Association of temporal change in body mass index with sudden cardiac arrest in diabetes mellitus.

BACKGROUND: Underweight imposes significant burden on cardiovascular outcomes in patients with diabetes mellitus. However, less is known about the impact of serial change in body weight status measured as body mass index (BMI) on the risk of sudden cardiac arrest (SCA). This study investigated the association between SCA and temporal change in BMI among patients with diabetes mellitus. METHODS: Based on Korean National Health Insurance Service database, participants with diabetes mellitus who underwent health examination between 2009 and 2012 and had prior health examination data (four years ago, 2005-2008) were retrospectively analyzed. BMI was measured at baseline (2005-2008) and 4-year follow-up health examination (2009-2012). Patients were classified in four groups according to the body weight status and its temporal change: sustained non-underweight, sustained underweight, previous underweight, and newly developed underweight. Primary outcome was defined as occurrence of SCA. RESULTS: A total of 1,355,746 patients with diabetes mellitus were included for analysis, and SCA occurred in 12,554 cases. SCA was most common in newly developed underweight (incidence rate = 4.45 per 1,000 person-years), followed by sustained underweight (incidence rate = 3.90), previous underweight (incidence rate = 3.03), and sustained non-underweight (incidence rate = 1.34). Adjustment of covariates resulted highest risk of SCA in sustained underweight (adjusted hazard ratio = 2.60, 95% confidence interval [2.25-3.00], sustained non-underweight as a reference), followed by newly developed underweight (2.42, [2.15-2.74]), and previous underweight (2.12, [1.77-2.53]). CONCLUSIONS: In diabetes mellitus, sustained underweight as well as decrease in body weight during 4-year follow-up imposes substantial risk on SCA. Recovery from underweight over time had relatively lower, but yet increased risk of SCA. Both underweight and dynamic decrease in BMI can be associated with increased risk of SCA.

Atrial Fibrillation and Risk of Sudden Cardiac Arrest in Young Adults.

BACKGROUND AND AIMS: Evidence of an association between atrial fibrillation (AF) and sudden cardiac arrest (SCA) in young adults is limited. We aimed to evaluate this association in a general population aged between 20-39 years. METHODS: Young adults who underwent health check-ups between 2009 and 2012 were screened from a nationwide healthcare database in South Korea. A history of AF diagnosis before the health check-ups was identified based on the relevant International Classification of Diseases, 10th edition codes reported in the database. Associations between an established diagnosis of AF and the risk of SCA during follow-up were examined. RESULTS: A total of 6,345,162 young people were analyzed with a mean follow-up duration of 9.4 years. The mean age was 30.9 ± 5.0 years, and 5,875 (0.09%) individuals were diagnosed with AF. During follow-up, SCA occurred in 5,352 (0.08%) individuals, and the crude incidence was 0.56 and 0.09 events per 1,000 person-years for participants with and without AF, respectively. Individuals with AF had a 3.0-fold higher risk in a multivariate model adjusted for age, sex, lifestyle, anthropometric data, and medical comorbidities (adjusted hazard ratio 2.96, 95% confidence interval 1.99-4.41, p<0.001). Both incident and prevalent AF were associated with an increased risk of SCA, with no significant differences between the two groups. CONCLUSION: Atrial fibrillation was associated with a significantly higher risk of developing SCA in healthy young adults. Whether the rate or rhythm affects the risk of SCA in young patients with AF remains to be examined.

Long-term increase in fasting blood glucose is associated with increased risk of sudden cardiac arrest.

BACKGROUND: Diabetes mellitus (DM) is associated with various cardiovascular complications, including sudden cardiac arrest (SCA). Furthermore, the severity of DM, as assessed by fasting blood glucose (FBG), is associated with the risk of SCA. However, whether long-term changes in FBG influence on SCA risk remains to be determined. METHODS: This study used sequential nationwide health screening data from 2009 and 2011. FBG was measured at each health screening, and ΔFBG was calculated as FBG in 2011-FBG in 2009. RESULTS: Overall, 2,801,153 people were analyzed, and the mean follow-up duration was 6.33 years. Compared with the euglycemic group (- 20 ≤ ΔFBG < 20), the 20 ≤ ΔFBG < 40, 40 ≤ ΔFBG < 100, and ΔFBG ≥ 100 groups had increased SCA risks of 25% (adjusted hazard ratio [HR] = 1.25; 95% confidence interval [CI] 1.16-1.35; p < 0.001), 66% (adjusted HR = 1.66; 95% CI 1.49-1.86; p < 0.001), and 2.9-fold (adjusted HR = 2.85; 95% CI 2.37-3.44; p < 0.001), respectively. The association between ΔFBG and SCA was maintained in people with DM but not in people without DM. However, sex, age, blood pressure, and presence of heart failure did not affect the association between ΔFBG and SCA. A decrease in ΔFBG over time was not associated with reduced risk of SCA: the adjusted HR was 1.11 (95% CI 0.98-1.27; p = 0.113) for the ΔFBG < -40 group and 1.12 (95% CI 1.03-1.22; p = 0.009) for the - 40 ≤ ∆FBG < - 20 group. CONCLUSIONS: A long-term increase in ΔFBG can be associated with increased risk of SCA in people with DM. However, a long-term decrease in ΔFBG was not associated with reduced risk of SCA. Actions to prevent increase in FBG can have significant effects on public health in terms of SCA prevention.

Association between low-density lipoprotein cholesterol and sudden cardiac arrest in people with diabetes mellitus.

BACKGROUND: Dyslipidemia measured as low-density lipoprotein (LDL)-cholesterol is an established risk factor of cardiovascular disease, which is more pronounced in diabetes population. Less is known about the association of LDL-cholesterol level and sudden cardiac arrest (SCA) risk in diabetes mellitus patients. This study investigated the association of LDL-cholesterol level and SCA risk in diabetes population. METHODS: This study was based on Korean National Health Insurance Service database. Patients who received general examination from 2009 to 2012 and diagnosed as type 2 diabetes mellitus were analyzed. Primary outcome was defined as SCA event identified with International Classification of Disease code. RESULTS: A total of 2,602,577 patients were included, with total follow-up duration of 17,851,797 person * year. Mean follow-up duration was 6.86 years, and 26,341 SCA cases were identified. Overall incidence of SCA was highest in the lowest LDL-cholesterol group (< 70 mg/dL) and decreased in a linear manner as LDL-cholesterol rises, till 160 mg/dL. Adjustment of covariates resulted in U-shape association, with highest risk of SCA in the highest LDL-cholesterol group (≥ 160 mg/dL) followed by lowest LDL-cholesterol group (< 70 mg/dL). In subgroup analysis, U-shape association between SCA risk and LDL-cholesterol was more pronounced in male, non-obese people, and those who did not use statins. CONCLUSIONS: In people with diabetes, the association between SCA and LDL-cholesterol level was U-shaped with highest and lowest LDL-cholesterol group having higher risk of SCA than others. Low LDL-cholesterol level can be a surrogate marker for increased risk of SCA in people with diabetes mellitus and this paradoxical association should be recognized and extended to clinical preventive measures.

Korean vs. Western Exercise Capacity Nomograms for Korean Patients With Cardiovascular Disease.

BACKGROUND: Exercise capacity is known to be an independent predictor of cardiovascular events and mortality. However, most previous studies were based on Western populations. Further study is warranted for Asian patients according to ethnic or national standards. We aimed to compare prognostic values of Korean and Western nomograms for exercise capacity in Korean patients with cardiovascular disease (CVD). METHODS: In this retrospective cohort study, we enrolled 1,178 patients (62 ± 11 years; 78% male) between June 2015 and May 2020, who were referred for cardiopulmonary exercise testing in our cardiac rehabilitation program. The median follow-up period was 1.6 years. Exercise capacity was measured in metabolic equivalents by direct gas exchange method during the treadmill test. The nomogram for exercise capacity from healthy Korean individuals and a previous landmark Western study was used to determine the percentage of predicted exercise capacity. The primary endpoint was the composite of major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, repeat revascularization, stroke and hospitalization for heart failure). RESULTS: A multivariate analysis showed that the risk of primary endpoint was more than double (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.10-4.40) in the patients with lower exercise capacity (< 85% of predicted) by Korean nomogram. The lower exercise capacity was one of the strong independent predictors along with left ventricular ejection fraction, age, and level of hemoglobin. However, the lower exercise capacity by Western nomogram could not predict the primary endpoint (HR, 1.33; 95% CI, 0.85-2.10). CONCLUSION: Korean patients with CVD with lower exercise capacity have higher risk of MACE. Considering inter-ethnic differences in cardiorespiratory fitness, the Korean nomogram provides more suitable reference values than the Western nomogram to determine lower exercise capacity and predict cardiovascular events in Korean patients with CVD.

E/e' Ratio Predicts the Atrial Pacing-Induced Left Atrial Pressure Response in Patients with Preserved Ejection Fraction.

Background and Objectives: Left atrial hypertension is one of the pathophysiologies of heart failure with preserved ejection fraction. We hypothesized that left atrial pressure response (LAPR) to incremental pacing is higher in patients with atrial fibrillation (AF) and can predict left ventricular diastolic dysfunction. Materials and Methods: Patients requiring left atrial access as a part of a therapeutic procedure for AF (n = 204, AF group) or supraventricular tachycardia (n = 34, control group) were analyzed (male n = 183, 54 ± 12 years old). LAPR was measured during incremental pacing. Results: Baseline left atrial pressure and LAPR at all pacing rates were not different between the AF and control groups. They were higher in patients with a high E/e' (≥ 8) than in those with a low E/e' (<8). LAPR at a pacing interval of 400 ms and E/e' were positively correlated (r = 0.373, p < 0.001). Body mass index and a high E/e' were independent predictors of pacing-induced left atrial hypertension. Conclusions: LAPR to incremental pacing was constant regardless of AF. The non-invasive echocardiographic marker E/e' reflected pacing-induced left atrial hypertension.

Combined epicardial and endocardial approach for redo radiofrequency catheter ablation in patients with persistent atrial fibrillation: a randomized clinical trial.

AIMS: An epicardial approach is an effective means to detect and eliminate residual potentials in non-transmural lesions created during prior endocardial ablation. We sought to determine the impact of a combined epicardial and endocardial approach compared with a conventional endocardial approach, on recurrence-free survival after redo ablation. METHODS AND RESULTS: Participants with recurred persistent atrial fibrillation after prior endocardial ablation were randomized (1:1) to undergo treatment with the combined approach (epicardial followed by endocardial ablation) for the treatment group or conventional approach (endocardial ablation only) for the control group. The primary outcome was the time to recurrence of atrial fibrillation or atrial tachycardia following a 90-day blanking period within 12 months after the procedure. The secondary safety outcome was the occurrence of procedure-related complications within 24 h after the procedure. Of 100 randomized participants {median age, 59.0 [(interquartile range (IQR): 53.8-64.3] years, including 16% women, with one prior ablation (IQR: 1-1)}, 93 (93%) completed the trial. Events relevant to the primary outcome occurred in 16 patients in the treatment group and in 21 patients in the control group {Kaplan-Meier estimator percentages, 32 vs. 42%; hazard ratio, 0.71 [95% confidence interval (CI): 0.37-1.37]}. The periprocedural complication rate was lower in the treatment group [2 vs. 16%; odds ratio, 0.11 (95% CI: 0.00-0.87)] with similar achievement of the procedural endpoint in the two groups. CONCLUSION: In the redo procedure for persistent atrial fibrillation, the combined approach had no significant difference of recurrence-free survival and a lower procedural complication rate compared with the conventional approach.

Role of early short-term cardiac rehabilitation in patients undergoing pacemaker implantation.

Exercise-based cardiac rehabilitation (CR) improves the clinical outcomes in patients with cardiovascular diseases. However, few data exist regarding the role of early short-term CR in patients undergoing pacemaker (PM) implantation. We assessed whether short-term CR following PM implantation was sufficient to improve both physical function and quality of life (QOL). A total of 27 patients with a 6-minute walking distance (6MWD) of less than 85% of the predicted value on the day following PM implantation were randomly assigned to either the CR group (n = 12, 44.4%) or the non-CR group (n = 15, 55.6%). The CR group involved individualized exercise-based training with moderate intensity for 4 weeks after PM implantation. Cardiopulmonary exercise test (CPET), 6MWD, muscle strength, and Short Form (SF)-36 were assessed at baseline and at the 4-week follow-up. After a mean follow-up period of 38.3 days, both groups showed significantly improved 6MWD. Peak oxygen uptake improved in both groups on CPET, but the difference was not statistically significant. Knee extension power and handgrip strength were similar in both groups. Regarding QOL, only the CR group showed improved SF-36 scores in the items of vitality and mental health. There was no difference in any subscale in the non-CR group. Neither lead dislodgement nor significant changes in PM parameters were observed in any patient. Early short-term CR following PM implantation was associated with improved psychological subscales and can be safely performed without increasing the risk of procedure-related complications.

Age and sex dependent association of uric acid and incident hypertension.

BACKGROUND AND AIMS: A previous meta-analysis suggested that the relationship between hyperuricemia and hypertension may be stronger in younger individuals and women. We aimed to investigate the age and sex dependent association of uric acid (UA) and incident hypertension. METHODS AND RESULTS: We analyzed data from the Health Examinees Study, a community-based prospective cohort study conducted in Korea from 2004 to 2013. It included 29,088 non-hypertensive subjects aged 40-79 (age, 52.5 ± 7.8 years; men, 31.4%) who had serum UA measurement and participated in the follow-up survey. The risk factors of hypertension were assessed using Cox regression. Over a mean 3.8 years of follow-up, 1388 men (15.2%) and 1942 women (9.7%) were newly diagnosed with hypertension. Upon age- and sex-based stratification, the risk of hypertension was highest in hyperuricemic subjects aged 40-49 years (HR: women, 2.16; men, 1.30). Across the entire cohort, the risk of incident hypertension was higher in groups with higher serum UA levels, and highest in women aged 40-49 years (HR, 1.44; P < 0.001). On multivariable linear regression analysis, the higher the baseline serum UA level, the greater the increase in blood pressure during follow-up, and this effect was strongest in women aged 40-49 years (ß = 0.87 and P < 0.01 for systolic blood pressure). CONCLUSIONS: The relationship between uric acid and incident hypertension tended to be dependent on age and sex. Younger women are at highest risk of UA-related incident hypertension.

The Impact of Personal Thoracic Impedance on Electrical Cardioversion in Patients with Atrial Arrhythmias.

Background and Objectives: Direct current cardioversion (DCCV) is a safe and useful treatment for atrial tachyarrhythmias. In the past, the energy delivered in DCCV was decided upon empirically, based only on the type of tachyarrhythmia. This conventional method does not consider individual factors and may lead to unnecessary electrical damage. Materials and Methods: We performed DCCV in patients with atrial tachyarrhythmias. The impedance and electrical current at the moment of shock were measured. The human thoracic impedance between both defibrillator patches and the electric current that was used were measured. Results: A total of 683 DCCVs were performed on 466 atrial tachyarrhythmia patients. The average impedance was 64 ± 11 Ω and the average successful current was 23 ± 6 mA. The magnitude of the electrical current that was successful depended upon the human impedance (linear regression, B = -0.266, p < 0.001) and the left atrial diameter (B = 0.092, p < 0.001). Impedance was directly proportional to body mass index (BMI) (B = 1.598, p < 0.001) and was higher in females than in males (77 ± 15 Ω vs. 63 ± 11 Ω, p < 0.001). Notably, the high-impedance (>70 Ω) group had a higher BMI (27 ± 4 kg/m2 vs. 25 ± 3 kg/m2, p < 0.001) and a higher proportion of females (37% vs. 9%, p < 0.001) than the low-impedance group (<70 Ω). However, thoracic impedance was not an independent predictor for successful DCCV. Conclusions: Human thoracic impedance was one of the factors that impacted the level of electrical current required for successful DCCV in patients with atrial arrhythmias. In the future, it will be helpful to consider individual predictors, such as BMI and gender, to minimize electrical damage during DCCV.

Impact of Sleep-Disordered Breathing on Functional Outcomes in Ischemic Stroke: A Cardiopulmonary Coupling Analysis.

BACKGROUND AND PURPOSE: Cardiopulmonary coupling (CPC) analysis is an easily assessable method to evaluate sleep-disordered breathing (SDB); however, its prognostic impact in patients with acute ischemic stroke needs to be investigated. We performed a CPC analysis using Holter monitoring at the early stage of noncardioembolic ischemic stroke to investigate the prognostic effect of SDB on functional impairment at the 3-month follow-up. METHODS: A total 615 patients with acute noncardioembolic ischemic stroke who underwent Holter monitoring within 30 days of stroke onset were enrolled from a multicenter, prospective, all-comer cohort. CPC analysis was conducted, and SDB was defined by the presence of narrow-band coupling during sleep time. We investigated the association between SDB and functional impairment at 3 months as measured by the modified Rankin Scale. RESULT: Narrow-band coupling was present in 191 (31.1%) of 615 patients (mean age 64.5±12.6 years). The narrow-band group showed a significantly higher rate of severe functional impairment (modified Rankin Scale score >2; 45.5% versus 12.9%, P<0.001) and persistent disability (Δmodified Rankin Scale score ≤0; 53.9% versus 39.8%, P<0.001) at the 3-month follow-up. In multivariate analysis, narrow-band coupling was an independent predictor of higher risk of severe and persistent functional impairment at 3 months (odds ratio, 3.98 [95% CI, 2.34-6.78]; P<0.001; and odds ratio, 1.81 [95% CI, 1.23-2.66]; P<0.001, respectively). The results remained consistent after propensity-score matched analysis with 157 patient pairs (C-statistic=0.770). CONCLUSIONS: SDB assessed by CPC analysis at the early stage of ischemic stroke could predict severe and prolonged functional impairment at 3 months. CPC analysis using Holter monitoring can help predicting functional impairment in acute ischemic stroke.

Cilostazol-based triple versus potent P2Y12 inhibitor-based dual antiplatelet therapy in patients with acute myocardial infarction undergoing percutaneous coronary intervention.

Although potent P2Y12 inhibitor-based dual antiplatelet therapy (DAPT) has replaced clopidogrel-based therapy as the standard treatment in patients with acute myocardial infarction (AMI), there is a concern about the risk of bleeding in East Asian patients. We compared the efficacy and safety of cilostazol-based triple antiplatelet therapy (TAT) with potent P2Y12 inhibitor-based DAPT in Korean patients. A total of 4152 AMI patients who underwent percutaneous coronary intervention (PCI) in the Korea Acute Myocardial Infarction Registry were analyzed retrospectively. Patients were divided into two groups: the TAT group (aspirin + clopidogrel + cilostazol, n = 3161) and the potent DAPT group (aspirin + potent P2Y12 inhibitors [ticagrelor or prasugrel], n = 991). Major clinical outcomes at 30 days and 2 years were compared between the two groups using propensity score matching (PSM) analysis. After PSM (869 pairs), there were no significant differences between the two groups in the incidence of total death, cardiac death, myocardial infarction (MI), target vessel revascularization, stent thrombosis, and stroke at 30 days and 2 years. However, the Thrombolysis in Myocardial Infarction (TIMI) major or minor bleeding rates were significantly lower in the TAT group compared with the potent DAPT group at 2 years (6.4% vs. 3.6%, p = 0.006). In Korean AMI patients undergoing PCI, TAT with cilostazol was associated with lower bleeding than the potent P2Y12 inhibitor-based DAPT without increased ischemic risk. These results could provide a rationale for the use of TAT in East Asian AMI patients.

The Effects of Single Nucleotide Polymorphisms in Korean Patients with Early-onset Atrial Fibrillation after Catheter Ablation.

BACKGROUND: This study evaluated the status of single nucleotide polymorphisms (SNPs) in Korean patients with early-onset (< 40 years old) atrial fibrillation (AF) and their effects on the outcome after catheter ablation. METHODS: A total of 89 patients (35.7 ± 3.7 years, 81 males) with drug-refractory AF (paroxysmal 64.0%) who underwent catheter ablation were included in this study. Sixteen SNPs, including rs13376333, rs10465885, rs10033464, rs2200733, rs17042171, rs6843082, rs7193343, rs2106261, rs17570669, rs853445, rs11708996, rs6800541, rs251253, rs3807989, rs11047543, and rs3825214, were genotyped. Serial 48-hour Holter monitoring was conducted to detect AF recurrences during long-term follow up. RESULTS: Wild-type genotypes of rs11047543 (GG; 26/69 [37.7%] vs. GA; 13/18 [72.2%] vs. AA; 0/0 [0%], P = 0.009) and rs7193343 (CC; 0/7 [0%] vs. CT; 22/40 [55.0%] vs. TT; 18/41 [43.9%], P = 0.025) and the homozygous variant of rs3825214 (AA; 16/31 [51.6%] vs. AG; 22/43 [51.2%] vs. GG; 2/13 [15.4%], P = 0.056) were significantly associated with a lower rate of late recurrence. When the patients were assigned to four groups according to the number of risk alleles (n = 0-3), there were significant differences in recurrence rate (n = 0; 0/3 vs. n = 1; 2/13 [15.4%] vs. n = 2; 24/52 [46.2%] vs. n = 3; 13/17 [76.5%], P = 0.003). When correcting for multiple variables, rs11047543 (hazard ratio [HR], 2.723; 95% confidence interval [CI], 1.358-5.461; P = 0.005) and the number of risk alleles (HR, 2.901; 95% CI, 1.612-5.219; P < 0.001) were significantly associated with recurrence of AF after catheter ablation. CONCLUSION: Polymorphisms on rs7193343 closest to ZFHX3 (16q22), rs3825214 near to TBX5 (12q24), and rs11047543 near to SOX5 (12p12) modulate the risk for AF recurrence after catheter ablation. The number of risk alleles of these 3 SNPs was an independent predictor of recurrence during long-term follow up in Korean patients with early-onset AF.

Chromosome 4q25 variants and biomarkers of myocardial fibrosis in patients with atrial fibrillation.

INTRODUCTION: Little is known about how genetic predisposition and fibrosis relate in atrial fibrillation (AF). Hence, we sought to determine whether the genetic variants and biomarkers for fibrosis enhance prediction of outcomes after catheter ablation. METHODS AND RESULTS: Consecutive patients who underwent catheter ablation of AF (paroxysmal, 158; nonparoxysmal, 137) or supraventricular tachycardia without AF (n = 70) were studied retrospectively. Plasma levels of transforming growth factor ß1 (TGF-ß1), tissue inhibitor of metalloproteinase 1 (TIMP-1), and 4q25 single-nucleotide polymorphisms (SNPs) (rs10033464 and rs220073) were measured. Mean plasma levels of both TGF-ß1 and TIMP-1 were higher in patients with AF than in the control (all P < .001). Plasma levels of TIMP-1 were higher in patients with recurrence compared with those without recurrence (P = .039). Patients with variant alleles of rs10033464 showed increased recurrence after catheter ablation in patients with paroxysmal AF including after adjustment (P = .027). Patients with TIMP-1 < 107 ng/mL and no variant allele (GG) at rs10033464 had lower recurrence rates compared with other groups in those with paroxysmal AF (logrank; P = .007), whereas there was no significant difference among those patients with persistent forms of AF. Inclusion of biomarkers and genotype improved discrimination of AF recurrence in patients with paroxysmal AF (C-statistic .499 vs .600). CONCLUSIONS: The combination of plasma TIMP-1 concentrations less than 107 ng/mL and the absence of a variant allele at rs10033464 was associated with lower recurrence rates in patients with paroxysmal AF. This study suggests that 4q25 SNPs and biomarkers for fibrosis may provide additive value in risk stratification for AF recurrence after catheter ablation.

Comparison between linear and focal ablation of complex fractionated atrial electrograms in patients with non-paroxysmal atrial fibrillation: a prospective randomized trial.

AIMS: Findings regarding efficacy of substrate modification for non-paroxysmal atrial fibrillation (AF) are inconsistent. We prospectively compared clinical outcomes of complex fractionated atrial electrogram (CFAE)-guided focal ablation (CFA) and CFAE-guided linear ablation (CLA) in patients with non-paroxysmal AF. METHODS AND RESULTS: We randomized 150 patients with non-paroxysmal AF into CFA and CLA groups in a 1:1 ratio. Complex fractionated atrial electrogram distribution was evaluated using an automated algorithm of a three-dimensional mapping system. After pulmonary vein isolation (PVI), CFAE-guided ablation was performed in the left atrium and then in the right atrium (RA). When compared with conventional CFA, CLA was performed based on conventional lines, with additional lines. Atrial fibrillation was not induced after PVI alone or with cavotricuspid isthmus ablation in 20.7% of patients. To achieve the endpoint, additional CFAE-guided RA ablation was required in 42.7% and 36.0% of patients undergoing CFA and CLA, respectively (P = 0.403). Atrial fibrillation was terminated during CFAE-guided ablation in 72.9% and 75.0% of patients undergoing CFA and CLA, respectively (P = 0.792). Termination of atrial tachycardia (AT) or non-inducibility of AF/AT was achieved in 61.3% and 68.0% of patients undergoing CFA and CLA, respectively (P = 0.393). The CLA group showed decreased 1-year freedom from AF/AT recurrence (60.0%, CFA vs. 47.3%, CLA; log rank P = 0.085), but no significant difference throughout the follow-up (22.2 ± 21.0 months) (67.1%, CFA vs. 68.9%, CLA; log rank P = 0.298). CONCLUSION: Long-term efficacy of CFAE-guided ablation was unaffected by the ablation technique in patients with non-paroxysmal AF.

Trends in the use of implantable cardioverter-defibrillators for prevention of sudden cardiac arrest: A South Korean nationwide population-based study.

BACKGROUND: The benefits of implantable cardioverter-defibrillators (ICDs) for the prevention of sudden cardiac arrest (SCA) are well established. However, a significant knowledge gap remains regarding current indications and utilization of ICDs in real-world settings in Asia. METHODS: Patients who underwent ICD implantation in South Korea from 2007 to 2015 were identified using the Health Insurance Review and Assessment Service database. We investigated trends in use of ICD for the prevention of SCA. RESULTS: A total of 4649 ICDs were implanted during 9 years. ICDs were implanted in 1448 (31.2%) patients for primary prevention and in 3201 (68.8%) for secondary prevention. The proportion of ICDs for primary prevention increased from 6.1% in 2007 to 41.9% in 2015. Primary prevention was more frequent in older (≥40 years) recipients (34.4% vs. 14.6%, P < .0001). The rates of ICD implantation for primary prevention were highest for nonischemic dilated cardiomyopathy (55.1%) and lowest (9.7%) for inherited primary arrhythmia syndrome (IPAS). CONCLUSION: Our data showed a trend of progressively increasing rates of ICD implantation in Asia, especially for primary prevention of SCA. Primary prevention as an indication for ICD in patients with IPAS remained low.

Long-term clinical outcomes of catheter ablation in patients with atrial fibrillation predisposing to tachycardia-bradycardia syndrome: a long pause predicts implantation of a permanent pacemaker.

BACKGROUND: There is a controversy as to whether catheter ablation should be the first-line therapy for tachycardia-bradycardia syndrome (TBS) in patients with atrial fibrillation (AF). METHODS: We aimed to investigate long-term clinical outcomes of catheter ablation in patients with TBS and AF. Among 145 consecutive patients who underwent catheter ablation of AF with TBS, 121 patients were studied. RESULTS: Among 121 patients, 11 (9.1%) received implantation of a permanent pacemaker during a mean 21 months after ablation. Length of pause on termination of AF was significantly greater in patients who received pacemaker implantation after ablation than those who underwent ablation only (7.9 ± 3.5 vs. 5.1 ± 2.1 s, p < 0.001). Using a multivariate model, a long pause of 6.3 s or longer after termination of AF was associated with the requirement to implant a permanent pacemaker after ablation (HR 1.332, 95% CI 1.115-1.591, p = 0.002). CONCLUSION: This study suggests that, in patients with AF predisposing to TBS, long pause on termination of AF predicts the need to implant a permanent pacemaker after catheter ablation.

Bibliographical Characteristics of North Korean Medical Journals and Articles.

The aim of our work was to analyze the bibliographical characteristics of 9 North Korean medical journals and articles. All journals show only ten pieces of information, such as publication dates and table of contents, and do not provide submission guidelines and journal policy. Most of the journals were published four times a year. Editorials often share government policy. Research articles are very short and compressed. The journals often publish articles on oriental medicine and medical information useful to the public. In conclusion, the journals were published in their own unique style and format, which are far from the global standard.

Atrial Fibrillation: Relationship between Left Atrial Pressure and Left Atrial Appendage Emptying Determined with Velocity-encoded Cardiac MR Imaging.

Purpose To investigate the relationship between left atrial appendage (LAA) blood flow determined with cardiac magnetic resonance (MR) imaging and left atrial pressure (LAP) estimated from invasive catheter measurements in patients with atrial fibrillation (AF). Materials and Methods This retrospective study was approved by the institutional review board, and patients provided written informed consent. Seventy-seven patients with AF (mean age, 57.8 years ± 9.8; range, 31-76 years) underwent cardiac MR imaging and catheter-based measurement of LAP, sequentially. Velocity-encoded (VENC) cardiac MR imaging was performed perpendicular to the ostium of the LAA. The maximum blood flux (in milliliters per second) from the LAA to the left atrium (LA) as determined with VENC MR imaging was defined as LAA emptying. Patients were classified into two groups: those with elevated LAP (peak LAP ≥19 mm Hg) and those with nonelevated LAP (peak LAP <19 mm Hg). Receiver operating characteristic curves were used to determine the cut-off values of LAA emptying in the assessment of the LAP status. Results LAA emptying showed a significantly inverse relationship (P < .01) with the peak LAP. Patients with elevated LAP showed significantly less LAA emptying than did patients with nonelevated LAP (mean, 39.3 mL/sec ± 13.7 vs 61.2 mL/sec ± 20.7, respectively; P < .01). In the assessment of elevated LAP with use of VENC MR imaging in normal sinus rhythm, the LAA emptying cut-off value of 47 mL/sec had a sensitivity of 75.0%, specificity of 87.5%, positive predictive value of 66.6%, and negative predictive value of 91.3%. At multivariate analysis, the odds ratio of low LAA emptying (<47 mL/sec) was independently associated with elevated LAP. Conclusion Evaluation of LAA emptying with use of VENC MR imaging is helpful for assessing the LAP status of patients with AF. © RSNA, 2017.

Long-Term Outcome of Catheter Ablation for Atrial Fibrillation in Patients With Apical Hypertrophic Cardiomyopathy.

INTRODUCTION: Atrial fibrillation (AF) is a common manifestation in cases of hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) for AF in patients with asymmetric septal HCM (SeHCM) is selectively effective and often needs a repeat procedure. Apical HCM (ApHCM) has a better prognosis than SeHCM. However, the outcome of CA for AF in patients with ApHCM is unclear. METHODS AND RESULTS: Eighteen patients with ApHCM (ApHCM group) and 13 SeHCM patients (SeHCM group) underwent CA for AF. Ninety sex-, age-, and AF type-matched non-HCM patients who underwent CA for AF were selected as controls (5 controls for each ApHCM patient). During a median follow-up of 44.7 ± 30.8 months, 50% of the patients remained free from AF/atrial tachycardia (AT) in the ApHCM group. The ApHCM patients displayed enlarged left atrial (LA) diameter (47.1 ± 6.0 mm vs. 42.4 ± 5.5 mm, P = 0.006) and increased E/Ea ratio (13.5 ± 4.4 vs. 9.1 ± 3.1, P < 0.001) as compared to the control group. In contrast, the mean LA diameter and E/Ea ratio of the ApHCM group were not different than those of the SeHCM group. The overall freedom from AF/AT in the ApHCM group was significantly worse than in the control group (log rank P = 0.028), but there was no difference between the ApHCM and SeHCM groups (P = 0.831). High LA diameter index ≥25 mm/m(2) (HR 12.8, 95% CI [1.2-142.1]; P = 0.037) was an independent predictor of AF/AT recurrence among patients with ApHCM. CONCLUSION: Long-term outcome of CA for AF was worse in patients with ApHCM, as compared to controls, but was similar to patients with SeHCM.