Identifying Atrial Fibrillation With Sinus Rhythm Electrocardiogram in Embolic Stroke of Undetermined Source: A Validation Study With Insertable Cardiac Monitors

Background and Objectives@#Paroxysmal atrial fibrillation (AF) is a major potential cause of embolic stroke of undetermined source (ESUS). However, identifying AF remains challenging because it occurs sporadically. Deep learning could be used to identify hidden AF based on the sinus rhythm (SR) electrocardiogram (ECG). We combined known AF risk factors and developed a deep learning algorithm (DLA) for predicting AF to optimize diagnostic performance in ESUS patients. @*Methods@#A DLA was developed to identify AF using SR 12-lead ECG with the database consisting of AF patients and non-AF patients. The accuracy of the DLA was validated in 221 ESUS patients who underwent insertable cardiac monitor (ICM) insertion to identify AF. @*Results@#A total of 44,085 ECGs from 12,666 patient were used for developing the DLA. The internal validation of the DLA revealed 0.862 (95% confidence interval, 0.850–0.873) area under the curve (AUC) in the receiver operating curve analysis. In external validation data from 221 ESUS patients, the diagnostic accuracy of DLA and AUC were 0.811 and 0.827, respectively, and DLA outperformed conventional predictive models, including CHARGE-AF,C2HEST, and HATCH. The combined model, comprising atrial ectopic burden, left atrial diameter and the DLA, showed excellent performance in AF prediction with AUC of 0.906. @*Conclusions@#The DLA accurately identified paroxysmal AF using 12-lead SR ECG in patients with ESUS and outperformed the conventional models. The DLA model along with the traditional AF risk factors could be a useful tool to identify paroxysmal AF in ESUS patients.

Lifestyle Modification in the Management of Metabolic Syndrome:Statement From Korean Society of CardioMetabolic Syndrome (KSCMS)

With the recent rapid increase in obesity worldwide, metabolic syndrome (MetS) has gained significant importance. MetS is a cluster of obesity-related cardiovascular risk factors including abdominal obesity, atherogenic dyslipidemia, high blood pressure and impaired glucose tolerance. MetS is highly prevalent and strongly associated with an increased risk of developing diabetes and cardiovascular disease, putting a great burden on human society. Therefore, it is very important to reduce MetS risk, which can improve patients’cardiovascular prognosis. The primary and most effective strategy to control each component of MetS is lifestyle change such as losing body weight, keeping regular exercise, adopting a healthy diet, quitting smoking and alcohol drinking in moderation. Many studies have shown that lifestyle modification has improved all components of MetS, and reduces the incidence of diabetes and cardiovascular disease. Here, the Korean Society of CardioMetabolic Syndrome has summarized specific and practical methods of lifestyle modification in the management of MetS in the healthcare field.

Association of Quantitative Flow Ratio with Lesion Severity and Its Ability to Discriminate Myocardial Ischemia

Background and Objectives@#Quantitative flow ratio (QFR) is an angiography-based technique for functional assessment of coronary artery stenosis. This study investigated the response of QFR to different degree of stenosis severity and its ability to predict the positron emission tomography (PET)-defined myocardial ischemia. @*Methods@#From 109 patients with 185 vessels who underwent both 13 N-ammonia PET and invasive physiological measurement, we compared QFR, fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) for the responses to the different degree of anatomical (percent diameter stenosis [%DS]) and hemodynamic (relative flow reserve [RFR], coronary flow reserve, hyperemic stenosis resistance, and stress myocardial flow) stenosis severity and diagnostic performance against PET-derived parameters. @*Results@#QFR, FFR, and iFR showed similar responses to both anatomic and hemodynamic stenosis severity. Regarding RFR, the diagnostic accuracy of QFR was lower than FFR (76.2% vs. 83.2%, p=0.021) and iFR (76.2% vs. 84.3%, p=0.031). For coronary flow capacity (CFC), QFR showed a lower accuracy than iFR (74.1% vs. 82%, p=0.031) and lower discriminant function than FFR (area under curve: 0.74 vs. 0.79, p=0.044). Discordance between QFR and FFR or iFR was shown in 14.6% of cases and was driven by the difference in %DS and heterogeneous distribution of PET-derived RFR and stress myocardial blood flow. @*Conclusions@#QFR demonstrated a similar response to different anatomic and hemodynamic stenosis severity as FFR or iFR. However, its diagnostic performance was inferior to FFR and iFR when PET-derived RFR and CFC were used as a reference.

Association of Quantitative Flow Ratio with Lesion Severity and Its Ability to Discriminate Myocardial Ischemia

Background and Objectives@#Quantitative flow ratio (QFR) is an angiography-based technique for functional assessment of coronary artery stenosis. This study investigated the response of QFR to different degree of stenosis severity and its ability to predict the positron emission tomography (PET)-defined myocardial ischemia. @*Methods@#From 109 patients with 185 vessels who underwent both 13 N-ammonia PET and invasive physiological measurement, we compared QFR, fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) for the responses to the different degree of anatomical (percent diameter stenosis [%DS]) and hemodynamic (relative flow reserve [RFR], coronary flow reserve, hyperemic stenosis resistance, and stress myocardial flow) stenosis severity and diagnostic performance against PET-derived parameters. @*Results@#QFR, FFR, and iFR showed similar responses to both anatomic and hemodynamic stenosis severity. Regarding RFR, the diagnostic accuracy of QFR was lower than FFR (76.2% vs. 83.2%, p=0.021) and iFR (76.2% vs. 84.3%, p=0.031). For coronary flow capacity (CFC), QFR showed a lower accuracy than iFR (74.1% vs. 82%, p=0.031) and lower discriminant function than FFR (area under curve: 0.74 vs. 0.79, p=0.044). Discordance between QFR and FFR or iFR was shown in 14.6% of cases and was driven by the difference in %DS and heterogeneous distribution of PET-derived RFR and stress myocardial blood flow. @*Conclusions@#QFR demonstrated a similar response to different anatomic and hemodynamic stenosis severity as FFR or iFR. However, its diagnostic performance was inferior to FFR and iFR when PET-derived RFR and CFC were used as a reference.

Safety and Efficacy of Biodegradable Polymer-biolimus-eluting Stents (BP-BES) Compared with Durable Polymer-everolimus-eluting Stents (DP-EES) in Patients Undergoing Complex Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES: There are no data comparing clinical outcomes of complex percutaneous coronary intervention (PCI) between biodegradable polymer-biolimus-eluting stents (BP-BES) and durable polymer-everolimus-eluting stents (DP-EES). We sought to evaluate the safety and efficacy of BP-BES compared with DP-EES in patients undergoing complex PCI. METHODS: Patients enrolled in the SMART-DESK registry were stratified into 2 categories based on the complexity of PCI. Complex PCI was defined as having at least one of the following features: unprotected left main lesion, ≥2 lesions treated, total stent length >40 mm, minimal stent diameter ≤2.5 mm, or bifurcation as target lesion. The primary outcome was target lesion failure (TLF), defined as a composite of cardiac death, target vessel-related myocardial infarction (TV-MI), or target lesion revascularization (TLR) at 2 years of follow-up. RESULTS: Of 1,999 patients, 1,145 (57.3%) underwent complex PCI: 521 patients were treated with BP-BES and 624 with DP-EES. In propensity-score matching analysis (481 pairs), the risks of TLF (3.8% vs. 5.2%, adjusted hazard ratio [HR], 0.578; 95% confidence interval [CI], 0.246–1.359; p=0.209), cardiac death (2.5% vs. 2.5%, adjusted HR, 0.787; 95% CI, 0.244–2.539; p=0.689), TV-MI (0.5% vs. 0.4%, adjusted HR, 1.128; 95% CI, 0.157–8.093; p=0.905), and TLR (1.1% vs. 2.9%, adjusted HR, 0.390; 95% CI, 0.139–1.095; p=0.074) did not differ between 2 stent groups after complex PCI. CONCLUSIONS: Clinical outcomes of BP-BES were comparable to those of DP-EES at 2 years after complex PCI. Our data suggest that use of BP-BES is acceptable, even for complex PCI.

High Incidence and Mortality of Out-of-Hospital Cardiac Arrest on Traditional Holiday in South Korea

BACKGROUND AND OBJECTIVES@#This study aimed to confirm the effects of traditional holidays on the incidence and outcomes of out-of-hospital cardiac arrest (OHCA) in South Korea.@*METHODS@#We studied 95,066 OHCAs of cardiac cause from a nationwide, prospective study from the Korea OHCA Registry from January 2012 to December 2016. We compared the incidence of OHCA, in-hospital mortality, and neurologic outcomes between traditional holidays, Seollal (Lunar New Year's Day) and Chuseok (Korean Thanksgiving Day), and other day types (weekday, weekend, and public holiday).@*RESULTS@#OHCA occurred more frequently on traditional holidays than on the other days. The median OHCA incidence were 51.0 (interquartile range [IQR], 44.0–58.0), 53.0 (IQR, 46.0–60.5), 52.5 (IQR, 45.3–59.8), and 60.0 (IQR, 52.0–69.0) cases/day on weekday, weekend, public holiday, and traditional holiday, respectively (p<0.001). The OHCA occurred more often at home rather than in public place, lesser bystander cardiopulmonary resuscitation (CPR) was performed, and the rate of cessation of CPR within 20 minutes without recovery of spontaneous circulation was higher on traditional holiday. After multivariable adjustment, traditional holiday was associated with higher in-hospital mortality (adjusted hazard ratio [HR], 1.339; 95% confidence interval [CI], 1.058–1.704; p=0.016) but better neurologic outcomes (adjusted HR, 0.503; 95% CI, 0.281–0.894; p=0.020) than weekdays.@*CONCLUSIONS@#The incidence of OHCAs was associated with day types in a year. It occurred more frequently on traditional holidays than on other day types. It was associated with higher in-hospital mortality and favorable neurologic outcomes than weekday.

Development and Validation of Deep-Learning Algorithm for Electrocardiography-Based Heart Failure Identification

BACKGROUND AND OBJECTIVES@#Screening and early diagnosis for heart failure (HF) are critical. However, conventional screening diagnostic methods have limitations, and electrocardiography (ECG)-based HF identification may be helpful. This study aimed to develop and validate a deep-learning algorithm for ECG-based HF identification (DEHF).@*METHODS@#The study involved 2 hospitals and 55,163 ECGs of 22,765 patients who performed echocardiography within 4 weeks were study subjects. ECGs were divided into derivation and validation data. Demographic and ECG features were used as predictive variables. The primary endpoint was detection of HF with reduced ejection fraction (HFrEF; ejection fraction [EF]≤40%), and the secondary endpoint was HF with mid-range to reduced EF (≤50%). We developed the DEHF using derivation data and the algorithm representing the risk of HF between 0 and 1. We confirmed accuracy and compared logistic regression (LR) and random forest (RF) analyses using validation data.@*RESULTS@#The area under the receiver operating characteristic curves (AUROCs) of DEHF for identification of HFrEF were 0.843 (95% confidence interval, 0.840–0.845) and 0.889 (0.887–0.891) for internal and external validation, respectively, and these results significantly outperformed those of LR (0.800 [0.797–0.803], 0.847 [0.844–0.850]) and RF (0.807 [0.804–0.810], 0.853 [0.850–0.855]) analyses. The AUROCs of deep learning for identification of the secondary endpoint was 0.821 (0.819–0.823) and 0.850 (0.848–0.852) for internal and external validation, respectively, and these results significantly outperformed those of LR and RF.@*CONCLUSIONS@#The deep-learning algorithm accurately identified HF using ECG features and outperformed other machine-learning methods.

Safety and Efficacy of Biodegradable Polymer-biolimus-eluting Stents (BP-BES) Compared with Durable Polymer-everolimus-eluting Stents (DP-EES) in Patients Undergoing Complex Percutaneous Coronary Intervention

BACKGROUND AND OBJECTIVES@#There are no data comparing clinical outcomes of complex percutaneous coronary intervention (PCI) between biodegradable polymer-biolimus-eluting stents (BP-BES) and durable polymer-everolimus-eluting stents (DP-EES). We sought to evaluate the safety and efficacy of BP-BES compared with DP-EES in patients undergoing complex PCI.@*METHODS@#Patients enrolled in the SMART-DESK registry were stratified into 2 categories based on the complexity of PCI. Complex PCI was defined as having at least one of the following features: unprotected left main lesion, ≥2 lesions treated, total stent length >40 mm, minimal stent diameter ≤2.5 mm, or bifurcation as target lesion. The primary outcome was target lesion failure (TLF), defined as a composite of cardiac death, target vessel-related myocardial infarction (TV-MI), or target lesion revascularization (TLR) at 2 years of follow-up.@*RESULTS@#Of 1,999 patients, 1,145 (57.3%) underwent complex PCI: 521 patients were treated with BP-BES and 624 with DP-EES. In propensity-score matching analysis (481 pairs), the risks of TLF (3.8% vs. 5.2%, adjusted hazard ratio [HR], 0.578; 95% confidence interval [CI], 0.246–1.359; p=0.209), cardiac death (2.5% vs. 2.5%, adjusted HR, 0.787; 95% CI, 0.244–2.539; p=0.689), TV-MI (0.5% vs. 0.4%, adjusted HR, 1.128; 95% CI, 0.157–8.093; p=0.905), and TLR (1.1% vs. 2.9%, adjusted HR, 0.390; 95% CI, 0.139–1.095; p=0.074) did not differ between 2 stent groups after complex PCI.@*CONCLUSIONS@#Clinical outcomes of BP-BES were comparable to those of DP-EES at 2 years after complex PCI. Our data suggest that use of BP-BES is acceptable, even for complex PCI.

Development and Validation of Deep-Learning Algorithm for Electrocardiography-Based Heart Failure Identification

BACKGROUND AND OBJECTIVES: Screening and early diagnosis for heart failure (HF) are critical. However, conventional screening diagnostic methods have limitations, and electrocardiography (ECG)-based HF identification may be helpful. This study aimed to develop and validate a deep-learning algorithm for ECG-based HF identification (DEHF). METHODS: The study involved 2 hospitals and 55,163 ECGs of 22,765 patients who performed echocardiography within 4 weeks were study subjects. ECGs were divided into derivation and validation data. Demographic and ECG features were used as predictive variables. The primary endpoint was detection of HF with reduced ejection fraction (HFrEF; ejection fraction [EF]≤40%), and the secondary endpoint was HF with mid-range to reduced EF (≤50%). We developed the DEHF using derivation data and the algorithm representing the risk of HF between 0 and 1. We confirmed accuracy and compared logistic regression (LR) and random forest (RF) analyses using validation data. RESULTS: The area under the receiver operating characteristic curves (AUROCs) of DEHF for identification of HFrEF were 0.843 (95% confidence interval, 0.840–0.845) and 0.889 (0.887–0.891) for internal and external validation, respectively, and these results significantly outperformed those of LR (0.800 [0.797–0.803], 0.847 [0.844–0.850]) and RF (0.807 [0.804–0.810], 0.853 [0.850–0.855]) analyses. The AUROCs of deep learning for identification of the secondary endpoint was 0.821 (0.819–0.823) and 0.850 (0.848–0.852) for internal and external validation, respectively, and these results significantly outperformed those of LR and RF. CONCLUSIONS: The deep-learning algorithm accurately identified HF using ECG features and outperformed other machine-learning methods.

High Incidence and Mortality of Out-of-Hospital Cardiac Arrest on Traditional Holiday in South Korea

BACKGROUND AND OBJECTIVES: This study aimed to confirm the effects of traditional holidays on the incidence and outcomes of out-of-hospital cardiac arrest (OHCA) in South Korea. METHODS: We studied 95,066 OHCAs of cardiac cause from a nationwide, prospective study from the Korea OHCA Registry from January 2012 to December 2016. We compared the incidence of OHCA, in-hospital mortality, and neurologic outcomes between traditional holidays, Seollal (Lunar New Year's Day) and Chuseok (Korean Thanksgiving Day), and other day types (weekday, weekend, and public holiday). RESULTS: OHCA occurred more frequently on traditional holidays than on the other days. The median OHCA incidence were 51.0 (interquartile range [IQR], 44.0–58.0), 53.0 (IQR, 46.0–60.5), 52.5 (IQR, 45.3–59.8), and 60.0 (IQR, 52.0–69.0) cases/day on weekday, weekend, public holiday, and traditional holiday, respectively (p<0.001). The OHCA occurred more often at home rather than in public place, lesser bystander cardiopulmonary resuscitation (CPR) was performed, and the rate of cessation of CPR within 20 minutes without recovery of spontaneous circulation was higher on traditional holiday. After multivariable adjustment, traditional holiday was associated with higher in-hospital mortality (adjusted hazard ratio [HR], 1.339; 95% confidence interval [CI], 1.058–1.704; p=0.016) but better neurologic outcomes (adjusted HR, 0.503; 95% CI, 0.281–0.894; p=0.020) than weekdays. CONCLUSIONS: The incidence of OHCAs was associated with day types in a year. It occurred more frequently on traditional holidays than on other day types. It was associated with higher in-hospital mortality and favorable neurologic outcomes than weekday.

Risk Scoring System to Assess Outcomes in Patients Treated with Contemporary Guideline-Adherent Optimal Therapies after Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: A risk prediction is needed even in the contemporary era of acute myocardial infarction (AMI). We sought to develop a risk scoring specific for patients with AMI being treated with guideline-adherent optimal therapies, including percutaneous coronary intervention and all 5 medications (aspirin, thienopyridine, β-blocker, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, and statin). METHODS: From registries, 12,174 AMI patients were evaluated. The primary outcome was 1-year all-cause death or AMI. The Korea Working Group in Myocardial Infarction (KorMI) system was compared with the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX AMI), Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC), and Global Registry of Acute Coronary Events scores (GRACE) models. RESULTS: Ten predictors were identified: left ventricular dysfunction (hazard ratio [HR], 2.3), bare-metal stent (HR, 2.0), Killip class ≥II (HR, 1.9), renal insufficiency (HR, 1.8), previous stroke (HR, 1.6), regional wall-motion- score >20 on echocardiography (HR, 1.5), body mass index ≤24 kg/m2 (HR, 1.4), age ≥70 years (HR, 1.4), prior coronary heart disease (HR, 1.4), and diabetes (HR, 1.4). Compared with the previous models, the KorMI system had good discrimination (time-dependent C statistic, 0.759) and showed reasonable goodness-of-fit by Hosmer-Lemeshow test (p=0.84). Moreover, the continuous-net reclassification improvement varied from −27.3% to −19.1%, the integrated discrimination index varied from −2.1% to −0.9%, and the median improvement in risk score was from −1.0% to −0.4%. CONCLUSIONS: The KorMI system would be a useful tool for predicting outcomes in survivors treated with guideline-adherent optimal therapies after AMI.

Risk Scoring System to Assess Outcomes in Patients Treated with Contemporary Guideline-Adherent Optimal Therapies after Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES@#A risk prediction is needed even in the contemporary era of acute myocardial infarction (AMI). We sought to develop a risk scoring specific for patients with AMI being treated with guideline-adherent optimal therapies, including percutaneous coronary intervention and all 5 medications (aspirin, thienopyridine, β-blocker, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, and statin).@*METHODS@#From registries, 12,174 AMI patients were evaluated. The primary outcome was 1-year all-cause death or AMI. The Korea Working Group in Myocardial Infarction (KorMI) system was compared with the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX AMI), Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC), and Global Registry of Acute Coronary Events scores (GRACE) models.@*RESULTS@#Ten predictors were identified: left ventricular dysfunction (hazard ratio [HR], 2.3), bare-metal stent (HR, 2.0), Killip class ≥II (HR, 1.9), renal insufficiency (HR, 1.8), previous stroke (HR, 1.6), regional wall-motion- score >20 on echocardiography (HR, 1.5), body mass index ≤24 kg/m2 (HR, 1.4), age ≥70 years (HR, 1.4), prior coronary heart disease (HR, 1.4), and diabetes (HR, 1.4). Compared with the previous models, the KorMI system had good discrimination (time-dependent C statistic, 0.759) and showed reasonable goodness-of-fit by Hosmer-Lemeshow test (p=0.84). Moreover, the continuous-net reclassification improvement varied from −27.3% to −19.1%, the integrated discrimination index varied from −2.1% to −0.9%, and the median improvement in risk score was from −1.0% to −0.4%.@*CONCLUSIONS@#The KorMI system would be a useful tool for predicting outcomes in survivors treated with guideline-adherent optimal therapies after AMI.

Current Concepts in Stem Cell Therapy for Cardiovascular Diseases: What We Know and Don't Know / 한양의대학술지

Medical therapies and mechanical interventions for the treatment of myocardial infarction (MI) and ischemic heart failure have seen great progress. However, current therapies only slow the progression to heart failure, but do not stimulate regeneration to recover the loss of functional myocytes. Stem cell-based therapy is a novel modality that can potentially be used for the treatment of ischemic cardiac injury and heart failure wherein cardiac tissue is regenerated thereby improving cardiac function and reducing the morbidity and mortality of patients. Many preclinical and clinical trials have employed various types of stem cells including bone marrow-derived mononuclear cells, skeletal myoblasts, resident cardiac stem cells, mesenchymal stem cells, and endothelial progenitor cells, and these studies have suggested great potential for the clinical application of stem cell therapy for cardiac disease. Here we will review and summarize the current evidence indicating the potential of stem cell therapy, focusing on the clinical trials conducted to date.

A case of malignant pericardial mesothelioma misdiagnosed as tuberculosis pericarditis / 대한내과학회지

Primary pericardial mesothelioma is an extremely rare neoplasm with a bleak prognosis. It is often misdiagnosed as constrictive pericarditis initially, especially as tuberculosis pericarditis in Korea due to the high incidence of active tuberculosis. A targeted pericardial biopsy and noninvasive imaging modalities, such as delayed phase contrast chest computed tomography (CT) images and magnetic resonance imaging (MRI), can play an important role in the differential diagnosis of pericardial disease. We present the case of a 37-year-old man with a 3-week history of exertional dyspnea. A large pericardial effusion with pericardial thickening was noted, but its etiology was not revealed after conventional diagnostic procedures, including a closed pericardial biopsy. Empirical antituberculosis treatment was started, but the dyspnea recurred 5 months later. A malignant pericardial mesothelioma was diagnosed through a pericardiectomy and biopsy under direct visualization

A Case of Ulcerative Colitis with Growth Disturbance

Ulcerative colitis is a chronic relapsing inflammatory disease of the colonic and rectal mucosa, which affects children as well as adults. Inflammation caused by ulcerative colitis is limited to the colon and rectum, to the mucosa and submucosa, and is involved continuously, with varying degrees of ulceration, hemorrhage, edema, and regenerating epithelium. Ulcerative colitis most commonly presents with the onset of diarrhea, later associated with hematochezia, but usually without systemic signs of fever, weight loss, or hypoalbuminemia. Approximately 30% of cases have moderate signs of systemic illness. Although less commonly seen than in Crohn's disease, the first sign of ulcerative colitis may be growth failure characterized by decreased linear growth velocity. We experienced a case of ulcerative colitis with growth disturbance and treated with sulfasalazine. During follow up for a year, the symptoms subsided, and the height and weight increased.

Three Cases of Symptomatic Huge Arachnoid Cysts / 대한소아신경학회지

Congenital arachnoid cysts are commonly located at sylvian cistern or middle cranial fossa which are usually asymptomatic and incidentally found. Posterior fossa cysts, however, are usually large when diagnosed, and symptomatic. Three cases of large posterior fossa cysts were recognized on the diagnostic MRI investigation for infantile spasm, developmental delay, and the precocious puberty. Surgical decompression of the cysts by craniectomy, cyst excision and fenestration were performed successfully in two patients with arachnoid cysts in the cerebellopontine cistern and the suprasellar, right cerebellopontine, and prepontine cisterns, but an additional cystoperitoneal shunt was needed in a case with the cyst in the quadrigemial cistern with obstructive hydrocephalus. Infantile spasm was treated with vigabatrin and pyridoxine, and the true precocious puberty was managed with LHRH analogue(Decapeptyl ).