Junior doctors' workplace well-being and the determinants based on ability-motivation-opportunity (AMO) theory: Educational and managerial implications from a three-year longitudinal observation after graduation.

PURPOSE: Junior doctors function as trainees from an educational perspective and as employees from a human resource management perspective. Employing the ability-motivation-opportunity (AMO) theory as a conceptual framework, this study longitudinally investigated the factors affecting the workplace well-being and career progression of junior doctors over a 3-year period following their graduation from medical schools. MATERIALS AND METHODS: This 3-year prospective cohort study enrolled junior doctors who graduated from 2 medical schools in June 2019 in Taiwan. This study collected data by implementing web-based, self-administered structured questionnaires at 3-month intervals between September 2019 and July 2022. The collected data encompassed ability indicators (i.e. academic performance and perceived preparedness for clinical practice), motivation indicators (i.e. educational and clinical supervision), opportunity indicators (i.e. clinical unit cultures), and workplace well-being indicators (i.e. burnout, compassion satisfaction, and job performance). A total of 107 junior doctors participated, providing 926 total responses. The data were analysed using univariate analyses and structural equation modelling with path analysis. RESULTS: Over the 3-year period following graduation, the junior doctors' confidence in their preparedness for clinical practice and the educational and clinical supervision had varying degrees of influence on the junior doctors' workplace well-being. The influence of clinical unit cultures, which can provide opportunities for junior doctors, became evident starting from the second year postgraduation; notably, unit cultures that emphasised flexibility and discretion played positive and critical roles in enhancing the junior doctors' workplace well-being lasted to the third year. CONCLUSIONS: Our findings provide insights into the distinct critical factors that affect the socialisation of junior doctors within workplace environments over 3 consecutive years. These findings can provide guidance for medical educators and healthcare managers, helping them understand and support the progressive integration of junior doctors into their work environments.

Bacillus coagulans TCI711 Supplementation Improved Nonalcoholic Fatty Liver by Modulating Gut Microbiota: A Randomized, Placebo-Controlled, Clinical Trial.

Background: Nonalcoholic fatty liver disease (NAFLD) has become one of the major problems of chronic liver disease worldwide. It not only causes damage to the liver but also engenders chronic hepatitis and cirrhosis. Recent studies have shown that regulating Bacillus coagulans can improve NAFLD. Objectives: This trial explores whether B. coagulans TCI711 (BCT) could ameliorate NAFLD. Methods: A total of 57 patients with NAFLD were recruited through FibroScan liver fibrosis scanner and divided into placebo (n = 28) and BCT-supplemented groups (n = 29). Specifically, 1 BCT probiotic capsule was supplemented daily for 8 wk. Furthermore, the blood, stool, and fatty liver content were then examined. Results: Parameters evaluated for liver and kidney indicators showed no side effects after supplementing BCT. A significant reduction of 8.7% in the fatty liver was achieved by effectively suppressing the grade of fatty liver as revealed by controlled attenuation parameter. BCT also regulated gut microbiota profiles, with significant increases observed in Bifidobacterium, Eubacterium, Ruminococcaceae, and Sellimonas compared with the baseline. Conclusions: BCT may improve NAFLD by regulating gut microbiota, and parameters evaluated for liver and kidney indicate no side effects.

Effectiveness of Fish Roe, Snow Fungus, and Yeast Supplementation for Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

The brain is one of the most critical organs in the human body, regulating functions such as thinking, memory, learning, and perception. Studies have indicated that fish roe, snow fungus, and yeast may have the potential to modulate cognitive, memory, and emotional functions. However, more relevant clinical research in this area still needs to be conducted. This study explored the cognition-enhancing potential of a formula beverage including fish roe, snow fungus, and yeast. Sixty-four subjects were divided into a placebo group (n = 32) and a formula-drink group (n = 32), who consumed the product for 8 weeks. Cognitive tests were administered and analyzed at weeks 0, 4, and 8. After 4 and 8 weeks, there was a significant increase in the number of memory cards, and the response times among those who consumed the formula beverage were significantly faster than those in the placebo group. The subjects remembered the old items better and were more impressed with similar items based on the week effect. There was a significant increase in the cue effect of happy facial expressions after the subjects consumed the formula beverage for 8 weeks. In addition, there was a significant decrease in anxiety and fatigue, and improved quality of life. This formula beverage is a promising option that could be used to prevent further cognitive decline in adults with subjective cognitive complaints.

Optimizing inorganic carbon and salinity for enhanced biomass and pigment production in Colaconema formosanum: Implications for sustainable carbon sequestration and stress responses.

This study investigates a cultivation strategy for the macroalga Colaconema formosanum by determining optimal inorganic carbon concentration and salinity for maximizing biomass and photosynthetic pigment production while also facilitating carbon sequestration. The response surface method was used with a central composite design (CCD-RSM) to determine the optimal conditions. Results showed that adding 1.2 g/L of carbon increased the specific growth rate to 18%-19% per day. The maximum amount of pigment, including phycobiliprotein and chlorophyll, was achieved by adjusting both carbon content and salinity. This strategy enables mass pigment production and offers an eco-friendly approach to carbon sequestration while reducing culture period. This study also sheds light on algal mechanisms against enriched inorganic carbon and salinity content, contributing to an enhanced understanding of these vital processes.

Novel compounds of Djulis (Chenopodium formosanum Koidz) increases collagen, antioxidants, inhibits adipogenesis.

Djulis (Chenopodium formosanum Koidz), is rich in nutrients and contains various bioactive components such as polyphenols and alkaloids. The new compound has a broad application prospect, including food additives, health products, drugs, etc. The purpose of this study was to find out new compounds from Djulis. It was found that 24 compounds including 7 phenols, 11 flavonoids, 4 plant alkaloids, 2 sterols. Among those, TCI-CF-22-S (Methyl 3,6-dihydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-23-S (Methyl 6-hydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-24-S (Kaempferol-3-O-b-D-apifuranosyl-(1→2)-a-L-arabinopyranoside) were isolated from djulis sources for the first time, and the structures of compounds were assigned by 1D, 2D NMR spectroscopy. TCI-CF-01(Caffeic acid), TCI-CF-02 (20-Hydroxyecdysone), TCI-CF-03 (Japonicone), TCI-CF-04 (3,4-Dihydroxyphenylacetiate), TCI-CF-05 (Quercetin-3-O-rutinoside-7-O-rhamnopyranoside), TCI-CF-06 (Guanosine), TCI-CF-07(Adenine), TCI-CF-08 (Coumaric acid) increased collagen production, and TCI-CF-03 (Japonicone), TCI-CF-04 (3,4-Dihydroxyphenylacetiate), TCI-CF-06 (Guanosine), TCI-CF-17 (Rutin), TCI-CF-20 (Protocatechuic acid) decreased advanced glycation end products (AGEs). In addition, TCI-CF-22-S (Methyl 6-hydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-23-S (Methyl 3,6-dihydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate) inhibited the formation of fatty oil droplets. Djulis has 24 compounds that may have various applications, including increasing collagen production and reducing advanced glycation end products and fatty oil droplets.

Lactobacillus delbrueckii subsp. bulgaricus strain TCI904 reduces body weight gain, modulates immune response, improves metabolism and anxiety in high fat diet-induced obese mice.

The multiple probiotic characteristics of strain TCI904 isolated in this study from natural fermented milk were investigated using a mouse model. TCI904 was identified as Lactobacillus delbrueckii subsp. bulgaricu (LDB), a well-known lactic acid starter bacterium found in yogurt. TCI904 exhibited an outstanding pancreatic lipase inhibition activity among several strains of lactic acid bacteria in vitro. Its in vivo effects were further studied. In a comparison of mice fed a high-fat diet (HFD) and those fed a HFD combined with TCI904 for 9 weeks, differences were observed in various aspects of health, and the adverse effects of a HFD were prevented in the latter group. TCI904 effectively prevented fat and body weight accumulation without reducing food intake; it also modulated innate immunity and increased the level of IgA in feces, reversing the increased blood sugar and insulin levels and attenuated the hyperlipidemia caused by a HFD. Based on biochemical test data, compared with the HFD group, a HFD combined with TCI904 induced significant lowering of insulin resistance indicator, homeostasis model assessment-insulin resistance (HOMA-IR) and atherogenic indices of plasma (AIP), the atherogenic coefficient (AC) and cardiac risk ratio (CRR) and increased the cardioprotective index (CPI). In addition, the administration of TCI904 alleviated mood disorders caused by a HFD. Taking the recommended human dose of TCI904 did not affect the liver or kidney function, indicating that TCI904 has sufficient in vivo safety. Taken together, the results of the present study contributed towards validation of the probiotic benefits of lactic acid starter microflora. Orally taken TCI904 exhibited positive immune- and metabolic-modulating, and anxiolytic properties, especially in HFD-induced obesity. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03356-3.

A New Biorecognition-Element-Free IDµE Sensor for the Identification and Quantification of E. coli.

The label-free biosensor has emerged as an effective tool for the purpose of early detection of causative pathogens such as Escherichia coli as a preventive measure. In this study, a biorecognition-element-free interdigitated microelectrode (IDµE) sensor is designed and developed with this in mind, with good reliability and affordability. Results show that the designed sensor can identify E. coli with good selectivity using an impedance and capacitance of 7.69 MHz. At its optimum impedance of 1.3 kHz, the IDµE sensor can reliably quantify E. coli in a range of measurement (103.2~106 cfu/mL), linearity (R2 = 0.97), sensitivity (18.15 kΩ/log (cfu/mL)), and limit of detection (103.2 cfu/mL). In summary, the IDµE sensor developed possesses high potential for industrial and clinical applications.

The potential of immature poken (Citrus reticulata) extract in the weight management, lipid and glucose metabolism.

OBJECTIVES: The prevalence of obesity was increasing globally, with nearly half a billion of the world's population now considered to be overweight or obese. The immature poken (Citrus reticulata) was a good source of flavonoids and phenolic acids, which may exert an anti-obesity effect. However, the current efficacy in clinical trials was still unclear. Thus, the object of this study was to explore whether immature poken had an anti-obesity effect in the clinical trial. METHODS: In this study, we identified nine major compounds from immature poken extract (IPE), and most compounds significantly decreased the lipid accumulation in adipocytes. In addition, 20 subjects with body mass index (BMI) ≥ 24 or body fat > 30 were recruited and randomly allocated to placebo and experimental (IPE) groups for 6 week intervention and 2 week follow-up. RESULTS: In comparison with the baseline results (week 0), the body weight, body fat, and waist circumference at week 6 in the IPE group were significantly decreased by 1.49 kg, 0.33%, 2.1 cm. Moreover, in blood biochemical analysis, total cholesterol (TC), triglyceride (TG), fasting blood sugar (FBS), and insulin levels at week 6 in IPE group were also decreased by 3.6, 4.6, 2.1 (mg/dL), and 2.9 (µU/mL), respectively. CONCLUSIONS: The finding showed that immature poken had important roles in fat metabolism by suppressing adipogenesis, and immature poken may provide new weight loss strategies for obese people.

Relationship between medical students' negative perceptions of colleagues' work-life and burn-out during clerkships: a longitudinal observational cohort study.

OBJECTIVE: Because work and educational environments are closely related and can affect each other, this study examined whether medical students' negative perceptions of their colleagues' work-life balance (NWLB) during their clinical rotations would be related to burn-out in clerkships and investigated the effect of students' gender on this relationship. DESIGN: A longitudinal, prospective 2-year cohort study conducted between September 2013 and April 2015. SETTING: Medical students from a university school of medicine in Taiwan. PARTICIPANTS: One voluntary cohort of undergraduate medical students in clerkships was invited to participate. Among 190 medical students recruited in September 2013, a total of 124 students provided written informed consent. Participants were free to decide whether to complete each survey; therefore, varying numbers of responses were obtained during the study period. Those who responded to our survey for more than 6 months were included in our analyses. Overall, 2128 responses from 94 medical students were analysed, with each student providing an average of 23 responses for 2 years. PRIMARY OUTCOME MEASURE: Burn-out was measured using the Professional Quality of Life Scale. RESULTS: Our study found that a strong NWLB was related to high burn-out levels among medical students during their clerkships (p<0.001). However, the gender of the student had no effect on this relationship (p>0.05). In addition, our study indicated that medical students living with a companion had decreased burn-out levels than did those living alone during their clerkships. CONCLUSIONS: The significance of policies promoting employee work-life balance should be emphasised because of the potential for social contagion effects on medical students. Clerkship trainees might be vulnerable to such negative contagion effects during the transition to their early clinical workplace training and may, therefore, require advanced socialisation and mentoring.

CCL2 associated with CD38 expression during ex vivo expansion in human cord blood-derived hematopoietic stem cells.

To date, different experimental strategies have been developed for the ex vivo expansion of human hematopoietic stem cells (HSCs) for clinical applications. However, differences in the genomic function of expanded HSCs under different culture systems remain unclear. In this study, we compared the gene expression profiles of HSCs in ex vivo expanded serum (10% FBS, fetal bovine serum) and serum-free culture systems and analyzed the molecular functions of differentially expressed genes using microarray chips. We identified 839 differentially expressed genes between the two culture systems. These genes were enriched in the TNF -regulated inflammatory pathway in an FBS culture system. In addition, the mRNA expression of CCL2 (C-C motif chemokine ligand 2), TNF (tumor necrosis factor) and FOS (FBJ murine osteosarcoma viral oncogene homolog) was validated by RT-qPCR. Our data revealed that ex vivo expansion of HSCs using the FBS culture system induces an inflammatory response and high CD38 expression, indicating that this system might activate an inflammatory pathway and induce expression of the cancer marker CD38 during ex vivo expansion of HSCs. This study provides a transcriptional profile and new insights into the genomic functions of HSCs under different expanded cultures.

Medical students' preclinical service-learning experience and its effects on empathy in clinical training.

BACKGROUND: Service learning (SL) is an educational methodology presumed to help medical students be more empathetic and compassionate. We longitudinally investigated the level of empathy in medical students and how preclinical SL experience was related to their level of empathy in their clinical clerkships. METHODS: Our cohort comprised fifth-year medical students engaged in clerkships as part of a 7-year medical programme at one medical school in Taiwan. Surveys were conducted at the beginning of the clerkship in September 2015 (T1) to collect data on the medical students' preclinical SL experience in curriculum-based service teams (CBSTs) and extracurricular service teams (ECSTs) and their SL self-efficacy, demographic characteristics, and empathy level. Subsequently, three follow-up surveys were conducted once every 3 months to determine the empathy level of the students during their clinical clerkships (T2-T4). Seventy students who returned the written informed consent and completed the baseline (T1) and two or more follow-up surveys (T2-T4) were included in our analysis with the response rate of 34%. In total, 247 responses across the 1-year clerkship were analysed. Descriptive statistics, paired t tests, and generalised estimating equations were employed. RESULTS: Our study revealed that changes in empathy level in the dimensions of perspective taking, compassionate care, and standing in patients' shoes in their clinical clerkships. Relative to that at T1, their empathy decreased in perspective taking and compassionate care at T2-T4 but increased in standing in patients' shoes at T3. Additionally, our study verified the positive effect of medical students' preclinical SL experience in CBSTs and ECSTs on empathy in terms of compassionate care and perspective taking, respectively, but not on that of standing in patients' shoes. CONCLUSIONS: Separate investigations into subconstructs of empathy, such as perspective taking, compassionate care, and standing in patients' shoes, in medical students may be necessary for exploring the various driving forces or barriers to developing empathy in medical students. Moreover, SL experience through both CBSTs and ECSTs at medical academies may have positive effects on medical students' empathy in their clinical clerkships and should be promoted at medical schools.

Enhancing growth, phycoerythrin production, and pigment composition in the red alga Colaconema sp. Through optimal environmental conditions in an indoor system.

Phycoerythrin (PE) is a compound with strong potential for both basic research and industrial applications, but short supply and high prices have so far hindered its development. One common problem is a shortage of biomass for extraction. The aim of the present study was to determine a cultivation strategy (optimizing temperature, irradiance, photoperiod, and light quality) to produce greater biomass and higher PE concentrations in the alga Colaconema sp. We found that an optimized culture process could increase algae growth 7-9 fold while allowing extraction of 9-10 mg g-1 total phycobiliproteins, containing 60%-65% PE. Low energy costs make this approach economically feasible and competitive when compared with existing methods. Our results suggest an improved strategy for the large-scale production of PE and offer valuable applications in the algae industry.

Investigation of the Synergistic Effect of Brown Sugar, Longan, Ginger, and Jujube (Brown Sugar Longan Ginger Tea) on Antioxidation and Anti-Inflammation in In Vitro Models.

This research unveils the synergistic effect of brown sugar, longan, ginger, and jujube on the beneficial effects of antioxidation and anti-inflammation. Longan, ginger, and jujube are ubiquitous herbs in traditional Chinese medicine (TCM) and are frequently used in folk remedies. Longan and ginger have been reported to be beneficial for antioxidation, anti-inflammation, ant-obesity, and nonalcoholic fatty liver disease (NAFLD) improvements. However, the potential scientific and medical benefits of their combination Brown Sugar Longan Ginger Tea (BSLGT), a popular drink in Chinese cultures, are elusive. Through the in vitro methodologies, we discovered that BSLGT could significantly improve the mitochondrial activity, antioxidant capacity, lipid content, and inflammatory response in human hepatocytes. In addition, BSLGT also exerted positive effects on the downregulation of atherosclerosis-associated, vasoconstrictor, and thrombosis-related gene expression in human umbilical vein endothelial cells. In short, our experimental results successfully revealed that the antioxidative and anti-inflammatory effects of BSLGT may have the potential to improve liver metabolism and cardiovascular inflammation although solid evidence requires further investigation.

Do teaching strategies matter? Relationships between various teaching strategies and medical students' wellbeing during clinical workplace training.

Introduction: In the later years of medical school, medical students learn through clinical rotations at medical institutions. Using cognitive apprenticeships as the theoretical reference for teaching strategies, this study aimed to assess how clinical teaching strategies benefit medical students' wellbeing in the workplace.Methods: Our target population comprised two cohorts of medical students in the seventh year of a 7-year medical education program in Taiwan, undergoing clinical training at a tertiary medical center between August 2012 and May 2014. After informed consent was obtained, participants were regularly mailed a validated, structured, and self-administered questionnaire to evaluate their clinical teachers' teaching strategies and their personal wellbeing at the end of individual specialty rotations, and medical students' were freely permitted to respond to each invitation. Eighty-seven medical students returned 1364 responses, which were included in the structural equation modeling.Results: We determined that the Inspiring teaching strategy, characterized by articulation, reflection, and exploration, was related to reduced burnout among medical students and an increased sense of compassion satisfaction; the Directing teaching strategy, characterized by modeling, coaching, and scaffolding, was related only to reduced burnout among medical students but not to compassion satisfaction during the clinical training.Conclusions: Clinical teaching strategies were demonstrated to affect, to various extents, medical students' wellbeing with respect to factors such as burnout and compassion satisfaction in the workplace. Clinical teachers and educators should increase efforts to develop Inspiring teaching skills to shift the balance of responsibility and to support students in the teaching and learning relationship.

Medical students' resilience: a protective role on stress and quality of life in clerkship.

BACKGROUND: Resilience refers to the ability to be flexible and adaptive in response to challenges. Medical students in clerkship who are transitioning from medical studies to clinical practice face a variety of workplace demands that can lead to negative learning experiences and poor quality of life. This study explored whether medical students' resilience plays a protective role against the stresses incurred during workplace training and on their professional quality of life during clerkships. METHODS: This was a 1-year prospective web-based questionnaire study comprising one cohort of medical students in their fifth year who were working as clerks as part of their 6-year medical education programme at one medical school in Taiwan between September 2017 and July 2018. Web-based, validated, structured, self-administered questionnaires were used to measure the students' resilience at the beginning of the clerkship and their perceived training stress (i.e. physical and psychological demands) and professional quality of life (i.e. burnout and compassion satisfaction) at each specialty rotation. Ninety-three medical students who responded to our specialty rotation surveys at least three times in the clerkship were included and hierarchical regressions were performed. RESULTS: This study verified the negative effects of medical students' perceived training stress on burnout and compassion satisfaction. However, although the buffering (protective) effects of resilience were observed for physical demands (one key risk factor related to medical students' professional quality of life), this was not the case for psychological demands (another key risk factor). In addition, through the changes in R square (∆R2) values of the hierarchical regression building, our study found that medical students' perceived training stresses played a critical role on explaining their burnout but their resilience on their compassion satisfaction. CONCLUSIONS: Medical students' resilience demonstrated a buffering effect on the negative relationship between physical demands and professional quality of life during clerkships. Moreover, different mechanisms (predictive paths) leading to medical students' professional quality of life such as burnout and compassion satisfaction warrant additional studies.

Extracts from Fermented Black Garlic Exhibit a Hepatoprotective Effect on Acute Hepatic Injury.

The mechanism of hepatoprotective compounds is usually related to its antioxidant or anti-inflammatory effects. Black garlic is produced from garlic by heat treatment and its anti-inflammatory activity has been previously reported. Therefore, the aim of this study was to investigate the hepatoprotective effect of five different extracts of black garlic against carbon tetrachloride (CCl4)-induced acute hepatic injury (AHI). In this study, mice in the control, CCl4, silymarin, and black garlic groups were orally administered distilled water, silymarin, and different fraction extracts of black garlic, respectively, after CCl4 was injected intraperitoneally to induce AHI. The results revealed that the n-butanol layer extract (BA) and water layer extract (WS) demonstrated a hepatoprotective effect by reducing the levels of alanine aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and hepatic malondialdehyde (MDA). Furthermore, the BA and WS fractions of black garlic extract increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd), tumor necrosis factor alpha (TNF-α), and the interleukin-1 (IL-1ß) level in liver. It was concluded that black garlic exhibited significant protective effects on CCl4-induced acute hepatic injury.

Determinants and effects of medical students' core self-evaluation tendencies on clinical competence and workplace well-being in clerkship.

Core self-evaluation (CSE) is a personality trait that involves a person's evaluation of his or her own worth, competence, and capability. The objective of this study was to determine whether medical students' CSEs exert beneficial effects on their adaptation to their clerkship in terms of their clinical competence and workplace well-being and whether their preclinical academic performance can be a trait-relevant situation that enhances their CSE expression. In total, 127 medical students from 2 cohorts were included as participants in this study. We analyzed complete measures of personal background, objective and subjective preclinical academic performance (course evaluation grades and self-reported efficacy), CSE tendencies, and clinical competence (as objective structured clinical examination scores) and workplace well-being (as compassion satisfaction and burnout) during their 2-year clerkship. Mixed linear models for repeated measures and multiple regressions were employed. Participants' CSE tendencies had positive effects on their workplace compassion satisfaction and burnout but not on their clinical competence during their clerkship. Additionally, using the objective and subjective preclinical academic performance of the medical students as indicators, we observed that neither could be trait-relevant situations to enhance their CSE expression. CSE personality tendencies might be key to medical students' ability to noncognitively adapt to clinical training during their clerkships. These tendencies should be identified earlier so that mentors can provide prompt care and support to mentees (medical students) during clerkships.

Coronary Stent Infection Presented as Recurrent Stent Thrombosis.

Percutaneous transluminal coronary angioplasty with metal stent placement has become a well-developed treatment modality for coronary stenotic lesions. Although infection involving implanted stents is rare, it can, however, occur with high morbidity and mortality. We describe herein a case of an inserted coronary stent that was infected and complicated with recurrent stent thrombosis, pseudoaneurysm formation and severe sepsis. Despite repeated intervention and bypass surgery, the patient died from severe sepsis.

Successful extracorporeal resuscitation after perioperative anaphylactic shock during living donor liver transplantation.

A 46-year-old man was admitted for emergent donor hepatectomy. His circulatory condition became unstable 75 minutes after induction and then deteriorated to ventricular fibrillation due to latex-induced anaphylaxis. Following 35 minutes of futile conventional resuscitation without spontaneous cardiac rhythm, extracorporeal resuscitation was initiated and electric cardiac activity returned 10 minutes later. He was discharged home without any sequelae. Extracorporeal cardiopulmonary resuscitation would offer an alternative choice compared with conventional cardiopulmonary resuscitation.

Excellent mid-term durability of the On-X mechanical aortic valve in the pulmonary position with a low international normalized ratio.

BACKGROUND AND AIM OF THE STUDY: Although the pulmonary position has been preferred for the placement of homografts or bioprosthetic valves, the limited longevity of these implants makes reoperation almost unavoidable. Good durability of mechanical valves in the pulmonary position has been reported. The mid-term outcomes were analyzed of patients who received an On-X mechanical heart valve for pulmonary valve replacement (PVR) with a relatively low International Normalized Ratio (INR). METHODS: Between February 2008 and February 2011, mechanical On-X valves (size range: 19 to 25 mm) were implanted for PVR in six patients. Tetralogy of Fallot (ToF) was the most common diagnosis (n = 6). Postoperatively, warfarin was used to maintain the INR at 1.5-2.0. The surgical results and follow up were reviewed retrospectively, with valve failure, thrombosis, embolism, bleeding, reoperation and death being defined as end-points. RESULTS: There was no intraoperative or in-hospital mortality. The mean age of patients at the time of PVR was 31 +/- 19.7 years (range: 16-61 years). In patients who underwent repair of ToF (n = 4) the average duration between PVR and previous right ventricular outflow tract (RVOT) reconstruction was 8.75 +/- 3.3 years (range: 5-12 years). The mean follow up period was 3.13 +/- 1.31 years (range: 2-5 years). There was no 30-day mortality, late death, thromboembolism, major bleeding event or valve dysfunction, and no patient needed reoperation. All survivors were categorized as NYHA class I or II. CONCLUSION: A three-year experience with the On-X bileaflet mechanical valve in the pulmonary position demonstrated excellent mid-term durability, with no thromboembolisms or bleeding events when the INR was maintained at 1.5-2.0. For patients who require PVR, either as primary procedure or reoperation, the On-X mechanical heart valve might represent an appropriate option.