1.Nationwide Trends in Coronary Artery Bypass Grafting in the Republic of Korea, 2005–2022: A Comparison with International Data
Min Ho JU ; Jun Ho LEE ; Yun Jin KIM ; Ho Jin KIM ; Ho Young HWANG ; Sang Yoon YEOM ; Hee Jung KIM ; Young-Nam YOUN ; Wook Sung KIM ; Man-Jong BAEK ; Hyun Keun CHEE ;
Journal of Chest Surgery 2026;59(1):7-16
Coronary artery bypass grafting (CABG) remains a key revascularization strategy for ischemic heart disease; however, nationwide trends in the Republic of Korea have not been thoroughly investigated. Using data from the Korean National Health Insurance Service, we analyzed adult patients who underwent isolated CABG between 2005 and 2022. We evaluated surgical volume, patient demographics, procedural strategies (off-pump vs. onpump), and outcomes. International comparisons were conducted using national cardiac surgery registry data. A total of 51,923 CABG cases were identified. Annual surgical volume declined until 2013 but gradually increased thereafter, reaching 3,717 cases in 2022. Despite this recovery, Korea’s per capita CABG rate remains among the lowest worldwide.In contrast, more than 60% of procedures were performed off-pump—the highest rate worldwide. Over time, the average patient age and prevalence of diabetes increased, whereas in-hospital mortality showed a modest decline. Compared with other countries, the Republic of Korea demonstrated a uniquely low procedural volume and a strong preference for off-pump CABG. This nationwide analysis highlights Korea’s distinctive CABG practice patterns and provides valuable insights for optimizing future clinical and policy decisions in cardiac surgical care.
2.Clinical Outcomes of Arteriovenous Grafts Using the Superficial Vein versus Venae Comitantes as Venous Outflow
Yo Seb LEE ; Song Am LEE ; Jae Joon HWANG ; Jun Seok KIM ; Hyun Keun CHEE
Journal of Chest Surgery 2024;57(2):178-183
Background:
The superficial veins are commonly used in conventional autogenous arteriovenous fistulas and the placement of prosthetic grafts. When they are unsuitable, however, the use of the deep veins (venae comitantes) is generally considered to be a reasonable alternative. This study conducted a comparative analysis of clinical outcomes for arteriovenous grafts between 2 groups based on the type of venous outflow: superficial veins or venae comitantes.
Methods:
In total, 151 patients who underwent arteriovenous grafts from November 2005 to March 2022 were retrospectively analyzed. The patients were divided into 2 groups: group A (superficial veins, n=89) and group B (venae comitantes, n=62). The primary, secondary patency, and complication rates were analyzed in each group. A propensity score-matched analysis was performed.
Results:
In total, 55 well-balanced pairs were matched. Kaplan-Meier analysis revealed no significant differences in the primary patency rate between the 2 groups at 1-year, 3-year and 5-year intervals (group A, 54.7%, 35.9%, 25.4% vs. group B, 47.9%, 16.8%, 12.6%; p=0.14), but there was a difference in the secondary patency rate (group A, 98.2%, 95.3%, 86.5% vs.group B, 87.3%, 76.8%, 67.6%; p=0.0095). The rates of complications, simple percutaneous transluminal angioplasty, and stent insertion were comparable between the groups.
Conclusion
Although this study demonstrated not particularly favorable secondary patency rates in the venae comitantes group, the venae comitantes may still be a viable option for patients with unsuitable superficial veins because there were no significant differences in the primary patency and complication rates between the 2 groups.
3.Endovenous radiofrequency ablation using a new bipolar electrode in a canine model: a new endovenous radiofrequency electrode
Jin Ho HWANG ; Sang Woo PARK ; Jeeyoung MIN ; Woo Young YANG ; Yong Wonn KWON ; Jae Joon HWANG ; Jun Seok KIM ; Song Am LEE ; Hyun Keun CHEE
Annals of Surgical Treatment and Research 2023;104(3):164-169
Purpose:
This study aimed to determine the effectiveness and safety of a newly developed endovenous radiofrequency (RF) catheter compared with that of the existing RF catheter in a canine model.
Methods:
Seven dogs underwent ablation using 1 control catheter (ClosureFAST, CF; Covidien) and 1 experimental catheter (VENISTAR, VS; STARmed Co., Ltd.) in the femoral and cephalic veins. The ablated vein was evaluated macroscopically (2,3,5-triphenyltetrazolium chloride staining, TTC), microscopically (hematoxylin and eosin staining), and ultrasonographically. Vessel injury score was used to evaluate the ablating effect objectively. Veins from 1 dog were evaluated on the day of ablation, while in the remaining 6 dogs, the ablated veins were evaluated 2 weeks later.
Results:
A total of 23 veins (CF, 11 veins; VS, 12 veins) were ablated in 7 dogs. Non–TTC-stained vein wall areas were identified in all ablated veins. No significant difference was observed in the mean vessel injury score (2.54 ± 1.16 vs. 2.42 ± 1.13, P = 0.656) and the mean vessel wall thickness (0.32 ± 0.03 mm vs. 0.31 ± 0.05 mm, P = 0.212) between CF and VS. There was no blood flow in all veins ablated with VS, whereas there was remaining blood flow in 1 vein ablated with CF. Perivenous complication was not observed.
Conclusion
Endovenous RF ablation using a newly developed VS RF catheter seems to provide comparable occlusion rate and degree of vein wall injury without perivenous adverse events compared to the most commonly used RF catheter (CF).
4.Historical Review and Future of Cardiac Xenotransplantation
Jiwon KOH ; Hyun Keun CHEE ; Kyung-Hee KIM ; In-Seok JEONG ; Jung-Sun KIM ; Chang-Ha LEE ; Jeong-Wook SEO
Korean Circulation Journal 2023;53(6):351-366
Along with the development of immunosuppressive drugs, major advances on xenotransplantation were achieved by understanding the immunobiology of xenograft rejection. Most importantly, three predominant carbohydrate antigens on porcine endothelial cells were key elements provoking hyperacute rejection: α1,3-galactose, SDa blood group antigen, and N-glycolylneuraminic acid. Preformed antibodies binding to the porcine major xenoantigen causes complement activation and endothelial cell activation, leading to xenograft injury and intravascular thrombosis. Recent advances in genetic engineering enabled knock-outs of these major xenoantigens, thus producing xenografts with less hyperacute rejection rates. Another milestone in the history of xenotransplantation was the development of co-stimulation blockaded strategy. Unlike allotransplantation, xenotransplantation requires blockade of CD40-CD40L pathway to prevent T-cell dependent B-cell activation and antibody production. In 2010s, advanced genetic engineering of xenograft by inducing the expression of multiple human transgenes became available.So-called ‘multi-gene’ xenografts expressing human transgenes such as thrombomodulin and endothelial protein C receptor were introduced, which resulted in the reduction of thrombotic events and improvement of xenograft survival. Still, there are many limitations to clinical translation of cardiac xenotransplantation. Along with technical challenges, zoonotic infection and physiological discordances are major obstacles. Social barriers including healthcare costs also need to be addressed. Although there are several remaining obstacles to overcome, xenotransplantation would surely become the novel option for millions of patients with end-stage heart failure who have limited options to traditional therapeutics.
5.We Always Have a Choice: Pericardial Versus Porcine Valves for Surgical Aortic Valve Replacement
Korean Circulation Journal 2022;52(2):147-149
no abstract available.
6.The Association between Morphological and Functional Characteristics of the Bicuspid Aortic Valve and Bicuspid Aortopathy
Bo Hwa CHOI ; Sung Min KO ; Je Kyoun SHIN ; Hyun Keun CHEE ; Jun Seok KIM
Korean Journal of Radiology 2021;22(6):890-900
Objective:
To identify the association between morphological and functional characteristics of the bicuspid aortic valve (BAV) and bicuspid aortopathy and to identify the determinants of aortic dilatation using transthoracic echocardiography (TTE) and cardiac computed tomography (CCT).
Materials and Methods:
This study included 312 subjects (mean [SD] age, 52.7 [14.3] years; 227 males [72.8%]) who underwent TTE and CCT. The BAVs were classified by anterior-posterior (BAV-AP) or right-left (BAV-RL) orientation of the cusps and divided according to the presence (raphe+) or absence of a raphe (raphe-) based on the CCT and intraoperative findings. The dimensions of the sinus of Valsalva and the proximal ascending aorta were measured by CCT. We assessed the determinants of aortic root and proximal ascending aortic dilatation (size index > 2.1 cm/m2) by Univariable and multivariable logistic regression analyses.
Results:
Of the 312 patients, BAV-AP was present in 188 patients (60.3%), and 185 patients (59.3%) were raphe+. Moderateto-severe aortic stenosis (AS) was the most common hemodynamic abnormality (54.8%). The most common type of aortopathy was the combined dilated root and mid-ascending aortic phenotype (62.5%). On multivariable analysis, age and AS severity were significantly associated with aortic root dilatation (p < 0.05), and age, sex, and AS severity were significantly associated with ascending aortic dilatation (p < 0.05). However, the orientation of the cusps, presence of a raphe, and severity of aortic regurgitation were not associated with aortic root and ascending aortic dilatation.
Conclusion
BAV morphological characteristics were not determinants of aortic dilatation. Age, sex, and AS severity were predictors of bicuspid aortopathy. Therefore, age, sex, and AS severity, rather than valve morphology, need to be considered when planning treatment for BAV patients.
7.The Association between Morphological and Functional Characteristics of the Bicuspid Aortic Valve and Bicuspid Aortopathy
Bo Hwa CHOI ; Sung Min KO ; Je Kyoun SHIN ; Hyun Keun CHEE ; Jun Seok KIM
Korean Journal of Radiology 2021;22(6):890-900
Objective:
To identify the association between morphological and functional characteristics of the bicuspid aortic valve (BAV) and bicuspid aortopathy and to identify the determinants of aortic dilatation using transthoracic echocardiography (TTE) and cardiac computed tomography (CCT).
Materials and Methods:
This study included 312 subjects (mean [SD] age, 52.7 [14.3] years; 227 males [72.8%]) who underwent TTE and CCT. The BAVs were classified by anterior-posterior (BAV-AP) or right-left (BAV-RL) orientation of the cusps and divided according to the presence (raphe+) or absence of a raphe (raphe-) based on the CCT and intraoperative findings. The dimensions of the sinus of Valsalva and the proximal ascending aorta were measured by CCT. We assessed the determinants of aortic root and proximal ascending aortic dilatation (size index > 2.1 cm/m2) by Univariable and multivariable logistic regression analyses.
Results:
Of the 312 patients, BAV-AP was present in 188 patients (60.3%), and 185 patients (59.3%) were raphe+. Moderateto-severe aortic stenosis (AS) was the most common hemodynamic abnormality (54.8%). The most common type of aortopathy was the combined dilated root and mid-ascending aortic phenotype (62.5%). On multivariable analysis, age and AS severity were significantly associated with aortic root dilatation (p < 0.05), and age, sex, and AS severity were significantly associated with ascending aortic dilatation (p < 0.05). However, the orientation of the cusps, presence of a raphe, and severity of aortic regurgitation were not associated with aortic root and ascending aortic dilatation.
Conclusion
BAV morphological characteristics were not determinants of aortic dilatation. Age, sex, and AS severity were predictors of bicuspid aortopathy. Therefore, age, sex, and AS severity, rather than valve morphology, need to be considered when planning treatment for BAV patients.
8.Non-invasive Myocardial Strain Imaging to Evaluate Graft Failure in Cardiac Xenotransplantation.
Hyun Suk YANG ; Hyun Keun CHEE ; Jun Seok KIM ; Wan Seop KIM ; Jung Hwan PARK ; Ki Cheul SHIN ; Kyoung Sik PARK ; Seon Won LEE ; Ka Hee CHO ; Wan Je PARK ; Keon Bong OH ; Curie AHN ; Ik Jin YUN
The Journal of the Korean Society for Transplantation 2017;31(1):25-33
BACKGROUND: The shortage of human hearts for allotransplantation makes xenotransplantation a possible option for controllable organ providers. To detect acute xenograft rejection, invasive biopsy seems inevitable; however, this occasionally results in poor incision wound healing or infection. To date, no method of noninvasive imaging for early detection of xenograft rejection has been established. We hypothesized that ultrasound speckle tracking would better detect xenograft failure than routine left ventricular ejection fractions (EF). METHODS: From August 2013 to July 2015, a total of six cardiac heterotopic xenotransplants (α 1, 3-galactosyltransferase gene-knockout porcine heart) into cynomolgus monkeys were monitored with echocardiography every 3 to 7 days. M-mode and two-dimensional (2D)-EF measurements and myocardial strain analyses were performed. Cardiac xenograft pathology was reviewed from the immediate postoperative biopsy, as well as the necropsy. RESULTS: Myocardial speckle tracking analysis was feasible in all six cases. The longest survival was 43 days. Only one pathology-proven immunologic rejection occurred. Cardiac xenograft failure appeared as two types: a dilated pattern with decreased EF or a myocardial-thickening pattern with preserved EF. Both antibody-mediated rejection (n=1) and sepsis-induced myocardial dysfunction (n=2) revealed decreased radial or circumferential strains, but normal-range EF. Xenograft functional decline was significant with respect to radial or circumferential strain (P=0.028), but not to conventional M-mode or 2D-EFs (P=0.600, P=0.340, respectively). CONCLUSIONS: Radial and circumferential strains were significantly decreased in both types of xenograft failure, regardless of EF. Further studies are warranted to correlate the strain analysis and immunopathological details.
Biopsy
;
Echocardiography
;
Heart
;
Heart Transplantation
;
Heterografts
;
Humans
;
Macaca fascicularis
;
Methods
;
Pathology
;
Stroke Volume
;
Transplantation, Heterologous*
;
Transplants*
;
Ultrasonography
;
Wound Healing
9.Morphological and Functional Evaluation of Quadricuspid Aortic Valves Using Cardiac Computed Tomography.
Inyoung SONG ; Jung Ah PARK ; Bo Hwa CHOI ; Sung Min KO ; Je Kyoun SHIN ; Hyun Keun CHEE ; Jun Seok KIM
Korean Journal of Radiology 2016;17(4):463-471
OBJECTIVE: The aim of this study was to identify the morphological and functional characteristics of quadricuspid aortic valves (QAV) on cardiac computed tomography (CCT). MATERIALS AND METHODS: We retrospectively enrolled 11 patients with QAV. All patients underwent CCT and transthoracic echocardiography (TTE), and 7 patients underwent cardiovascular magnetic resonance (CMR). The presence and classification of QAV assessed by CCT was compared with that of TTE and intraoperative findings. The regurgitant orifice area (ROA) measured by CCT was compared with severity of aortic regurgitation (AR) by TTE and the regurgitant fraction (RF) by CMR. RESULTS: All of the patients had AR; 9 had pure AR, 1 had combined aortic stenosis and regurgitation, and 1 had combined subaortic stenosis and regurgitation. Two patients had a subaortic fibrotic membrane and 1 of them showed a subaortic stenosis. One QAV was misdiagnosed as tricuspid aortic valve on TTE. In accordance with the Hurwitz and Robert's classification, consensus was reached on the QAV classification between the CCT and TTE findings in 7 of 10 patients. The patients were classified as type A (n = 1), type B (n = 3), type C (n = 1), type D (n = 4), and type F (n = 2) on CCT. A very high correlation existed between ROA by CCT and RF by CMR (r = 0.99) but a good correlation existed between ROA by CCT and regurgitant severity by TTE (r = 0.62). CONCLUSION: Cardiac computed tomography provides comprehensive anatomical and functional information about the QAV.
Aortic Valve Insufficiency
;
Aortic Valve Stenosis
;
Aortic Valve*
;
Classification
;
Consensus
;
Constriction, Pathologic
;
Echocardiography
;
Humans
;
Magnetic Resonance Imaging
;
Membranes
;
Multidetector Computed Tomography
;
Retrospective Studies
10.Trends in Percutaneous Coronary Intervention and Coronary Artery Bypass Surgery in Korea.
Heeyoung LEE ; Kun Sei LEE ; Sung Bo SIM ; Hyo Seon JEONG ; Hye Mi AHN ; Hyun Keun CHEE
The Korean Journal of Thoracic and Cardiovascular Surgery 2016;49(Suppl 1):S60-S67
BACKGROUND: Coronary angioplasty has been replacing coronary artery bypass grafting (CABG) because of the relative advantage in terms of recovery time and noninvasiveness of the procedure. Compared to other Organization for Economic Cooperation and Development (OECD) countries, Korea has experienced a rapid increase in coronary angioplasty volumes. METHODS: We analyzed changes in procedure volumes of CABG and of percutaneous coronary intervention (PCI) from three sources: the OECD Health Data, the National Health Insurance Service (NHIS) surgery statistics, and the National Health Insurance claims data. RESULTS: We found the ratio of procedure volume of PCI to that of CABG per 100,000 population was 19.12 in 2014, which was more than triple the OECD average of 5.92 for the same year. According to data from NHIS statistics, this ratio was an increase from 11.4 to 19.3 between 2006 and 2013. CONCLUSION: We found that Korea has a higher ratio of total procedure volumes of PCI with respect to CABG and also a more rapid increase of volumes of PCI than other countries. Prospective studies are required to determine whether this increase in absolute volumes of PCI is a natural response to a real medical need or representative of medical overuse.
Administrative Claims, Healthcare
;
Angioplasty
;
Coronary Angiography
;
Coronary Artery Bypass*
;
Coronary Vessels*
;
Korea
;
Medical Overuse
;
Myocardial Infarction
;
National Health Programs
;
Organisation for Economic Co-Operation and Development
;
Percutaneous Coronary Intervention*
;
Prospective Studies
;
Quality of Health Care

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