Background and Objectives: Comprehensive epidemiological data are lacking on the incident atrial fibrillation (AF) in patients with cardiac implantable electronic devices (CIEDs). This study aimed to examine the incidence, risk factors, and AF-related adverse outcomes of patients with CIEDs. Methods: This was an observational cohort study that analyzed patients without prevalent AF who underwent CIED implantation in 2009–2018 using a Korean nationwide claims database. The subjects were divided into three groups by CIED type and indication: pacemaker (n=21,438), implantable cardioverter defibrillator (ICD)/cardiac resynchronization therapy (CRT) with heart failure (HF) (n=3,450), and ICD for secondary prevention without HF (n=2,146). The incidence of AF, AF-associated predictors, and adverse outcomes were evaluated. Results: During follow-up, the incidence of AF was 4.3, 7.3, and 5.1 per 100 person-years in the pacemaker, ICD/CRT with HF, and ICD without HF cohorts, respectively. Across the three cohorts, older age and valvular heart disease were commonly associated with incident AF.Incident AF was consistently associated with an increased risk of ischemic stroke (3.8–11.4-fold), admission for HF (2.6–10.5-fold), hospitalization for any cause (2.4–2.7-fold), all-cause death (4.1–5.0-fold), and composite outcomes (3.4–5.7-fold). Oral anticoagulation rates were suboptimal in patients with incident AF (pacemaker, 51.3%; ICD/CRT with HF, 51.7%; and ICD without HF, 33.8%, respectively). Conclusions A substantial proportion of patients implanted CIED developed newly diagnosed AF. Incident AF was associated with a higher risk of adverse events. The importance of awareness, early detection, and appropriate management of AF in patients with CIED should be emphasized.

Background: Nasal bone fractures are the most common type of facial bone fracture, but are under-studied in adults above 65 years of age. Therefore, we investigated the epidemiology and patterns of nasal bone fractures among older adults in comparison to different age groups. Methods: This retrospective study included 2,321 nasal bone fracture patients who underwent surgery at our hospital from January 2010 to December 2017. The patients were classified by age as preschoolers, school-age children, young and middle-aged adults, and the elderly. We performed pairwise comparisons between elderly patients and each other age group in terms of sex, cause of injury, and fracture type. Results: The 2,321 nasal bone fracture patients included 76 elderly patients (50 men [65.8%] and 26 women [34.2%]). In these patients, the two most common injury causes were falling or slipping down (n = 39; 51.3%) and road traffic accidents (n = 19; 25.0%). According to the Stranc and Robertson classification, the most common force vector was lateral, and plane 2 fractures with lateral forces predominated. Conclusion The elderly showed similar patterns of nasal bone fractures to those observed in young and middle-aged adults, but significant differences from preschoolers (in the injury vector and plane of fracture) and from school-age children (in the sex ratio and plane of fracture). However, elderly patients presented significantly different epidemiological characteristics compared to the other three groups. Therefore, it is necessary to improve the quality of life of the elderly and prepare for the upcoming super-aged society by taking steps to reduce the incidence and severity of fractures. Possible options for doing so include strengthening individual-level safety factors and expanding the social safety net for the elderly.

Background and Objectives: Although long QT syndrome (LQTS) is a potentially lifethreatening inherited cardiac channelopathy, studies documenting the long-term clinical data of Korean patients with LQTS are scarce. Methods: This retrospective cohort study included 105 patients with LQTS (48 women; 45.7%) from a single tertiary center. The clinical outcomes were analyzed for the rate of freedom from breakthrough cardiac events (BCEs), additional treatment needed, and death. Results: LQTS was diagnosed at a median age of 11 (range, 0.003–80) years. Genetic testing was performed on 90 patients (yield, 71.1%). The proportions of genetically confirmed patients with LQTS types 1, 2, 3, and others were 34.4%, 12.2%, 12.2%, and 12.2%, respectively. In the symptomatic group (n=70), aborted cardiac arrest was observed in 30% of the patients. Treatments included medications in 60 patients (85.7%), implantable cardioverter-defibrillators in 27 (38.6%; median age, 17 years; range, 2–79 years), and left cardiac sympathetic denervation surgery in 7 (10%; median age, 13 years; range, 2–34). The 10-year BCE-free survival rate was 73.2%. By genotype, significant differences were observed in BCEs despite medication (p<0.001). The 10-year BCE-free survival rate was the highest in patients with LQTS type 1 (81.8%) and the lowest in those with multiple LQTS-associated mutations (LQTM). All patients with LQTS survived, except for one patient who had LQTM. Conclusions Good long-term outcomes can be achieved by using recently developed genetically tailored management strategies for patients with LQTS.

Background: Although the zygomatic arch is an important structure determining facial prominence and width, no consensus exists regarding the classification of isolated zygomatic arch fractures, and the literature on this topic is scarce. To date, five papers have subdivided zygomatic arch fractures; however, only one of those proposed classifications includes the injury vector, although the injury vector is one of the most important factors to consider in fracture cases. Furthermore, the only classification that does include the injury vector is too complicated to be suitable for daily practice. In addition, the existing classifications are clinically limited because they do not consider greenstick fractures, nondisplaced fractures, or coronoid impingement. In the present study, we present a rearrangement of the previously published classifications and propose a modified classification of isolated zygomatic arch fractures that maximizes the advantages and overcomes the disadvantages of previous classification systems. Methods: The classification criteria for isolated zygomatic arch fractures described in five previous studies were analyzed, rearranged, and supplemented to generate a modified classification. The medical records, radiographs, and facial bone computed tomography findings of 134 patients with isolated zygomatic arch fractures who visited our hospital between January 2010 and December 2019 were also retrospectively analyzed. Results: We analyzed major classification criteria (displacement, the force vector of the injury, V-shaped fracture, and coronoid impingement) for isolated zygomatic arch fracture from the five previous studies and developed a modified classification by subdividing zygomatic arch fractures. We applied the modified classification to cases of isolated zygomatic arch fracture at our hospital. The surgery rate and injury severity differed significantly from fracture types I to VI. Conclusion Using our modified classification, we could determine that both the injury force and the injury vector meaningfully influenced the surgery rate and the severity of the injuries.

Background and Objectives: Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF. Methods: Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF). Results: Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation. Conclusions Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

Background and Objectives: Antithrombotic therapy after percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF) has changed in recent years with new data from large randomized trials and updates to clinical guidelines. This study aimed to investigate the trends in periprocedural antithrombotic regimens in Korean patients with AF undergoing PCI with non-vitamin K antagonist oral anticoagulants (NOACs). Methods: Using the claims database of the Health Insurance Review and Assessment during 2013–2018, 27,594 patients with AF undergoing PCI were identified. The annual prevalence of PCI and prescriptions of each antithrombotic agent, including antiplatelet agents and oral anticoagulants, within 30 days after PCI were investigated. Results: During 2013–2018, the number of patients with AF undergoing PCI increased up to 1.3-fold (from 3,913 to 5,075 patients per year). After the introduction of NOACs, the proportion of dual antiplatelet therapy (DAPT) decreased from 71.9% to 49.8% but still occupied the largest proportion among antithrombotic regimens. Triple antithrombotic therapy (TAT) use increased from 25.4% to 46.0%, and NOAC has rapidly replaced warfarin as the oral anticoagulant of choice. TAT was preferred to DAPT for patients with CHA2 DS2 -VASc score ≥2. Among various factors, prior intracranial hemorrhage was the most powerful predictor of favoring DAPT use over TAT. Conclusion Since the introduction of NOACs, the patterns of periprocedural antithrombotic regimens have changed rapidly toward more use of TAT, specifically with NOAC-based regimen. Appropriate stroke prevention with oral anticoagulants is still underutilized in patients with AF undergoing PCI in Korea.

Background and Objectives: Antithrombotic therapy after percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF) has changed in recent years with new data from large randomized trials and updates to clinical guidelines. This study aimed to investigate the trends in periprocedural antithrombotic regimens in Korean patients with AF undergoing PCI with non-vitamin K antagonist oral anticoagulants (NOACs). Methods: Using the claims database of the Health Insurance Review and Assessment during 2013–2018, 27,594 patients with AF undergoing PCI were identified. The annual prevalence of PCI and prescriptions of each antithrombotic agent, including antiplatelet agents and oral anticoagulants, within 30 days after PCI were investigated. Results: During 2013–2018, the number of patients with AF undergoing PCI increased up to 1.3-fold (from 3,913 to 5,075 patients per year). After the introduction of NOACs, the proportion of dual antiplatelet therapy (DAPT) decreased from 71.9% to 49.8% but still occupied the largest proportion among antithrombotic regimens. Triple antithrombotic therapy (TAT) use increased from 25.4% to 46.0%, and NOAC has rapidly replaced warfarin as the oral anticoagulant of choice. TAT was preferred to DAPT for patients with CHA2 DS2 -VASc score ≥2. Among various factors, prior intracranial hemorrhage was the most powerful predictor of favoring DAPT use over TAT. Conclusion Since the introduction of NOACs, the patterns of periprocedural antithrombotic regimens have changed rapidly toward more use of TAT, specifically with NOAC-based regimen. Appropriate stroke prevention with oral anticoagulants is still underutilized in patients with AF undergoing PCI in Korea.

Background: The major cause of recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF) is PV recon‑ nection, and thicker wall could be associated with reconnection. Objectives: This study aimed to evaluate the wall thickness of the PV antrum in reconnection sites using a threedimensional (3D) wall thickness map. Methods: A total of 91 patients who underwent a second ablation procedure due to AF recurrence were evalu‑ ated. The locations of the PV reconnection sites were confirmed in electroanatomical maps. A 3D atrial wall thickness (AWT) map was created using computed tomography scan data. The AWT values of the ablation lines of the index procedure were graded in each segment of the PV antrum: grade 1, 0.5 < AWT ≤ 1.0 mm; grade 2, 1.0 < AWT ≤ 1.5  mm; grade 3, 1.5 < AWT ≤ 2.0 mm; grade 4, 2.0 < AWT ≤ 2.5 mm; grade 5, AWT > 2.5 mm. Results: A total of 281 PV reconnection sites among 1256 segments of the PV antrum in 79 patients were detected. The average AWT grades were 2.7 ± 1.0 and 2.2 ± 1.0 in the reconnected and non-reconnected segments, respectively (P < 0.01). Higher AWT grades were observed in the reconnected superior segments of the left superior PV, carina and inferior segments of the left inferior PV, superior and posterior segments of the right superior PV, and posterior and inferior segments of the right inferior PV. Conclusion The reconnected segments of the PV antrum showed thicker myocardium than the non-reconnected ones in patients with recurrent AF after catheter ablation. A wall thickness map for PV isolation could be considered for customized ablation in order to reduce PV reconnection.

Background: In patients with atrial fibrillation (AF), most biomarkers are still of limited use due to cost-effectiveness and complexity in clinical practice.
Hypotheses
Biomarkers from routine blood tests improve the current risk stratification in AF patients. Methods: This prospective study enrolled 600 patients diagnosed with non-valvular AF, of whom 537 were analyzed. Platelet count; platelet distribution width (PDW); red cell distribution width (RDW); and creatinine, D-dimer, and troponin I levels were measured at enrollment. Results: During the mean follow-up period (2.2 ± 0.6 years), 1.9% patients developed ischemic stroke. According to the optimal cutoff of each biomarker, the risk of ischemic stroke was higher in patients with RDW ≥ 13.5%, creatinine ≥ 1.11 mg/dL, or PDW ≥ 13.2% (significant biomarkers; P value: < 0.01, 0.04, or 0.07, respectively). These 3 significant biomarkers had higher information gain than clinical risk factors in predicting ischemic stroke. The cumulative incidence of ischemic stroke was 1.2%, 1.1%, 8.4%, and 40.0% in patients with 0, 1, 2, and 3 significant biomarkers, respectively (P-for-trend < 0.001). Patients with  ≥ 2 significant biomarkers had a significantly higher risk of ischemic stroke than those with  < 2 significant biomarkers (adjusted hazard ratio 11.5, 95% confidence interval 3.3–40.2, P < 0.001). The predictability for ischemic stroke was significantly improved when  ≥ 2 significant biomarkers were added to the CHA2DS2–VASc score (area under the curve 0.790 vs. 0.620, P = 0.043). Conclusion Routine blood tests can provide better risk stratification of AF along with clinical risk factors.

Objective: : We attempted to compare the incidence of pyogenic spondylitis (PS) and tuberculous spondylitis (TS) between 2007 and 2016. Furthermore, we investigated the patients who underwent surgery in 2016 compared to that in 2007. Methods: : We used a nationwide database managed by the Korean National Health Insurance Service (NHIS) in 2007 and 2016. Total 9655 patients with a newly diagnosis of PS or TS were enrolled in PS or TS group. Among them, 1721 patients underwent either fusion or decompression surgery. We analyzed demographic distribution of patients according to gender and age and year of diagnosis. Results: : Comparing between 2007 and 2016, the incidence of PS has increased in 2016 than in 2007 (4874 vs. 2431, p<0.0001). Conversely, declination of incidence of TS was discovered in 2016 compared to 2007 (594 vs. 1756, p<0.0001). Females showed predominance over males regarding both PS and TS (5228 vs. 4427, p<0.0001). Among them, the number of PS patients who underwent surgery increased significantly in 2016 relative to that in 2007 (979 vs. 592, p<0.0001). Conclusion : This nationwide study suggests that PS may increase and TS may decrease in Korea. In addition, demand for surgery regarding PS may increase.