Differentiation Between Invasive Adenocarcinoma and Focal Interstitial Fibrosis among Persistent Pulmonary Part-solid Nodules: With Emphasis on the CT Morphologic Analysis.

PURPOSE: Focal interstitial fibrosis (FIF) manifesting as a persistent part-solid nodule (PSN) has been mistakenly treated surgically due to similar imaging features to invasive adenocarcinoma (ADC). The purpose of this study was to observe predictive imaging features correlated with FIF through CT morphologic analysis. MATERIALS AND METHODS: From January 2009 to December 2020, 44 patients with surgically proven FIF in a single institution were enrolled and compared with 88 ADC patients through propensity score matching. Patient characteristics and CT morphologic analysis of persistent PSNs were used to identify predictive imaging features of FIF. Receiver operating characteristic (ROC) curve analysis was used to quantify the performance of imaging features. RESULTS: A total of 132 patients with 132 PSNs (44 FIF, 88 ADC; mean age, 67.7±7.58; 75 females) were involved in our analysis. Multivariable analysis demonstrated that preserved peritumoral vascular margin (preserved vascular margin), preserved secondary pulmonary lobule margin (preserved lobular margin), and lower coronal to axial ratio (C/A ratio; cutoff: 1.005) were significant independent predictors of FIF (P<0.05). ROC curve analysis to evaluate the predictive value of the logistic model based on the imaging features of FIF, and the AUC value was 0.881. CONCLUSION: CT imaging features of preserved vascular margin, preserved lobular margin, and lower C/A ratio (cutoff, <1.005) might be helpful imaging features in discriminating FIF over ADC among persistent PSN in clinical practice.

Clinical approaches for poststroke seizure: a review.

Poststroke seizure is a potential complication of stroke, which is the most frequent acute symptomatic seizure in adults. Patients with stroke may present with an abnormal or aggressive behavior accompanied by altered mental status and symptoms, such as hemiparesis, dysarthria, and sensory deficits. Although stroke manifestations that mimic seizures are rare, diagnosing poststroke seizures can be challenging when accompanied with negative postictal symptoms. Differential diagnoses of poststroke seizures include movement disorders, syncope, and functional (nonepileptic) seizures, which may present with symptoms similar to seizures. Furthermore, it is important to determine whether poststroke seizures occur early or late. Seizures occurring within and after 7 d of stroke onset were classified as early and late seizures, respectively. Early seizures have the same clinical course as acute symptomatic seizures; they rarely recur or require long-term antiseizure medication. Conversely, late seizures are associated with a risk of recurrence similar to that of unprovoked seizures in a patient with a focal lesion, thereby requiring long-term administration of antiseizure medication. After diagnosis, concerns regarding treatment strategies, treatment duration, and administration of primary and secondary prophylaxis often arise. Antiseizure medication decisions for the initiation of short-term primary and long-term secondary seizure prophylaxis should be considered for patients with stroke. Antiseizure drugs such as lamotrigine, carbamazepine, lacosamide, levetiracetam, phenytoin, and valproate may be administered. Poststroke seizures should be diagnosed systematically through history with differential diagnosis; in addition, classifying them as early or late seizures can help to determine treatment strategies.

Chemical tools to define and manipulate interferon-inducible Ubl protease USP18.

Ubiquitin-specific protease 18 (USP18) is a multifunctional cysteine protease primarily responsible for deconjugating interferon-inducible ubiquitin-like (Ubl) modifier ISG15 from protein substrates. Here, we report the design and synthesis of activity-based probes (ABPs) capable of selectively detecting USP18 activity over other ISG15 cross-reactive deubiquitinases (DUBs) by incorporating unnatural amino acids into the C-terminal tail of ISG15. Combining with a ubiquitin-based DUB ABP, the selective USP18 ABP is employed in a chemoproteomic screening platform to identify and assess inhibitors of DUBs including USP18. We further demonstrate that USP18 ABPs can be utilized to profile differential activities of USP18 in lung cancer cell lines, providing a strategy that will help define the activity-related landscape of USP18 in different disease states and unravel important (de)ISGylation-dependent biological processes.

Discovery of a Tunable Heterocyclic Electrophile 4-Chloro-pyrazolopyridine That Defines a Unique Subset of Ligandable Cysteines.

Electrophilic small molecules with novel reactivity are powerful tools that enable activity-based protein profiling and covalent inhibitor discovery. Here, we report a reactive heterocyclic scaffold, 4-chloro-pyrazolopyridine (CPzP) for selective modification of proteins via a nucleophilic aromatic substitution (SNAr) mechanism. Chemoproteomic profiling reveals that CPzPs engage cysteines within functionally diverse protein sites including ribosomal protein S5 (RPS5), inosine monophosphate dehydrogenase 2 (IMPDH2), and heat shock protein 60 (HSP60). Through the optimization of appended recognition elements, we demonstrate the utility of CPzP for covalent inhibition of prolyl endopeptidase (PREP) by targeting a noncatalytic active-site cysteine. This study suggests that the proteome reactivity of CPzPs can be modulated by both electronic and steric features of the ring system, providing a new tunable electrophile for applications in chemoproteomics and covalent inhibitor design.

Cardiovascular outcomes in solid organ transplant recipients undergoing cardiac surgery: A matched pair analysis.

INTRODUCTION: This study aimed to compare postoperative outcomes after cardiac surgery in solid-organ transplant recipients and nontransplant patients. METHODS: We performed a retrospective analysis of 78 consecutive transplant recipients who underwent cardiac surgery at Asan Medical Center between 2000 and 2022 and were matched with 312 nontransplant patients who underwent cardiac surgery at a 1:4 ratio. The outcomes included 30-day mortality, all-cause death, cardiac death, readmission, and cardiac readmission. RESULTS: There was no significant difference in baseline characteristics between the two groups. The most common type of cardiac surgery performed in solid organ transplant recipients was isolated valve surgery, followed by isolated CABG. The 30-day mortality was not significantly different between transplant recipients and nontransplant patients (3.9% vs. 3.5%; P > .99). Solid organ transplant recipients showed a higher all-cause mortality compared to nontransplant patients (29.1% vs. 14.3% at 5 years; P = .001); however, there was no significant difference in cardiac death between the two groups (2.6% vs. 3.2% at 5 years; P = .80). In addition, the readmission and cardiac readmission rates showed comparable findings to that of mortality. CONCLUSION: Cardiac surgery can be performed safely in solid organ transplant recipients, with postoperative cardiovascular outcomes comparable to those observed in nontransplant patients.

High-resolution 3-D scanning electron microscopy (SEM) images of DOTTM polynucleotides (PN): Unique scaffold characteristics and potential applications in biomedicine.

INTRODUCTION: Polynucleotides (PN) are becoming more prominent in aesthetic medicine. However, the structural characteristics of PN have not been published and PN from different companies may have different structural characteristics. This study aimed to elucidate the structural attributes of DOT™ PN and distinguish differences with polydeoxyribonucleotides (PDRN) using high-resolution scanning electron microscopy (SEM) imaging. MATERIALS AND METHODS: DOT™ PN was examined using a Quanta 3-D field emission gun (FEG) Scanning Electron Microscope (SEM). Sample preparation involved cryogenic cooling, cleavage, etching, and metal coating to facilitate high-resolution imaging. Cryo-FIB/SEM techniques were employed for in-depth structural analysis. RESULTS: PDRN exhibited an amorphous structure without distinct features. In contrast, DOT™ PN displayed well-defined polyhedral shapes with smooth, uniformly thick walls. These cells were empty, with diameters ranging from 3 to 8 micrometers, forming a seamless tessellation pattern. DISCUSSION: DOT™ PN's distinct geometric tessellation design conforms to the principles of biotensegrity, providing both structural reinforcement and integrity. The presence of delicate partitions and vacant compartments hints at possible uses in the field of pharmaceutical delivery systems. Within the realms of beauty enhancement and regenerative medicine, DOT™ PN's capacity to bolster cell growth and tissue mending could potentially transform approaches to rejuvenation treatments. Its adaptability becomes apparent when considering its contributions to drug administration and surgical procedures. CONCLUSION: This study unveils the intricate structural scaffold features of DOT™ PN for the first time, setting it apart from PDRN and inspiring innovation in biomedicine and materials science. DOT™ PN's unique attributes open doors to potential applications across healthcare and beyond.

Particulate matter reduction efficiency analysis of sprinkler system as targeted control measures for construction activity.

Air pollution caused by the construction industry in the form of particulate matter (PM) has increased to an alarming level. The effects on the health of construction workers are found to be hazardous despite the current advancement in construction methods and practices. In particular, the efficiency of existing control measures for reducing PM from various construction activities has not been improved to the desired level. This study investigated the factors that influence the efficiency of a sprinkler system-based control measure when water spraying and dust suppressant solutions are used. The real-time PM exposure was measured during hollow-block cutting activity using Alphanese OPC-N3 sensors in dust chamber. The dust suppressant suppresses dust particles by initially forming a solidified film on the particle surface, and the high cohesion of this film enhances the suppression rate by promoting dust particle coagulation. It was observed that when using a dust suppressant, the PM concentration at 100 bar exceeded concentrations at other pressures, resulting in increased efficacy in reducing PM10. Additionally, water spraying at 115 bar was determined to be the optimal control measure for achieving a significant percentage of PM reduction in a shorter period. These findings can be highly beneficial if the water sprinkler system can be modified into a smart mobility-based sprinkler system either ground-based or drone-based at construction sites in improving PM reduction efficiency particularly on high PM emitting activities.

In-depth correlation analysis between tear glucose and blood glucose using a wireless smart contact lens.

Tears have emerged as a promising alternative to blood for diagnosing diabetes. Despite increasing attempts to measure tear glucose using smart contact lenses, the controversy surrounding the correlation between tear glucose and blood glucose still limits the clinical usage of tears. Herein, we present an in-depth investigation of the correlation between tear glucose and blood glucose using a wireless and soft smart contact lens for continuous monitoring of tear glucose. This smart contact lens is capable of quantitatively monitoring the tear glucose levels in basal tears excluding the effect of reflex tears which might weaken the relationship with blood glucose. Furthermore, this smart contact lens can provide an unprecedented level of continuous tear glucose data acquisition at sub-minute intervals. These advantages allow the precise estimation of lag time, enabling the establishment of the concept called 'personalized lag time'. This demonstration considers individual differences and is successfully applied to both non-diabetic and diabetic humans, as well as in animal models, resulting in a high correlation.

Reprogramming of tumor-associated macrophages by metabolites generated from tumor microenvironment.

The tumor microenvironment comprises both tumor and non-tumor stromal cells, including tumor-associated macrophages (TAMs), endothelial cells, and carcinoma-associated fibroblasts. TAMs, major components of non-tumor stromal cells, play a crucial role in creating an immunosuppressive environment by releasing cytokines, chemokines, growth factors, and immune checkpoint proteins that inhibit T cell activity. During tumors develop, cancer cells release various mediators, including chemokines and metabolites, that recruit monocytes to infiltrate tumor tissues and subsequently induce an M2-like phenotype and tumor-promoting properties. Metabolites are often overlooked as metabolic waste or detoxification products but may contribute to TAM polarization. Furthermore, macrophages display a high degree of plasticity among immune cells in the tumor microenvironment, enabling them to either inhibit or facilitate cancer progression. Therefore, TAM-targeting has emerged as a promising strategy in tumor immunotherapy. This review provides an overview of multiple representative metabolites involved in TAM phenotypes, focusing on their role in pro-tumoral polarization of M2.

"The Prognostic Role of Aspartate Transaminase to Platelet Ratio Index (APRI) on Outcomes Following Non-emergent Minor Hepatectomy".

INTRODUCTION: Fibrosis and cirrhosis are associated with worse outcomes after hepatectomy. Aspartate transaminase to platelet ratio index (APRI) is associated with fibrosis and cirrhosis in hepatitis C patients. However, APRI has not been studied to predict outcomes after hepatectomy in patients without viral hepatitis. METHODS: We reviewed the ACS-NSQIP dataset to identify patients who underwent a minor hepatectomy between 2014 and 2021. We excluded patients with viral hepatitis or ascites as well as patients who underwent emergent operations or biliary reconstruction. APRI was calculated using the following equation: (AST/40)/(platelet count) × 100. APRI ≥0.7 was used to identify significant fibrosis. Univariable analysis was performed to identify factors associated with APRI ≥0.7, transfusion, serious morbidity, overall morbidity, and 30-day mortality. Multivariable logistic regression was performed to identify adjusted predictors of these outcomes. RESULTS: Of the 18,069 patients who met inclusion criteria, 1630 (9.0%) patients had an APRI ≥0.7. A perioperative blood transfusion was administered to 2139 (11.8%). Overall morbidity, serious morbidity, and mortality were experienced by 3162 (17.5%), 2475 (13.7%), and 131 (.7%) patients, respectively. APRI ≥0.7 was an independent predictor of transfusion (adjusted OR: 1.48 [1.26-1.74], P < .001), overall morbidity (1.17 [1.02-1.33], P = .022), and mortality (1.97 [1.22-3.06], P = .004). Transfusion was an independent predictor of overall morbidity (3.31 [2.99-3.65], P < .001), serious morbidity (3.70 [3.33-4.11], P < .001), and mortality (5.73 [4.01-8.14], P < .001). CONCLUSIONS: APRI ≥0.7 is associated with perioperative transfusion, overall morbidity, and 30-day mortality. APRI may serve as a noninvasive tool to risk stratify patients prior to elective minor hepatectomy.

Association between nonalcoholic fatty liver disease and gallstone risk in nonobese and lean individuals.

PURPOSE: The association between nonobese/lean nonalcoholic fatty liver disease (NAFLD) and gallstone formation remains unclear. We aimed to assess whether NAFLD is an independent risk factor for gallstones, even in nonobese or lean individuals. METHODS: We analyzed 265 353 asymptomatic adults who underwent abdominal ultrasonography. The risk of gallstone was assessed on the basis of obesity and NAFLD status. RESULTS: The overall prevalence rates of NAFLD and gallstones were 27.1% and 2.6%, respectively. The prevalence rates of NAFLD among the 195 204 nonobese and 136 194 lean participants were 14.7% and 7.4%, respectively. Individuals with NAFLD had a significantly increased risk of gallstones (adjusted odds ratio [OR], 1.23; 95% confidence interval [CI], 1.14-1.32). Moreover, NAFLD significantly increased the risk of gallstone (adjusted OR, 1.29; 95% CI, 1.17-1.41) among nonobese individuals. Lean individuals with NAFLD also exhibited a significantly increased risk of gallstones (adjusted OR, 1.20; 95% CI, 1.03-1.40). Furthermore, these findings remained consistent even in nonobese and lean individuals without insulin resistance. CONCLUSION: Nonobese/lean NAFLD is an independent risk factor for gallstone formation, suggesting its role in gallstone pathogenesis, regardless of obesity status. Therefore, when hepatic steatosis is detected on abdominal ultrasonography, a more thorough evaluation of the gallstones may be necessary, even in nonobese or lean individuals.

Prognostic impact of muscle mass loss in elderly patients with oesophageal cancer receiving neoadjuvant chemoradiation therapy.

BACKGROUND: We aimed to identify the impact of muscle mass on locally advanced oesophageal cancer (LAEC) in elderly patients receiving neoadjuvant chemoradiation therapy (NACRT). METHODS: We reviewed the medical records of 345 patients diagnosed with LAEC who underwent NACRT and surgery. Physical variables, including height, weight, skeletal muscle mass, and laboratory values, were obtained before and after NACRT. Body mass index (BMI, kg/m2), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and prognostic nutritional index (PNI) were calculated as height/(weight)2, ANC/ALC, platelet count/ALC, and (10 × albumin + 0.05 × ALC), respectively. The cutoff for low muscle mass was 43.0 cm2/m2 for BMI below 25 kg/m2 and 53.0 cm2/m2 for BMI 25 kg/m2 or higher. The skeletal muscle index (SMI) was defined as skeletal muscle area/(height)2 (cm2/m2). The ΔSMI (%/50 days) was defined as (SMI after NACRT - SMI before NACRT)/interval (days) × 50 (days) to compare changes over the same period. The excessive muscle loss (EML) group was defined as patients with ΔSMI ≤-10% following NACRT. An elderly patient was defined as aged ≥65 years. The primary outcome measure was overall survival (OS). RESULTS: During a median follow-up of 32.8 months (range, 2.0-176.2), 192 patients died, with a median OS of 50.2 months. Elderly patients did not show inferior OS (young vs. elderly, 57.7% vs. 54.0% at 3 years, P = 0.247). 71.0% and 87.2% of all patients had low muscle mass before and after NACRT, respectively, which was not associated with OS (P = 0.270 and P = 0.509, respectively). Inflammatory (NLR and PLR) and nutritional index (PNI) values or their changes did not correlate with OS. However, the EML group had worse OS (41.6% vs. 63.2% at 3 years, P < 0.0001). In the multivariate analysis, EML was also a significant prognostic factor for OS. In the subgroup analysis by age, EML was a strong prognostic factor for OS in the elderly group. The 3-year OS was 36.8% in the EML group and 64.9% in the non-EML group (P < 0.0001) in elderly patients, and 47.4% and 62.1% (P = 0.063) in the young patients. In multivariate analysis of each subgroup, EML remained prognostic only in the elderly group (P = 0.008). CONCLUSIONS: EML may be strongly associated with a deteriorated OS in elderly patients undergoing NACRT, followed by surgery for LAEC. The strategies for decreasing muscle loss in these patients should be investigated.

Early-term outcome of apical fusion with vertebral body tethering for thoracolumbar curves in adolescent idiopathic scoliosis: a preliminary study.

INTRODUCTION: Vertebral body tethering (VBT) has become an alternative option for select patients with idiopathic scoliosis. However, studies have shown a high number of tether breakages, specifically after thoracolumbar (TL) VBT, that can have a negative impact on the outcome, when the breakage occurs within the first year after surgery. In order to overcome this problem, we have started to apply an apical fusion (AF) in combination with TL VBT for select patients. This study aims to analyze the outcome after AF plus VBT. METHODS: This is a retrospective single surgeon's data analysis. All patients were included who have had TL VBT after January 2022 and a follow-up of 12 months. Patients were grouped based on whether they only had VBT or VBT + AF. RESULTS: Twenty-five patients were analyzed (15 VBT, 10 VBT + AF). Both groups showed a significant curve correction for thoracic and TL curves. Minor loss of correction was observed in both groups. A significant difference was seen regarding early tether breakages, which were found in 60% of VBT patients and 10% of VBT + AF patients. CONCLUSION: The preliminary data shows a significant reduction of early tether breakages when TL VBT is applied in combination with AF.

Risk Factor Analysis of Morbidity and 90-Day Mortality of Curative Resection in Patients with Stage IIIA-N2 Non-Small Cell Lung Cancer after Induction Concurrent Chemoradiation Therapy.

Background: Major pulmonary resection after neoadjuvant concurrent chemoradiation therapy (nCCRT) is associated with a substantial risk of postoperative complications. This study investigated postoperative complications and associated risk factors to facilitate the selection of suitable surgical candidates following nCCRT in stage IIIA-N2 non-small cell lung cancer (NSCLC). Methods: We conducted a retrospective analysis of patients diagnosed with clinical stage IIIA-N2 NSCLC who underwent surgical resection following nCCRT between 1997 and 2013. Perioperative characteristics and clinical factors associated with morbidity and mortality were analyzed using univariable and multivariable logistic regression. Results: A total of 574 patients underwent major lung resection after induction CCRT. Thirty-day and 90-day postoperative mortality occurred in 8 patients (1.4%) and 41 patients (7.1%), respectively. Acute respiratory distress syndrome (n=6, 4.5%) was the primary cause of in-hospital mortality. Morbidity occurred in 199 patients (34.7%). Multivariable analysis identified significant predictors of morbidity, including patient age exceeding 70 years (odds ratio [OR], 1.8; p=0.04), low body mass index (OR, 2.6; p=0.02), and pneumonectomy (OR, 1.8; p=0.03). Patient age over 70 years (OR, 1.8; p=0.02) and pneumonectomy (OR, 3.26; p<0.01) were independent predictors of mortality in the multivariable analysis. Conclusion: In conclusion, the surgical outcomes following nCCRT are less favorable for individuals aged over 70 years or those undergoing pneumonectomy. Special attention is warranted for these patients due to their heightened risks of respiratory complications. In high-risk patients, such as elderly patients with decreased lung function, alternative treatment options like definitive CCRT should be considered instead of surgical resection.

Biphasic Regulation of Apoptosis Following Gastric Irreversible Electroporation Using Tissue Immunohistochemistry of Activated Caspase-3 with TUNEL Method.

The regulation of apoptosis is the primary goal of ablation therapy. Irreversible electroporation (IRE) is a promising non-thermal tissue ablation-based therapy that induces apoptosis by manipulating electrical conditions. This study aimed to investigate IRE-induced gastric tissue apoptosis in response to changes in the electric field intensity, followed by the repair process. Among the 52 rats used in this study, 24 were used to explore apoptosis, and 28 were used to study regeneration. The apoptosis-to-necrosis ratio of the electrical field strength was evaluated using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and caspase-3 immunohistochemistry. The size of IRE-induced ulcers in the gastric tissue continuously increased with increasing electrical intensity (r2 = 0.830, p < 0.001). The level of apoptosis gradually decreased after peaking at 200 V (1000 V/cm). The size of the 400 V-ablated ulcers continued to decrease, and they were not visible by day 14. The proliferation and migration of epithelial cells with fibroblasts were observed on day 3 and augmented on day 7 post-ablation. This investigation demonstrated the biphasic activation of apoptosis with respect to the electrical field strength. Visually and histologically, IRE-induced gastric ulcers demonstrated complete tissue regeneration after two weeks.

Hidden Blood Loss and Its Risk Factors for Oblique Lumbar Interbody Fusion.

(1) Background: The amount of blood loss during oblique lumber interbody fusion (OLIF) surgery is often underestimated and may contribute to adverse postoperative outcomes. This study aims to evaluate hidden blood loss (HBL) in patients who underwent OLIF for degenerative lumbar spine disease and to analyze its risk factors. (2) Methods: The medical records of 179 patients who underwent OLIF surgery from 2015 to 2022 were reviewed. The HBL and total blood loss (TBL) were estimated using the Gross formula. Pearson correlation, Spearman correlation, and multivariate linear regression analyses were used to investigate risk factors for HBL. (3) Results: The mean HBL was 675.2 mL, and the mean hemoglobin loss was 1.7 g/dL during OLIF surgery. In the multivariate linear regression analysis, TBL (p < 0.001), estimated blood loss (p < 0.001), and pedicle screw fixation type (p = 0.039) were identified as independent risk factors of HBL. (4) Conclusions: The OLIF is associated with substantial perioperative HBL, for which we identified risk factors of TBL, EBL, and pedicle screw fixation type. Notably, OLIF with percutaneous pedicle screw fixation resulted in greater HBL than stand-alone OLIF or OLIF with open pedicle screw fixation.

Omission of Breast Surgery in Predicted Pathologic Complete Response after Neoadjuvant Systemic Therapy: A Multicenter, Single-Arm, Non-inferiority Trial.

PURPOSE: Advances in chemotherapeutic and targeted agents have increased pathologic complete response (pCR) rates after neoadjuvant systemic therapy (NST). Vacuum-assisted biopsy (VAB) has been suggested to accurately evaluate pCR. This study aims to confirm the non-inferiority of the 5-year disease-free survival of patients who omitted breast surgery when predicted to have a pCR based on breast magnetic resonance imaging (MRI) and VAB after NST, compared with patients with a pCR who had undergone breast surgery in previous studies. METHODS: The Omission of breast surgery for PredicTed pCR patients wIth MRI and vacuum-assisted bIopsy in breaST cancer after neoadjuvant systemic therapy (OPTIMIST) trial is a prospective, multicenter, single-arm, non-inferiority study enrolling in 17 tertiary care hospitals in the Republic of Korea. Eligible patients must have a clip marker placed in the tumor and meet the MRI criteria suggesting complete clinical response (post-NST MRI size ≤ 1 cm and lesion-to-background signal enhancement ratio ≤ 1.6) after NST. Patients will undergo VAB, and breast surgery will be omitted for those with no residual tumor. Axillary surgery can also be omitted if the patient was clinically node-negative before and after NST and met the stringent criteria of MRI size ≤ 0.5 cm. Survival and efficacy outcomes are evaluated over five years. DISCUSSION: This study seeks to establish evidence for the safe omission of breast surgery in exceptional responders to NST while minimizing patient burden. The trial will address concerns about potential undertreatment due to false-negative results and recurrence as well as improved patient-reported quality of life issues from the omission of surgery. Successful completion of this trial may reshape clinical practice for certain breast cancer subtypes and lead to a safe and less invasive approach for selected patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05505357. Registered on August 17, 2022. Clinical Research Information Service Identifier: KCT0007638. Registered on July 25, 2022.

Mechanical versus Bioprosthetic Aortic Valve Replacement in Patients Aged 50 to 70 Years.

Background: This study compared the outcomes of surgical aortic valve replacement (AVR) in patients aged 50 to 70 years based on the type of prosthetic valve used. Methods: We compared patients who underwent mechanical AVR to those who underwent bioprosthetic AVR at our institution between January 2000 and March 2019. Competing risk analysis and the inverse probability of treatment weighting (IPTW) method based on propensity score were employed for comparisons. Results: A total of 1,580 patients (984 patients with mechanical AVR; 596 patients with bioprosthetic AVR) were enrolled. There was no significant difference in early mortality between the mechanical AVR and bioprosthetic AVR groups (0.9% vs. 1.7%, p=0.177). After IPTW adjustment, the risk of all-cause mortality was significantly higher in the bioprosthetic AVR group than in the mechanical AVR group (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.07-1.80; p=0.014). Competing risk analysis revealed lower risks of stroke (sub-distributional hazard ratio [sHR], 0.44; 95% CI, 0.28-0.67; p<0.001) and anticoagulation-related bleeding (sHR, 0.35; 95% CI, 0.23-0.53; p<0.001) in the bioprosthetic AVR group. Conversely, the risk of aortic valve (AV) reintervention was higher in the bioprosthetic AVR group (sHR, 6.14; 95% CI, 3.17-11.93; p<0.001). Conclusion: Among patients aged 50 to 70 years who underwent surgical AVR, those receiving mechanical valves showed better survival than those with bioprosthetic valves. The mechanical AVR group exhibited a higher risk of stroke and anticoagulation-related bleeding, while the bioprosthetic AVR group showed a higher risk of AV reintervention.