Scalable Quantum Monte Carlo with Direct-Product Trial Wave Functions.

The computational demand posed by applying multi-Slater determinant trials in phaseless auxiliary-field quantum Monte Carlo methods (MSD-AFQMC) is particularly significant for molecules exhibiting strong correlations. Here, we propose using direct-product wave functions as trials for MSD-AFQMC, aiming to reduce computational overhead by leveraging the compactness of multi-Slater determinant trials in direct-product form (DP-MSD). This efficiency arises when the active space can be divided into noncoupling subspaces, a condition we term "decomposable active space". By employing localized-active space self-consistent field wave functions as an example of such trials, we demonstrate our proposed approach across a range of molecular systems, each exhibiting varying degrees of complexity in their electronic structures. Our findings indicate that the compact DP-MSD trials can reduce computational costs substantially, by up to 36 times for the C2H6N4 molecule where the two double bonds between nitrogen N=N are clearly separated by a C-C single bond, while maintaining accuracy when active spaces are decomposable. In the case of larger systems such as the benzene dimer, characterized by weak coupling between the two monomers, we observed a decrease in computational cost compared to using a complete active space trial, yet we retained the same level of accuracy. However, for systems where these active subspaces strongly couple, a scenario we refer to as "strong subspace coupling", the method's accuracy decreases compared to that achieved with a complete active space approach. We anticipate that our method will be beneficial for systems with noncoupling to weakly coupling subspaces that require local multireference treatments.

Dual optical detection approach for capillary electrophoresis following two-step liquid-liquid extraction to determine ten phenols in water samples.

In this research, the analytical method was developed and evaluated for determining phenol and its nine derivatives belong to the US EPA priority pollutant list in water samples by using dual-channeled capillary electrophoresis (CE) coupled with two types of optical detectors, namely LED-induced fluorescence (LEDIF) and ultraviolet (UV) detectors. The optimal background electrolytes for the first and second CE channels were 20 mM borate (pH 9.80) with 400 µM fluorescein and 55 mM borate (pH 11.75), respectively. The two-step liquid-liquid extraction (LLE) was used for sample preparation and enrichment, in which phenol and its derivatives were extracted from the aqueous phase using 10 mL of n-hexane/1-octanol (60/40, v/v) and then were back extracted into a 0.1 M NaOH as a final acceptor phase. Under the optimal CE and two-step LLE conditions, the enrichment factors of 10 phenols were 184 - 1120-fold, and the method detection limits were lowered to 0.02-0.60 µg/L. The obtained intra-day and inter-day precisions in terms of relative standard deviations (RSD) were between 4.0 and 7.3 % and 6.7 and 14 %, respectively. This approach was used to determine phenols in water samples, with recoveries ranging from 82.0 to 108.9 %. In combination with sample enrichment by two-step LLE extraction, this is the first CE study conducted to determine phenols in the EPA list using two detector approaches, specifically CE-LEDIF/CE-UV.

Evaluating Renal Benefits of Rivaroxaban Versus Vitamin K Antagonists in Atrial Fibrillation: A Systematic Review and Meta-analysis of Real-world Evidence.

Background: AF is a global health concern, with systemic complications including renal dysfunction. This systematic review and meta-analysis compares the effects of rivaroxaban, a Factor Xa inhibitor, and vitamin K antagonists (VKAs) on renal outcomes in AF patients. Methods: The study protocol is registered in PROSPERO (ID: CRD42023462756). We systematically searched the PubMed, Embase and Cochrane Library databases from 1 January 2017 to 30 June 2023 for real-world studies comparing the effects of rivaroxaban and VKAs on renal outcomes in AF patients, including acute kidney injury, a .30% decrease in estimated glomerular filtration rate, doubling of serum creatinine and worsening renal function. Subgroup analyses targeted diabetes, pre-existing kidney disease, the elderly (age .65 years) and Asian populations. The risk of bias was assessed used the Robins-I tool. HRs and 95% CIs were synthesised through a random-effects model. Two sensitivity analyses were performed, using a fixed-effects model and excluding conference abstracts. Results: We identified 1,666 records. After screening, 14 studies comparing rivaroxaban and VKAs were included. Rivaroxaban exhibited superiority over VKAs in preventing: acute kidney injury (HR 0.68; 95% CI [0.61.0.77]; p<0.00001); a .30% decrease in estimated glomerular filtration rate (HR 0.71; 95% CI [0.60.0.84]; p<0.0001); doubling of serum creatinine (HR 0.50; 95% CI [0.36.0.70]; p<0.0001); and worsening renal function (HR 0.56; 95% CI [0.45.0.69]; p<0.00001). Subgroup and sensitivity analyses consistently confirmed rivaroxaban's favourable effects on renal outcomes in diabetes, pre-existing kidney disease, the elderly and Asian populations. Conclusion: Our findings support the preference of rivaroxaban over VKAs for renal outcomes in AF. The findings endorse rivaroxaban as the preferred anticoagulant to mitigate renal complications, offering clinicians valuable insights for tailored strategies.

Electrocardiographic and genetic characteristics in first degree relatives of hypertrophic cardiomyopathy probands: A descriptive cross-sectional study from Vietnam.

Objectives: In order to study the phenotype-genotype relationship and to better understand the early consequences of the mutation, we would report the spectrum of electrocardiographic and genetic features in the relatives of hypertrophic cardiomyopathy (HCM) patients. Methods: Participants underwent a comprehensive clinical assessment, electrocardiography, standardized and echocardiography and genetic testing. In probands, next-generation sequencing was performed using the gene panel associated with HCM, while in relatives, Sanger sequencing was used to screen for mutations identified in their individual probands. Results: A total of 84 participants were included in this study. The interventricular septal and posterior wall thickness was highest in the G+/LVH+ group, followed by the G+/LVH- group, and was lowest in G-/LVH- group. Compared to the normal control group, the pathologic Q wave was statistically more prevalent in the G+/LVH- group. The prevalence of repolarization abnormalities and major abnormalities was highest in the G+/LVH+ group, followed by the G+/LVH- group, and lowest in G-/LVH- group. Conclusion: Our results suggested that sarcomere mutations have early consequences on myocardial biology. These findings suggest the possibility of implementing a mutation carrier detection model within families affected by HCM, where ECG could play a central role when combined with other relevant clinical factors. Longitudinal studies on a cohort of G+/LVH- patients are required.

Taxonomic revision of the Southeast Asian brook barb genus Poropuntius Smith, 1931 (Teleostei, Cyprinidae) with description of a new species from Vietnam.

Molecular data from samples encompassing 22 nominal species of Poropuntius indicate that the species-level diversity in the genus has been vastly overestimated, likely due to inadequate taxon and geographic sampling and reliance on morphological characters that vary intra-specifically. The latter includes discrete mouth morphologies related to alternate feeding strategies (ecomorphs) within populations. One new species is described, Poropuntiusanlaoensis Hoàng, Pham & Tran, sp. nov., and 17 synonyms of six valid species names of Poropuntius, P.krempfi, P.alloiopleurus, P.huangchuchieni, P.laoensis, P.kontumensis, and P.deauratus, are recognised. Additional taxonomic changes in this widespread and generally poorly known genus are likely as more molecular and morphological data become available.

Removal of perfluoroalkyl acids (PFAAs) from aqueous solution by water hyacinth (Eichhornia crassipes): Uptake, accumulation, and translocation.

Although Eichhornia crassipes, commonly known as water hyacinth, has been widely used in wastewater treatment, further investigations are still needed to explore the removal efficiency of perfluoroalkyl acids (PFAAs) from the aqueous environment using this floating aquatic plant. In this study, a hydroponic experiment was conducted to assess accumulation, bioconcentration factors (BCFs), translocation factors (TFs), and removal rates of eight PFAAs by water hyacinth. The obtained results indicated that all PFAAs, including five perfluoroalkyl carboxylic acids (PFCAs) with chain lengths C4-C8 and three perfluoroalkyl sulfonic acids (PFSAs) with C4, C6, and C8, were readily accumulated in water hyacinth. Throughout the duration of the experiment, there was a noticeable increase in PFAA concentrations and BCF values for different plant parts. For the root, PFAAs with more carbon numbers showed a higher uptake than the shorter homologues, with PFSAs being more readily accumulated compared to PFCAs with the same carbon number in the molecules. In contrast, the levels of long-chain PFAAs were comparatively lower than those of short-chain substances in the stem and leaf. Notably, PFAAs with less carbon numbers, like PFPeA, PFBA, and PFBS, showed a remarkable translocation from the root to the stem and leaf with TFs >1. For the whole plant, no significant correlation was found between BCFs and organic carbon-water partition coefficients (Koc), octanol-water partition coefficients (Kow), membrane-water distribution coefficients (Dmw), or protein-water distribution coefficients (Dpw). The removal rates of PFAAs ranged from 40.3 to 63.5 % throughout the three weeks of the experiment while the removal efficiencies varied from 48.9 % for PFHxS to 82.6 % for PFPeA in the last week.

Multifocal fatty liver nodules mimicking a metastatic disease: A case report.

Multifocal fatty liver nodules can present a diagnostic challenge due to their resemblance to metastatic liver disease. This case report illustrates the complexity of such scenarios through the presentation of a middle-aged male patient. Despite the common nature of fatty liver disease, characterized by hepatocyte fat accumulation leading to diffuse and uniform liver lesions, rare instances exhibit heterogeneous appearances. The case underlines the potential confusion arising from imaging modalities when multiple small nodules disperse throughout the liver, mimicking multifocal tumors or metastases. The report emphasizes the critical role of comprehensive diagnostic procedures in preventing misdiagnosis and unwarranted interventions. Effective management hinges on multidisciplinary collaboration among specialists, ensuring accurate differentiation and appropriate treatment. This study serves as a reminder of the intricacies involved in interpreting multifocal fatty liver nodules that may masquerade as metastatic disease, highlighting the need for precision in clinical practice.

Antibody Response after a Booster COVID-19 Vaccine Mixing in Vietnam.

BACKGROUND: The booster vaccine is essential for maintaining the antibody against the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) virus. This study sought to evaluate the antibody response after booster coronavirus disease 2019 (COVID-19) vaccines and compare the immunogenic by different vaccine combination strategies. METHODS: A cross-sectional study in Hanoi, Vietnam was conducted on 679 adult participants who received two doses of vaccines with any combination of AstraZeneca, Pfizer, and Moderna during the COVID-19 vaccination campaign in 2021. The SARS-CoV-2 S1/S2 Immunoglobulin G (IgG) antibody concentrations were measured by the LIAISON SARS-CoV-2 S1/S2 IgG and presented as arbitrary units. RESULTS: We found that the median (interquartile range (IQR)) of IgG level among those who completed two doses of Moderna and Pfizer was 484.55 (284.80) AU/mL and 349.00 (362.50) AU/mL, respectively. Meanwhile, the counterpart of AstraZeneca was 110.00 (128.10) AU/mL. Mixing two doses of AstraZeneca-Pfizer has higher odds of having high IgG level than two doses of Pfizer (Odds Ratios (OR) = 2.94, 95% Confidence Intervals (CI): 1.57-5.51), AstraZeneca (OR = 28.50, 95% CI: 15.00-54.14). CONCLUSIONS: We found that the matching two doses of mRNA vaccines are more immunogenic as compared to the DNA vector vaccines. Furthermore, mixing AstraZeneca-Pfizer has higher antibody quantities as compared to matching vaccines, while lower the rate of advert events.

Infiltrating lobular carcinoma of LUMB HER2+ subtype with rhabdoid feature coexisting with synchronous malignant transformation of phyllodes tumor: An exceedingly rare clinicopathological characteristic in Vietnam.

The transformation of a benign phyllodes tumor (PT) into a malignant PT and/or carcinoma is extremely uncommon. We present a case of a 66-year-old female with a huge mass on the left breast which was successfully removed by surgical resection. The pathological diagnosis was infiltrating lobular carcinoma with pure rhabdoid features and the malignant transformation of a benign phyllodes tumor. The first time this rare case was reported, it is demonstrated a special phenomenon through the synchronous transformation of PT grades and the carcinomatous transformation of PT.

Bioaccessibility of halogenated flame retardants and organophosphate esters in settled dust: Influences of specific dust matrices from informal e-waste and end-of-life vehicle processing areas in Vietnam.

Bioaccessibility of halogenated flame retardants (HFRs) and organophosphorus esters (OPEs) is necessarily investigated to provide more accurate risk assessment and information about absorption behavior of these pollutants. In this study, total and bioaccessible concentrations of HFRs (including legacy and alternative substances) and OPEs were determined in settled dust samples collected from Vietnamese e-waste and end-of-life vehicle (ELV) processing areas. Concentrations of both HFRs and OPEs were significantly higher in the e-waste dust than ELV dust. Bioavailability of HFRs and OPEs in dust was determined by using an in vitro assay with human-simulated digestive fluids, dialysis membrane, and Tenax® TA sorptive sink. Bioaccessibility of HFRs was markedly lower than that of OPEs, which could be largely due to higher hydrophobicity of HFRs compared to OPEs. Bioaccessibility of almost hydrophobic compounds were markedly lower in the e-waste dust (containing micronized plastic debris) than in the ELV dust (containing oily materials), suggesting the influence of specific dust matrices on pollutant bioaccessibility. Although the daily uptake doses of selected HFRs and OPEs from dust were markedly higher in the e-waste sites compared to the ELV sites, the direct exposure risk was not significant. Our results suggest that bioaccessibility can partly explain the differences between dust and uptake profiles, which may relate to accumulation profiles of HFRs and OPEs in human samples.

Intussusception and Other Adverse Event Surveillance after Pilot Introduction of Rotavirus Vaccine in Nam Dinh and Thua Thien Hue Provinces-Vietnam, 2017-2021.

Rotavin-M1 (POLYVAC) was licensed in Vietnam in 2012. The association of Rotavin-M1 with intussusception, a rare adverse event associated with rotavirus vaccines, and with adverse events following immunization (AEFI) have not been evaluated and monitored under conditions of routine use. From February 2017 to May 2021, we conducted a pilot introduction of Rotavin-M1 into the routine vaccination program in two provinces. Surveillance for intussusception was conducted at six sentinel hospitals. AEFI reports at 30 min and 7 days after vaccination were recorded. Among 443 children <12 months of age admitted for intussusception, most (92.3%) were children ≥ 6 months. Of the 388 children who were age-eligible to receive Rotavin-M1, 116 (29.9%) had received ≥1 dose. No intussusception cases occurred in the 1-21 days after dose 1 and one case occurred on day 21 after dose 2. Among the 45,367 children who received ≥1 dose of Rotavin-M1, 9.5% of children reported at least one AEFI after dose 1 and 7.3% after dose 2. Significantly higher AEFI rates occurred among children given Rotavin-M1 with pentavalent vaccines (Quinvaxem®, ComBE Five®) compared to Rotavin-M1 without pentavalent vaccines. There was no association between intussusception and Rotavin-M1. The vaccine was generally safe when administered alone and when co-administered with other vaccines.

Cardiac diastolic maladaptation is associated with the severity of exercise intolerance in sickle cell anemia patients.

This pilot study focusing on Sickle Cell Anemia (SCA) patients offers a comprehensive and integrative evaluation of respiratory, cardiovascular, hemodynamic, and metabolic variables during exercise. Knowing that diastolic dysfunction is frequent in this population, we hypothesize that a lack of cardiac adaptation through exercise might lead to premature increase in blood lactate concentrations in SCA patients, a potential trigger for acute disease complication. SCA patients were prospectively included in PHYSIO-EXDRE study and underwent a comprehensive stress test with a standardized incremental exercise protocol up to 4 mmol L-1 blood lactate concentration (BL4). Gas exchange, capillary lactate concentration and echocardiography were performed at baseline, during stress test (at ∼ 2 mmol L-1) and BL4. The population was divided into two groups and compared according to the median value of percentage of theoretical peak oxygen uptake (% V ˙ O 2 p e a k t h ) at BL4. Twenty-nine patients were included (42 ± 12 years old, 48% of women). Most patients reached BL4 at low-intensity exercise [median value of predicted power output (W) was 37%], which corresponds to daily life activities. The median value of % V ˙ O 2 p e a k t h at BL4 was 39%. Interestingly, diastolic maladaptation using echocardiography during stress test along with hemoglobin concentration were independently associated to early occurrence of BL4. As BL4 occurs for low-intensity exercises, SCA patients may be subject to acidosis-related complications even during their daily life activities. Beyond assessing physical capacities, our study underlines that diastolic maladaptation during exercise is associated with an early increase in blood lactate concentration.

Atrial Arrhythmia in Sickle Cell Anemia Adults: A missing link towards understanding and preventing strokes.

Although sickle cell disease (SCD) patients carry both significant left atrial (LA) remodeling and increased risk of stroke, the prevalence of atrial arrhythmia (AA) has never been prospectively evaluated. This study aims to investigate the prevalence and predictors of atrial arrhythmia in homozygous SCD (SCA). From 2019 to 2022, 130 patients with SCA were referred to the physiology department to specifically analyze cardiac function and prospectively included in the DREPACOEUR registry. They underwent a 24-hour electrocardiogram monitoring (24h-Holter), transthoracic echocardiography, and laboratory tests on the same day. The primary endpoint was the occurrence of AA, defined by the presence of excessive supraventricular ectopic activity (ESVEA) on ECG-Holter (i.e., >720 premature atrial contractions [PACs] or any run ≥ 20 PACs), recent history of paroxysmal atrial fibrillation (AF), or persistent AF. The mean patient age was 45±12 years and 48% of male. Overall, AA was found in 34 (26%) patients. Age (52±9 vs. 42±12 years, P=0.002), LA dilation (LAVi, 71±24 vs. 52±14 ml/m², P<0.001) and history of stroke without underlying cerebral vasculopathy or other defined cause (26% vs. 5%, P=0.009, OR=6.6 [1.4; 30.3]) were independently associated with AA. Age and LAVi correlated with PAC load per 24 hours on ECG-Holter (R=0.56 and 0.33, P<0.001 respectively) and an age over 47 years or a LAVi >55mL/m² could predict AA with a PPV of 33% and a NPV of 92%. AAs are frequent in SCA patients and increase with age and LA remodeling, leading to a major additional risk factor for ischemic stroke. This study provides arguments and means to early screen for AA potentially preventing cerebral complications.

Safety, immunogenicity and efficacy of the self-amplifying mRNA ARCT-154 COVID-19 vaccine: pooled phase 1, 2, 3a and 3b randomized, controlled trials.

Combination of waning immunity and lower effectiveness against new SARS-CoV-2 variants of approved COVID-19 vaccines necessitates new vaccines. We evaluated two doses, 28 days apart, of ARCT-154, a self-amplifying mRNA COVID-19 vaccine, compared with saline placebo in an integrated phase 1/2/3a/3b controlled, observer-blind trial in Vietnamese adults (ClinicalTrial.gov identifier: NCT05012943). Primary safety and reactogenicity outcomes were unsolicited adverse events (AE) 28 days after each dose, solicited local and systemic AE 7 days after each dose, and serious AEs throughout the study. Primary immunogenicity outcome was the immune response as neutralizing antibodies 28 days after the second dose. Efficacy against COVID-19 was assessed as primary and secondary outcomes in phase 3b. ARCT-154 was well tolerated with generally mild-moderate transient AEs. Four weeks after the second dose 94.1% (95% CI: 92.1-95.8) of vaccinees seroconverted for neutralizing antibodies, with a geometric mean-fold rise from baseline of 14.5 (95% CI: 13.6-15.5). Of 640 cases of confirmed COVID-19 eligible for efficacy analysis most were due to the Delta (B.1.617.2) variant. Efficacy of ARCT-154 was 56.6% (95% CI: 48.7- 63.3) against any COVID-19, and 95.3% (80.5-98.9) against severe COVID-19. ARCT-154 vaccination is well tolerated, immunogenic and efficacious, particularly against severe COVID-19 disease.

A retrospective study of endogenous endophthalmitis-related pyogenic liver abscess: An increasing complication in North Vietnam.

Introduction: Endogenous endophthalmitis-related Klebsiella pyogenic liver abscess is a rare complication of metastatic infection. In most cases, visual acuity results are often impaired, even blind, and even with aggressive treatment with topical antibiotics, the final results are unsatisfactory. The objective of this study is to retrospectively based on medical records to describe clinical features, risk factors, and visual outcomes of patients with endogenous endophthalmitis-related pyogenic liver abscesses. Methods: We reported a case series of 12 endogenous endophthalmitis-related pyogenic liver abscess patients from March 2021 to 2023. All cases of endogenous endophthalmitis were diagnosed at admission or during the hospital stay. Results: From the medical records of 588 pyogenic liver abscess patients, we found 12 cases of endogenous endophthalmitis with 2.0%. The result showed a mean age of 61.5 ± 12.0 (41-78), diabetes mellitus (7 of 12), right lobe (7 of 12), single abscess (9 of 12), and the mean largest abscess diameter of 5.8 ± 1.7 cm (3.3-9). All patients had ocular symptoms such as eye pain (9 of 12), pus discharge (3 of 12), hypopyon (1 of 12), swollen eyelids (2 of 12), and corneal edema (2 of 12), pyogenic liver abscess before endogenous endophthalmitis (10 of 12), the median interval between endogenous endophthalmitis and pyogenic liver abscess 6.1 ± 1.9 days, ocular symptoms before diagnosis endogenous endophthalmitis 4.4 ± 2.3 days. All affected eyes were injected intravitreously with ceftazidime, amikacin, and vancomycin. Two patients underwent evisceration. Conclusions: Endogenous endophthalmitis has permanent morbidity, reducing visual acuity, poor quality of life, and lacks the warning signs, so it is essential for early detection of symptoms and referral to ophthalmologists.

Selection of Non-vitamin K Antagonist Oral Anticoagulant for Stroke Prevention in Atrial Fibrillation Based on Patient Profile: Perspectives from Vietnamese Experts. Part 2.

Part 1 of this review provided an overview of AF in Vietnam, with a particular focus on primary and secondary stroke prevention. Part 2 explores the management of AF in special, high-risk and clinically common patient populations, including those with renal impairment, diabetes, the elderly, and those with coronary artery disease. Furthermore, Part 2 addresses the challenges posed by patients with AF who have a bioprosthetic valve, a group situated in a grey area of consideration. Managing AF in these patient groups presents unique clinical challenges that require careful consideration. Physicians are tasked with addressing specific clinical questions to identify the optimal anticoagulation strategy for each individual. To inform these decisions, subgroup analyses from pivotal studies are presented alongside real-world data derived from clinical practice. By synthesising available information and considering the nuanced clinical context, the aim is to provide informed perspectives that align with current medical knowledge and contribute to the enhancement of patient care in these challenging scenarios.

Selection of Non-vitamin K Antagonist Oral Anticoagulant for Stroke Prevention in Atrial Fibrillation Based on Patient Profile: Perspectives from Vietnamese Experts. Part 1.

In Asia, especially Vietnam, AF is a common arrhythmia and is linked to a higher risk of stroke and systemic embolism. Anticoagulation therapy for stroke prevention in AF patients can result in bleeding complications. To effectively manage AF, adopting appropriate anticoagulation and addressing modifiable risk factors are crucial. Vietnamese clinicians are particularly interested in non-vitamin K antagonist oral anticoagulants (NOACs), a recent development in AF treatment. However, the lack of head-to-head trials comparing NOACs makes selecting a specific NOAC challenging. This review aims to provide a comprehensive overview of the available clinical evidence on NOACs for stroke prevention in AF to assist clinicians in making informed decisions and improving treatment outcomes in patients with AF. The first part of this review will present the current landscape of AF in Vietnam, focusing on AF prevalence and highlighting gaps in clinical practice. Furthermore, this part extensively discusses the anticoagulation strategy for both primary and secondary stroke prevention in AF.

Relationship between BMI and prognosis of chronic heart failure outpatients in Vietnam: a single-center study.

Background: Insufficient data exists regarding the relationship between body mass index (BMI) and the prognosis of chronic heart failure (CHF) specifically within low- and middle-income Asian countries. The objective of this study was to evaluate the impact of BMI on adverse outcomes of ambulatory patients with CHF in Vietnam. Methods: Between 2018 and 2020, we prospectively enrolled consecutive outpatients with clinically stable CHF in an observational cohort, single-center study. The participants were stratified according to Asian-specific BMI thresholds. The relationships between BMI and adverse outcomes (all-cause death and all-cause hospitalization) were analyzed by Kaplan-Meier survival curves and Cox proportional-hazards model. Results: Among 320 participants (age 63.5 ± 13.3 years, 57.9% male), the median BMI was 21.4 kg/m2 (IQR 19.5-23.6), and 10.9% were underweight (BMI <18.50 kg/m2). Over a median follow-up time of 32 months, the cumulative incidence of all-cause mortality and hospitalization were 5.6% and 19.1%, respectively. After multivariable adjustment, underweight patients had a significantly higher risk of all-cause mortality than patients with normal BMI (adjusted hazard ratios = 3.03 [95% CI: 1.07-8.55]). Lower BMI remained significantly associated with a worse prognosis when analyzed as a continuous variable (adjusted hazard ratios = 1.27 [95% CI: 1.03-1.55] per 1 kg/m2 decrease for all-cause mortality). However, BMI was not found to be significantly associated with the risk of all-cause hospitalization (p > 0.05). Conclusion: In ambulatory patients with CHF in Vietnam, lower BMI, especially underweight status (BMI < 18.5 kg/m2), was associated with a higher risk of all-cause mortality. These findings suggest that BMI should be considered for use in risk classification, and underweight patients should be managed by a team consisting of cardiologists, nutritionists, and geriatricians.