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.

Association between alcohol consumption and subclinical atrial fibrillation

Background@#It has become important to identify and manage risk factors for subclinical atrial fibrillation (AF) with an increase in its detection rate. Thus, this research aimed to investigate whether alcohol consumption contrib‑ utes to the development of subclinical AF. @*Methods@#This prospective study enrolled 467 patients without AF from a multicenter pacemaker registry. The incidence of subclinical AF (episodes of atrial rate > 220 beats per minute without symptoms) was compared between alcohol-drinking and non-drinking groups. @*Results@#During followup (median 18 months), the incidence and risk of long-duration atrial high-rate episodes (AHRE) ≥ 24 h were increased in the alcohol group compared to the non-alcohol group [5.47 vs. 2.10 per 100 personyears, adjusted hazard ratio (HR), 2.83; 95% confidence interval (CI), 1.14–7.04; P = 0.03]. After propensity score match‑ ing, the incidence and risk of long-duration AHRE were higher in the alcohol group (6.97 vs. 1.27 per 100 personyears, adjusted HR, 7.84; 95% CI, 1.21–50.93; P = 0.03). The mean burden of long-duration subclinical AF was higher in the alcohol group than in the non-alcohol group (0.18 vs. 1.61% during follow-up, P = 0.08). @*Conclusion@#Alcohol consumption was associated with an increased risk of subclinical AF. Long-duration AHRE inci‑ dence and AHRE burden were higher in alcohol drinkers than in non-drinkers.

A Retrospective Clinical Evaluation of an Artificial Intelligence Screening Method for Early Detection of STEMI in the Emergency Department

Background@#Rapid revascularization is the key to better patient outcomes in ST-elevation myocardial infarction (STEMI). Direct activation of cardiac catheterization laboratory (CCL) using artificial intelligence (AI) interpretation of initial electrocardiography (ECG) might help reduce door-to-balloon (D2B) time. To prove that this approach is feasible and beneficial, we assessed the non-inferiority of such a process over conventional evaluation and estimated its clinical benefits, including a reduction in D2B time, medical cost, and 1-year mortality. @*Methods@#This is a single-center retrospective study of emergency department (ED) patients suspected of having STEMI from January 2021 to June 2021. Quantitative ECG (QCG™), a comprehensive cardiovascular evaluation system, was used for screening. The non-inferiority of the AI-driven CCL activation over joint clinical evaluation by emergency physicians and cardiologists was tested using a 5% non-inferiority margin. @*Results@#Eighty patients (STEMI, 54 patients [67.5%]) were analyzed. The area under the curve of QCG score was 0.947. Binned at 50 (binary QCG), the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 98.1% (95% confidence interval [CI], 94.6%, 100.0%), 76.9% (95% CI, 60.7%, 93.1%), 89.8% (95% CI, 82.1%, 97.5%) and 95.2% (95% CI, 86.1%, 100.0%), respectively. The difference in sensitivity and specificity between binary QCG and the joint clinical decision was 3.7% (95% CI, −3.5%, 10.9%) and 19.2% (95% CI, −4.7%, 43.1%), respectively, confirming the non-inferiority. The estimated median reduction in D2B time, evaluation cost, and the relative risk of 1-year mortality were 11.0 minutes (interquartile range [IQR], 7.3–20.0 minutes), 26,902.2 KRW (22.78 USD) per STEMI patient, and 12.39% (IQR, 7.51–22.54%), respectively. @*Conclusion@#AI-assisted CCL activation using initial ECG is feasible. If such a policy is implemented, it would be reasonable to expect some reduction in D2B time, medical cost, and 1-year mortality.

Catheter ablation of atrial fibrillation in Korea: results from the Korean Heart Rhythm Society Ablation Registry for Atrial Fibrillation (KARA)

Background@#This study aims to investigate the current status of AF (atrial fibrillation) catheter ablation in Korea. @*Methods@#The patients who underwent AF catheter ablation from September 2017 to December 2019 were pro‑ spectively enrolled from 37 arrhythmia centers. Demographic data, procedural characteristics, the extent of catheter ablation, acute success of the ablation lesion set, rate and independent risk factor for recurrence of AF were analyzed. @*Results@#A total of 2402 AF patients [paroxysmal AF (PAF) 45.7%, persistent AF (PeAF) 43.1% and redo AF 11.2%] were included. Pulmonary vein isolation (PVI) was performed in 2378 patients (99%) and acute success rate was 97.9%.Additional non-PV ablation (NPVA) were performed in 1648 patients (68.6%). Post-procedural complication rate was 2.2%. One-year AF-free survival rate was 78.6% and the PeAF patients showed poorer survival rate than the ones with other types (PeAF 72.4%, PAF 84.2%, redo AF 80.0%). Additional NPVA did not influence the recurrence of AF in the PAF patients (PVI 17.0% vs. NPVA 14.6%, P value 0.302). However, it showed lower AF recurrence rate in the PeAF patients (PVI 34.9% vs. NPVA 24.4%, P value 0.001). Valvular heart disease, left atrial diameter, PeAF, PVI alone, need of NPVA for terminating AF, and failed ablation were independent predictors of AF recurrence. @*Conclusions@#Additional NPVA was associated better rhythm outcome in the patients with PeAF, not in the ones with PAF. The independent risk factors for AF recurrence in Korean population were similar to previous studies. Further research is needed to discover optimal AF ablation strategy.

Prevalence and Predictors of Clinically Relevant Atrial High-Rate Episodes in Patients with Cardiac Implantable Electronic Devices

Background and Objectives@#Atrial high-rate episodes (AHREs) can be continuously detected by cardiovascular implantable electronic devices (CIEDs); however, the predictors of clinically relevant AHREs are unclear. @*Methods@#This prospective multicenter study monitored 816 patients (median age 73 years, 40.4% male) without atrial fibrillation (AF) from September 2017 to July 2020. AHREs was defined as a programmed atrial detection rate >220 beats/min. The reference values of 6 minutes and 6 hours were set to analyze clinical implication of AHREs based on previously published data that the 6 minutes excluded most episodes of oversensing. @*Results@#During a median follow-up of 18 months (interquartile interval 9–26 months), AHREs with the longest durations of >15 seconds, >6 minutes, and >6 hours and clinically documented AF by electrocardiography were noted in 246 (30.1%), 112 (13.7%), 49 (6.0%), and 24 (2.9%) patients, respectively. Among patients developing AHREs >6 minutes, 102 (91.1%) of 112 patients were identified at the 6-month visit. Patients with AHREs >6 minutes had higher proportions of sick sinus syndrome, subjects with atrial premature beat >1% on Holter monitoring, and larger left atrium (LA) size than patients with AHREs ≤6 minutes.Multivariable logistic regression analysis showed that LA diameter >41 mm (odds ratio [OR], 2.08; 95% confidence interval [95% CI], 1.25–3.45), and sick sinus syndrome (OR, 3.22; 95% CI, 1.91–5.43) were associated with AHREs >6 minutes. @*Conclusions@#In patients with LA diameter >41 mm, and sick sinus syndrome before CIEDs implantation is associated with risk of developing AHREs >6 minutes.

Left Atrial Diameter and Atrial Ectopic Burden in Patients with Embolic Stroke of Undetermined Source:Risk Stratification of Atrial Fibrillation with Insertable Cardiac Monitor Analysis

Background@#and Purpose An insertable cardiac monitor (ICM) has been demonstrated to be a useful tool for detecting subclinical atrial fibrillation (AF) in patients with embolic stroke of undetermined source (ESUS). This study aimed to identify the clinical predictors of AF in ESUS patients with ICMs. @*Methods@#We retrospectively selected consecutive patients with an ICM implanted for AF detection following ESUS. The primary endpoint was defined as any AF episode lasting for longer than 5 min. The atrial ectopic burden (AEB) was calculated as the percentage of the number of conducted QRS from atrial ectopy on Holter monitoring. @*Results@#This study included 136 patients. AF lasting ≥5 min was detected in 20 patients (14.7%) during a median follow-up period of 6.6 months (interquartile range, 3.3–10.8 months).AF patients had a higher AEB (0.20% vs. 0.02%,p<0.001) and a larger left atrial diameter (LAD, 41.0 mm vs. 35.3 mm, p<0.001) than those without AF. The areas under the receiver operating characteristic curves were 0.795 and 0.816 for the LAD and log-transformed AEB, respectively, for the best cutoff values of 38.5 mm for LAD and 0.050% for AEB. AF lasting ≥5 min was detected in 34.6% (9/26) of patients with LAD ≥38.5 mm and AEB ≥0.050%, and in 0% (0/65) of those with LAD <38.5 mm and AEB <0.050%. @*Conclusions@#AF was detected in a significant proportion of ESUS patients during a 6.6-month follow-up. The LAD and AEB are good predictors of AF and might be useful for AF risk stratification in ESUS patients.

Prevalence and Predictors of Clinically Relevant Atrial High-Rate Episodes in Patients with Cardiac Implantable Electronic Devices

Background and Objectives@#Atrial high-rate episodes (AHREs) can be continuously detected by cardiovascular implantable electronic devices (CIEDs); however, the predictors of clinically relevant AHREs are unclear. @*Methods@#This prospective multicenter study monitored 816 patients (median age 73 years, 40.4% male) without atrial fibrillation (AF) from September 2017 to July 2020. AHREs was defined as a programmed atrial detection rate >220 beats/min. The reference values of 6 minutes and 6 hours were set to analyze clinical implication of AHREs based on previously published data that the 6 minutes excluded most episodes of oversensing. @*Results@#During a median follow-up of 18 months (interquartile interval 9–26 months), AHREs with the longest durations of >15 seconds, >6 minutes, and >6 hours and clinically documented AF by electrocardiography were noted in 246 (30.1%), 112 (13.7%), 49 (6.0%), and 24 (2.9%) patients, respectively. Among patients developing AHREs >6 minutes, 102 (91.1%) of 112 patients were identified at the 6-month visit. Patients with AHREs >6 minutes had higher proportions of sick sinus syndrome, subjects with atrial premature beat >1% on Holter monitoring, and larger left atrium (LA) size than patients with AHREs ≤6 minutes.Multivariable logistic regression analysis showed that LA diameter >41 mm (odds ratio [OR], 2.08; 95% confidence interval [95% CI], 1.25–3.45), and sick sinus syndrome (OR, 3.22; 95% CI, 1.91–5.43) were associated with AHREs >6 minutes. @*Conclusions@#In patients with LA diameter >41 mm, and sick sinus syndrome before CIEDs implantation is associated with risk of developing AHREs >6 minutes.

Left Atrial Diameter and Atrial Ectopic Burden in Patients with Embolic Stroke of Undetermined Source:Risk Stratification of Atrial Fibrillation with Insertable Cardiac Monitor Analysis

Background@#and Purpose An insertable cardiac monitor (ICM) has been demonstrated to be a useful tool for detecting subclinical atrial fibrillation (AF) in patients with embolic stroke of undetermined source (ESUS). This study aimed to identify the clinical predictors of AF in ESUS patients with ICMs. @*Methods@#We retrospectively selected consecutive patients with an ICM implanted for AF detection following ESUS. The primary endpoint was defined as any AF episode lasting for longer than 5 min. The atrial ectopic burden (AEB) was calculated as the percentage of the number of conducted QRS from atrial ectopy on Holter monitoring. @*Results@#This study included 136 patients. AF lasting ≥5 min was detected in 20 patients (14.7%) during a median follow-up period of 6.6 months (interquartile range, 3.3–10.8 months).AF patients had a higher AEB (0.20% vs. 0.02%,p<0.001) and a larger left atrial diameter (LAD, 41.0 mm vs. 35.3 mm, p<0.001) than those without AF. The areas under the receiver operating characteristic curves were 0.795 and 0.816 for the LAD and log-transformed AEB, respectively, for the best cutoff values of 38.5 mm for LAD and 0.050% for AEB. AF lasting ≥5 min was detected in 34.6% (9/26) of patients with LAD ≥38.5 mm and AEB ≥0.050%, and in 0% (0/65) of those with LAD <38.5 mm and AEB <0.050%. @*Conclusions@#AF was detected in a significant proportion of ESUS patients during a 6.6-month follow-up. The LAD and AEB are good predictors of AF and might be useful for AF risk stratification in ESUS patients.

Effects of renin-angiotensin system blockers on the risk and outcomes of severe acute respiratory syndrome coronavirus 2 infection in patients with hypertension

Background/Aims@#There are concerns that the use of renin-angiotensin system (RAS) blockers may increase the risk of being infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or progressing to a severe clinical course after infection. This this study aimed to investigate the influence of RAS blockers on the risk and severity of SARS-CoV-2 infection. @*Methods@#We conducted a retrospective cohort study analyzing nationwide claims data of 215,184 adults who underwent SARS-CoV-2 tests in South Korea. The SARS-CoV-2 positive rates and clinical outcomes were evaluated according to the use of RAS blockers in patients with hypertension (n = 64,243). @*Results@#In total, 38,919 patients with hypertension were on RAS blockers. The SARS-CoV-2 positive rates were significantly higher in the RAS blocker group than in the control group after adjustments (adjusted odds ratio [OR], 1.22; 95% confidence interval [CI], 1.10 to 1.36; p < 0.001), and matching by propensity score (adjusted OR, 1.16; 95% CI, 1.03 to 1.32; p = 0.017). Among the 1,609 SARS-CoV-2-positive patients with hypertension, the use of RAS blockers was not associated with poor outcomes, such as mortality (adjusted OR, 0.81; 95% CI, 0.56 to 1.17; p = 0.265), and a composite of admission to the intensive care unit and mortality (adjusted OR, 0.95; 95% CI, 0.73 to 1.22; p = 0.669). Analysis in the propensity scorematched population showed consistent results. @*Conclusions@#In this Korean nationwide claims dataset, the use of RAS blockers was associated with a higher risk to SARS-CoV-2 infection but not with higher mortality or other severe clinical courses.

Automatic consultation system for patients with cardiac implantable electronic devices undergoing magnetic resonance imaging

Background@#Safety evaluation for patients with cardiac implantable electronic devices (CIEDs) undergoing magnetic resonance imaging (MRI) scanning is often overlooked. We developed an automatic consultation system (ACS) to improve the screening rate in these patients. @*Methods@#ACS was developed by the Hospital Information System Development Department of Seoul National University Bundang Hospital. It was designed to automatically request pre-MRI cardiac evaluation in patients with CIED when MRI orders are issued. The proportion of the patients without pre-MRI cardiologic evaluation was evaluated before and after the ACS application. @*Results@#From January 2016 to June 2018, a total of 157 patients with CIEDs [pacemaker 136 (86.6%), ICD or CRT-D 21 (13.4%), MR-conditional 117 (74.5%)] visited the MRI facility. Before the ACS application, 23 out of 84 patients (27.4%) did not have adequate pre-MRI cardiologic evaluation. Despite urgent request for pre-MRI cardiac evaluation, MRI examination was postponed or cancelled in 14 (60.8%) cases. After the ACS application, all 73 patients underwent proper cardiologic evaluation before their MRI examinations (P < 0.001). The proportion of immediate request for pre-MRI evaluation at the moment of MRI order also improved with the ACS application (before ACS 57.1%, after ACS 100%, P < 0.001). @*Conclusions@#The newly developed ACS helped the patients with CIED receive MRI scan safely on the schedule, improving the quality of care in this population.

Clinical and Hospital Factors Affecting Treatment with Primary Prevention Implantable CardioverterDefibrillators in Ischemic Cardiomyopathy Patients

Purpose@#Implantable cardioverter defibrillators (ICD) are the standard of care for primary prevention (PP) in patients with ischemic cardiomyopathy (ICM). However, PP ICD implantation is underused in Asian countries. This study investigated ICD implantation rates and factors associated with appropriate PP ICD implants for ICM. @*Materials and Methods@#In this prospective multicenter observational registry (ADVANCE-ICM registry), ICM patients who were eligible for PP ICD were screened and enrolled. Factors associated with appropriate ICD implantation, including hospital and clinical factors, were investigated. @*Results@#Of the 1453 ICM patients eligible for PP ICD [1111 male; median age, 71.0 (61.0–78.0) years], only 76 (5.2%) patients underwent ICD implantation. Among hospital factors, a non-monetary incentive for referral (72.4% vs. 52.9%, p=0.001) and total hospital system score (6.0 vs. 5.0, p=0.013) were higher in the ICD than in the no-ICD group. In multivariate analysis, total hospital system score [odds ratio (OR), 1.28; 95% confidence interval (CI), 1.10–1.50] was an independent factor for predicting ICD implantation, along with clinical factors, including high New York Heart Association class (≥III: OR, 7.29; 95% CI, 2.97–17.87) and younger age (<70 years: OR, 2.14; 95% CI, 1.30–3.53). @*Conclusion@#PP ICD implantation for ICM patients is underused in Korea. Hospital factors were important for improving PP ICD implantation rate, suggesting that new screening and referral systems for ICM patients would improve the PP ICD implantation rate (Clinical trial registration No. NCT03590925).

Implantable Cardioverter-defibrillator Utilization and Its Outcomes in Korea:Data from Korean Acute Heart Failure Registry

Background@#There are sparse data on the utilization rate of implantable cardioverterdefibrillator (ICD) and its beneficial effects in Korean patients with heart failure with reduced left ventricular ejection fraction (LVEF). @*Methods@#Among 5,625 acute heart failure (AHF) patients from 10 tertiary university hospitals across Korea, 485 patients with reassessed LVEF ≤ 35% at least 3 months after the index admission were enrolled in this study. The ICD implantation during the follow-up was evaluated. Mortality was compared between patients with ICDs and age-, sex-, and follow-up duration matched control patients. @*Results@#Among 485 patients potentially indicated for an ICD for primary prevention, only 56 patients (11.5%) underwent ICD implantation during the follow-up. Patients with ICD showed a significantly lower all-cause mortality compared with their matched control population: adjusted hazard ratio (HR) (95% confidence interval [CI]) = 0.39 (0.16–0.92), P = 0.032. The mortality rate was still lower in the ICD group after excluding patients with cardiac resynchronization therapy (adjusted HR [95% CI] = 0.09 [0.01–0.63], P = 0.015).According to the subgroup analysis for ischemic heart failure, there was a significantly lower all-cause mortality in the ICD group than in the no-ICD group (HR [95% CI] = 0.20 [0.06– 0.72], P = 0.013), with a borderline statistical significance (interaction P = 0.069). @*Conclusion@#Follow-up data of this large, multicenter registry suggests a significant underutilization of ICD in Korean heart failure patients with reduced LVEF. Survival analysis implies that previously proven survival benefit of ICD in clinical trials could be extrapolated to Korean patients.

Experiences of magnetic resonance imaging scanning in patients with pacemakers or implantable cardioverter-defibrillators

BACKGROUND/AIMS: Despite the U.S. Food and Drug Adminstration approving a magnetic resonance imaging (MRI)-conditional pacemaker system in 2011, many physicians remain reluctant to perform MRI scanning in patients with cardiac implantable electronic devices. Herein, we aimed to evaluate the real-world safety of MRI in these patients. METHODS: This single-center retrospective study examined the interrogation data and outcomes of patients with pacemakers or implantable cardioverter defibrillators who underwent MRI. MRI interrogation data were collected pre- and post-MRI and after 1 month of follow-up; these included the lead impedance, measured P- and R-wave amplitudes, and capture threshold. We compared these results between the magnetic resonance (MR)-conditional and conventional groups. RESULTS: From September 2013 to December 2015, 35 patients with cardiac implantable electronic devices underwent 43 MRI scans, with a mean follow-up of 5 months. Among these 35 patients, 14 (40%) had MR-conditional devices and 21 (60%) had conventional devices. Seven patients had high voltage devices, which were all the conventional type. There were no adverse events associated with MRI during the follow-up period, and there were no significant differences in the interrogation data changes between the conventional and MR-conditional groups. CONCLUSIONS: This single-center retrospective study found that MRI can be performed safely in patients with pacemakers or implantable cardioverter defibrillators, regardless of the MRI support, as long as appropriate precautions are taken.

Prognostic Implication of Ventricular Conduction Disturbance Pattern in Hospitalized Patients with Acute Heart Failure Syndrome

BACKGROUND AND OBJECTIVES@#Conflicting data exist regarding the prognostic implication of ventricular conduction disturbance pattern in patients with heart failure (HF). This study investigated the prognostic impact of ventricular conduction pattern in hospitalized patients with acute HF.@*METHODS@#Data from the Korean Acute Heart Failure registry were used. Patients were categorized into four groups: narrow QRS (<120 ms), right bundle branch block (RBBB), left bundle branch block (LBBB), and nonspecific intraventricular conduction delay (NICD). The NICD was defined as prolonged QRS (≥120 ms) without typical features of LBBB or RBBB. The primary endpoint was the composite of all-cause mortality or rehospitalization for HF aggravation within 1 year after discharge.@*RESULTS@#This study included 5,157 patients. The primary endpoint occurred in 39.7% of study population. The LBBB group showed the highest incidence of primary endpoint followed by NICD, RBBB, and narrow QRS groups (52.5% vs. 49.7% vs. 44.4% vs. 37.5%, p<0.001). In a multivariable Cox-proportional hazards regression analysis, LBBB and NICD were associated with 39% and 28% increased risk for primary endpoint (LBBB hazard ratio [HR], 1.392; 95% confidence interval [CI], 1.152–1.681; NICD HR, 1.278; 95% CI, 1.074–1.520) compared with narrow QRS group. The HR of RBBB for the primary endpoint was 1.103 (95% CI, 0.915–1.329).@*CONCLUSIONS@#LBBB and NICD were independently associated with an increased risk of 1-year adverse event in hospitalized patients with HF, whereas the prognostic impacts of RBBB were limited.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01389843

Small but Persistent Infection of Cardiac Implantable Electronic Devices (CIED)

No abstract available.

Prognostic Implication of Ventricular Conduction Disturbance Pattern in Hospitalized Patients with Acute Heart Failure Syndrome

BACKGROUND AND OBJECTIVES: Conflicting data exist regarding the prognostic implication of ventricular conduction disturbance pattern in patients with heart failure (HF). This study investigated the prognostic impact of ventricular conduction pattern in hospitalized patients with acute HF. METHODS: Data from the Korean Acute Heart Failure registry were used. Patients were categorized into four groups: narrow QRS (<120 ms), right bundle branch block (RBBB), left bundle branch block (LBBB), and nonspecific intraventricular conduction delay (NICD). The NICD was defined as prolonged QRS (≥120 ms) without typical features of LBBB or RBBB. The primary endpoint was the composite of all-cause mortality or rehospitalization for HF aggravation within 1 year after discharge. RESULTS: This study included 5,157 patients. The primary endpoint occurred in 39.7% of study population. The LBBB group showed the highest incidence of primary endpoint followed by NICD, RBBB, and narrow QRS groups (52.5% vs. 49.7% vs. 44.4% vs. 37.5%, p<0.001). In a multivariable Cox-proportional hazards regression analysis, LBBB and NICD were associated with 39% and 28% increased risk for primary endpoint (LBBB hazard ratio [HR], 1.392; 95% confidence interval [CI], 1.152–1.681; NICD HR, 1.278; 95% CI, 1.074–1.520) compared with narrow QRS group. The HR of RBBB for the primary endpoint was 1.103 (95% CI, 0.915–1.329). CONCLUSIONS: LBBB and NICD were independently associated with an increased risk of 1-year adverse event in hospitalized patients with HF, whereas the prognostic impacts of RBBB were limited. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01389843

Intravascular imaging analysis of a drug-eluting balloon followed by a bare metal stent compared to a drug-eluting stent for treatment of de novo lesions

BACKGROUND/AIMS@#After a study comparing drug-eluting stents (DESs) to sequential treatment with drug-eluting balloons (DEBs) and bare metal stents (BMSs), we retrospectively analysed strut malapposition and neointimal hyperplasia in de novo coronary lesions using optical coherence tomography (OCT) or intravascular ultrasonography (IVUS).@*METHODS@#We obtained OCT data from 16 patients (eight per group) and IVUS data from 40 patients (20 per group). OCT or IVUS was performed after the index procedure and after 9 months. Parameters including obstruction volume due to neointimal hyperplasia (neointimal hyperplasia volume/stent volume, %), strut malapposition (% of malapposed struts), and intra-individual inhomogeneity of in-stent restenosis were compared.@*RESULTS@#Although obstruction volume due to neointimal hyperplasia was significantly higher in the DEB-BMS group (14.90 ± 15.36 vs. DES 7.03 ± 11.39, p = 0.025), there was no difference in strut malapposition between the two groups (DEB-BMS 1.99 ± 5.37 vs. DES 0.88 ± 2.22, p = 0.856). The DEB-BMS group showed greater intra-individual inhomogeneity of in-stent restenosis pattern than the DES group.@*CONCLUSIONS@#Treatment with DEB followed by BMS failed to improve strut malapposition despite higher in-stent neointimal growth, probably because of the inhomogeneous inhibition of in-stent neointimal hyperplasia by DEB. DEB technology should be improved to obtain even drug delivery to the vessel wall and homogeneous prevention of neointimal growth comparable to contemporary DES.

Quality of Anticoagulation and Treatment Satisfaction in Patients with Non-Valvular Atrial Fibrillation Treated with Vitamin K Antagonist: Result from the KORean Atrial Fibrillation Investigation II

BACKGROUND: Vitamin K antagonist (VKA) to prevent thromboembolism in non-valvular atrial fibrillation (NVAF) patients has limitations such as drug interaction. This study investigated the clinical characteristics of Korean patients treated with VKA for stroke prevention and assessed quality of VKA therapy and treatment satisfaction. METHODS: We conducted a multicenter, prospective, non-interventional study. Patients with CHADS2 ≥ 1 and treated with VKA (started within the last 3 months) were enrolled from April 2013 to March 2014. Demographic and clinical features including risk factors of stroke and VKA treatment information was collected at baseline. Treatment patterns and international normalized ratio (INR) level were evaluated during follow-up. Time in therapeutic range (TTR) > 60% indicated well-controlled INR. Treatment satisfaction on the VKA use was measured by Treatment Satisfaction Questionnaire for Medication (TSQM) after 3 months of follow-up. RESULTS: A total of 877 patients (age, 67; male, 60%) were enrolled and followed up for one year. More than half of patients (56%) had CHADS2 ≥ 2 and 83.6% had CHA2DS2-VASc ≥ 2. A total of 852 patients had one or more INR measurement during their follow-up period. Among those patients, 25.5% discontinued VKA treatment during follow-up. Of all patients, 626 patients (73%) had poor-controlled INR (TTR < 60%) measure. Patients' treatment satisfaction measured with TSQM was 55.6 in global satisfaction domain. CONCLUSION: INR was poorly controlled in Korean NVAF patients treated with VKA. VKA users also showed low treatment satisfaction.

Validation of the mobile wireless digital automatic blood pressure monitor using the cuff pressure oscillometric method, for clinical use and self-management, according to international protocols

The purpose of this study was to evaluate the accuracy of a mobile wireless digital automatic blood pressure monitor for clinical use and mobile health (mHealth). In this study, a manual sphygmomanometer and a digital blood pressure monitor were tested in 100 participants in a repetitive and sequential manner to measure blood pressure. The guidelines for measurement used the Korea Food & Drug Administration protocol, which reflects international standards, such as the American National Standard Institution/Association for the Advancement of Medical Instrumentation SP 10: 1992 and the British Hypertension Society protocol. Measurements were generally consistent across observers according to the measured mean ± SD, which ranged in 0.1 ± 2.6 mmHg for systolic blood pressure (SBP) and 0.5 ± 2.2 mmHg for diastolic blood pressure (DBP). For the device and the observer, the difference in average blood pressure (mean ± SD) was 2.3 ± 4.7 mmHg for SBP and 2.0 ± 4.2 mmHg for DBP. The SBP and DBP measured in this study showed accurate measurements that satisfied all criteria, including an average difference that did not exceed 5 mmHg and a standard deviation that did not exceed 8 mmHg. The mobile wireless digital blood pressure monitor has the potential for clinical use and managing one's own health.

Unsolved Questions on the Anatomy of the Ventricular Conduction System

We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.