Continued heart failure can lead to an enlarged heart and mitral regurgitation, where the mitral valve does not close properly, causing blood to flow backward. In severe cases, this can lead to respiratory distress and even death. However, complications from valve disease often do not improve with standard drug treatments for heart failure. A research team led by Professor Duk-Hyun Kang of the Division of Cardiology at Asan Medical Center recently announced that using a gliflozin class drug, which were originally developed to treat diabetes, resulted in significant improvements in both heart failure symptoms and mitral regurgitation.
The study involved 114 patients with heart failure and accompanying mitral regurgitation. These patients were randomly assigned to two groups: 58 patients received standard drug treatment plus gliflozin, and 56 patients received standard treatment plus a placebo. After one year, the gliflozin group showed a significant reduction in the amount of blood regurgitation through the mitral valve, with a decrease of -9.1±10.2mL compared to an increase of 2.1±15.6mL in the placebo group. Statistically, the gliflozin group experienced about a 33% reduction in blood regurgitation compared to the placebo group. Additionally, the study found that 44.8% of patients in the gliflozin group showed improvement in heart failure symptoms, as measured by the New York Heart Association (NYHA) functional class, compared to only 14.3% in the placebo group. Major adverse events, such as hospitalization and death due to heart failure, occurred in 2% of the gliflozin group, compared to 9% in the placebo group.
The results of this study were recently published in the prestigious cardiology journal, ‘Circulation.’

A research team led by Professor Hun Sik Kim of the Department of Microbiology and Professor Chang Ohk Sung of the Department of Pathology at Asan Medical Center recently became the first to establish that overexpression of HPK1, a specific protein of natural killer (NK) cells, causes NK cells to lose their function during cancer metastasis process, thereby promoting cancer metastasis. To prevent cancer metastasis, the immune system needs to be activated, and NK cells play a key role in this. Previous studies have shown that the loss of NK cell function could promote cancer metastasis, but the mechanism remained unknown.
While the research team was searching for therapeutic targets to restore NK cell function, they discovered that NK cell function in the blood and metastatic sites is lost and HPK1 is overexpressed during cancer metastasis. To verify this in reverse, they genetically modified mice to overexpress HPK1 in NK cells and injected melanoma cancer cells into their veins to analyze the trend of lung metastasis according to HPK1 expression levels.
The results showed that HPK1 overexpression promotes metastasis to various organs, not just the lungs. Notably, HPK1 was found to influence metastatic cancer more than primary cancer. On the other hand, HPK1 deficiency activated NK cell function, effectively suppressing cancer metastasis and further enhancing the therapeutic effects of immune checkpoint inhibitors. This confirmed that HPK1 regulation is a promising target for treating metastatic cancer in practice.
This study was recently published in the prestigious academic journal, ‘Advanced Science.’

Researchers at Asan Medical Center have developed the world’s first angiosarcoma derived-organoid model. Organoids, cancer tissue-like structures generated by harvesting cancer tissue from patients, have recently become a pivotal foundation for the development of personalized anticancer drugs and diagnostic markers. While patient-derived cancer organoids have been confirmed to form from various cancer tissues, a culturing method for sarcoma-derived organoids has not been reported in the academic community until now.
A research team comprising Professor Gi Seok Jeong and Dr. Da Jung Jung of the Biomedical Engineering Research Center and Professors Jong Woo Choi, Woo Shik Jeong, and Young Chul Kim of the Department of Plastic Surgery at Asan Medical Center confirmed that since angiosarcoma originates from vascular endothelial stem cells, three-dimensional organoid culture is not achieved through the traditional generation within Matrigel (a complex of extracellular matrix components), commonly used in conventional organoid studies, due to the sprouting of new blood vessels. Consequently, the research team conducted a two-dimensional culture of angiosarcoma cells on uncoated culture dishes and observed that the cells self-assembled in areas of high cell density.
The resulting cell aggregates were three-dimensional clusters of cells that detached from the adherent surface and floated in the culture medium, forming three-dimensional angiosarcoma-derived organoids. These organoids mimicked patients' molecular and morphological features and showed vessel sprouting within the extracellular matrix. Additionally, no specific biomarkers have been discovered in angiosarcoma until this study, which observed overexpression of protein C receptor (PROCR) in cancer tissues and organoids. This finding suggested the potential of PROCR as a biomarker for angiosarcoma.
This research was supported by the Research-driven Hospital Project of the Ministry of Health and Welfare and Individual Basic Research Project of the National Research Foundation. The study findings were recently published in the prestigious academic journal, ‘Journal of Hematology and Oncology.’

Isocitrate dehydrogenase (IDH) mutations are a crucial molecular biomarker determining the prognosis of glioma treatment. Accurate diagnosis of IDH mutations is, therefore, essential for effective treatment. When diagnosing genetic mutations using deep learning, sufficient training and accurate IDH mutation prediction have been challenging using only real-world patient data. A recent study showed that generative artificial intelligence (AI), which creates realistic data, can improve prediction accuracy.
A team led by Professors Ji Eun Park and Hye Hyeon Moon of the Department of Radiology, and Professor Namkug Kim of the Department of Convergence Medicine at Asan Medical Center used generative AI-based augmentation (GAA) to train contrast-enhanced T1 and FLAIR MRI images of 565 glioma patients diagnosed between August 2008 and September 2020. Based on this, GAA generated similar images of glioma with high realism and diversity. It was also demonstrated that the IDH mutation prediction accuracy was optimized when the number of generated images reached 110,000.
The research team performed internal and external validations using data from 119 and 108 patients, respectively. The results showed an accuracy rate of 93.8% internal and 83.3% external, which was higher than that of neuroimaging specialists in their 8th year of career (86.4% internal, 81.9% external) and 2nd year of career (79% internal, 74.3% external).
The study findings were recently published in the world’s leading neuro-oncology journal, ‘Neuro-Oncology.’

For the first time worldwide, a high-risk patient with a Body Mass Index (BMI) of 52 and numerous surgical adhesions underwent a hysterectomy using a single-port (SP) robotic system. Previously, the most obese patient recorded for a robotic hysterectomy had a BMI of 41.5.
The team led by Professor Sa Ra Lee from the Department of Obstetrics and Gynecology at Asan Medical Center recently announced their success in safely performing a hysterectomy for, a severely morbidly obese patient (38 years old) from the UAE suffering from severe adhesions, endometriosis, and pelvic pain caused by previous cesarean sections and ovarian surgeries. They utilized the Da Vinci SP system, making only a single incision inside the navel, to successfully remove the uterus.
The patient was experiencing severe pelvic pain after multiple childbirths and surgeries, but additional surgery was difficult due to obesity and adhesions. Various treatments were attempted in the patient's home country, but they were ineffective. As a result, the patient was referred to Asan Medical Center through the Department of Health-Abu Dhabi.
Professor Sa Ra Lee reviewed the feasibility of surgery for the patient using the remote consultation system of the International Healthcare Center and decided to proceed with a single-port robotic hysterectomy. This procedure involves making an incision only inside the navel, which results in fewer incisions, quicker recovery, and minimal scarring. The patient safely underwent the surgery and returned to the United Arab Emirates on March 11.

For patients with endometrioma whose ovarian function has already declined or who have had a recurrence after surgery, ethanol sclerotherapy is widely performed instead of surgery to preserve ovarian function as much as possible. This procedure involves removing only the foreign substance within the endometrioma using a thin needle and chemically destroying it by injecting ethanol. However, the sticky nature of the foreign substance within the endometrioma made complete removal difficult with a thin needle.
A research team led by Professor Ji Hoon Shin of the Department of Radiology and Professor Sung Hoon Kim of the Department of Obstetrics and Gynecology at Asan Medical Center recently published their study finding that performing two sessions of catheter-directed sclerotherapy using ethanol over two days instead of a needle resulted in significantly reduced endometrioma size while preserving ovarian function. The research team analyzed the treatment effects six months after performing two sessions of catheter-directed sclerotherapy using ethanol on 22 endometrioma patients (31 lesions) from June 2020 to March 2023. According to the analysis, the diameter of the endometrioma decreased by approximately 74.5% from an average of 5.5 cm before the procedure to 1.4 cm after the procedure. The volume of the endometrioma decreased from 114.6cm3 to 3.4cm3, a reduction of approximately 96.4%.
The change in the blood AMH concentration, which measures ovarian function, remained healthy with no statistically significant change, from 1.37ng/ml before the procedure to 1.18ng/ml after the procedure. During the observation period, no growth was confirmed from treated endometrioma, and no major complications occurred in association with the procedure. Patient satisfaction was high, as the procedure was performed by inserting a catheter through the vagina without skin incision, leaving no scar and causing less pain.
The study findings were recently published in the international journal ‘CardioVascular and Interventional Radiology.’

An analysis of 15 years of treatment records by AMC Children's Hospital revealed that, as of May this year, approximately 60,000 pediatric patients with severe diseases, such as pediatric cancer and congenital heart disease, have undergone surgery.
A breakdown of surgeries by medical department shows that pediatric surgeries, including those for pediatric cancer like hepatoblastoma, pediatric liver transplantation, and congenital diaphragmatic hernia, accounted for about 19,000 cases, the highest number.
Pediatric cardiac surgeries, such as heart transplants and surgeries for complex congenital heart defects, along with pediatric orthopedic surgeries for conditions like congenital limb deformities and severe traumatic fractures, each accounted for about 10,000 cases.
Pediatric urology surgeries, including treatments for hydronephrosis and vesicoureteral reflux, numbered about 7,000 cases. Pediatric ophthalmology surgeries, including those for pediatric cataracts and glaucoma, amounted to 5,700 cases. Pediatric neurosurgeries for conditions like brain tumors, craniofacial abnormalities, and moyamoya disease totaled approximately 3,600 cases.
Last year alone, the hospital treated about 38,000 pediatric emergency patients, with a cumulative total of around 450,000 patients, the highest number in Korea. To systematically treat pediatric emergency patients, AMC Children’s Hospital established Korea's first pediatric emergency center, separate from the adult emergency center, in 2010. It operates on a 24/7 basis with dedicated specialists, and since its opening, there has never been an interruption in the treatment of pediatric emergency patients.
Additionally, to provide intensive care and management for children with severe diseases, AMC Children’s Hospital operates a 29-bed pediatric intensive care unit (PICU) and a 62-bed neonatal intensive care unit (NICU). At its inception, AMC Children’s Hospital set up the largest pediatric intensive care system in Korea and has continuously expanded its scale, maintaining its status as the largest to date. So far, about 13,000 patients have received treatment in the pediatric and neonatal intensive care units.
In 2021, a small-for-dates micro-preemie born at 24 weeks and 6 days, weighing just 288 grams, the smallest birth weight recorded in Korea, received round-the-clock intensive care in the neonatal intensive care unit for 153 days. This remarkable case highlights the advancements in pediatric and neonatal critical care of AMC Children’s Hospital.

Professor Jae Suk Yoo of the Department of Thoracic & Cardiovascular Surgery at Asan Medical Center recently performed Korea’s first 500th totally 3D endoscopic minimally invasive cardiac surgery.
Totally 3D endoscopic minimally invasive cardiac surgery involves making a small incision of about 3-4 cm between the ribs to insert an endoscope equipped with a 3D camera. During surgery, the surgeon uses special glasses to view the 3D images transmitted by the camera, which allows for visual perception of distance and thickness within the body and enables transmission on a bright screen.
In 2017, using demonstration equipment, Professor Jae Suk Yoo first introduced 3D endoscopy for heart valve surgery in Korea. Professor v officially started performing totally 3D endoscopic minimally invasive cardiac surgery in January 2018, achieving 500 cases in 6 years and 3 months.
Except for cases covering large surgical sites, such as heart transplantation, most procedures, including valve surgery, heart tumor surgery, atrial septal defect surgery, and atrial fibrillation surgery, were operable with totally 3D endoscopic minimally invasive cardiac surgery.
Mitral valve repair, for which totally 3D endoscopic minimally invasive cardiac surgery was most frequently performed, displayed a success rate of 99%, which is comparable to conventional open surgery. Without the need to open or close the breastbone, anesthesia time was reduced by 30 to 40 minutes. Patients also recovered much faster and could return to their daily routines, even leisure activities, shortly after discharge.
Meanwhile, Professor Jae Suk Yoo was recently registered as the first Korean member of the Endoscopic Cardiac Surgeons Club, centered in Europe, where minimally invasive cardiac surgery began, in recognition of achieving 500 cases of totally 3D endoscopic minimally invasive cardiac surgery and ongoing research contributions.

With the development of immunotherapy to treat inoperable liver cancer, it has shown high therapeutic effects and established itself as a first-line treatment. However, there is no standard treatment for patients whose cancer has worsened despite immunotherapy. In this context, a prospective study reported that the use of targeted therapy for liver cancer resulted in an average survival of more than 14 months.
A team led by Professor Changhoon Yoo of the Division of Oncology at Asan Medical Center conducted a study from October 2020 to May 2022 on 47 patients with hepatocellular carcinoma whose cancer had worsened despite undergoing immunotherapy, as they were not eligible for surgery. The patients were treated with cabozantinib, a multi-targeted agent. The research team comparatively analyzed the patients by dividing them into subgroups based on the type and number of prior immunotherapy before cabozantinib treatment and the sequence of cabozantinib treatment.
The results showed that, regardless of the type of immunotherapy agent, the average survival was 14.3 months for 17 patients who used cabozantinib as a second-line treatment after immunotherapy. When cabozantinib was used as a third-line treatment, the average survival was 6.5 months. The patients were treated for an average of 2.8 months, and the overall average survival after starting cabozantinib treatment was 9.9 months. As known from previous studies, adverse events such as palmar-plantar erythrodysesthesia, fatigue, hypertension, and diarrhea were observed after cabozantinib treatment, but most were managed with appropriate medication.
The study findings were recently published in the ‘Journal of Hepatology,’ one of the prestigious journals in liver diseases.

For gastric adenoma less than 1 cm in size, tissue removal and argon plasma coagulation, involving cauterizing abnormal tissue, have been found to be effective treatments. Previously, endoscopic procedures, such as endoscopic mucosal resection and endoscopic submucosal dissection, have been recognized as effective treatments. However, they have been difficult to perform depending on the patient’s condition and lesion due to the risk of complications.
A team led by Professor Ji Yong Ahn of the Division of Gastroenterology at Asan Medical Center performed argon plasma coagulation on 618 patients with gastric low-grade dysplastic at Asan Medical Center from 2007 to 2022 and analyzed recurrence rates with an average follow-up of 30 months. The results showed that gastric adenomas smaller than 1 cm had a recurrence rate of 2.6%, which was no different from the conventional endoscopic resection. However, the recurrence rate of lesions larger than 1 cm increased to 9.5%, suggesting that careful treatment decisions and close monitoring are necessary based on the size of the gastric adenoma.
Argon plasma coagulation is a therapeutic technique in which electrical energy is delivered at the moment argon gas hits the tissue, cauterizing abnormal tissue in the gastrointestinal tract. While this technique allows for treatment without incisions or cutting, reducing the risk of complications like bleeding, it has been perceived to be unpredictable in terms of the depth of the lesion and with a high risk of recurrence. However, this study proved that argon plasma coagulation is an effective treatment with a low recurrence rate for gastric adenomas with small lesions.
The study findings were recently published in ‘Gastrointestinal Endoscopy,’ the official journal of the American Society for Gastrointestinal Endoscopy.

Iron oxide nanoparticles used for drug delivery interact with cellular organelles after entering cells, undergoing various changes and destruction processes. A team led by Professor Chan-Gi Pack and Professor Jun Ki Kim from the Department of Convergence Medicine at Asan Medical Center recently identified specific conditions under which cell apoptosis can be induced through the entry and destruction processes of iron oxide nanoparticles.
By combining super-resolution confocal microscopy, electron microscopy, and high-sensitivity fluorescence detection technology, the research team analyzed the change in location and decomposition process of intracellular iron oxide nanoparticles over time at a single cell level. The findings showed that once inside the cell, iron oxide nanoparticles concentrate around the cell nucleus over time and are subsequently destroyed by inducing autophagy. When combined with ascorbic acid, apoptosis was found to occur through ferroptosis.
Previously, conventional simple fluorescence imaging could only analyze fragmented intracellular collective distribution. However, the newly adopted three high-sensitivity and super-resolution analysis systems can track intracellular nanoparticles at a single cell level to accurately reveal intracellular changes, such as apoptosis, under specific conditions. In the future, the system is expected to provide optimal conditions for the tailored design of various drug-delivery nanoparticles.
The research findings were recently published and featured on the cover of ‘Nano Today,’ a prestigious journal in nanoscience and technology.

Guidelines for diagnosing the cause of dysphagia include sequentially conducting upper GI endoscopy to confirm structural abnormalities in the esophagus, proton pump inhibitors (PPIs) if the cause is suspected to be gastroesophageal reflux disease (GERD), and esophageal manometry to check for achalasia. However, research findings were published showing some patients with unexplained dysphagia had microscopically thick esophageal muscles that were difficult to detect even with endoscopy.
The research team led by Professor Kee Wook Jung of the Division of Gastroenterology at Asan Medical Center selected 200 patients diagnosed as normal after undergoing upper GI endoscopy and PPI treatment, followed by esophageal manometry from January 2021 to September 2022. The team analyzed the patients' esophageal muscle thickness using computed tomography (CT) and endoscopic ultrasound (EUS). In eight patients (4%), the esophageal muscles were slightly thickened by about 5mm. Furthermore, the esophageal manometry showed a peculiar pattern of repeated esophageal contraction in seven of the eight patients with thickened esophageal muscles.
It is speculated that if the esophageal muscles surrounding the esophageal wall are thicker than ordinary, the esophageal muscles may not expand and contract, leading to difficulty in swallowing food. In this case, the dilated esophageal muscles can be loosened by performing a surgical procedure to remove part of the esophageal muscles.
The research findings were recently published in ‘Neurogastroenterology & Motility,’ the official academic journal of the American Neurogastroenterology and Motility Society and the European Society of Neurogastroenterology and Motility.

Autism spectrum disorder (ASD) is a complex condition characterized by difficulties in social communication and interaction, repetitive behaviors, and even gastrointestinal symptoms. While ASD is commonly known to be associated with mid-pregnancy brain development, environmental factors can have a significant impact on its severity in some children. Professor Hyo-Won Kim of the Department of Psychiatry at Asan Medical Center recently published study findings that suggest the microbial composition of the gut microbiome could serve as a new marker for differentiating the severity and predicting the clinical presentation of ASD.
The gut microbiome is known to influence immune and nervous system development. Given that the microbiome can vary depending on environmental factors such as race, residence, and diet, it is crucial to investigate the correlation between the microbiome and ASD in South Korean patients. Professor Kim conducted an analysis of the fecal microbiome of 456 individuals, including 249 ASD patients. The research team classified gut microbiome species and utilized machine learning to compare the severity differences of ASD based on microbiome type. The results indicated that certain bacteria, such as Megamonas and Intestinibacter bartlettii, were more prevalent in the ASD group, while the severity was lower when beneficial microbial species, such as Bifidobacterium longum, were more abundant. Furthermore, the ASD group was divided into two groups based on gut microbiome composition, revealing that the group with slower gut microbiome maturation exhibited lower social and self-help skills.
The research was the largest-scale study of the autism spectrum microbiome in South Korea, and the findings were recently published in the international journal ‘Psychiatry Research.’

Since 1990, the Organ Transplantation Center of Asan Medical Center has performed over 25,000 organ transplantations, including liver, heart, kidney, lung, pancreas, cornea, and bone marrow. The survival rates after transplantation are impressive, with one-year survival rates of 98% for liver, 95% for heart, 98.5% for kidney, and 80% for lung transplantations, showcasing outcomes on par with or surpassing those of leading organ transplantation centers worldwide.
Liver transplantation, in particular, boasts outstanding numbers, with over 8,600 surgeries performed and survival rates of 98% at one year, 90% at three years, and 89% at ten years, showcasing some of the best results globally. Noteworthy recipients of liver transplantation from Asan Medical Center include the longest-surviving liver transplantation recipient in Korea (42 years old in 1992), the first pediatric living-donor liver transplantation recipient (9 months old in 1994), the first adult living-donor liver transplantation recipient (38 years old in 1997), the world's first modified right-lobe liver transplantation recipient (41 years old in 1999), and the world's first 2-to-1 living-donor liver transplantation recipient (49 years old in 2000), all leading healthy lives to this day.
Asan Medical Center excels in ABO-incompatible living-donor liver transplantation, a high-risk immunological category, demonstrating outcomes comparable to those of blood-type compatible liver transplantation. Asan Medical Center also prioritizes the safety of liver donors in addition to transplantation recipients. Donor hepatectomy using laparoscopy and minimal incisions reduces the donor's recovery period and minimizes scarring, contributing to a higher quality of life. Notably, there have been no deaths or severe complications among living liver donors.
Since its inception with the first domestic heart transplantation in 1992 for a 50-year-old woman suffering from end-stage cardiomyopathy, Asan Medical Center has amassed a record of over 900 heart transplantations, the highest in Korea. The survival rates stand at 95% at one year, 86% at five years, and 76% at ten years, significantly surpassing the survival rates of the International Society for Heart and Lung Transplantation (ISHLT). Despite the high success rates of heart transplantation, patients with end-stage heart failure face an uncertain wait due to the reliance on donations from brain-dead individuals. Asan Medical Center addresses this issue by implanting left ventricular assist devices (pumps to assist heart function), acting as artificial hearts, in patients who have to rely on medication for prolonged periods awaiting heart transplantation or for whom heart transplantation is not feasible, preventing symptom deterioration and improving their quality of life. To date, over 100 LVAD implants have been performed.
Kidney transplantation at Asan Medical Center is equally remarkable. Since 2015, Asan Medical Center has performed over 400 kidney transplantations annually, totaling over 7,500 procedures, targeting end-stage renal failure patients who would otherwise require lifelong dialysis. The survival rate of transplanted kidneys (the percentage of patients with well-functioning kidneys post-transplantation, eliminating the need for dialysis or re-transplantation) stands at 98.5% at one year, 90% at five years, and 77.1% at ten years, comparable to the United Network for Organ Sharing (UNOS) kidney transplantation survival rates of 99.9% at one year and 85.4% at five years.
Since the first lung transplantation for a patient with idiopathic pulmonary fibrosis using lungs from a brain-dead individual in 2008, Asan Medical Center has conducted over 250 lung transplantations to date. Despite nearly 70% of the 250 lung transplantation recipients being severely ill patients who had been maintained on extracorporeal membrane oxygenation (ECMO) or mechanical ventilators for prolonged periods, the survival rates post-transplantation are impressive, at 80% at one year, 71% at three years, and 68% at five years. These rates exceed the International Society for Heart and Lung Transplantation (ISHLT) lung transplantation survival rates. Asan Medical Center has elevated survival rates to a global standard through an advanced critical care management system, appropriately regulating immunosuppressant therapy and assisting in proper respiratory rehabilitation exercises for transplantation patients. In addition, Asan Medical Center has performed ▲ 510 pancreas transplantation, ▲ 1,200 cornea transplantation, and ▲ 6,200 bone marrow transplantation.

The fundamental treatment for vulnerable atherosclerotic coronary plaques, known as vulnerable plaques, which are at high risk of rupture, involves medical therapy such as anticoagulants and cholesterol-lowering agents. However, this treatment alone does not easily prevent the occurrence of myocardial infarction due to sudden rupture.
A large-scale clinical study conducted by Endowed-Chair Professor Seung-Jung Park, Professor Duk-Woo Park, Professor Jung-Min Ahn, and Professor Do-Yoon Kang of the Division of Cardiology at Asan Medical Center revealed that preventive percutaneous coronary intervention (PCI) for patients with high-risk vulnerable plaques is more effective than optimal medical therapy. This research was presented at the American College of Cardiology’s 73rd Annual Scientific Session & Expo (ACC.24), the highest authority in the field of cardiology. This study is the world's first to compare the occurrence rates of major clinical events between optimal medical therapy and preventive PCI in patients with vulnerable plaques.
The research team targeted patients diagnosed with vulnerable plaques using vascular imaging equipment from 15 institutions in Korea, Japan, Taiwan, and New Zealand from 2015 to 2021. They divided the patients into two groups: one receiving optimal medical therapy alone (803 patients) and the other receiving optimal medical therapy along with preventive PCI (803 patients) and analyzed the treatment outcomes. Typically, PCI is performed in severe coronary artery stenosis with severe blood flow disorders, but this study was conducted on patients without severe blood flow disorders. Treatment outcomes were evaluated based on major clinical event occurrence rates such as death from cardiac causes, acute myocardial infarction, revascularization, and hospitalization due to unstable angina.
As a result, the occurrence rate of major clinical events two years after treatment in the preventive PCI group was 0.4%, which was approximately 8.5 times lower than the 3.4% in the optimal medical therapy-only group. Furthermore, after observing them for an average of 4.4 years (up to 7.9 years), the occurrence rate of major clinical events in the preventive PCI group was 6.5%, which was approximately 1.4 times lower than the 9.4% in the optimal medical therapy group.
These research findings were presented at the Late-Breaking Clinical Trial session of the ACC.24, held in Atlanta on April 8th (local time), with over two thousand cardiology experts from around the world in attendance. Additionally, the same day, the results were published in 'The Lancet,' the world's leading journal in the field of medical science and technology.

Hepatocellular carcinoma (HCC) presents a wide range of factors to consider, including the location and size of the tumor, metastasis, and residual liver function, with various treatment methods available. Therefore, it is challenging to determine the direction of treatment. To address this, a research team led by Professor Kang Mo Kim of the Division of Gastroenterology and Professor Namkug Kim of the Department of Convergence Medicine at Asan Medical Center developed an AI-based clinical decision support system (CDSS) that suggests treatment methods for individual patients and predicts survival rates.
The research team collected data from 2,685 patients diagnosed with HCC from nine domestic medical institutions, including AMC, and treated with various therapies from January 2010 to December 2012. Artificial intelligence was trained for their basic clinical information, type of initial treatment after cancer diagnosis, and post-therapy survival data divided by hospital. The research findings showed treatment prediction accuracies of 87.27% and 86.06% for internal and external datasets of AMC, respectively, with survival prediction accuracies of 91.89% and 86.48%, demonstrating high diagnostic performance.
Notably, in this study, different treatment methods were recommended to the same patient based on the characteristics of each institution, and predicted survival rates differed for each treatment. From this, there is potential for use as a ‘digital twin’ that converts real situations into virtual models to simulate various situations.
The research findings were recently published online in the ‘npj Digital Medicine.’

When a vertebral fracture occurs, surgery is required to fix the fractured vertebra and several vertebrae above and below it. Contrary to previous cases, recent research has revealed that minimal segment fixation of three vertebrae—the fractured vertebra, one above, and one below—is sufficient.
A team led by Professor Jin hoon Park of the Department of Neurosurgery at Asan Medical Center performed short-segment fixation on 10 patients with thoracolumbar burst fractures from 2018 to 2022. The team compared and analyzed their Cobb angles at 3 time points: preoperatively, postoperatively, and a year later. A higher absolute value of the Cobb angle indicates severe spinal curvature, with less than 5 degrees considered normal for the thoracolumbar structure.
The results showed that the 10 patients had severe kyphosis with a mean preoperative Cobb angle of approximately -11.6. The angle improved to approximately 11.4 degrees after surgery and about 4.8 degrees one year later. This short-segment fixation effectively corrected kyphosis while maximizing the patient's postoperative spinal mobility. The research team’s analysis revealed that each patient's spine took about a year to regain its proper alignment after surgery naturally.
The research findings were recently published in the international journal ‘World Neurosurgery.’

Asan Medical Center has been honored as Korea’s Most Admired Hospital for 18 consecutive years since the survey began in 2007. The award is given to hospitals that receive the highest evaluations from patients, caregivers, and medical professionals for outstanding medical achievements and social contributions.
The survey, organized by the Korea Management Association Consulting (KMAC), was conducted over four months from September 2023, with 12,000 respondents, including industry professionals, securities analysts, and general consumers. Asan Medical Center achieved the highest score among hospitals in Korea, with an overall score of 8.36, including 8.57 points for comprehensive evaluation, 8.29 points for innovation capability, 8.28 points for image value, and 8.25 points for customer value.
Asan Medical Center has also been named among the ‘Korea’s Top 30 Corporations,’ awarded across all domestic industries,’ for 11 consecutive years, ranking alongside leading companies that represent each industry.

It is reported that three out of ten liver cancer patients still experience rapid deterioration of the disease, even with combination therapy of targeted agents and recently released immune checkpoint inhibitors (ICI). However, a target substance that could improve the effectiveness of immune checkpoint inhibitors for liver cancer has been discovered.
A research team led by Professor Changhoon Yoo and Professor Hyung-Don Kim of the Division of Oncology at Asan Medical Center administered a combination therapy of nivolumab, an immune checkpoint inhibitor, and regorafenib, a targeted agent, to forty-two patients with unresectable hepatocellular carcinoma (uHCC). Their research recently revealed that in fourteen patients whose hepatocellular carcinoma rapidly worsened despite the treatment, a specific protein called TMEM176A/B was expressed more than twice as much.
TMEM176A/B is an inflammasome inhibitor, activating an inflammatory response in our body’s immune system. Therefore, overexpression of TMEM176A/B implies that the immune system works less, reducing the effectiveness of immune checkpoint inhibitor therapy. Through further research, the effectiveness of immune checkpoint inhibitor therapy in HCC patients is expected to improve upon new drug development for TMEM176A/B inhibition.
In addition, the response rate of the combination therapy of nivolumab and regorafenib was approximately 31%. This finding marks the potential as a new treatment since the response rate of existing combination therapies for HCC is reported at about 30%.
The research findings were recently published in ‘Nature Medicine,’ a prestigious sister journal of Nature, the globally renowned academic journal.

Achieving 22nd place globally, 7 notches up from last year…Korea's No. 1 Hospital for 6 consecutive years
Hospitals ranked globally from 1st to 250th based on recommendations from 85,000 medical experts across 30 countries

Asan Medical Center of ASAN Foundation (Chairman Chung Mong-Joon) has achieved the highest ranking among Korean hospitals, reaching 22nd place in the world in ‘World’s Best Hospital 2024’ rankings conducted by Newsweek, a U.S. weekly magazine.
Newsweek, in collaboration with Statista, the global market and consumer data firm, announced the ‘World's Best Hospitals 2024’ ranking on its official website. This ranking is based on recommendations from 85,000 medical professionals across 30 countries as well as patient satisfaction and other factors.
Asan Medical Center recorded a significant rise, climbing seven places from last year to secure the 22nd position globally, placing it alongside renowned hospitals from countries such as the United States, Canada, and Germany. It has consistently held the top position in Korea for 6 consecutive years.
Among over 2,400 hospitals worldwide, the top-ranking hospital in this survey was Mayo Clinic in the United States. Following Mayo Clinic were Cleveland Clinic in the United States, Toronto General Hospital in Canada, Johns Hopkins Hospital in the United States, and Massachusetts General Hospital in the United States, securing the 2nd to 5th positions globally.
The evaluation criteria included results from △online survey of 85,000 doctors, healthcare professionals, and hospital administrators from 30 countries (45%), △medical performance indicators (35.25%), △patient satisfaction surveys (16.25%), and △the implementation of Patient-Reported Outcome Measures (PROMs) (3.5%). For hospitals in Korea, evaluations also considered results from assessments of the appropriateness of intensive care units, acute disease, cancer, and drug evaluations as well as patient experience evaluations regarding physicians, nurses, and hospital environments and more conducted by the Health Insurance Review and Assessment Service.
Furthermore, in the 'World’s Best Specialized Hospitals 2024' rankings released by Newsweek in the latter half of last year, Asan Medical Center was ranked first in Korea in 6 specialties including endocrinology, urology, gastroenterology, neurology, cardiology, and cardiac surgery. It achieved top 10 rankings globally in 5 fields, including 3rd in endocrinology, 4th in urology, 5th in gastroenterology, 6th in cancer, and 8th in neurology.
Last year, a total of 20,086 international patients visited Asan Medical Center for treatment, surpassing pre-COVID-19 pandemic levels. Leveraging this global reputation, Asan Medical Center is leading global healthcare by collaborating with prestigious institutions and thus establishing Asan GI Hospital-UAE (tentative name) and providing medical consulting in Qatar. Over the past decade, more than 3,700 healthcare professionals from over 90 countries including the United States, Germany, and Singapore have visited Asan Medical Center to learn advanced medical techniques and research systems. Through projects like 'Asan in Asia,' Asan Medical Center is transferring high-level medical technology to medically underdeveloped countries.

‘Fenestrated capillaries’ are a type of blood capillary that have small pores or “windows" in the cell membrane, and these pores have a structure partially closed with a diaphragm. The pores in fenestrated capillaries facilitate the rapid exchange of substances, such as oxygen and nutrients, and efficiently remove body waste. The diaphragm acts as a gatekeeper to ensure that essential substances in the blood circulate normally without leaking. Although problems with “windows” can cause various diseases, how these openings are formed has been unknown so far. A team led by Professor Junyeop Lee and Researcher Soo Jin Kim of the Department of Ophthalmology recently became the first to establish the mechanism by which the pores in fenestrated capillaries are formed.
Plasmalemma Vesicle-Associated Protein (PLVAP) is a structural protein that forms pores and diaphragms in fenestrated capillaries and is known to play a crucial role in regulating vascular permeability during substance transfer. The research team conducted an analysis using single-molecule imaging and machine learning with a focus on PLVAP. As a result, they confirmed that the movement and binding forms of PLVAP molecules determine the formation and patterns of the “windows” and that this transition is reversible. The research team also validated these findings in animal models.
The research findings were recently published in ‘Nano Letters,’ a prestigious journal in chemistry, and were selected as the cover story.

Many elderly patients diagnosed with advanced gastric cancer often hesitate to undergo surgery due to the burden of treatment itself or concerns about complications. A recent study analyzed risk factors affecting the long-term survival rate of elderly patients who underwent surgery for gastric cancer.
A team led by Professor Chung Sik Gong and Professor Chang Seok Ko of the Division of Stomach Surgery at Asan Medical Center tracked 237 patients aged 75 and older who underwent surgery for stage 2 or 3 advanced gastric cancer between 2007 and 2015 for approximately 71 months. They found that there were no deaths caused by surgery, with a 3-month survival rate of 99.2%, indicating no short-term risks associated with surgery. The 5-year survival rate of elderly patients who underwent surgery for stage 2 or higher advanced gastric cancer was 51.4%. Typically, the 5-year survival rate is 70% for stage 2 gastric cancer and 40% for stage 3 gastric cancer. Statistical analysis of risk factors that lower the survival rate revealed that weight, complications, tumor stage, and extent of gastrectomy were influential factors. According to the risk ratio analysis by risk factor, underweight patients had a 1.45 times higher risk of death compared to standard or overweight patients, and patients with complications faced a 2.07 times higher risk of death than patients without complications. It was also found that the risk of death for stage 3 gastric cancer patients was 2.61 times higher than for stage 2 patients, while patients who underwent total gastrectomy had a 1.57 times higher risk of death than those who underwent partial gastrectomy.
The research findings were published in the ‘Aging Clinical and Experimental Research.’

Patients with chronic hepatitis B take antiviral agents such as tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF) to suppress viral replication. While concerns have been raised about the prolonged use of TAF potentially increasing the risk of cardiovascular diseases, recent research by a team of Professor Jonggi Choi and Specialist Hyeyeon Hong of the Division of Gastroenterology at Asan Medical Center found no difference in cardiovascular disease incidence between TDF and TAF users.
TAF is an antiviral agent that reduces the side effects of osteoporosis and renal function impairment associated with TDF, providing the same therapeutic effect at 10% of TDF’s dosage. However, TAF has raised concerns about the possible occurrence of cardiovascular diseases because it does not decrease lipid parameters, unlike TDF, which reduces all lipid parameters, including total cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol.
The research team studied 4,124 patients with chronic hepatitis B from 2021 to 2022, dividing them into 3,186 patients on TDF and 938 patients on TAF to follow up on the cumulative incidence of cardiovascular diseases. During the observation period of 15,527 person-years (1 person-year is a 1-year observation on 1 patient), the number of cardiovascular disease occurrences was 37 in TDF users and 5 in TAF users. The cumulative incidence rates in TDF users at 1 year, 3 years, and 5 years were 0.4%, 0.8%, and 1.2% respectively. This was comparable to 0.2%, 0.7%, and 0.7% in TAF users, with no statistically significant differences.
Notably, no difference was found in propensity score matching analysis where differing characteristics of underlying diseases between the two groups are adjusted for. There were also no significant differences in the total cholesterol to HDL ratio, which is known to be associated with the risk of cardiovascular diseases.
The research findings were recently published in the ‘Clinical and Molecular Hepatology.’

International Patient Numbers Surpass Pre-COVID-19 Levels, Reaching 20,086

The total number of patients who visited Asan Medical Center last year was 3,469,589. Categorized by type, there were 3,313,333 outpatient visits and 156,256 inpatient admissions. This reflects an approximately 11.4% increase in outpatients and a 6.9% increase in inpatients compared to 2019, the period before the COVID-19 pandemic, when there were 2,974,392 outpatients and 146,051 inpatients.
In 2023, Asan Medical Center conducted 78,920 surgeries, surpassing the figures of 66,838 in 2020, 71,844 in 2021, and 69,542 in 2022, marking a return to over 70,000 surgeries once again after 2021. The rise in surgical cases is attributed to factors such as an increase in new patients and the efficient operation of the same-day surgery system.
The number of international patients who received treatment at Asan Medical Center last year was 20,086. This marks the highest number ever recorded, exceeding the pre-COVID-19 level of 17,835 in 2022 by 12.6%. When segmented by type, there were 18,627 outpatient cases, 617 inpatient cases, and 842 health check-up recipients. By nationality, the top five were the United States with 4,894 (24.3%), the United Arab Emirates with 3,537 (17.6%), Mongolia with 2,552 (12.7%), China with 1,973 (9.8%), and Kazakhstan and Vietnam with 941 each (4.6%).

Mothers diagnosed with breast cancer at a young age may feel sorry and even guilty, thinking they cannot provide adequate care for their children. However, recent research suggested that being diagnosed with breast cancer at a young age has little impact on the emotional development of their children. Thus, it is more important for patients to worry less and focus on their treatment.
A team led by Professor Hee Jeong Kim of the Division of Breast Surgery and Professor Hyo-Won Kim of the Department of Psychiatry at Asan Medical Center conducted the Child Behavior Checklist (CBCL) test for children under 12 of 499 patients aged between 20 and 45 diagnosed with young breast cancer. CBCL evaluates children or adolescents in terms of social adjustment in addition to emotional and behavioral issues. The analysis revealed that 87% of the children had emotional development in the normal range. Given that 84% of the general CBCL test takers would fall in the normal range, this is 3% higher, showing that a breast cancer diagnosis has little impact on children’s emotional development. Additionally, a comparison between young breast cancer patients and 200 breast cancer patients without children showed that those with children had a 2.3 times higher risk of developing depression, indicating that they were more emotionally unstable. Higher Korean Parenting Stress Index scores were also associated with a 1.06 times higher risk of depression.
The research findings were recently published in ‘JAMA Network Open,’ a publication of the American Medical Association.

Mother and son who were both suffering from dilated cardiomyopathy, a condition where the heart enlarges abnormally beyond the heart muscle, received their second hearts as gifts at Asan Medical Center. The mother underwent a heart transplant in 2009, while the son, having received an artificial heart transplant at the end of last year, recently recovered and was discharged in good health.
Heart Failure and Cardiac Transplantation Center at Asan Medical Center achieved a milestone by successfully completing the implantation procedure of a left ventricular assist device (LVAD) in Mr. Lee, who was diagnosed with dilated cardiomyopathy in late November last year. This marked the 100th LVAD implantation at Asan Medical Center. The mother of Mr. Lee, who also suffered from the same condition, had underwent a heart transplant at Asan Medical Center 15 years ago.
In June 2015, Asan Medical Center pioneered the implementation of the third-generation LVAD in Korea and performed 26 procedures in the past year alone. The one-year survival rate for patients with a LVAD worldwide is approximately 80%, and Asan Medical Center has achieved a rate of 82.6%, providing a relatively safe waiting period for heart transplantation. The average age of patients who underwent LVAD at Asan Medical Center was 58.7 years, ranging from the youngest at 17 to the oldest at 78, demonstrating our capability to safely treat patients across various age groups. Among them, 41 individuals waited healthily after LVAD implantation and eventually received a new heart through heart transplantation.

Children who had been unable to hear since birth but received cochlear implants showed no significant difference in educational and occupational status when they reached adulthood compared to the general population.
A research team led by Professor Hong Ju Park and Professor Woo Seok Kang of the Department of Otolaryngology-Head and Neck Surgery examined the schooling and employment rates of 71 children with bilateral hearing impairment who underwent cochlear implants between 2000 and 2007. Their average age at the time of surgery was 3.9 years, and their current average age is 22.4 years.
The analysis revealed that all subjects had either graduated from high school or obtained equivalent educational qualifications. The college admission rate was 74.6%, comparable to the general population's (70.4%, the university admission rate for Korean high school graduates in 2020). 
Excluding 30 subjects currently enrolled in college, 26 (62%) of the remaining 41 are employed and engaged in various occupational activities. This employment rate is similar to that of general graduate students, which is 65.1% (based on the Korea National Statistical Office in December 2020). Of the employed 26 subjects, 21 were confirmed to have been hired through vocational training institutions or special hiring policies for people with disabilities.
The research findings were published in the recent issue of Otolaryngology-Head & Neck Surgery, the official journal of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS).

CAR T-cell therapy (Chimeric Antigen Receptor T cell therapy) is a treatment method that involves expressing T-cells on chimeric antigen receptors that respond to specific cancer cells and infusing them into patients to eliminate cancer cells. Existing CAR T-cell therapies, including Kymriah, all use an antibody binding site derived from mice called FMC63. However, the new treatment, 'AT101,' utilizes a humanized antibody binding site that is closer to cancer cells compared to FMC63. Research results verifying the effectiveness and safety of AT101 have recently been published.
Team led by Professor Dok Hyun Yoon and Professor Hyungwoo Cho of the Division of Oncology at Asan Medical Center conducted a study from March 2022 to nine months on 12 patients with B-cell lymphoma who were refractory to treatment or had relapsed and were no longer eligible for standard treatment options. The patients were divided into DL(dose level)-1, DL-2, and DL-3 groups, and the administration of AT101 resulted in cytokine release syndrome and neurotoxicity of grade 3 or higher observed in only one person each. The overall response rate to the treatment was 91.7%, with a 100% response rate observed in the DL-2 and DL-3 groups.
The results of this study were recently published in the international journal ‘Molecular Cancer.’

The graduation ceremony for the WEO International School of EUS (WISE) Training, a training program on endoscopic ultrasound procedures offered to young medical professionals worldwide, was held on January 19th. Last year, 44 international physicians participated in the program.
WISE, led by Professor Dong Wan Seo, Professor Tae Jun Song, and Professor Dongwook Oh of the Division of Gastroenterology at Asan Medical Center, was established in 2018 for young medical professionals wishing to learn endoscopic ultrasound procedures systematically. Applications for training are received from medical professionals worldwide who are screened to select final successful candidates. The selected trainees are given a five-stage training course for one year, from essential to interventional procedures. Each stage includes various training programs such as lectures and live EUS procedures. The trainees present a case study applying the EUS techniques they have been trained to patients and are allowed to upgrade their skills through detailed coaching from AMC experts. Until last year, 221 medical professionals from 41 countries, including the United States, India, and Brazil, had been trained at WISE.

Bladder cancer is a common cancer, accounting for 3% of global cancer diagnoses. Early diagnosis and tumor evaluation are crucial because high-risk tumors are associated with a significant increase in mortality. A recent technology has been developed using surface-enhanced Raman spectroscopy (SERS) with machine learning algorithms to diagnose bladder cancer from urine samples.
A research team led by Professor Jun Ki Kim of the Department of Convergence Medicine and Dr. Sanghwa Lee of the Biomedical Engineering Research Center at Asan Medical Center conducted research based on the fact that targeting nano-scale biomarkers in liquid biopsy is associated with highly likely presence of the targeted biomarkers even in small samples. The research team used a sensing chip that selectively captures Raman signals while filtering nano-meter markers.
The research team induced tumor development in the bladder of mice by supplying the carcinogen ‘BBN’ to their drinking water. Then, they used a 1mm-diameter endoscope to follow up on the tumor development process minimally invasively. After obtaining urine samples from the early and severe stages of tumors in the experimental and control groups using the endoscope, the samples were placed on a sensing chip to acquire Raman signals. The analysis of diagnostic performance demonstrated a well-separated data distribution of Raman spectra into groups of no cancer, early cancer, and polyp-type cancer. In addition, the discrimination accuracy of each group exceeded 99.6% according to AI-facilitated discrimination analysis.
The research findings were published in the latest issue of ‘Biosensors and Bioelectronics,’ a prestigious journal in the field of chemistry and life sciences.

On January 29th, Asan Medical Center signed an MOU with Emirates Health Services (EHS), one of the UAE's healthcare-related government agencies.
The two institutions have agreed to collaborate on various aspects, including expanding opportunities for knowledge transfer through visiting physicians programs, developing an integrated healthcare system for mutual clinical collaboration, establishing joint research and innovation programs, and conducting training and leadership education for medical professionals.
Asan Medical Center has built a longstanding relationship with the UAE, involving patient referrals, medical staff training, and an operation and management agreement of a gastrointestinal specialized hospital, among other initiatives. Through this recent MOU, the scope of collaboration is set to expand, fostering even more active exchanges.
Last year alone, a total of 20,860 international patients visited Asan Medical Center, with UAE patients accounting for 3,537, representing the second-highest proportion at 18%.
Notably, severely ill patients from the UAE, facing treatment challenges locally, have undergone complex surgeries at Asan Medical Center, resulting in successful recoveries. For instance, in February of last year, a patient with colon cancer from Abu Dhabi underwent robotic surgery, and in September, a baby born with biliary atresia received a liver transplantation.
Since 2018, Emirates Health Services has been requesting visits from medical professionals at Asan Medical Center to contribute to the development of local medical technology. The medical staff of Asan Medical Center has been sharing advanced medical technology and expertise with Middle Eastern patients through surgeries, clinical treatments, and medical staff training.

Asan Medical Center Medical Volunteers carried out volunteer activities in Uganda, East Africa, from January 14th for four days. AMC Medical Volunteers consisted of a total of 26 participants, including 7 doctors, 18 nurses, and 1 staff from Biomedical Engineering.
AMC Medical Volunteers, with surgical medical staff as the main participants, divided into two teams and traveled by bus for an additional 8 hours to visit Kumi and Bududa, which are considered medically vulnerable areas within Uganda. Both areas suffer from frequent interruptions in water and electricity supply, as well as inadequate medical facilities and personnel shortages. Upon hearing that medical professionals from Korea were providing treatment, local residents gathered. Patients with conditions such as unable to lie down due to a bump on the back and a girl with congenital finger deformities were treated. From January 14th for four days, AMC Medical Volunteers set up temporary treatment facilities at Kumi University Clinic and Bududa General Hospital, providing medical treatment to a total of 1,450 patients. In particular, this medical volunteer mission involved surgical specialists such as breast surgery, acute care surgery, pediatric surgery, and plastic surgery, who performed a total of 72 surgeries, including breast tumor excision, hernia repair, and skin reconstruction surgery, which are difficult to perform in local hospitals. Additionally, 68 endoscopies, 55 ultrasounds, and 60 blood tests were conducted, and Mr. Sung Bum Lee from the Biomedical Engineering Team repaired faulty medical equipment at Bududa General Hospital. Ugandan medical professionals learned advanced surgical techniques and infection control by observing consultations and surgeries.