronavirus disease (COVID-19) patients tend to have poorer clinical outcomes than female patients, while the myocardial injury is strongly associated with COVID-19-related adverse events. Owing to a lack of corresponding data, we aimed to investigate the sex differences in the incidence of myocardial injury in COVID-19 patients and to identify the potential underlying mechanisms, which may partly account for the sex bias in the incidence of adverse events. This retrospective study included 1,157 COVID-19 patients who were hospitalized in Huoshenshan Hospital from 12 March 2020 to 11 April 2020. Data on the patients' demographic characteristics, initial symptoms, comorbidities and laboratory tests were collected. Totally, 571 (49.4%) female and 586 (50.6%) male COVID-19 patients were enrolled. The incidence of myocardial injury was higher among men than women (9.2 vs. 4.9%, p = 0.004). In the logistic regression analysis, age, and chronic kidney disease were associated with myocardial injury in both sexes. However, hypertension [odds ratio (OR) = 2.25, 95% confidence interval (CI) 1.20-4.22], coronary artery disease (OR = 2.46, 95% CI 1.14-5.34), leucocyte counts (OR = 3.13, 95% CI 1.24-7.86), hs-CRP (OR = 4.45, 95% CI 1.33-14.83), and D-dimer [OR = 3.93 (1.27-12.19), 95% CI 1.27-12.19] were independent risk factors only in the men. The correlations of hs-CRP and D-dimer with hs-cTnI and BNP were stronger in the men. The incidence of myocardial injury in COVID-19 patients is sex-dependent, predominantly in association with a greater degree of inflammation and coagulation disorders in men. Our findings can be used to improve the quality of clinical management in such settings.

Assessment of right atrial dyssynchrony by 2D speckle-tracking in healthy young men following high altitude exposure at 4100 m.

BACKGROUND: High altitude exposure induces overload of right-sided heart and may further predispose to supraventricular arrhythmia. It has been reported that atrial mechanical dyssynchrony is associated with atrial arrhythmia. Whether high altitude exposure causes higher right atrial (RA) dyssynchrony is still unknown. The aim of study was to investigate the effect of high altitude exposure on right atrial mechanical synchrony. METHODS: In this study, 98 healthy young men underwent clinical examination and echocardiography at sea level (400 m) and high altitude (4100 m) after an ascent within 7 days. RA dyssynchrony was defined as inhomogeneous timing to peak strain and strain rate using 2D speckle-tracking echocardiography. RESULTS: Following high altitude exposure, standard deviation of the time to peak strain (SD-TPS) [36.2 (24.5, 48.6) ms vs. 21.7 (12.9, 32.1) ms, p<0.001] and SD-TPS as percentage of R-R' interval (4.6 ± 2.1% vs. 2.5 ± 1.8%, p<0.001) significantly increased. Additionally, subjects with higher SD-TPS (%) at high altitude presented decreased right ventricular global longitudinal strain and RA active emptying fraction, but increased RA minimal volume index, which were not observed in lower group. Multivariable analysis showed that mean pulmonary arterial pressure and tricuspid E/A were independently associated with SD-TPS (%) at high altitude. CONCLUSION: Our data for the first time demonstrated that high altitude exposure causes RA dyssynchrony in healthy young men, which may be secondary to increased pulmonary arterial pressure. In addition, subjects with higher RA dyssynchrony presented worse RA contractile function and right ventricular performance.

Atrial performance in healthy subjects following high altitude exposure at 4100 m: 2D speckle-tracking strain analysis.

High altitude (HA) exposure has been considered as a cardiac stress and might impair ventricular diastolic function. Atrial contraction is involved in ventricular passive filling, however the atrial performance to HA exposure is poorly understood. This study aimed to evaluate the effect of short-term HA exposure on bi-atrial function. Physiological and 2D-echocardiographic data were collected in 82 healthy men at sea level (SL, 400 m) and 4100 m after an ascent within 7 days. Atrial function was measured using volumetric and speckle-tracking analyses during reservoir, conduit and contractile phases of cardiac cycle. Following HA exposure, significant decreases of reservoir and conduit function indexes were observed in bi-atria, whereas decreases of contractile function indexes were observed in right atrium (RA), estimated via RA active emptying fraction (SL 41.7 ± 13.9% vs. HA 35.4 ± 12.2%, p = 0.001), strain during the contractile phase [SL 13.5 (11.4, 17.8) % vs. HA 12.3 (9.3, 15.9) %, p = 0.003], and peak strain rate during the contractile phase [SL - 1.76 (- 2.24, - 1.48) s-1 vs. HA - 1.57 (- 2.01, - 1.23) s-1, p = 0.002], but not in left atrium (LA). In conclusion, short-term HA exposure of healthy individuals impairs bi-atrial performance, mostly observed in RA. Especially, atrial contractile function decreases in RA rather than LA, which seems not to compensate for decreased ventricular filling after HA exposure. Our findings may provide a novel evidence for right-sided heart dysfunction to HA exposure.

Prediction of High-Altitude Cardiorespiratory Fitness Impairment Using a Combination of Physiological Parameters During Exercise at Sea Level and Genetic Information in an Integrated Risk Model.

Insufficient cardiorespiratory compensation is closely associated with acute hypoxic symptoms and high-altitude (HA) cardiovascular events. To avoid such adverse events, predicting HA cardiorespiratory fitness impairment (HA-CRFi) is clinically important. However, to date, there is insufficient information regarding the prediction of HA-CRFi. In this study, we aimed to formulate a protocol to predict individuals at risk of HA-CRFi. We recruited 246 volunteers who were transported to Lhasa (HA, 3,700 m) from Chengdu (the sea level [SL], <500 m) through an airplane. Physiological parameters at rest and during post-submaximal exercise, as well as cardiorespiratory fitness at HA and SL, were measured. Logistic regression and receiver operating characteristic (ROC) curve analyses were employed to predict HA-CRFi. We analyzed 66 pulmonary vascular function and hypoxia-inducible factor- (HIF-) related polymorphisms associated with HA-CRFi. To increase the prediction accuracy, we used a combination model including physiological parameters and genetic information to predict HA-CRFi. The oxygen saturation (SpO2) of post-submaximal exercise at SL and EPAS1 rs13419896-A and EGLN1 rs508618-G variants were associated with HA-CRFi (SpO2, area under the curve (AUC) = 0.736, cutoff = 95.5%, p < 0.001; EPAS1 A and EGLN1 G, odds ratio [OR] = 12.02, 95% CI = 4.84-29.85, p < 0.001). A combination model including the two risk factors-post-submaximal exercise SpO2 at SL of <95.5% and the presence of EPAS1 rs13419896-A and EGLN1 rs508618-G variants-was significantly more effective and accurate in predicting HA-CRFi (OR = 19.62, 95% CI = 6.42-59.94, p < 0.001). Our study employed a combination of genetic information and the physiological parameters of post-submaximal exercise at SL to predict HA-CRFi. Based on the optimized prediction model, our findings could identify individuals at a high risk of HA-CRFi in an early stage and reduce cardiovascular events.

The Prevalence of Pulmonary Hypertension Among Maintenance Dialysis Patients With ESRD and Its Associated Factors: A Retrospective Study.

Aim: To determine the prevalence of pulmonary hypertension (PH) and its associated factors among end-stage renal disease (ESRD) patients who underwent maintenance dialysis. Methods: A total of 491 patients received echocardiography examinations and underwent pulmonary artery systolic pressure (PASP) assessments. A subgroup of 283 patients were subjected to plasma creatinine (Cr) and blood urea nitrogen concentration (BUN) tests, routine blood examinations and electrolyte analysis. First, we compared the differences in echocardiographic, Cr and BUN, blood routine and electrolyte parameters between PH and non-PH groups. The correlations between PASP and the parameters mentioned above were also analyzed. Furthermore, univariate and adjusted logistic regression analyses were performed to identify the independent associated factors. Results: The incidence of PH among ESRD patients who were treated with maintenance dialysis was 34.6%. Most of the echocardiographic parameters, including end-diastolic internal diameters of the left atrium, left ventricle, right atrium, and pulmonary artery, as well as interventricular septum mobility, left ventricular posterior wall mobility, fractional shortening, stroke volume and left ventricle ejection fraction (LVEF), were associated with PH. Furthermore, Mg2+ (p = 0.037) and Cl- (p = 0.043) were significantly associated with PASP. However, after adjustments were made in the regression analysis, only internal diameters of the left atrium, right atrium, and LVEF were independently associated with PH. Conclusion: PH is prevalent, with a relatively high incidence among ESRD patients who undergo maintenance dialysis. The sizes of the left and right atria as well as LVEF were independently associated with PH, but further cohort and basic mechanistic studies are needed to confirm this finding.

New HIV diagnoses in patients with COVID-19: two case reports and a brief literature review.

BACKGROUND: COVID-19 is novel infectious disease with an evolving understanding of its epidemiology and clinical manifestations. Severe cases developed life-threatening complications, such as respiratory failure, shock, and multiple organs dysfunction. Immunocompromised patients often present atypical presentations of viral infected diseases. CASE PRESENTATION: We report newly diagnosed HIV infections in two patients with COVID-19 in China. In our two cases, both patients with elevated IL-6 received Tocilizumab treatment, but did not present obvious therapeutic effect. CONCLUSIONS: These cases highlight possible co-detection of known immunocompromised diseases such as HIV. The two cases we reported stressed the risk of misdiagnosis, especially during the pandemic of an infectious disease and the importance of extended testing even if in immune-compromised condition the immune state may be ignored.

Influence of blood pressure control and application of renin-angiotensin-aldosterone system inhibitors on the outcomes in COVID-19 patients with hypertension.

Hypertension is proved to be associated with severity and mortality in coronavirus disease 2019 (COVID-19). However, little is known about the effects of pre-admission and/or in-hospital antihypertension treatments on clinical outcomes. Thus, this study aimed to investigate the association between in-hospital blood pressure (BP) control and COVID-19-related outcomes and to compare the effects of different antihypertension treatments. This study included 2864 COVID-19 patients and 1628 were hypertensive. Patients were grouped according to their BP during hospitalization and records of medication application. Patients with higher BP showed worse cardiac and renal functions and clinical outcomes. After adjustment, subjects with pre-admission usage of renin-angiotensin-aldosterone system (RAAS) inhibitors (HR = 0.35, 95%CI 0.14-0.86, P = .022) had a lower risk of adverse clinical outcomes, including death, acute respiratory distress syndrome, respiratory failure, septic shock, mechanical ventilation, and intensive care unit admission. Particularly, hypertension patients receiving RAAS inhibitor treatment either before (HR = 0.35, 95%CI 0.13-0.97, P = .043) or after (HR = 0.18, 95%CI 0.04-0.86, P = .031) admission showed a significantly lower risk of adverse clinical outcomes than those receiving application of other antihypertensive medicines. Furthermore, consecutive application of RAAS inhibitors in COVID-19 patients with hypertension showed better clinical outcomes (HR = 0.10, 95%CI 0.01-0.83, P = .033) than non-RAAS inhibitors users. We revealed that COVID-19 patients with poor BP control during hospitalization had worse clinical outcomes. Compared with other antihypertension medicines, RAAS inhibitors were beneficial for improving clinical outcomes in COVID-19 patients with hypertension. Our findings provide direct evidence to support the administration of RAAS inhibitors to COVID-19 patients with hypertension before and after admission.

Pulmonary function tests at low altitude predict pulmonary pressure response to short-term high altitude exposure.

BACKGROUND: Travelling to high altitude (HA) presents a risk of the high levels of pulmonary artery pressure (PAP) at altitude, which is associated with impaired exercise capacity and fatal HA pulmonary oedema. However, prediction of high levels of PAP at altitude is still unclear. METHODS: Echocardiography and pulmonary function tests were performed on 121 healthy men at low altitude (LA) and 4100 m (5 ± 2 h after a 7 day ascent). RESULTS: HA exposure increased the levels of FEV1/FVC ratio, FEF25%, 50%, 75%, MMEF, mPAP, total pulmonary vascular resistance (PVR) and systolic pulmonary arterial pressure (SPAP). More smokers and lower forced expiratory flow at 25% of forced vital capacity (FEF25%) at LA were observed in subjects with mPAP≥30 mmHg than those with mPAP<30 mmHg at HA. Multivariate logistic regression identified that FEF25% at LA [odds ratio (OR) 0.50, 95%CI 0.33-0.76, p = 0.001] and smoking (OR 3.09, 95%CI 1.31-7.27, p = 0.010) were the independent predictors for identifying subjects with mPAP≥30 mmHg at HA. Moreover, FEF25% at LA was linearly correlated with mPAP at HA (r = -0.31, p < 0.001), which mainly existed in smokers. Compared to subjects with FEF25% ≥7.55 L/sec at LA, those with FEF25% <7.55 L/sec at LA showed higher levels of mPAP, and total PVR, and a multivariable OR of 11.16 (95%CI, 3.48-35.81) for developing mPAP ≥ 30 mmHg at HA. However, there was no significant difference in the incidences of AMS and its related clinical symptoms in subjects with different levels of FEF25%. CONCLUSIONS: Thus, these findings suggest that subjects with low FEF25% values at LA are susceptible to high levels of PAP at altitude but not the incidence of AMS following short-term HA exposure, especially in smokers.

Preliminary Study of Right Ventricular Dyssynchrony Under High-Altitude Exposure: Determinants and Impacts.

The aims of this study were to explore the effect of high-altitude (HA) exposure on the incidence, determinants, and impacts of right ventricular dyssynchrony (RVD). In our study, 108 healthy young men were enrolled, and physiological and echocardiographic variables were recorded at both sea level and 4,100 m. By using two-dimensional speckle-tracking echocardiography, RVD was evaluated by calculating the R-R interval-corrected standard deviation of the time-to-peak systolic strain for the four mid-basal RV segments (RVSD4) and defined by RVSD4 > 18.7 ms. After HA exposure, RVSD4 was significantly increased, and the incidence of RVD was approximately 32.4%. Subjects with RVD showed lower oxygen saturation (SaO2) and RV global longitudinal strain and higher systolic pulmonary artery pressure than those without RVD. Moreover, myocardial acceleration during isovolumic contraction was increased in all subjects and those without RVD, but not in those with RVD. Multivariate logistic regression revealed that SaO2 is an independent determinant of RVD at HA (odds ratio: 0.72, 95% CI: 0.56-0.92; P = 0.009). However, the mean pulmonary artery pressure was linearly correlated with the magnitude of RVD in the presence of Notch. No changes were found in RV fractional area change, tricuspid annular motion, or tricuspid s' velocity between subjects with and without RVD. Collectively, we demonstrated for the first time that HA exposure could induce RVD in healthy subjects, which may be mainly attributed to the decline in SaO2 as well as RV overload; the incidence of RVD was associated with reduced RV regional function and blunted myocardial acceleration.

Effects of baseline heart rate at sea level on cardiac responses to high-altitude exposure.

High-altitude (HA) exposure has been widely considered as a cardiac stress, and associated with altered cardiac function. However, the characteristics of cardiac responses to HA exposure are unclear. In total, 240 healthy men were enrolled and ascended to 4100 m by bus within 7 days. Standard echocardiography and color tissue Doppler imaging were performed at sea level and at 4100 m. In all subjects, HA exposure increased HR [65 (59, 71) vs. 72 (63, 80) beats/min, p < 0.001] but decreased the stroke volume index (SVi) [35.5 (30.5, 42.3) vs. 32.9 (27.4, 39.5) ml/m2, p < 0.001], leading to an unchanged cardiac index (CI). Moreover, baseline HR was negatively correlated with HA exposure-induced changes in HR (r = - 0.410, p < 0.001) and CI (r = - 0.314, p < 0.001). Following HA exposure, subjects with lowest tertile of baseline HR showed an increased HR [56 (53, 58) vs. 65 (58, 73) beats/min, p < 0.001], left ventricular ejection fraction (LVEF) [61.7 (56.5, 68.0) vs. 66.1 (60.7, 71.5) %, p = 0.004] and mitral S' velocity [5.8 ± 1.4 vs. 6.5 ± 1.9 cm/s, p = 0.040]. However, subjects with highest tertile of baseline HR showed an unchanged HR, LVEF and mitral S' velocity, but a decreased E' velocity [9.2 ± 2.0 vs. 8.4 ± 1.8 cm/s, p = 0.003]. Our findings indicate that baseline HR at sea level could determine cardiac responses to HA exposure; these responses were characterized by enhanced LV function in subjects with a low baseline HR and by reduced LV myocardial velocity in early diastole in subjects with a high baseline HR.

The Prevalence and Independent Risk Factors of Significant Tricuspid Regurgitation Jets in Maintenance Hemodialysis Patients With ESRD.

BACKGROUND AND AIM: Tricuspid regurgitation (TR) is a frequent complication in various cardiovascular diseases. However, few studies have reported the prevalence of TR especially the moderate to severe or significant TR (ms-TR) maintenance dialysis patients. Thus, we aimed to identify the prevalence of ms-TR and its associated factors. METHODS: A total of 491 maintenance dialysis patients underwent echocardiographic examinations, while a subgroup (n = 283) also received routine blood tests, renal function examinations, and electrolyte analysis. We first compared the differences in abovementioned parameters among groups with various TR areas (TRAs). Finally, univariate and adjusted regression were also used to identify factors that were independently associated with ms-TR. RESULTS: The incidence of TR jets was 62.6%, which included a mildly increased TRA (47.8%), moderately increased TRA (10.4%), and severely increased TRA (3.5%). Most of the cardiac structures and functional parameters, such as the end-diastolic internal diameters of the left atrium (LA), left ventricle (LVDD), right atrium (RA), right ventricle (RV), left ventricular ejection fraction (LVEF), and fractional shortening (FS), were significantly associated with ms-TR. Among serum ions, only total CO2 (TCO2; r = -0.141, p = 0.047) was negatively correlated with TRA. After adjusted, only Na+ [odds ratio (OR): 0.871 0.888, p = 0.048], RA (OR: 1.370, p < 0.001), and FS (OR: 0.887, p < 0.001) were independently associated with ms-TR. CONCLUSION: Tricuspid regurgitation occurs in maintenance hemodialysis patients with ESRD. Na+ FS and RA were independently associated with ms-TR, and these parameters may be potential risk factors/predictors for ms-TR.