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.

Recent Outcomes of Surgical Redo Aortic Valve Replacement in Prosthetic Valve Failure.

BACKGROUND: As redo surgical aortic valve replacement (AVR) is relatively high risk, valve-in-valve transcatheter AVR has emerged as an alternative for failed prostheses. However, the majority of studies are outdated. This study assessed the current clinical outcomes of redo AVR. METHODS AND RESULTS: This study enrolled 324 patients who underwent redo AVR due to prosthetic valve failure from 2010 to 2021 in four tertiary centers. The primary outcome was operative mortality. The secondary outcomes were overall survival, cardiac death, and aortic valve-related events. Logistic regression analysis, clustered Cox proportional hazards models, and competing risk analysis were used to evaluate the independent risk factors. Redo AVR was performed in 242 patients without endocarditis and 82 patients with endocarditis. Overall operative mortality was 4.6% (15 deaths). Excluding patients with endocarditis, the operative mortality of redo AVR decreased to 2.5%. Multivariate analyses demonstrated that endocarditis (hazard ratio [HR]: 3.990, p = 0.014), longer cardiopulmonary bypass time (HR: 1.006, p = 0.037), and lower left ventricular ejection fraction (LVEF) (HR: 0.956, p = 0.034) were risk factors of operative mortality. Endocarditis and lower LVEF were independent predictors of overall survival. CONCLUSION: The relatively high risk of redo AVR was due to reoperation for prosthetic valve endocarditis. The outcomes of redo AVR for nonendocarditis are excellent. Our findings suggest that patients without endocarditis, especially with acceptable LVEF, can be treated safely with redo AVR.

Covalent Inhibition by a Natural Product-Inspired Latent Electrophile.

Strategies to target specific protein cysteines are critical to covalent probe and drug discovery. 3-Bromo-4,5-dihydroisoxazole (BDHI) is a natural product-inspired, synthetically accessible electrophilic moiety that has previously been shown to react with nucleophilic cysteines in the active site of purified enzymes. Here, we define the global cysteine reactivity and selectivity of a set of BDHI-functionalized chemical fragments using competitive chemoproteomic profiling methods. Our study demonstrates that BDHIs capably engage reactive cysteine residues in the human proteome and the selectivity landscape of cysteines liganded by BDHI is distinct from that of haloacetamide electrophiles. Given its tempered reactivity, BDHIs showed restricted, selective engagement with proteins driven by interactions between a tunable binding element and the complementary protein sites. We validate that BDHI forms covalent conjugates with glutathione S-transferase Pi (GSTP1) and peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), emerging anticancer targets. BDHI electrophile was further exploited in Bruton's tyrosine kinase (BTK) inhibitor design using a single-step late-stage installation of the warhead onto acrylamide-containing compounds. Together, this study expands the spectrum of optimizable chemical tools for covalent ligand discovery and highlights the utility of 3-bromo-4,5-dihydroisoxazole as a cysteine-reactive electrophile.

A vertically paired electrode for redox cycling and its application to immunoassays.

An electrochemical immunoassay based on the redox cycling method was presented using vertically paired electrodes (VPEs), which were fabricated using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as an electrode material and parylene-C as a dielectric layer. For the application to immunoassays, different electrochemical properties of PEDOT:PSS were analyzed for the redox reaction of 3,3',5,5'-tetramethylbenzidine (TMB, the chromogenic substrate for enzyme-immunoassays) at different pH conditions, including the conductivity (σ), electron transfer rate constant (kapp), and double-layer capacitance (Cdl). The influencing factors on the sensitivity of redox cycling based on VPE based on PEDOT:PSS were analyzed for the redox reaction of TMB, such as the electrode gap and number of electrode pairs. Computer simulation was also performed for the redox cycling results based on VPEs, which had limitations in fabrication, such as VPEs with an electrode gap of less than 100 nm and more than five electrode pairs. Finally, the redox cycling based on VPE was applied to the medical diagnosis of human hepatitis-C virus (hHCV) using a commercial ELISA kit. The sensitivity of the redox cycling method for the medical diagnosis of hHCV was compared with conventional assay methods, such as TMB-based chromogenic detection, luminol-based chemiluminescence assay, and a rapid test kit (lateral flow immunoassay).

Effects of hole transporting PEDOT:PSS on the photoemission of upconverted hot electron in Mn-doped CdS/ZnS quantum dots.

In this work, we investigated the effect of hole transporting poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) interfacing with Mn-doped CdS/ZnS quantum dots (QDs) deposited on an indium tin oxide (ITO) substrate on the photoemission of upconverted hot electrons under weak continuous wave photoexcitation in a vacuum. Among the various factors that can influence the photoemission of the upconverted hot electrons, we studied the role of PEDOT:PSS in facilitating the hole transfer from QDs and altering the energy of photoemitted hot electrons. Compared to hot electrons emitted from QDs deposited directly on the ITO substrate, the addition of the PEDOT:PSS layer between the QD and ITO layers increased the energy of the photoemitted hot electrons. The increased energy of the photoemitted hot electrons is attributed in part to the reduced steady-state positive charge on the QDs under continuous photoexcitation, which reduces the energy required to eject the electron from the conduction band.

Homogeneous One-Step Immunoassay Based on Switching Peptides for Detection of the Influenza Virus.

In this study, a homogeneous one-step immunoassay based on switching peptides is presented for the detection of influenza viruses A and B (Inf-A and Inf-B, respectively). The one-step immunoassay represents an immunoassay method that does not involve any washing steps, only treatment of the sample. In this method, fluorescence-labeled switching peptides quantitatively dissociate from the antigen-binding site of immunoglobulin G (IgG). In particular, the one-step immunoassay based on soluble detection antibodies with switching peptides is called a homogeneous one-step immunoassay. The immunoassay developed uses switching peptides labeled with two types of fluorescence dyes (FAM and TAMRA) and detection antibodies labeled with two types of fluorescence quenchers (TQ2 for FAM and TQ3 for TAMRA). The optimal switching peptides for the detection of Inf-A and Inf-B have been selected as L1-peptide and H2-peptide. The interactions between the four kinds of switching peptides and IgG have been analyzed using computational docking simulation and SPR biosensor. The location of labeling for the fluorescence quenchers has been determined based on the distance between the fluorescence dyes of the switching peptides and the fluorescence quenchers, calculated on the basis of the efficiency of fluorescence quenching, using the Förster equation. To demonstrate the feasibility of the one-step immunoassay, binding constants (KD) have been calculated for detection antibodies against Inf-A and Inf-B with target antigens (Inf-A and Inf-B) and switching peptides (L1- and H2-peptides), using an isotherm model. The immunoassay has been demonstrated to be feasible using antigens as well as real samples of Inf-A and Inf-B with a critical cycle number (Ct). The immunoassay has also been compared to other commercially available rapid test kits for Inf-A and Inf-B and found to be far more sensitive for detection of Inf-A and Inf-B over the entire detection range.

Carbon electrode obtained via pyrolysis of plasma-deposited parylene-C for electrochemical immunoassays.

In this study, parylene-C films from plasma deposition as well as thermal deposition were pyrolyzed to prepare a carbon electrode for application in electrochemical immunoassays. Plasma deposition could prepare parylene-C in a faster deposition rate and more precise control over the thickness in comparison with the conventional thermal deposition. To analyze the influence of the deposition method, the crystal and electronic structures of the pyrolyzed parylene-C films obtained via both deposition methods were compared using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. For application as a carbon electrode in immunoassays, the electrochemical properties of the pyrolyzed carbon films from two both deposition methods were analyzed, including the double layer capacitance (2.10 µF cm-2 for plasma deposition and 2.20 µF cm-2 for thermal deposition), the apparent electron transfer rate (approximately 1.1 × 10-3 cm s-1 for both methods), and the electrochemical window (approximately -1.0 ∼ 2.1 V for both methods). Finally, the applicability of the pyrolyzed carbon electrode from parylene-C was demonstrated for the diagnosis of human hepatitis-C using various amperometric methods, such as cyclic voltammetry, chronoamperometry, square-wave voltammetry and differential pulse voltammetry.

One-step immunoassay for the detection of food-poisoning related bacteria using a switching peptide.

A one-step immunoassay was developed for five types of food-poisoning-related bacteria using a switching peptide and antibodies isolated from unimmunized horse serum. The one-step immunoassay involves mixing samples and reagents in a homogeneous solution without any washing steps. In this work, a one-step immunoassay configuration was developed using isolated antibodies labelled with an organic fluorescence quencher and a switching-peptide labelled with a fluorescent dye. The fluorescence-labelled switching-peptide was bound to the antigen-binding site of the isolated antibodies before binding to the bacteria (no fluorescence signal), and the switching-peptide dissociated from the antibodies as soon as they bound to the bacteria (fluorescence signal turns on). By quantifying the generated fluorescence signal, the one-step immunoassay presented here allows microbial detection without any washing step.

Stereoselective Synthesis of (S)- and (N)-Cyclopropyl-Fused Carbocyclic Nucleosides Using Stereoselective Cyclopropanation.

To determine which sugar conformation is favorable in binding to peroxisome proliferator-activated receptors, the conformationally locked south (S) and north (N) analogues were asymmetrically synthesized using a bicyclo[3.1.0]hexane template. The (S)-conformer was synthesized by employing "reagent-controlled" Charette asymmetric cyclopropanation in a 100% stereoselective manner, whereas the (N)-conformer was stereoselectively synthesized by using "substrate-controlled" hydroxyl-directed Simmons-Smith cyclopropanation as a key step.

UBC12-mediated SREBP-1 neddylation worsens metastatic tumor prognosis.

Activation of sterol regulatory element-binding protein 1 (SREBP-1), a master lipogenic transcription factor, is associated with cancer metabolism and metabolic disorders. Neddylation, the process of adding NEDD8 to its substrate, contributes to diverse biological processes. Here, we identified SREBP-1 as a substrate for neddylation by UBC12 and explored its impact on tumor aggressiveness. In cell-based assays, SREBP-1 neddylation prolonged SREBP-1 stability with a decrease in ubiquitination. Consequently, NEDD8 overexpression facilitated proliferation, migration, and invasion of SK-Hep1 liver tumor cells. MLN4924 (an inhibitor of the NEDD8-activating enzyme-E1) treatment or UBC12 knockdown prevented SREBP-1 neddylation and tumor cell phenotype change. This effect was corroborated in an in vivo xenograft model. In human specimens, SREBP-1, UBC12, and NEDD8 were all upregulated in hepatocellular carcinoma (HCC) compared to nontumorous regions. Moreover, SREBP-1 levels positively correlated with UBC12. In GEO database analyses, SREBP-1 levels were greater in metastatic HCC samples accompanying UBC12 upregulation. In HCC analysis, tumoral SREBP-1 and UBC12 levels discriminated overall patient survival rates. Additionally, MLN4924 treatment destabilized SREBP-1 in MDA-MB-231 breast cancer cells and in the tumor cell xenograft. SREBP-1 and UBC12 were also highly expressed in human breast cancer tissues. Moreover, most breast cancers with lymph node metastasis displayed predominant SREBP-1 and UBC12 expressions, which compromised overall patient survival rates. In summary, SREBP-1 is neddylated by UBC12, which may contribute to HCC and breast cancer aggressiveness through SREBP-1 stabilization, and these events can be intervented by MLN4924 therapy. Our findings may also provide potential reliable prognostic markers for tumor metastasis.

Biodegradation of Polystyrene by Pseudomonas sp. Isolated from the Gut of Superworms (Larvae of Zophobas atratus).

Recently, various attempts have been made to solve plastic waste problems, such as development of biodegradation without producing pollution. Polystyrene (PS) is the fifth most used plastic in many industries; therefore, degrading PS becomes a critical global issue. Here, we reported Pseudomonas aeruginosa strain DSM 50071, initially isolated from the gut of the superworms, Zophobas atratus, and the PS degradation by Pseudomonas sp. DSM 50071. We examined PS degradation using electronic microscopy and measured changes in atomic composition and contact angles with water droplets on the PS surface that represents a chemical change from hydrophobicity to hydrophilicity. We have further examined chemical structural changes using X-ray photoelectron spectroscopy, Fourier-transform-infrared spectroscopy, and nuclear magnetic resonance (NMR) to confirm the formation of carbonyl groups (C═O) in the oxidation pathway during PS biodegradation. In reverse transcription quantitative polymerase chain reaction analysis, the gene expression level of serine hydrolase (SH) in Pseudomonas sp. DSM 50071 was highly increased during PS degradation, and the enzyme-mediated biodegradation of PS was further confirmed by the SH inhibitor treatment test. Thus, the significance of these findings goes beyond the discovery of a novel function of Pseudomonas sp. DSM 50071 in the gut of superworms, highlighting a potential solution for PS biodegradation.

Tumor Identification in Colorectal Histology Images Using a Convolutional Neural Network.

Colorectal cancer (CRC) is a major global health concern. Its early diagnosis is extremely important, as it determines treatment options and strongly influences the length of survival. Histologic diagnosis can be made by pathologists based on images of tissues obtained from a colonoscopic biopsy. Convolutional neural networks (CNNs)-i.e., deep neural networks (DNNs) specifically adapted to image data-have been employed to effectively classify or locate tumors in many types of cancer. Colorectal histology images of 28 normal and 29 tumor samples were obtained from the National Cancer Center, South Korea, and cropped into 6806 normal and 3474 tumor images. We developed five modifications of the system from the Visual Geometry Group (VGG), the winning entry in the classification task in the 2014 ImageNet Large Scale Visual Recognition Competition (ILSVRC) and examined them in two experiments. In the first experiment, we determined the best modified VGG configuration for our partial dataset, resulting in accuracies of 82.50%, 87.50%, 87.50%, 91.40%, and 94.30%, respectively. In the second experiment, the best modified VGG configuration was applied to evaluate the performance of the CNN model. Subsequently, using the entire dataset on the modified VGG-E configuration, the highest results for accuracy, loss, sensitivity, and specificity, respectively, were 93.48%, 0.4385, 95.10%, and 92.76%, which equates to correctly classifying 294 normal images out of 309 and 667 tumor images out of 719.

Modified Bicaval Technique in Orthotopic Heart Transplantation　- Comparison With Conventional Bicaval Technique.

BACKGROUND: Orthotopic heart transplantation (HT) is the treatment of choice for patients with end-stage heart failure (HF). The bicaval technique was introduced as a safe alternative minimizing modification of atrial geometry. The modification of bicaval anastomosis is suggested to compensate for caliber mismatch and small donor. The present study was performed to compare these 2 techniques in terms of postoperative CT scan and clinical outcomes. Methods and Results: Retrospectively, 158 consecutive patients with end-stage HF underwent orthotopic HT between January 2009 and June 2013 were analyzed. Of these, we excluded 3 patients with total HT. The study group was divided into modified technique (n=37) or conventional technique (n=118). A total of 113 patients (modified: n=29, conventional: n=84) were examined with cardiac CT. Discrepancy in the size of the vena cava compared with that of the anastomosis site was assessed. There was no significant difference in the complication and survival rates. There was 1 incident of moderate-to-severe tricuspid valve regurgitation in the modified group (n=1, 2.7%). Both the SVC ratio (1.07±0.13 vs. 1.28±0.32, P=0.001) and IVC ratio (1.06±0.07 vs. 1.13±0.19, P=0.009) were higher in the conventional group, which meant more stenotic imaging findings were observed in the conventional group. CONCLUSIONS: Orthotopic HT with modified bicaval anastomosis is an attractive alternative with easy orientation and equivocal outcomes.

A novel endoscopic fluorescent band ligation method for tumor localization.

BACKGROUND: Accurate tumor localization is essential for minimally invasive surgery. This study describes the development of a novel endoscopic fluorescent band ligation method for the rapid and accurate identification of tumor sites during surgery. METHODS AND MATERIALS: The method utilized a fluorescent rubber band, made of indocyanine green (ICG) and a liquid rubber solution mixture, as well as a near-infrared fluorescence laparoscopic system with a dual light source using a high-powered light-emitting diode (LED) and a 785-nm laser diode. The fluorescent rubber bands were endoscopically placed on the mucosae of porcine stomachs and colons. During subsequent conventional laparoscopic stomach and colon surgery, the fluorescent bands were assayed using the near-infrared fluorescence laparoscopy system. RESULTS: The locations of the fluorescent clips were clearly identified on the fluorescence images in real time. The system was able to distinguish the two or three bands marked on the mucosal surfaces of the stomach and colon. Resection margins around the fluorescent bands were sufficient in the resected specimens obtained during stomach and colon surgery. CONCLUSION: These novel endoscopic fluorescent bands could be rapidly and accurately localized during stomach and colon surgery. Use of these bands may make possible the excision of exact target sites during minimally invasive gastrointestinal surgery.

Tailored surgical strategies for mini-access open total arch repair.

Objective: Open arch repair is perceived as a challenging, high-risk procedure, with a barrier against the use of a minimally invasive approach. We aimed to present a mini-access total arch replacement performed by stratified approaches and to evaluate perioperative outcomes to contribute to the body of evidence. Methods: We evaluated 40 consecutive patients (aged 69.5 years; interquartile range, 65.6-76.3 years) undergoing elective total arch replacement using 5- to 8-cm upper mini-sternotomy between 2018 and 2022. Surgical strategies, including arterial inflow site and methods of branching vessel reconstruction, were systematically selected at the individual level. To evaluate comparative outcomes, contemporary cases undergoing total arch replacement via sternotomy with similar eligibility criteria served as a control group, and the inverse-treatment-weighting method was used to adjust for baseline characteristics. Results: Arch-first anastomosis using trifurcate graft, distal-first anastomosis using 4-branch graft, and island anastomosis were used in 18 (45%), 12 (30.0%), and 10 (25%) patients, respectively. Lower body and cardiac ischemic times were 23.4 minutes (interquartile range, 18.0-29.0 minutes) and 66.7 minutes (interquartile range, 50.1-78.2 minutes). There was no early (30-day or in-hospital) mortality, and 2 patients experienced disabling stroke (5.0%). The contemporary control group comprised 55 patients. After an adjustment, a mini-access group showed lower risks of stroke (odds ratio, 0.88; 95% CI, 0.78-1.00; P = .049) and a composite of major complications (odds ratio, 0.79; 95% CI, 0.68-0.92; P = .003), compared with a sternotomy approach. Conclusions: Based on present results, mini-access total arch replacement may be performed with reasonable safety and efficiency.

Identification of plastic-degrading bacteria in the human gut.

Environmental pollution caused by the excessive use of plastics has resulted in the inflow of microplastics into the human body. However, the effects of microplastics on the human gut microbiota still need to be better understood. To determine whether plastic-degrading bacteria exist in the human gut, we collected the feces of six human individuals, did enrichment cultures and screened for bacterial species with a low-density polyethylene (LDPE) or polypropylene (PP)-degrading activity using a micro-spray method. We successfully isolated four bacterial species with an LDPE-degrading activity and three with a PP-degrading activity. Notably, all bacterial species identified with an LDPE or PP-degrading activity were opportunistic pathogens. We analyzed the microbial degradation of the LDPE or PP surface using scanning electron microscopy and confirmed that each bacterial species caused the physical changes. Chemical structural changes were further investigated using X-ray photoelectron spectroscopy and Fourier-transform-infrared spectroscopy, confirming the oxidation of the LDPE or PP surface with the formation of carbonyl groups (C=O), ester groups (CO), and hydroxyl groups (-OH) by each bacterial species. Finally, high temperature gel permeation chromatography (HT-GPC) analysis showed that these bacterial species performed to a limited extent depolymerization. These results indicate that, as a single species, these opportunistic pathogens in the human gut have a complete set of enzymes and other components required to initiate the oxidation of the carbon chains of LDPE or PP and to degrade them. Furthermore, these findings suggest that these bacterial species can potentially biodegrade and metabolize microplastics in the human gut.

Surgical Outcomes of Centrifugal Continuous-Flow Implantable Left Ventricular Assist Devices: Heartmate 3 versus Heartware Ventricular Assist Device.

Background: Left ventricular assist devices (LVADs) are widely employed as a therapeutic option for end-stage heart failure. We evaluated the outcomes associated with centrifugal-flow LVAD implantation, comparing 2 device models: the Heartmate 3 (HM3) and the Heartware Ventricular Assist Device (HVAD). Methods: Data were collected from patients who underwent LVAD implantation between June 1, 2015 and December 31, 2022. We analyzed overall survival, first rehospitalization, and early, late, and LVAD-related complications. Results: In total, 74 patients underwent LVAD implantation, with 42 receiving the HM3 and 32 the HVAD. A mild Interagency Registry for Mechanically Assisted Circulatory Support score was more common among HM3 than HVAD recipients (p=0.006), and patients receiving the HM3 exhibited lower rates of preoperative ventilator use (p=0.010) and extracorporeal membrane oxygenation (p=0.039). The overall early mortality rate was 5.4% (4 of 74 patients), with no significant difference between groups. Regarding early right ventricular (RV) failure, HM3 implantation was associated with a lower rate (13 of 42 [31.0%]) than HVAD implantation (18 of 32 [56.2%], p=0.051). The median rehospitalization-free period was longer for HM3 recipients (16.9 months) than HVAD recipients (5.3 months, p=0.013). Furthermore, HM3 recipients displayed a lower incidence of late hemorrhagic stroke (p=0.016). In the multivariable analysis, preoperative use of continuous renal replacement therapy (odds ratio, 22.31; p=0.002) was the only significant predictor of postoperative RV failure. Conclusion: The LVAD models (HM3 and HVAD) demonstrated comparable overall survival rates. However, the HM3 was associated with a lower risk of late hemorrhagic stroke.

Prognostic impact of the E/e' ratio in patients with chronic severe aortic regurgitation undergoing aortic valve replacement.

OBJECTIVES: The study objective was to evaluate the clinical implication of left ventricular diastolic dysfunction in patients with chronic severe aortic regurgitation undergoing aortic valve replacement. METHODS: We reviewed the medical records of 323 patients (age, 56.3 ± 14.1 years; 111 female) who underwent aortic valve replacement for chronic severe aortic regurgitation between 2005 and 2019. Left ventricular diastolic dysfunction was assessed by the ratio of peak left ventricular inflow velocity over mitral annular velocity (E/e'). The study end point was the composite of death and heart failure requiring hospital admission. RESULTS: The E/e' ratio was significantly correlated with age, left atrial dimension, left ventricular end-diastolic volume, mitral regurgitation grade, and tricuspid regurgitation grade (all P < .001). During follow-up (1748.3 patient-years), death and heart failure occurred in 36 patients (2.06/patient-year) and 9 patients (0.53/patient-year), respectively. In multivariable analysis, E/e' ratio (per 5 increment, hazard ratio, 1.32; 95% confidence interval, 1.02-1.71; P = .03), age (hazard ratio, 1.06; 95% confidence interval, 1.03-1.10; P < .001), and left ventricular ejection fraction (hazard ratio, 0.94; 95% confidence interval, 0.90-0.98; P = .002) were independent predictors of death and heart failure. The 5-year heart failure-free survival was 94.9% ± 1.7% in patients with E/e' less than 15% and 84.2% ± 4.2% in patients with E/e' 15 or greater (P < .001). CONCLUSIONS: The E/e' ratio was significantly associated with adverse outcomes in patients with chronic severe aortic regurgitation undergoing aortic valve replacement and may be useful as a prognostic marker in such patients.

Mitral Valve Repair with Leaflet Resection versus Preservation for Degenerative Posterior Leaflet Prolapse.

OBJECTIVES: The optimal technique for repairing posterior mitral valve (MV) leaflet (PMVL) prolapse remains undetermined. We aimed to compare leaflet resection and neo-chordae implantation in patients undergoing MV repair for posterior leaflet prolapse, focusing on trans-mitral pressure gradient (PG) and recurrence of mitral regurgitation (MR). METHODS: We enrolled patients undergoing MV repair using either leaflet resection or neo-chordae implantation for single-segment prolapse of PMVL between 2000 and 2021 at our institution. Longitudinal outcomes were evaluated after adjustments with inverse-probability-of-treatment weighting (IPTW). Repeat echocardiographic measurements (n=3,473, 5.4/patient) of trans-mitral PG and significant (moderate or severe) MR recurrence were estimated using nonlinear mixed-effect models. Subgroup analyses were conducted based on the size and type of prosthesis. RESULTS: Among 639 patients, leaflet resection was used in 479 (75.0%) and neo-chordae implantation in 160 (25.0%). In the IPTW-adjusted cohort, the risk of death (P=0.623) and MV reoperation (P=0.340) did not significantly differ between the two groups during a median follow-up of 97.3 months. Echocardiographic data showed comparable mean (at 5 years, 3.8 vs. 4.0 mmHg; P=0.442) and peak (9.6 vs. 10.4mmHg; P=0.131) PGs between groups, which persisted in most subgroup analyses. However, neo-chordae implantation was associated with a higher probability of significant MR recurrence compared to leaflet resection (at 5 years, 16.1% vs. 7.0%; P<0.001). CONCLUSIONS: Leaflet resection yielded similar clinical outcomes and trans-mitral PGs compared to neo-chordae implantation after MV repair, with a lower MR recurrence rate. These findings underscore the need to reassess the efficacy of neo-chordae implantation relative to leaflet resection.

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.