Background: Recently, a ring-type cuffless blood pressure (BP) measuring device has been developed. This study was a prospective, single arm, first-in-human pivotal trial to evaluate accuracy of BP measurement by the new device. Methods: The ring-type smart wearable monitoring device measures photoplethysmography signals from the proximal phalanx and transmits the data wirelessly to a connected smartphone. For the BP comparison, a cuff was worn on the arm to check the reference BP by auscultatory method, while the test device was worn on the finger of the opposite arm to measure BP simultaneously. Measurements were repeated for up to three sets each on the left and right arms. The primary outcome measure was mean difference and standard deviation of BP differences between the test device and the reference readings. Results: We obtained 526 sets of systolic BP (SBP) and 513 sets of diastolic BP (DBP) from 89 subjects, with ranges of 80 to 175 mmHg and 43 to 122 mmHg for SBP and DBP, respectively.In sample-wise comparison, the mean difference between the test device and the reference was 0.16 ± 5.90 mmHg (95% limits of agreement [LOA], −11.41, 11.72) in SBP and −0.07 ± 4.68 (95% LOA, −9.26, 9.10) in DBP. The test device showed a strong correlation with the reference for SBP (r = 0.94, P < 0.001) and DBP (r = 0.95, P < 0.001). There were consistent results in subject-wise comparison. Conclusion The new ring-type BP measuring device showed a good correlation for SBP and DBP with minimal bias compared with an auscultatory method.

Purpose: The incidence and prognostic implications of atrial fibrillation (AF) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) are controversial, especially for Korean patients. Furthermore, the pattern of antithrombotic therapy for these patients is unknown. The present study sought to identify the impact of AF on Korean patients undergoing TAVI and demonstrate the status of antithrombotic therapy for these patients. Materials and Methods: A total of 660 patients who underwent TAVI for severe AS were recruited from the nationwide K-TAVI registry in Korea. The enrolled patients were stratified into sinus rhythm (SR) and AF groups. The primary endpoint was all-cause death at 1-year. Results: AF was recorded in 135 patients [pre-existing AF 108 (16.4%) and new-onset AF 27 (4.1%)]. The rate of all-cause death at 1 year was significantly higher in patients with AF than in those with SR [16.2% vs. 6.4%, adjusted hazard ratio (HR): 2.207, 95% confidence interval (CI): 1.182–4.120, p=0.013], regardless of the onset timing of AF. The rate of new pacemaker insertion at 1 year was also significantly higher in patients with AF than in those with SR (14.0% vs. 5.5%, adjusted HR: 3.137, 95%CI: 1.621–6.071, p=0.001).Among AF patients, substantial number of patients received the combination of multiple antithrombotic agents (77.8%), and the most common combination was that of aspirin and clopidogrel (38.1%). Conclusion AF was an independent predictor of 1-year mortality and new pacemaker insertion in Korean patients undergoing TAVI.

Hypertrophic cardiomyopathy (HCM) is one of the most common inheritable cardiomyopathies. Contemporary management strategies, including the advent of implantable cardioverter-defibrillators and effective anticoagulation, have substantially improved the clinical course of HCM patients; however, the disease burden of HCM is still high in Korea. Sudden cardiac death (SCD), atrial fibrillation and thromboembolic risk, dynamic left ventricular outflow tract (LVOT) obstruction, and heart failure (HF) progression remain important issues in HCM. SCD in HCM can be effectively prevented with implantable cardioverter-defibrillators. However, appropriate patient selection is important for primary prevention, and the 5-year SCD risk score and the presence of major SCD risk factors should be considered. Anticoagulation should be initiated in all HCM patients with atrial fibrillation regardless of the CHA 2 DS 2 -VASc score, and non-vitamin K antagonist oral anticoagulants are the first option. Symptomatic dynamic LVOT obstruction is first treated medically with negative inotropes, and if symptoms persist, septal reduction therapy is considered. The recently approved myosin inhibitor mavacamten is promising. HF in HCM is usually related to diastolic dysfunction, while about 5% of HCM patients show reduced left ventricular ejection fraction <50%, also referred to as “end-stage” HCM. Myocardial fibrosis plays an important role in the progression to advanced HF in patients with HCM. Patients who do not respond to guideline-directed medical therapy can be considered for heart transplantation. The development of imaging techniques, such as myocardial deformation on echocardiography and late gadolinium enhancement on cardiac magnetic resonance, can provide better risk evaluation and decision-making for management strategies in HCM.

Background: Reduced exercise capacity reflects symptom severity and clinical outcomes in patients with hypertrophic cardiomyopathy (HCM). The present study aimed to identify factors that may affect exercise capacity in patients with HCM. Methods: In 294 patients with HCM and preserved left ventricular (LV) ejection fraction, we compared peak oxygen consumption (peak VO2 ) evaluated by cardiopulmonary exercise testing as a representative parameter of exercise tolerance with clinical and laboratory data, including N-terminal pro-hormone of brain natriuretic peptide (NT-proBNP), diastolic parameters on echocardiography, and the grade of myocardial fibrosis on cardiac magnetic resonance imaging (CMR). Results: Median peak VO2 , was 29.0 mL/kg/min (interquartile range [IQR], 25.0–34.0). Age (estimated β = −0.140, P < 0.001), female sex (β = −5.362, P < 0.001), NT-proBNP (β = −1.256, P < 0.001), and E/e′ ratio on echocardiography (β = −0.209, P = 0.019) were significantly associated with exercise capacity. Peak VO2 was not associated with the amount of myocardial fibrosis on CMR (mean of late gadolinium enhancement 12.25 ± 9.67%LV). Conclusion Decreased exercise capacity was associated with age, female sex, increased NTproBNP level, and E/e′ ratio on echocardiography. Hemodynamic changes and increased filling pressure on echocardiography should be monitored in this population for improved outcomes.

Purpose: Preclinical data indicate that response to radiotherapy (RT) depends on DNA damage repair. In this study, we investigated the role of mutations in genes related to DNA damage repair in treatment outcome after RT. Materials and Methods: Patients with solid tumor who participated in next generation sequencing panel screening using biopsied tumor tissue between October 2013 and February 2019 were reviewed and 97 patients that received RT were included in this study. Best response to RT and the cumulative local recurrence rate (LRR) were compared according to absence or presence of missense, nonsense, and frameshift mutations in ATM and/or BRCA1/2. Results: Of the 97 patients, five patients harbored mutation only in ATM, 22 in only BRCA1/2, and six in both ATM and BRCA1/2 (ATMmtBRCAmt). Propensity score matching was performed to select the control group without mutations (ATMwtBRCAwt, n=33). In total, 90 RT-treated target lesions were evaluated in 66 patients. Highest objective response rate of 80% was observed in ATMmtBRCAmt lesions (p=0.007), which was mostly durable. Furthermore, the cumulative 1-year LRR was the lowest in ATMmtBRCAmt lesions and the highest in ATMwtBRCAwt lesions (0% vs. 47.9%, p=0.008). RT-associated toxicities were observed in 10 treatments with no significant difference among the subgroups (p=0.680). Conclusion Tumors with ATM and BRCA1/2 mutations exhibited superior tumor response and local control after RT compared to tumors without these mutations. The results are hypothesis generating and suggest the need for integrating the tumor mutation profile of DNA repair genes during treatment planning.

Background: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. Methods: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. Results: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI;additionally, age (65–74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. Conclusions Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

In 2017, Korean Society of Medical Oncology (KSMO) published the Korean management guideline of metastatic prostate cancer. This paper is the 2nd edition of the Korean management guideline of metastatic prostate cancer. We updated recent many changes of management in metastatic prostate cancer in this 2nd edition guideline. The present guideline consists of the three categories: management of metastatic hormone sensitive prostate cancer; management of metastatic castration resistant prostate cancer; and clinical consideration for treating patients with metastatic prostate cancer. In category 1 and 2, levels of evidence (LEs) have been mentioned according to the general principles of evidence-based medicine. And grades of recommendation (GR) was taken into account the quality of evidence, the balance between desirable and undesirable effects, the values and preferences, and the use of resources and GR were divided into strong recommendations (SR) and weak recommendations (WR). A total of 16 key questions are selected. And we proposed recommendations and described key evidence for each recommendation. The treatment landscape of metastatic prostate cancer is changing very rapid and many trials are ongoing. To verify the results of the future trials is necessary and should be applied to the treatment for metastatic prostate cancer patients in the clinical practice. Especially, many prostate cancer patients are old age, have multiple underlying medical comorbidities, clinicians should be aware of the significance of medical management as well as clinical efficacy of systemic treatment.

BACKGROUND: For stem cell applications in regenerative medicine, it is very important to produce high-quality stem cells in large quantities in a short time period. Recently, many studies have shown big potential of graphene oxide as a biocompatible substance to enhance cell growth. We investigated if graphene oxide-coated culture plate can promote production efficiency of stem cells. METHODS: Three types of graphene oxide were used for this study. They are highly concentrated graphene oxide solution, single-layer graphene oxide solution, and ultra-highly concentrated single-layer graphene oxide solution with different single-layer ratios, and coated on cell culture plates using a spray coating method. Physiochemical and biological properties of graphene oxide-coated surface were analyzed by atomic force microscope (AFM), scanning electron microscope (SEM), cell counting kit, a live/dead assay kit, and confocal imaging. RESULTS: Graphene oxide was evenly coated on cell culture plates with a roughness of 6.4 * 38.2 nm, as measured by SEM and AFM. Young’s Modulus value was up to 115.1 GPa, confirming that graphene oxide was strongly glued to the surface. The ex vivo stem cell expansion efficiency was enhanced as bone marrow-derived stem cell doubling time on the graphene oxide decreased compared to the control (no graphene oxide coating), from 64 to 58 h, and the growth rate increased up to 145%. We also observed faster attachment and higher affinity of stem cells to the graphene oxide compared to control by confocal microscope. CONCLUSION This study demonstrated that graphene oxide dramatically enhanced the ex vivo expansion efficiency of stem cells. Spray coating enabled an ultra-thin coating of graphene oxide on cell culture plates. The results supported that utilization of graphene oxide on culture plates can be a promising mean for mass production of stem cells for commercial applications.

In 2017, Korean Society of Medical Oncology (KSMO) published the Korean management guideline of metastatic prostate cancer. This paper is the 2nd edition of the Korean management guideline of metastatic prostate cancer. We updated recent many changes of management in metastatic prostate cancer in this 2nd edition guideline. The present guideline consists of the three categories: management of metastatic hormone sensitive prostate cancer; management of metastatic castration resistant prostate cancer; and clinical consideration for treating patients with metastatic prostate cancer. In category 1 and 2, levels of evidence (LEs) have been mentioned according to the general principles of evidence-based medicine. And grades of recommendation (GR) was taken into account the quality of evidence, the balance between desirable and undesirable effects, the values and preferences, and the use of resources and GR were divided into strong recommendations (SR) and weak recommendations (WR). A total of 16 key questions are selected. And we proposed recommendations and described key evidence for each recommendation. The treatment landscape of metastatic prostate cancer is changing very rapid and many trials are ongoing. To verify the results of the future trials is necessary and should be applied to the treatment for metastatic prostate cancer patients in the clinical practice. Especially, many prostate cancer patients are old age, have multiple underlying medical comorbidities, clinicians should be aware of the significance of medical management as well as clinical efficacy of systemic treatment.