Dynamic LVEF Decline and Serum NT-proBNP and Uric Acid Levels before Heart Transplantation are Independent Predictors of Adverse Outcomes in Young Adult Patients with Dilated Cardiomyopathy.

Background: The present study investigated the predictors of adverse outcomes in young adult patients with dilated cardiomyopathy (DCM) who underwent heart transplantation (HTx). Methods: Twenty-four young adult patients (aged 18-45 years) with DCM who underwent HTx in our hospital from January 2012 to December 2022 were included in this retrospective analysis. Pre- and post-HTx data were collected for echocardiography, N-terminal pro-brain natriuretic peptide (NT-proBNP), and uric acid (UA). Data collected at the time of DCM diagnosis were designated as baseline data. Post-HTx assessments were conducted at 1 week and 3, 6, 12, and 36 months post-HTx. The primary endpoint was defined as any adverse event, including left ventricular ejection fraction (LVEF) < 50% (n = 3), 50% increase in right or left ventricular diameter (n = 12), or death (n = 2). Patients were categorized into a non-adverse-event group (n = 12) or an adverse-event group (n = 12). Results: Baseline NT-proBNP (p = 0.014) and UA (p = 0.012) were significantly higher in the adverse-event group than in the non-adverse-event group. Baseline NT-proBNP > 7390 pg/mL (relative risk (RR) = 7.412, p = 0.046), UA > 542 µmol/L (RR = 8.838, 95% confidence interval (95% CI) = 1.541-50.694, p = 0.014), and sustained reduction in LVEF ( ≥ 3%) over a 2-year pharmacological treatment prior to HTx (RR = 3.252, p = 0.046) were significantly associated with an increased risk of adverse events post-HTx. Conclusions: In young adult DCM patients post-HTx, heightened baseline levels of NT-proBNP and UA levels and a sustained reduction in LVEF over time prior to undergoing an HTx are significantly associated with an increased risk of adverse events post-HTx. Future studies are needed to observe whether individualized monitoring strategies could reduce the incidence of adverse events following HTx in these patients.

Evaluating the application of ChatGPT in China's residency training education: An exploratory study.

OBJECTIVE: The purpose of this study was to assess the utility of information generated by ChatGPT for residency education in China. METHODS: We designed a three-step survey to evaluate the performance of ChatGPT in China's residency training education including residency final examination questions, patient cases, and resident satisfaction scores. First, 204 questions from the residency final exam were input into ChatGPT's interface to obtain the percentage of correct answers. Next, ChatGPT was asked to generate 20 clinical cases, which were subsequently evaluated by three instructors using a pre-designed Likert scale with 5 points. The quality of the cases was assessed based on criteria including clarity, relevance, logicality, credibility, and comprehensiveness. Finally, interaction sessions between 31 third-year residents and ChatGPT were conducted. Residents' perceptions of ChatGPT's feedback were assessed using a Likert scale, focusing on aspects such as ease of use, accuracy and completeness of responses, and its effectiveness in enhancing understanding of medical knowledge. RESULTS: Our results showed ChatGPT-3.5 correctly answered 45.1% of exam questions. In the virtual patient cases, ChatGPT received mean ratings of 4.57 ± 0.50, 4.68 ± 0.47, 4.77 ± 0.46, 4.60 ± 0.53, and 3.95 ± 0.59 points for clarity, relevance, logicality, credibility, and comprehensiveness from clinical instructors, respectively. Among training residents, ChatGPT scored 4.48 ± 0.70, 4.00 ± 0.82 and 4.61 ± 0.50 points for ease of use, accuracy and completeness, and usefulness, respectively. CONCLUSION: Our findings demonstrate ChatGPT's immense potential for personalized Chinese medical education.

Association of Obesity Measures with Atrial Fibrillation Recurrence After Cryoablation in Patients with Paroxysmal Atrial Fibrillation.

BACKGROUND Obesity increases the risk of atrial fibrillation (AF) recurrence after ablation. This study explored the relationship between various obesity indexes and risk of recurrence after cryoablation of paroxysmal AF (PAF). MATERIAL AND METHODS Our prospective study included 100 patients with PAF who underwent first cryoablation. Physical examination and fasting blood lipids levels were measured at baseline. Seven obesity indexes were determined: body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-hip ratio (WHR), cardiometabolic index (CMI), lipid accumulation product (LAP), and body adiposity index (BAI). AF recurrence was confirmed by electrocardiograms and Holter monitor at follow-up visits after the initial 3-month blanking period. Receiver operating characteristic (ROC) curves were drawn to assess the abilities of obesity indicators in predicting AF recurrence. Multivariable Cox regression analysis was used to examine independent predictors of AF recurrence. RESULTS During a mean follow-up of 13.4 months, 31 patients (31.0%) had recurrent AF. Patients with recurrence had higher BMI, WC, WHtR, LAP, and BAI compared with those without recurrence. ROC analysis indicated the potential predictive value of BAI with an AUC of 0.657 (95% confidence interval [CI]: 0.534-0.779), followed by WC, WHtR, LAP, and BMI (all P<0.05). Diagnosis-to-ablation time (HR 1.034, 95% CI: 1.002-1.068), left atrial diameter (HR 1.147, 95% CI: 1.026-1.281), and WC (HR 1.026, 95% CI: 1.000-1.053) were independent predictive factors for AF recurrence after multivariable adjustment. CONCLUSIONS In this study population, WC appears to be a potential indicator for the prediction of recurrence in patients with PAF after cryoablation.

Effect of Zr2Al4C5 Content on the Mechanical Properties and Oxidation Behavior of ZrB2-SiC-Zr2Al4C5 Ceramics.

ZrB2-SiC-Zr2Al4C5 multi-phase ceramics with uniform structure and high density were successfully prepared through the introduction of in situ synthesized Zr2Al4C5 into ZrB2-SiC ceramic via SPS at 1800 °C. A systematic analysis and discussion of the experimental results and proposed mechanisms were carried out to demonstrate the composition-dependent sintering properties, mechanical properties and oxidation behavior. The results showed that the in situ synthesized Zr2Al4C5 could be evenly distributed in the ZrB2-SiC ceramic matrix and inhibited the growth of ZrB2 grains, which played a positive role in the sintering densification of the composite ceramics. With increasing Zr2Al4C5 content, the Vickers hardness and Young's modulus of composite ceramics gradually decreased. The fracture toughness showed a trend that first increased and then decreased, and was increased by about 30% compared with ZrB2-SiC ceramics. The major phases resulting from the oxidation of samples were ZrO2, ZrSiO4, aluminosilicate and SiO2 glass. With increasing Zr2Al4C5 content, the oxidative weight showed a trend that first increased then decreased; the composite ceramic with 30 vol.% Zr2Al4C5 showed the smallest oxidative weight gain. We believe that the presence of Zr2Al4C5 results in the formation of Al2O3 during the oxidation process, subsequently resulting in a lowering of the viscosity of the glassy silica scale, which in turn intensifies the oxidation of the composite ceramics. This would also increase oxygen permeation through the scale, adversely affecting the oxidation resistance of the composites with high Zr2Al4C5 content.

Diabetes Mellitus is Associated with Severe Infection and Mortality in Patients with COVID-19: A Systematic Review and Meta-analysis.

BACKGROUND AND AIM: Currently, the number of patients with coronavirus disease 2019 (COVID-19) infection is increasing rapidly worldwide. In this study, we aimed to assess whether diabetes mellitus (DM) would increase the risk of severe infection and death in patients with COVID-19. METHODS: We systematically searched the PubMed, Web of Science, MedRxiv and COVID-19 academic research communication platform for studies reporting clinical severity and/or overall mortality data on DM in patients with COVID-19 published up to July 10, 2020. The primary outcome was to compare the severe infection rate and mortality rate in COVID-19 patients with and without DM, and to calculate the odds ratio (OR) and 95% confidence interval (CI). RESULTS: A total of 76 studies involving 31,067 patients with COVID-19 were included in our meta-analysis. COVID-19 patients with DM had higher severe infection and case-mortality rates compared with those without DM (21.4 vs. 10.6% and 28.5 vs. 13.3%, respectively, all p <0.01). COVID-19 patients with DM were at significantly elevated risk of severe infection (OR = 2.38, 95% CI: 2.05-2.78, p <0.001) and mortality (OR = 2.21, 95% CI: 1.83-2.66, p <0.001). CONCLUSION: DM is associated with increased risk of severe infection and higher mortality in patients with COVID-19. Our study suggests that clinicians should pay more attention to the monitoring and treatment of COVID-19 patients with DM.

Elevated ß1-Adrenergic Receptor Autoantibody Levels Increase Atrial Fibrillation Susceptibility by Promoting Atrial Fibrosis.

OBJECTIVE: Beta 1-adrenergic receptor autoantibodies (ß1ARAbs) have been identified as a pathogenic factor in atrial fibrillation (AF), but the underlying pathogenetic mechanism is not well understood. We assessed the hypothesis that elevated ß1ARAb levels increase AF susceptibility by promoting atrial fibrosis. METHODS: A total of 70 patients with paroxysmal AF were continuously recruited. The serum levels of ß1ARAb and circulating fibrosis biomarkers were analyzed by ELISA. Linear regression was used to examine the correlations of ß1ARAb levels with left atrial diameter (LAD) and circulating fibrosis biomarker levels. Furthermore, we established a rabbit ß1ARAb overexpression model. We conducted electrophysiological studies and multielectrode array recordings to evaluate the atrial effective refractory period (AERP), AF inducibility and electrical conduction. AF was defined as irregular, rapid atrial beats > 500 bpm for > 1000 ms. Echocardiography, hematoxylin and eosin staining, Masson's trichrome staining, and picrosirius red staining were performed to evaluate changes in atrial structure and detect fibrosis. Western blotting and PCR were used to detect alterations in the protein and mRNA expression of TGF-ß1, collagen I and collagen III. RESULTS: Patients with a LAD ≥ 40 mm had higher ß1ARAb levels than patients with a smaller LAD (8.87 ± 3.16 vs. 6.75 ± 1.34 ng/mL, P = 0.005). ß1ARAb levels were positively correlated with LAD and circulating biomarker levels (all P < 0.05). Compared with the control group, the rabbits in the immune group showed the following: (1) enhanced heart rate, shortened AERP (70.00 ± 5.49 vs. 96.46 ± 3.27 ms, P < 0.001), increased AF inducibility (55% vs. 0%, P < 0.001), decreased conduction velocity and increased conduction heterogeneity; (2) enlarged LAD and elevated systolic dysfunction; (3) significant fibrosis in the left atrium identified by Masson's trichrome staining (15.17 ± 3.46 vs. 4.92 ± 1.72%, P < 0.001) and picrosirius red staining (16.76 ± 6.40 vs. 4.85 ± 0.40%, P < 0.001); and (4) increased expression levels of TGF-ß1, collagen I and collagen III. CONCLUSION: Our clinical and experiential studies showed that ß1ARAbs participate in the development of AF and that the potential mechanism is related to the promotion of atrial fibrosis.