Stroke and systemic embolism in patients with atrial fibrillation and heart failure according to heart failure type

Aims

This study aimed to elucidate the risk for stroke and systemic embolism (SE) in patients with atrial fibrillation and heart failure (HF) according to HF type.

Methods and results

A total of 10 780 patients with atrial fibrillation were enrolled in a multicentre prospective registry and divided according to HF type: no‐HF, HF with preserved ejection fraction (EF) (HFpEF), HF with mid‐range EF (HFmrEF), and HF with reduced EF (HFrEF). Each group included 237 age‐matched and sex‐matched patients (age, 69.0 ± 10.3 years; men, 69.6%). The baseline characteristics, cumulative incidence, and hazard ratios for stroke/SE and major bleeding were compared across the groups. Patients with HF accounted for 10.3% of the total population; HFpEF, HFmrEF, and HFrEF represented 43.7%, 23.6%, and 32.7% of the patients with HF, respectively. The CHA₂DS₂‐VASc score was significantly higher in the HFpEF, HFmrEF, and HFrEF groups than in the no‐HF group. The annual stroke/SE incidence rates were 2.8%, 0.7%, 1.1%, and 0.9% in the HFpEF, HFmrEF, HFrEF, and no‐HF groups, respectively. The cumulative incidence of stroke/SE was significantly highest in the HFpEF group at 22.8 ± 10.0 months (P = 0.020). The stroke/SE risk was higher in the HFpEF group than in the HFmrEF and HFrEF groups (hazard ratio, 3.192; 95% confidence interval, 1.039–9.810; P = 0.043). E/e' value was an independent risk factor for stroke/SE. There were no significant differences in the incidence of major bleeding across the groups.

Conclusions

The stroke/SE risk was the highest in the HFpEF group and comparable between the HFmrEF and HFrEF groups.

Comparative occurrence of ischemic stroke with the rhythm versus rate control strategy in a national prospective cohort of atrial fibrillation

BACKGROUND/AIMS

Comparative occurrence of ischemic stroke for rhythm versus rate control strategy in patients with non-valvular atrial fibrillation (NVAF) is still inconclusive. The purpose of this study was to investigate whether the rhythm control strategy is associated with a lower risk of ischemic stroke compared to the rate control strategy in NVAF patients.

METHODS

The CODE-AF registry prospectively enrolled 6,280 consecutive patients who were treated for NVAF at 10 tertiary referral centers in South Korea. Of these, 2,513 NVAF patients (age, 67 ± 10 years; male, 61.8%) were clinically followed up for over 1-year and divided into rate and rhythm control groups.

RESULTS

Those treated with the rhythm control strategy were younger and had less proportions of underlying disease compared to those treated with the rate control strategy. After the propensity matching analysis, those treated with the rhythm control strategy had similar baseline characteristics including the CHA2DS2-VASC score compared to those treated with the rate control strategy. The rate of oral anticoagulation, all bleeding, and hospitalization were also similarly between the two groups. The incidence rate of ischemic stroke in the rhythm control group was significantly lower than in the rate control group (0.7 vs. 6.9 per 1,000 person-years, p = 0.011).

CONCLUSION

The rhythm control strategy demonstrated a beneficial effect to lower the risk of ischemic stroke during a 1-year follow-up compared to the rate control strategy.

Solitary Testicular Myofibroma in a Rabbit

Myofibromas are mesenchymal tumours of myofibroblastic origin that occur in solitary or multicentric forms. Solitary benign myofibromas mainly occur on the head and neck, especially in the subcutaneous region. They rarely occur in visceral organs in humans, but visceral myofibroma has not been reported in animals. We now report a case of testicular myofibroma in a 6-year-old rabbit in which orchiectomy revealed an enlarged testis with a multinodular surface. The cut surface of the testis showed a thick, homogeneous white-yellow mass surrounding the testicular parenchyma. Histopathologically, the mass was composed of collagen and eosinophilic fascicles of spindle cells that were immunopositive for α-smooth muscle actin but not desmin, S-100 or von Willebrand factor. These features distinguished the myofibroma from other spindle cell tumours. To the best of our knowledge, this is the first report of solitary testicular myofibroma in any animal species.

Prognostic value of myocardial injury-related findings on resting electrocardiography for cardiovascular risk in the asymptomatic general population: the 12-year follow-up report from the Ansan-Ansung cohort

Background: We investigated the predictive values of myocardial injury-related findings (MIFs) including ST-T wave abnormalities (STA) and pathologic Q waves (PQ) in electrocardiography for long-term cardiovascular outcomes in an asymptomatic general population.Methods: We observed 8444 subjects without cardiovascular diseases and related symptoms biennially over a 12-year period. Major cardiovascular adverse events (MACEs) were defined as a composite of cardiovascular death, myocardial infarction, coronary artery disease and stroke.Results: MACEs occurred more frequently in subjects with STA (9.1% vs. 5.2%, p < .001) and in those with anterior PQ (11.5% vs. 5.2%, p = .001) than in those without any MIFs, whereas anterolateral/posterior PQ were not associated with a higher incidence of MACEs. Multivariate Cox regression analyses showed that STA and anterior PQ were independently associated with the risk of MACEs. However, survival receiver operating characteristic curve analysis showed that the composite of STA and anterior PQ did not improve the predictive power of the conventional cardiovascular risk estimators when added to the models.Conclusions: The presence of STA or anterior PQ was associated with worse cardiovascular outcomes in the asymptomatic general population. However, the addition of MIFs to the conventional risk estimators was of limited value in the prediction of MACEs.Key MessagesMyocardial injury-related findings including ST-T wave abnormalities and anterior pathologic Q waves in resting electrocardiography predict long-term cardiovascular outcomes in an asymptomatic low-risk population.However, ST-T wave abnormalities and anterior pathologic Q waves add only limited value to conventional cardiovascular risk estimators in the prediction of cardiovascular outcomes.

Cathepsin A regulates pluripotency, proliferation and differentiation in mouse embryonic stem cells

Mouse embryonic stem cells (mESCs) are pluripotent cells that possess the ability to self-renew and differentiate into three germ layers. Owing to these characteristics, mESCs act as important models for stem cell research and are being used in many clinical applications. Among the many cathepsins, cathepsin A (Ctsa), a serine protease, affects the function and properties of stem cells. However, studies on the role of Ctsa in stem cells are limited. Here, we observed a significant increase in Ctsa expression during mESC differentiation at protein levels. Furthermore, we established Ctsa knockdown mESCs. Ctsa knockdown led to Erk1/2 phosphorylation, which in turn inhibited the pluripotency of mESCs and induced G2/M cell cycle arrest to inhibit mESC proliferation. The knockdown also induced abnormal differentiation in mESCs and aberrant expression of differentiation markers. Furthermore, we identified inhibition of teratoma formation in nude mice. Our results suggested that Ctsa affects mESC pluripotency, proliferation, cell cycle and differentiation, and highlighted the potential of Ctsa to act as a core factor that can regulate various mESC properties. SIGNIFICANCE OF THE STUDY: Our results indicate that cathepsin A (Ctsa) affects the properties of mESCs. Inhibition of Ctsa resulted in a decrease in the pluripotency of mouse embryonic stem cells (mESCs). Further, Ctsa suppression resulted in decreased proliferation via cell cycle arrest. Moreover, Ctsa inhibition reduced differentiation abilities and formation of teratoma in mESCs. Our results demonstrated that Ctsa is an important factor controlling mESC abilities.

Effect of physical and psychocognitive function and perceived health status on 12-month adverse cardiac events among implantable cardioverter-defibrillator recipients

BACKGROUND

Post-implant recovery in patients with implantable cardioverter-defibrillators (ICDs) is often compromised because of reduced physical and psycho-cognitive function and poor health perception, leading to short event-free survival.

OBJECTIVES

To examine the effects of psychocognitive function, health perception, and ICD-related factors on 12-month cardiac events among ICD patients.

METHODS

Using a prospective study design, ICD patients underwent baseline assessment and were followed for 12 months to assess cardiac events.

RESULTS

Cardiac events occurred in 14 patients (18.9%) (N = 74: age, 58 years; primary ICDs, 45.9%). Time after ICD implant (odds ratio [OR] = 1.002; p = .028) and executive function (OR = 1.021; p = .027) were significant predictors of 12-month cardiac events, while other physical and psychological indices were not.

CONCLUSIONS

Reduced executive function and longer time after implant predicted the events. Healthcare professionals need to assess executive function and provide treatment and support to improve executive function.

Suppression of cathepsin a inhibits growth, migration, and invasion by inhibiting the p38 MAPK signaling pathway in prostate cancer

Prostate cancer has the highest incidence among men in advanced countries, as well as a high mortality rate. Despite the efforts of numerous researchers to identify a gene-based therapeutic target as an effective treatment of prostate cancer, there is still a need for further research. The cathepsin gene family is known to have a close correlation with various cancer types and is highly expressed across these cancer types. This study aimed at investigating the correlation between the cathepsin A (CTSA) gene and prostate cancer. Our findings indicated a significantly elevated level of CTSA gene expression in the tissues of patients with prostate cancer when compared with normal prostate tissues. Furthermore, the knockdown of the CTSA gene in the representative prostate cancer cell lines PC3 and DU145 led to reduced proliferation and a marked reduction in anchorage-independent colony formation, which was shown to be caused by cell cycle arrest in the S phase. In addition, CTSA gene-knockdown prostate cancer cell lines showed a substantial decrease in migration and invasion, as well as a decrease in the marker genes that promote epithelial mesenchymal transition (EMT). Such phenotypic changes in prostate cancer cell lines through CTSA gene suppression were found to be mainly caused by reduced p38 MAPK protein phosphorylation; i.e. the inactivation of the p38 MAPK cell signaling pathway. Tumorigenesis was also found to be inhibited in CTSA gene-knockdown prostate cancer cell lines when a xenograft assay was carried out using Balb/c nude mice, and the p38 MAPK phosphorylation was inhibited in tumor tissues. Thus, the CTSA gene is presumed to play a key role in human prostate cancer tissues through high-level expression, and the suppression of the CTSA gene leads to the inhibition of prostate cancer cell proliferation, colony formation, and metastasis. The mechanism, by which these effects occur, was demonstrated to be the inactivation of the p38 MAPK signaling pathway.

Dietary iodine, seaweed consumption, and incidence risk of metabolic syndrome among postmenopausal women: a prospective analysis of the Korean Multi-Rural Communities Cohort Study (MRCohort)

PURPOSE

Despite a beneficial role of iodine and seaweed consumption against metabolic syndrome (MetS), which is high in postmenopausal women, few studies investigated such associations in a prospective study. This study aimed to investigate the association of dietary iodine and seaweed consumption with the incidence of MetS and its components in postmenopausal women.

METHODS

A total of 2588 postmenopausal women aged ≥ 40 years were recruited between 2005 and 2011 in the Multi-Rural Communities Cohort (MRCohort). A validated semiquantitative food frequency questionnaire was used to collect dietary intake data. MetS was defined as three of five components [abdominal obesity, elevated blood pressure, glucose, triglyceride, and low-high density lipoprotein cholesterol (HDL-C)] and the incidence of MetS was checked every 2-4 years. The incidence rate ratio (IRR) was estimated using a modified Poisson regression model with a robust error estimator.

RESULTS

During the mean follow-up period (3.4 ± 2.1 years), MetS occurred in 481 participants. The median cumulative average iodine intake was 108.9 µg/day (interquartile range, 60.8-190.2 µg/day). In multivariable analyses, average iodine and seaweed consumption were inversely associated with MetS (IRR = 0.61, 95% CI 0.47-0.78 in the highest quartile of iodine intake, P for trend = 0.0018; IRR = 0.52, 95% CI 0.39-0.69 in the highest quartile of seaweed consumption, P for trend = 0.0004). Among MetS components, blood glucose (> 100 mg/dL), blood pressure (≥ 130/85 mmHg), and lipid profiles (triglyceride, ≥ 150 mg/dL and HDL-C, < 50 mg/dL) were significantly inversely associated with dietary iodine and seaweed consumption, but there was no clear association for waist circumference (≥ 85 cm).

CONCLUSION

Dietary iodine and seaweed consumption may be inversely associated with MetS incidence and its individual abnormalities in postmenopausal women.

Increasing incidence of macular edema in excessive morning blood pressure surge in patients with retinal vein occlusion

Morning blood pressure surge (MBPS) had been known to be associated with hypertensive target organ injury and vascular events. Retinal vein occlusion (RVO) is also known to be related with underlying cardiovascular risk factors. This study investigated the effect of MBPS on patients with RVO. In total, 76 patients with RVO who had undergone systemic cardiovascular examination including a 24-hour ambulatory blood pressure monitoring, carotid artery intima media thickness, and pulse wave velocity were evaluated between January 2015 and February 2019. The MBPS was calculated as follows: mean systolic blood pressure measured over two hours after awakening minus mean systolic blood pressure measured during the one hour that included the lowest sleep blood pressure. Macular edema was significantly more prevalent in the MBPS group compared with the non-MBPS group. After adjusting for confounding factors, multivariate regression analyses revealed that MBPS independently predicted macular edema in patients with RVO [Odds ratio 4.75, 95% confidence interval 1.136–16.6, p = 0.015]. In conclusion, evaluating blood pressure patterns, especially MBPS, using 24-hour ambulatory blood pressure monitoring may be useful for assessing and predicting ophthalmologic outcome and may facilitate better blood pressure control in patients with RVO.

Association between insulin resistance and risk of atrial fibrillation in non-diabetics

AIMS

Previous studies from Western countries have been unable to demonstrate a relationship between insulin resistance and new-onset atrial fibrillation. We aimed to evaluate this relationship in the nondiabetic Asian population.

METHODS

Between 2001-2003, 8175 adults (mean age 51.5 years, 53% women) without both existing atrial fibrillation and diabetes and with insulin resistance measures at baseline were enrolled and were followed by biennial electrocardiograms thereafter until 2014. We constructed multivariable-adjusted Cox proportional hazard models for risk of incident atrial fibrillation.

RESULTS

Over a median follow-up of 12.3 years, 136 participants (1.89/1000 person-years) developed atrial fibrillation. Higher homeostasis model assessment of insulin resistance (HOMA-IR) was independently associated with newly developed atrial fibrillation (hazard ratio 1.61, 95% confidence interval 1.14-2.28). Atrial fibrillation development increased at the HOMA-IR levels approximately between 1-2.5, and then plateaued afterwards (p = 0.031).

CONCLUSION

There is a significant relationship between insulin resistance and atrial fibrillation development independent of other known risk factors, including obesity in a nondiabetic Asian population.

Inhibition of MAGEA2 regulates pluripotency, proliferation, apoptosis, and differentiation in mouse embryonic stem cells

Mouse embryonic stem cells (mESCs) exhibit self-renewal and pluripotency, can differentiate into all three germ layers, and serve as an essential model in stem cell research and for potential clinical application in regenerative medicine. Melanoma-associated antigen A2 (MAGEA2) is not expressed in normal somatic cells but rather in different types of cancer, especially in undifferentiated cells, such as in the testis, differentiating cells, and ESCs. However, the role of MAGEA2 in mESCs remains to be clarified. Accordingly, in this study, we examined the expression and functions of MAGEA2 in mESCs. MAGEA2 messenger RNA (mRNA) expression was decreased during mESCs differentiation. MAGEA2 function was then evaluated in knockdown mESC. MAGEA2 knockdown resulted in decreased pluripotency marker gene expression in mESCs consequent to increased Erk1/2 phosphorylation. Decreased MAGEA2 expression inhibited mESC proliferation via S phase cell cycle arrest with a subsequent decrease in cell cycle-associated genes Cdk1, Cdk2, Cyclin A1, Cyclin D1, and Cdc25a. Apoptotic mESCs markedly increased along with cleaved forms of caspases 3, 6, and 7 and PARP expression, confirming caspase-dependent apoptosis. MAGEA2 knockdown significantly decreased embryoid body size in vitro when cells were differentiated naturally and teratoma size in vivo, concomitant with decreased ectoderm marker gene expression. These findings suggested that MAGEA2 regulates ESC pluripotency, proliferation, cell cycle, apoptosis, and differentiation. The enhanced understanding of the regulatory mechanisms underlying diverse mESC characteristics will facilitate the clinical application of mESCs.

Differences in anticoagulation strategy and outcome in atrial fibrillation patients with chronic kidney disease: a CODE-AF registry study

Purpose

Dose reduction of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in patients with atrial fibrillation (AF) with renal impairment. This study investigated anticoagulation patterns and outcomes in patients with chronic kidney disease (CKD).

Materials and methods

In a prospective observational registry (CODE-AF), 3445 patients with non-valvular AF including 1129 with CKD (estimated glomerular filtration rate ≤ 60 mL min−1 1.73 m−2) were identified between June 1, 2016, and July 3, 2017.

Results

Compared with patients with no-CKD, patients with CKD more frequently had a high stroke risk (94.9% vs. 67.0%, p < 0.001) and higher NOAC usage rate (61.1% vs. 47.8%, p < 0.001). Among 718 patients with renal indication for dose reduction (RIDR), 7.5% were potentially overdosed. Among 2587 patients with no-RIDR, 79% were potentially underdosed. Compared with patients with no-RIDR, the underdose rates of dabigatran (0% vs. 88.6%, p = 0.001) and rivaroxaban (0% vs. 79.5%, p = 0.001) were lower in patients with RIDR. However, the underdose rate of apixaban was not different (62.5% vs. 53.9%, p = 0.089). The overdose rate of dabigatran (7.5% vs. 0%) and rivaroxaban (13.7% vs. 0%) was higher in RIDR than in no-RIDR patients. Stroke/transient ischemic attack was significantly higher in CKD patients (1.4 vs. 0.6 per 100 person-years, p = 0.045). Aspirin significantly increased minor bleeding in CKD patients compared with controls (p = 0.037).

Conclusion

CKD patients might have a high stroke risk and NOAC usage rate. The underdose rate of NOACs decreased in CKD patients, except for apixaban. Aspirin significantly increased minor bleeding in CKD patients.

Changes in the Physical Function and Psychological Distress from Pre-Implant to 1, 6, and 12 Months Post-Implant in Patients Undergoing Implantable Cardioverter Defibrillator Therapy

Recipients of implantable cardioverter-defibrillator (ICD) therapy in Western countries often experience distressful physical and psychological adjustments. Sociocultural influences on post-implant recovery are likely; however, evidence from other ethnic/cultural backgrounds is lacking. This study aimed to examine the changes in physical function and psychological distress (anxiety and depressive symptoms) from pre-implant to one, six, and 12 months post-implant in Korean patients undergoing ICD therapy. A total of 34 patients underwent pre- to post-implant longitudinal assessments of physical and psychological function using mixed modeling procedures. Physical function significantly declined from pre-implant to one month post-implant (B = -10.05, p = 0.004) and then nearly returned to the pre-implant level at six months post-implant (B = 8.34, p = 0.028). This level of improvement continued through 12 months post-implant. In psychological distress, significant improvements were observed from pre-implant to one month (anxiety (B = -1.20, p = 0.020) and in depressive symptoms (B = -1.15, p = 0.037)), which then plateaued without significant changes from one to 12 months. We concluded that physical function recovery occurred six months post-implant, but function remained poor until 12 months post-implant. Psychological distress improved one month post-implant and it was maintained. Clinicians must provide more intensive interventions to improve long-term physical function after ICD therapy.

Characteristics of symptom burden in atrial fibrillation with concomitant heart failure

Background

Symptom burden is an important factor in determining the treatment of atrial fibrillation (AF). AF is frequently accompanied by heart failure (HF). This study investigated the characteristics of AF symptoms with concomitant HF.

Methods

A total of 4885 patients with AF were consecutively enrolled through a prospective observational registry (the Comparison Study of Drugs for Symptom Control and Complication Prevention of Atrial Fibrillation [CODE-AF] registry). Clinically diagnosed HF was divided into three categories (preserved, mid-range, and reduced ejection fraction [EF]). Symptom severity was assessed using the European Heart Rhythm Association (EHRA) classification.

Results

The presence of AF-related symptoms was comparable irrespective of concomitant HF. Patients with HF with reduced EF demonstrated severe (EHRA classes 3 and 4) and atypical symptoms. HF with preserved EF was also associated with atypical symptoms. Female sex and AF type were associated with the presence of symptoms in AF without HF, and non-maintenance of sinus rhythm and increased left atrial pressure (E/e′ ≥ 15) were factors related to the presence of symptoms in AF with HF.

Conclusion

AF with concomitant HF presented with more severe and atypical symptoms than AF without HF. Maintaining the sinus rhythm and reducing the E/e’ ratio are important factors for reducing symptoms in AF with concomitant HF.

A prospective survey of the persistence of warfarin or NOAC in nonvalvular atrial fibrillation: a COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation (CODE-AF)

BACKGROUND/AIMS

Efforts to reduce stroke in patients with atrial fibrillation (AF) have focused on increasing physician adherence to oral anticoagulant (OAC) guidelines; however, the high early discontinuation rate of vitamin K antagonists (VKAs) is a limitation. Although non-VKA OACs (NOACs) are more convenient to administer than warfarin, their lack of monitoring may predispose patients to nonpersistence. We compared the persistence of NOAC and VKA treatment for AF in real-world practice.

METHODS

In a prospective observational registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation [CODE-AF] registry), 7,013 patients with nonvalvular AF (mean age 67.2 ± 10.9 years, women 36.4%) were consecutively enrolled between June 2016 and June 2017 from 10 tertiary hospitals in Korea. This study included 3,381 patients who started OAC 30 days before enrollment (maintenance group) and 572 patients who newly started OAC (new-starter group). The persistence rate of OAC was evaluated.

RESULTS

In the maintenance group, persistence to OAC declined during 6 months, to 88.3% for VKA and 95.5% for NOAC (p < 0.0001). However, the persistence rate was not different among NOACs. In the new-starter group, persistence to OAC declined during 6 months, to 78.9% for VKA and 92.1% for NOAC (p < 0.0001). The persistence rate was lower for rivaroxaban (83.7%) than apixaban (94.6%) and edoxaban (94.1%, p < 0.001). In the new-starter group, diabetes, valve disease, and cancer were related to nonpersistence of OAC.

CONCLUSION

Nonpersistence was significantly lower with NOAC than VKA in both the maintenance and new-starter groups. In only the new-starter group, apixaban or edoxaban showed higher persistence rates than rivaroxaban.

Stroke and Systemic Embolism and Other Adverse Outcomes of Heart Failure With Preserved and Reduced Ejection Fraction in Patients With Atrial Fibrillation (from the COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation [CODE-AF])

It is unknown whether heart failure (HF) with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) carry a similar risk of stroke or systemic embolism (SE) and other outcomes in patients with nonvalvular atrial fibrillation (AF). A prospective, multicenter outpatient registry with echocardiographic data which enrolled 10,589 patients from June 2016 to May 2019 was analyzed. In this registry, 935 (8.8%) patients had HF, and the proportions of patients with HFpEF and HFrEF were 43.2% and 56.8%, respectively. During follow-up over 1.33 years, 11 (2.07 per 100 person-years [PYR]) and 5 (0.76 per 100 PYR) patients had stroke/SE in the HFpEF and HFrEF groups, respectively, whereas 102 patients (0.84 per 100 PYR) had these sequelae in the no-HF group. The HFpEF group had a significantly higher cumulative incidence of stroke/SE (p = 0.004) and risk of stroke/SE (adjusted hazard ratio [HR] 2.23, 95% confidence interval [CI] 1.19 to 4.18) than the no-HF group. The risk of stroke/SE in the HFpEF group compared with that in the no-HF group was consistently increased even in patients on oral anticoagulation therapy (adjusted HR 2.55, 95% CI 1.31 to 4.96). There was a correlation between larger left atrial size and risk of stroke/SE (adjusted HR 1.53, 95% CI 1.03 to 2.29), but not between reduced left ventricular ejection fraction and this risk. In conclusion, these results suggest that strict oral anticoagulation therapy helps reduce the risk of stroke/SE in patients with nonvalvular AF and HFpEF, especially in those with a larger left atrial size.

The Electrical Isolation of the Left Atrial Posterior Wall in Catheter Ablation of Persistent Atrial Fibrillation

OBJECTIVES

This study explored whether complete electrical isolation of the left atrial (LA) posterior wall improves the rhythm outcome of catheter ablation of persistent atrial fibrillation (AF).

BACKGROUND

Although the STAR AF2 (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II) proved no additional benefit of empirical extra-pulmonary vein (PV) LA ablation, the long-term recurrence rate after circumferential PV isolation (CPVI) alone remains high.

METHODS

We randomly assigned 217 patients with persistent AF (83.1% men, age 58.7 ± 10.8 years, 73.3% long-standing persistent AF) to ablation with CPVI alone (CPVI group) or CPVI with a POsterior wall Box Isolation (POBI group). The endpoint of the POBI group was the elimination of the posterior atrial potentials by roof and posterior inferior lines and touch-up focal ablation.

RESULTS

After a mean follow-up of 16.2 ± 8.8 months, the clinical recurrence rate did not significantly differ between the 2 groups (23.8% vs. 26.5%; p = 0.779) in the CPVI and POBI groups. The recurrence rate for atrial tachycardias (16.0% vs. 11.1%; p = 0.913) and cardioversion rates (6.7% vs. 13.7%; p = 0.093) to control clinical recurrences also did not significantly differ between the 2 groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 50.5% and 55.9% in the CPVI and POBI groups, respectively (p = 0.522). No significant difference was found in the major complication rates between the 2 groups, but the total ablation time was significantly longer in the POBI group (4,289 ± 1,837 s vs. 5,365 ± 2,358 s; p < 0.001).

CONCLUSIONS

In patients with persistent AF, an empirical complete POBI did not improve the rhythm outcome of catheter ablation or influence the type of recurrent atrial arrhythmia. (Comparison of Circumferential Pulmonary Vein Isolation Alone Versus Linear Ablation in Addition to Circumferential Pulmonary Vein Isolation for Catheter Ablation in Persistent Atrial Fibrillation: Prospective Randomized Controlled Trial; NCT02721121).

P5298Influence of the changes in body fat on all-cause and cardiovascular mortality in a general population: a report from Ansan-Ansung cohort in the Korean genome environment study

Background

Paradoxical beneficial effects of obesity on all-cause and cardiovascular mortality have been reported in multiple cohort studies based on patients with cardiovascular disease as well as general populations. However, the association between the presence of obesity at baseline and the better survival rates could not be directly interpreted into the beneficial effect of gain in obesity or fatness on the mortality, which makes it difficult to provide any recommendation for the management of obesity. Therefore, we investigated the influence of the changes in body fat on all-cause and cardiovascular mortality in a general population.

Methods

A population-based cohort study has been conducted for 12 years (from 2001 to 2012). A total of 5,259 subjects in whom body compositions using a bio-impedance method were measured at least 2 times during the observational period were included. The causes of death was identified from the nation-wide database in KOSTAT. I20-I82 and R99 in the International Classification of Disease-10 codes were defined as a cardiovascular death. The subjects were evenly divided into 3 groups by the percentages of the changes in body fat (Δ%BF; decreased [Δ%BF <0.0%] vs. increased [Δ%BF 0.0–13.7%] vs. highly increased [Δ%BF ≥13.7%]). Inverse probability of treatment weighting was applied to balance the covariate differences among the groups.

Results

The age was 51.2±8.5 years and 51.6% was male. Median observation duration was 163 (the interquartile range: 157–168) months. The all-cause death and cardiovascular death occurred most frequently in the decreased Δ%BF group and least frequent in the highly increased Δ%BF group in both unweighted and weighted cohort. Multivariate Cox proportional hazard models showed that the risk of all-cause death was lower in the increased and highly increased Δ%BF groups (hazard ratio [HR] 0.61 [0.47–0.80] and 0.24 [0.17–0.34], respectively) and the risk of cardiovascular death was lower in the highly increased Δ%BF group (HR 0.20 [0.08–0.48]), compared to those in the decreased Δ%BF group after adjustment for all covariates including physical activities and the changes in muscle mass. The risk of all-cause death and cardiovascular death linearly decreased with increasing Δ%BF (HR 0.72 [0.67–0.77] and 0.70 [0.60–0.82], respectively).

Conclusion

The increase in body fat is associated with a lower risk of all-cause death and cardiovascular death in a middle-age general population, independently with physical activities and the changes in muscle mass.

P5665The independent effect of insulin resistance on incidence of atrial fibrillation in non-diabetics

Purpose

Patients with diabetes mellitus have an elevated risk of atrial fibrillation (AF). However, whether insulin resistance may elevate risk of AF incidence in non-diabetic is inconsistent. The aim of our study was to verify the association between insulin resistance and incidence of AF in non-diabetics.

Methods

We evaluated population-based cohorts embedded in the Korean Genome Epidemiology Study. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin resistance (HOMA-IR). Baseline data including HOMA-IR and electrocardiography (ECG) were obtained at 2001. Subsequent biennial ECG was performed for identification of AF until 2016.

Results

Among the 8220 participants (46.8% male; median age 49 years), 25 participants had AF (0.3%) at baseline and 101 participants developed AF (1.2%) during follow up of 12 years. In multivariate Cox regression analysis, high HOMA-IR (≥1.4) was significantly associated with incident AF compared with low HOMA-IR (<1.40) (adjusted hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.3–3.0). In subgroup analysis, these association was consistent regardless of obesity (BMI<25; adjust HR 1.8, 95% CI 1.1–3.0, BMI≥25; adjust HR 2.3, 95% CI 1.3–4.0)

Subgroup analysis

Conclusion

Based on prospective cohort study, insulin resistance (HOMA-IR) was associated with AF independently of obesity in non-diabetics.

Sertoli Cell Tumor (SCT) in a Captive Black Bear (Ursus americanus)

A black bear of 29-year-old (Ursus americanus) died unexpectedly in captivity without any gross lesions or clinical signs. We identified a firm, lobulated, yellowish tan, and well-circumscribed mass embedded inside the testicular tissue at the time of necropsy. The tumor sections exhibited soft necrotic and hemorrhagic areas beneath its capsule. Histologically, the tumor comprised Sertoli cells arranged in tubules and solid sheets supported by prominent fibrous connective tissues. The Sertoli cells were positive for vimentin and ER-β expression, whereas it showed negative staining for inhibin-α, cytokeratin 19, and S-100. To the best of our knowledge, this is the rare case report of testicular Sertoli cell tumor in black bear.

Suppression of PRPF4 regulates pluripotency, proliferation, and differentiation in mouse embryonic stem cells

Mouse embryonic stem cells (mESCs) are characterized by their self-renewal and pluripotency and are capable of differentiating into all three germ layers. For this reason, mESCs are considered a very important model for stem cell research and clinical applications in regenerative medicine. The pre-mRNA processing factor 4 (PRPF4) gene is known to have a major effect on pre-mRNA splicing and is also known to affect tissue differentiation during development. In this study, we investigated the effects of PRPF4 knockdown on mESCs. First, we allowed mESCs to differentiate naturally and observed a significant decrease in PRPF4 expression during the differentiation process. We then artificially induced the knockdown of PRPF4 in mESCs and observed the changes in the phenotype. When PRPF4 was knocked down, various genes involved in mESC pluripotency showed significantly decreased expression. In addition, mESC proliferation increased abnormally, accompanied by a significant increase in mESC colony size. The formation of mESC embryoid bodies and teratomas was delayed following PRPF4 knockdown. Based on these results, the reduced expression of PRPF4 affects mESC phenotypes and is a key factor in mESC. SIGNIFICANCE OF THE STUDY: Our results indicate that PRPF4 affects the properties of mESCs. Suppression of PRPF4 resulted in a decrease in pluripotency of mESC and promoted proliferation. In addition, suppression of PRPF4 also resulted in decreased apoptosis. Moreover, the inhibition of PRPF4 reduced the ability to differentiate and formation of teratoma in mESC. Our results demonstrated that PRPF4 is a key factor of controlling mESC abilities.

Hepatic Cellular Distribution of Silica Nanoparticles by Surface Energy Modification

The cellular distribution of silica nanoparticles (NPs) in the liver is not well understood. Targeting specific cells is one of the most important issues in NP-based drug delivery to improve delivery efficacy. In this context, the present study analyzed the relative cellular distribution pattern of silica NPs in the liver, and the effect of surface energy modification on NPs. Hydrophobic NP surface modification enhanced NP delivery to the liver and liver sinusoid fFendothelial cells (LSECs). Conversely, hydrophilic NP surface modification was commensurate with targeting hepatic stellate cells (HSCs) rather than other cell types. There was no notable difference in NP delivery to Kupffer cells or hepatocytes, regardless of hydrophilic or hydrophobic NP surface modification, suggesting that both the targeting of hepatocytes and evasion of phagocytosis by Kupffer cells are not associated with surface energy modification of silica NPs. This study provides useful information to target specific cell types using silica NPs, as well as to understand the relationship between NP surface energy and the NP distribution pattern in the liver, thereby helping to establish strategies for cell targeting using various NPs.

Independent effect of physical activity and resting heart rate on the incidence of atrial fibrillation in the general population

While physical activity (PA) may influence resting heart rate (RHR), and a low RHR may be a risk factor for atrial fibrillation (AF), controversy exists regarding the association between PA and development of AF. Using data from a Korean, prospective population cohort, we investigated the independent effect of PA and RHR on the incidence of AF in the general population. A total of 8,811 participants aged 40-69 years were analyzed. Total PA assessed based on questionnaires was divided into quartiles, with the lowest to the highest being Q1, Q2, Q3, and Q4. During a median follow-up of 139 months, AF developed in 167 participants (1.9%). Q3 of total PA was associated with a significantly lower risk of AF than Q1 even after adjusting for RHR as a covariate, but Q4 was not. The risk of AF was higher in participants with RHR < 60 bpm than in those with RHR 70-85 bpm, and the significance persisted after adjusting for PA as a covariate. This study showed that a moderate amount of total PA was associated with a lower risk of incident AF independent of RHR and that low RHR was an independent risk factor for AF in the general Korean population.

The relationship between decreased pulmonary function and atrial fibrillation in general population: Findings from Ansung-Ansan cohort of the Korean Genome and Epidemiology Study

BACKGROUND

Decreased pulmonary function is a possible risk factor for atrial fibrillation (AF). However, data on this relationship in Asian populations are scant. The aim of this study was to evaluate the relationship between decreased pulmonary function and the incidence of AF in a prospective cohort of Koreans aged 40-69 years.

METHODS

We assessed AF in 9631 Korean people enrolled in the community-based cohort who were followed for up to 12 years. AF at baseline was identified by electrocardiography (ECG) performed during the baseline visit and/or the self-reported history of physician-determined diagnosis made before the baseline visit. Similarly, AF newly developed after the baseline visit was also identified by biennially performed ECGs and/or the self-reported history of physician-determined diagnosis that occurred between each biennial visit. If AF was identified by both ECGs and the history in the same subject, the earlier identification date was considered the time of AF development.

RESULTS

The median age was 50 (interquartile range, 44-60) years, and 4633 (48.1%) were male. The prevalence of AF at baseline was significantly higher in subjects with lower quartiles of forced expiratory volume in second (FEV₁)% predicted (1.2% in the lowest quartile versus 0.3% in the highest quartile; p<0.001). After adjustment for cardiovascular risk factors, FEV₁% predicted and forced vital capacity (FVC)% predicted were independent risk factors for AF at baseline. Over a median follow-up period of 138 (interquartile range, 70-141) months, AF was newly documented in 162 subjects (1.7%). The lowest quartiles of FEV₁% predicted (adjusted hazard ratio, 1.59; 95% confidence interval, 1.02-2.50) was associated with a higher risk of incident AF than the highest quartiles.

CONCLUSIONS

In this large community-based cohort study with a long-term follow-up, decreased pulmonary function was found to be an independent risk factor for AF in the general Korean population.