Objective:To investigate the ability of 18F-fibroblast activation protein inhibitor (FAPI) PET/CT imaging to identify involved myocardium in patients with hypertrophic cardiomyopathy (HCM) compared with cardiac MRI. Methods:A prospective study was conducted on 50 patients (32 males, 18 females, age (43±13) years) with HCM confirmed by ultrasound or cardiac MRI in Beijing Chaoyang Hospital from July 2021 to January 2022. All patients underwent both cardiac 18F-FAPI PET/CT and MRI. The SUV max and maximum target-to-background ratio (TBR max) of the left ventricular myocardium were obtained using post-processing software. Regions with 18F-FAPI uptake not less than predefined thresholds (SUV max 40%, 50%, 60%) were defined as myocardium with positive uptake. The FAPI amount was defined as the product of TBR max and the extent of FAPI-positive uptake (FAPI%). Cardiac MRI post-processing software was used to measure the extent of left ventricular myocardial late gadolinium enhancement (LGE) (expressed as LGE%), native T 1 value, extracellular volume fraction (ECV), and myocardial deformation characteristics. Spearman rank correlation analysis was employed to assess the correlation between 18F-FAPI imaging parameters and cardiac MRI parameters, as well as the correlation between FAPI amount and the 5-year risk score for sudden cardiac death (SCD). Linear regression analysis was utilized to identify factors associated with FAPI amount. Results:When the threshold for 18F-FAPI-positive uptake in the left ventricular myocardium was set at 60%, the correlations between FAPI amount, FAPI%, and MRI parameters were optimal ( rs values: from -0.465 to 0.460, all P<0.05). Multivariate linear regression analysis revealed that HCM duration ( β=0.128, 95% CI: 0.022-0.233, P=0.008), serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels ( β=0.190, 95% CI: 0.099-0.280, P<0.001), and left ventricular ejection fraction ( β=-0.005, 95% CI: -0.011 to 0.000, P=0.041) were independent predictors of FAPI amount. FAPI amount was positively correlated with the 5-year SCD risk score across different thresholds (40%: rs=0.32, P=0.026; 50%: rs=0.29, P=0.039; 60%: rs=0.29, P=0.040). Conclusions:When the threshold for 18F-FAPI-positive uptake is set at 60%, 18F-FAPI PET/CT imaging can more effectively identify the involved myocardium in HCM. FAPI amount is correlated with the 5-year SCD risk score in patients with HCM.

Objective To enhance the cyclic peptide compound's membrane permeability,structural stability,and neuroprotective activity,based on the amino acid sequence of peptides of Tat-GluA2-3Y,by designing and synthesizing a serial of cyclic peptides through strategies including polypeptide cyclization,replacement of the cell-penetrating peptide,substitution with D-amino acids,and incorporation of mini polyethylene glycol fragments.Methods The target peptides were synthesized based on standard Fmoc solid-phase method,followed by analysis and purification via reverse phase high-performance liguid chromatography(RP-HPLC).The cytoprotective activity of the peptides was evaluated by using the HT-22 cell model.The transmembrane transport efficiency of the peptides was determined based on the Caco-2 monolayer intestinal epithelial cell model.Plasmatic plasma and metabolic stability of the peptides were measured by in vitro co-incubation experiments with rat plasma and human liver microsomes.Finally,the in vivo neuroprotective activity of the peptides was validated by using a mouse middle cerebral artery occlusion model.Results Seven cyclic peptides were successfully designed and synthesized by using the standard Fmoc solid-phase method,with purities exceeding 90%as confirmed by RP-HPLC.Cytoprotective activity assay demonstrated that both Tat-GluA2-3Y and CMT-C3Y exhibited activity at concentrations above 125 nmol/L,with CMT-C3Y showing superior activity as compared to Tat-GluA2-3Y.The results of the transmembrane assay demonstrated that,compared to Tat-GluA2-3Y,CMT-C3Y exhibited significant transmembrane capabilities at all tested concentrations(P<0.001).CMT-C3Y was classified as a highly permeable compound,whereas Tat-GluA2-3Y was categorized as a moderately permeable compound.Plasma stability studies indicated that over 50%of Tat-GluA2-3Y was metabolized after 4 h of co-incubation with rat plasma.After 8 h of coincubation with CMT-C3Y,the remaining amount was 88.1%,and no obvious degradation phenomenon occurred.In human liver microsomal stability tests,the half-life of Tat-GluA2-3Y was 26.1 min,as compared to 103.8 min for CMT-C3Y,highlighting the enhanced stability of CMT-C3Y.Tat-GluA2-3Y and CMT-C3Y were classified as a fast-metabolizing drug and a moderate-metabolizing drug,respectively.Animal experiments further demonstrated that at a dose of 8 mg/kg the neuroprotective activity of CMT-C3Y was significantly superior to that of Tat-GluA2-3Y(P<0.001).Conclusion The designed bicyclic peptide CMT-C3Y demonstrates significantly higher cell-penetrating efficiency and superior plasma stability as compared to Tat-GluA2-3Y,along with enhanced neuroprotective activity at both cellular and animal levels.

Objective:To explore the value of cardiac magnetic resonance imaging (CMR) derived left ventricular late gadolinium enhancement (LV LGE) for the primary prevention of malignant ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients.Methods:This was a single-center retrospective study. Consecutive ARVC patients who underwent CMR at Fuwai Hospital between January 2016 and September 2020, with no history of malignant ventricular arrhythmias at diagnosis, were enrolled. Clinical data and CMR characteristics were collected. The primary endpoint was defined as new-onset malignant ventricular arrhythmias related events, including sustained ventricular tachycardia, ventricular fibrillation/flutter, sudden cardiac death, cardiac arrest, and appropriate implantable cardioverter-defibrillator discharge. Follow-up via telephone interviews and medical records was conducted to confirm endpoint occurrences, and patients were categorized into event-free and event groups based on endpoint status. Univariable and multivariable Cox regression analysis were performed to identify independent risk factors for malignant ventricular arrhythmias in ARVC patients. Subgroup analyses were conducted based on the ARVC 5-year risk score (cutoff: 25%) and the median value of LV LGE percentage (cutoff: 13%). Kaplan-Meier curves were plotted, and log-rank tests were used to compare the difference in the incidence of primary endpoint events between subgroups. Receiver operating characteristic curves and likelihood ratio test were used to evaluate the incremental prognostic value of LV LGE percentage beyond the ARVC 5-year risk score.Results:A total of 172 ARVC patients were enrolled, aged (39.0±16.6) years, including 73 females (42.4%). During a follow-up of 53.1 (25.4, 76.9) months, 51 patients (29.7%) experienced malignant ventricular arrhythmias related events, including 3 cases of sudden cardiac death, 1 cardiac arrest, 33 sustained ventricular tachycardia and 14 appropriate implantable cardioverter-defibrillator discharges. Multivariable Cox regression analysis indicated that the ARVC 5-year risk score ( HR=1.028, 95% CI 1.015-1.041, P<0.001) and LV LGE percentage ( HR=1.059, 95% CI 1.032-1.087, P<0.001) were independent risk factors of the primary endpoint events. Kaplan-Meier analysis using composite stratification (ARVC 5-year risk score cutoff: 25%; LV LGE percentage cutoff: 13%) demonstrated that patients with both high risk scores (≥25%) and extensive LV LGE (≥13%) had the highest risk of primary endpoint events. Notably, among patients with ARVC 5-year risk scores <25%, those with LV LGE≥13% had a higher incidence of primary endpoint events than those without (log-rank P=0.037). The composite prediction model combining the 5-year risk score and left ventricular LGE percentage demonstrated significantly improved predictive performance (area under the curve ( AUC)=0.82, 95% CI 0.75-0.90; likelihood ratio test all P<0.001) compared to single-variable models (left ventricular LGE percentage alone: AUC=0.71, 95% CI 0.63-0.82, P=0.01; 5-year risk score alone: AUC=0.71, 95% CI 0.62-0.81, P=0.02). Conclusion:LV LGE percentage independently predict new-onset malignant ventricular arrhythmias in ARVC patients and provided incremental prognostic value based on the existing ARVC 5-year risk score.

Objective:To investigate the ability of 18F-fibroblast activation protein inhibitor (FAPI) PET/CT imaging to identify involved myocardium in patients with hypertrophic cardiomyopathy (HCM) compared with cardiac MRI. Methods:A prospective study was conducted on 50 patients (32 males, 18 females, age (43±13) years) with HCM confirmed by ultrasound or cardiac MRI in Beijing Chaoyang Hospital from July 2021 to January 2022. All patients underwent both cardiac 18F-FAPI PET/CT and MRI. The SUV max and maximum target-to-background ratio (TBR max) of the left ventricular myocardium were obtained using post-processing software. Regions with 18F-FAPI uptake not less than predefined thresholds (SUV max 40%, 50%, 60%) were defined as myocardium with positive uptake. The FAPI amount was defined as the product of TBR max and the extent of FAPI-positive uptake (FAPI%). Cardiac MRI post-processing software was used to measure the extent of left ventricular myocardial late gadolinium enhancement (LGE) (expressed as LGE%), native T 1 value, extracellular volume fraction (ECV), and myocardial deformation characteristics. Spearman rank correlation analysis was employed to assess the correlation between 18F-FAPI imaging parameters and cardiac MRI parameters, as well as the correlation between FAPI amount and the 5-year risk score for sudden cardiac death (SCD). Linear regression analysis was utilized to identify factors associated with FAPI amount. Results:When the threshold for 18F-FAPI-positive uptake in the left ventricular myocardium was set at 60%, the correlations between FAPI amount, FAPI%, and MRI parameters were optimal ( rs values: from -0.465 to 0.460, all P<0.05). Multivariate linear regression analysis revealed that HCM duration ( β=0.128, 95% CI: 0.022-0.233, P=0.008), serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels ( β=0.190, 95% CI: 0.099-0.280, P<0.001), and left ventricular ejection fraction ( β=-0.005, 95% CI: -0.011 to 0.000, P=0.041) were independent predictors of FAPI amount. FAPI amount was positively correlated with the 5-year SCD risk score across different thresholds (40%: rs=0.32, P=0.026; 50%: rs=0.29, P=0.039; 60%: rs=0.29, P=0.040). Conclusions:When the threshold for 18F-FAPI-positive uptake is set at 60%, 18F-FAPI PET/CT imaging can more effectively identify the involved myocardium in HCM. FAPI amount is correlated with the 5-year SCD risk score in patients with HCM.

Objective:To explore the value of cardiac magnetic resonance imaging (CMR) derived left ventricular late gadolinium enhancement (LV LGE) for the primary prevention of malignant ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients.Methods:This was a single-center retrospective study. Consecutive ARVC patients who underwent CMR at Fuwai Hospital between January 2016 and September 2020, with no history of malignant ventricular arrhythmias at diagnosis, were enrolled. Clinical data and CMR characteristics were collected. The primary endpoint was defined as new-onset malignant ventricular arrhythmias related events, including sustained ventricular tachycardia, ventricular fibrillation/flutter, sudden cardiac death, cardiac arrest, and appropriate implantable cardioverter-defibrillator discharge. Follow-up via telephone interviews and medical records was conducted to confirm endpoint occurrences, and patients were categorized into event-free and event groups based on endpoint status. Univariable and multivariable Cox regression analysis were performed to identify independent risk factors for malignant ventricular arrhythmias in ARVC patients. Subgroup analyses were conducted based on the ARVC 5-year risk score (cutoff: 25%) and the median value of LV LGE percentage (cutoff: 13%). Kaplan-Meier curves were plotted, and log-rank tests were used to compare the difference in the incidence of primary endpoint events between subgroups. Receiver operating characteristic curves and likelihood ratio test were used to evaluate the incremental prognostic value of LV LGE percentage beyond the ARVC 5-year risk score.Results:A total of 172 ARVC patients were enrolled, aged (39.0±16.6) years, including 73 females (42.4%). During a follow-up of 53.1 (25.4, 76.9) months, 51 patients (29.7%) experienced malignant ventricular arrhythmias related events, including 3 cases of sudden cardiac death, 1 cardiac arrest, 33 sustained ventricular tachycardia and 14 appropriate implantable cardioverter-defibrillator discharges. Multivariable Cox regression analysis indicated that the ARVC 5-year risk score ( HR=1.028, 95% CI 1.015-1.041, P<0.001) and LV LGE percentage ( HR=1.059, 95% CI 1.032-1.087, P<0.001) were independent risk factors of the primary endpoint events. Kaplan-Meier analysis using composite stratification (ARVC 5-year risk score cutoff: 25%; LV LGE percentage cutoff: 13%) demonstrated that patients with both high risk scores (≥25%) and extensive LV LGE (≥13%) had the highest risk of primary endpoint events. Notably, among patients with ARVC 5-year risk scores <25%, those with LV LGE≥13% had a higher incidence of primary endpoint events than those without (log-rank P=0.037). The composite prediction model combining the 5-year risk score and left ventricular LGE percentage demonstrated significantly improved predictive performance (area under the curve ( AUC)=0.82, 95% CI 0.75-0.90; likelihood ratio test all P<0.001) compared to single-variable models (left ventricular LGE percentage alone: AUC=0.71, 95% CI 0.63-0.82, P=0.01; 5-year risk score alone: AUC=0.71, 95% CI 0.62-0.81, P=0.02). Conclusion:LV LGE percentage independently predict new-onset malignant ventricular arrhythmias in ARVC patients and provided incremental prognostic value based on the existing ARVC 5-year risk score.

Objective:To investigate the value of T 1ρ mapping in the assessment of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM). Methods:Forty HCM patients and 16 healthy volunteers who underwent CMR examination between December 2021 and May 2022 were prospectively enrolled. T 1ρ mapping, pre-and post-contrast T 1 mapping, and gadolinium contrast-enhanced delayed enhancement (LGE) imaging were performed in HCM patients, while T 1ρ mapping and T 1 mapping were performed in volunteers. HCM patients were further divided into LGE-positive (LGE+) and LGE-negative (LGE-) groups based on the presence or absence of LGE. The T 1ρ and pre-contrast T 1 values of the left ventricular myocardium of HCM patients and volunteers were measured, and the extracellular volume fraction (ECV) of the left ventricular myocardium of HCM patients was measured using pre-and post-contrast T 1 mapping. One-way ANOVA was used to compare the T 1ρ and pre-contrast T 1 values among the LGE+, LGE-, and volunteer groups, and pairwise comparisons were further corrected using the Bonferroni method. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of pre-contrast T 1 and T 1ρ values in distinguishing LGE+ and LGE- patients from volunteers. The chi-square test or Fisher′s exact probability test was used for categorical variable comparisons. Pearson correlation coefficient was used to evaluate the correlation between T 1ρ and pre-contrast T 1, and ECV. Results:There were no significant differences in age, gender, and body surface area among the LGE+, LGE-, and healthy control groups ( P>0.05). Compared to the HC group, both the T 1ρ value ( t=5.74, P<0.001) and the pre-contrast T 1 value ( t=3.99, P<0.001) increased in LGE positive group, as well as in the LGE negative group (T 1ρ: t=4.19, P<0.001; T 1: t=2.06, P<0.044). ROC analysis showed that the area under the curve (AUC) of T 1ρ and pre-contrast T 1 in distinguishing LGE+patients from healthy controls were 0.93 (sensitivity 84.0%, specificity 93.8%) and 0.87 (sensitivity 84.0%, specificity 87.5%), respectively. The AUC of T 1ρ and pre-contrast T 1 in distinguishing LGE-patients from healthy controls were 0.84 (sensitivity 86.7%, specificity 68.8%) and 0.68 (sensitivity 60%, specificity 68.8%), respectively. The correlation analysis showed that the T 1ρ value of the left ventricular myocardium was positively correlated with the pre-contrast T 1 value ( r=0.31, P=0.02) and ECV value ( r=0.38, P=0.02). Conclusion:Without the use of contrast agents, T 1ρ mapping shows good performance for myocardial replacement fibrosis and diffuse fibrosis in HCM patients.

Objective:To investigate the clinical and cardiac magnetic resonance (CMR) characteristics of heart involvement in patients with Fabry disease (AFD).Methods:From January 2018 to March 2021, eight AFD patients [3 males and 5 females, mean age (50±11) years old, range 26-60 years old] confirmed by genetic testing or pathology in Fuwai Hospital were retrospectively included in this study. At the same time, sixteen patients with hypertrophic cardiomyopathy (HCM) [6 males and 10 females, mean age (46±15) years old] and 16 healthy individuals [6 males and 10 females, mean age (51±11) years old] were included as controls. The clinical baseline data and CMR data of the patients were collected and analyzed. The CMR data were analyzed using the software CVI42, with the corresponding parameters automatically generated. One-way ANOVA or Kruskal-Wallis test was used to compare the differences in the parameters among the three groups. Independent-samples t test, Fisher precise test or Mann-Whitney U test were used for the comparison between each two groups. Results:Statistically significant difference was found in renal insufficiency between the HCM group and the AFD group; No other significant difference was found in other clinical factors and ECG results (all P>0.05). CMR results showed that in the AFD group, there were 5 cases with symmetric or roughly symmetric hypertrophy, and 3 with asymmetric hypertrophy. The late gadolinium enhancement (LGE) showed myocardial enhancement in 5 patients, mainly presenting as multiple intermural enhancement, and partially as local subendocardial enhancement. In the HCM group, fourteen cases suffered mainly asymmetric ventricular septal thickening, with or without thickening of other parts of left ventricular wall; and 2 cases had thickening of middle and distal part of the left ventricle. The LGE showed myocardial enhancement in 14 patients, which manifested as focal or patchy enhancement in hypertrophic myocardium, including focal enhancement in the right ventricular insertion of ventricular septum (more common) and subendocardial enhancement in the middle and far segments of left ventricle. Statistically significant difference was found in the differences between the left atrial anterior posterior diameter, the maximum wall thickness of left ventricular, the left ventricular myocardial mass index (LVMI) and the native T 1 value among the three groups (all P<0.001). However, there was no statistically significant difference in the left atrial anterior posterior diameter and the maximum wall thickness of left ventricular between AFD group and HCM group ( P>0.05). The LVMI in AFD group was higher than that in healthy group and HCM group (all P<0.05). Significant difference was found in the native T 1 value among the three groups, with the native T 1 value of the AFD group [(1 177.4±46.0) ms] was significantly lower than that of the healthy group [(1 244.5±34.3) ms] and the HCM group [(1 278.8±41.6) ms], with ( F=13.10, P<0.001). Conclusions:The clinical characteristics of AFD and HCM are quite similar. When AFD is suspected, CMR imaging should be the first choice for imaging examination. Especially, T 1 mapping imaging can provide important information for the diagnosis of AFD.

A patient aged 68 years old presented urinary frequency, urgency, and gross hematuria for 1 month, with initial PSA of 72.72 ng/ml and alkaline phosphatase (ALP)of 114 U/L. Prostate biopsy pathology showed small cell neuroendocrine carcinoma of prostate. The patient was immediately administered 6 cycle of chemotherapy including etoposide and cisplatin combined with medical castration. The CDK4 gene was detected 1.99 times amplification by peripheral blood free DNA (cfDNA)gene analysis. The chemotherapy was followed by parbosini therapy. The number and density of bone metastases continued to decrease significantly by bone scan at 3 and 6 months after treatment, with a continuous decline of ALP and PSA. After 1 year of follow-up, pelvic MRI and bone systemic imaging indicated stable lesions, with PSA of 0.05 ng/ml and ALP of 59 U/L.

Objective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2018 to December 2019. Antibiotic susceptibility tests were conducted with agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 14 778 bacterial strains were collected from 50 hospitals, of which 4 117 (27.9%) were Gram-positive bacteria and 10 661(72.1%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.2%), Klebsiella pneumoniae (17.0%), Staphylococcus aureus (9.7%), coagulase-negative Staphylococci (8.7%), Pseudomonas aeruginosa (3.7%), Enterococcus faecium (3.4%), Acinetobacter baumannii(3.4%), Enterobacter cloacae (2.9%), Streptococci(2.8%) and Enterococcus faecalis (2.3%). The the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus were 27.4% (394/1 438) and 70.4% (905/1 285), respectively. No glycopeptide-resistant Staphylococcus was detected. More than 95% of S. aureus were sensitive to amikacin, rifampicin and SMZco. The resistance rate of E. faecium to vancomycin was 0.4% (2/504), and no vancomycin-resistant E. faecalis was detected. The ESBLs-producing rates in no carbapenem-resistance E. coli, carbapenem sensitive K. pneumoniae and Proteus were 50.4% (2 731/5 415), 24.6% (493/2001) and 35.2% (31/88), respectively. The prevalence of carbapenem-resistance in E. coli and K. pneumoniae were 1.5% (85/5 500), 20.6% (518/2 519), respectively. 8.3% (27/325) of carbapenem-resistance K. pneumoniae was resistant to ceftazidime/avibactam combination. The resistance rates of A. baumannii to polymyxin and tigecycline were 2.8% (14/501) and 3.4% (17/501) respectively, and that of P. aeruginosa to carbapenem were 18.9% (103/546). Conclusions:The surveillance results from 2018 to 2019 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while E. coli was the most common pathogen, and ESBLs-producing strains were in majority; the MRSA incidence is getting lower in China; carbapenem-resistant E. coli keeps at a low level, while carbapenem-resistant K. pneumoniae is on the rise obviously.

Objective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2016 to December 2017. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI) 2019. WHONET 5.6 was used to analyze data.Results:During the study period, 8 154 bacterial strains were collected from 33 hospitals, of which 2 325 (28.5%) were Gram-positive bacteria and 5 829 (71.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (34.7%), Klebsiella pneumoniae (15.8%), Staphylococcus aureus (11.3%), coagulase-negative Staphylococci (7.4%), Acinetobacter baumannii (4.6%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.8%), Streptococci (2.9%), Enterobacter cloacae (2.7%) and Enterococcus faecalis (2.5%). Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MRCNS) accounted for 34.2%(315/922) and 77.7%(470/605), respectively. No vancomycin-resistant Staphylococcus was detected. The resistance rate of Enterococcus faecium to vancomycin was 0.6%(2/312), and no vancomycin-resistant Enterococcus faecium was detected. The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus were 55.7%(1 576/2 831), 29.9%(386/1 289) and 38.5%(15/39), respectively. The incidences of carbapenem-resistance in Escherichia coli, Klebsiella pneumoniae were 1.2%(33/2 831), 17.5%(226/1 289), respectively. The resistance rates of Acinetobacter baumannii to polymyxin and tigecycline were 14.8%(55/372) and 5.9%(22/372) respectively, and those of Pseudomonas aeruginosa to polymyxin and carbapenem were 1.3%(4/315) and 18.7%(59/315), respectively. Conclusion:The surveillance results from 2016 to 2017 showed that the main pathogens of blood stream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen; the MRSA incidence was lower than other surveillance data in the same period in China; carbapenem-resistant Escherichia coli was at a low level during this surveillance, while carbapenem-resistant Klebsiella pneumoniae is on the rise.