A Mendelian randomization study to assess the genetic liability of gastroesophageal reflux disease for cardiovascular diseases and risk factors.

Observational studies have reported that gastroesophageal reflux disease (GERD) is a risk factor for cardiovascular diseases (CVD); however, the causal inferences between them remain unknown. We conducted a Mendelian randomization (MR) study to estimate the causal associations between GERD and 10 CVD outcomes, as well as 14 cardiovascular risk factors. We used summary statistics from genome-wide association studies for GERD and the FinnGen consortium for CVD. We further investigated whether GERD correlated with cardiovascular risk factors and performed multivariable MR and mediation analyses to estimate the mediating effects of these risk factors on GERD-CVD progression. Sensitivity analyses and replication analyses were also performed. Our results indicated that GERD was positively associated with seven CVD outcomes with odds ratios of 1.26 [95% confidence interval (CI), 1.15, 1.37] for coronary artery disease, 1.41 (95% CI, 1.28, 1.57) for myocardial infarction, 1.34 (95% CI, 1.19, 1.51) for atrial fibrillation, 1.34 (95% CI, 1.21, 1.50) for heart failure, 1.30 (95% CI, 1.18, 1.43) for any stroke, 1.19 (95% CI, 1.06, 1.34) for ischemic stroke and 1.29 (95% CI, 1.16, 1.44) for venous thromboembolism. Furthermore, GERD was associated with nine cardiovascular risk factors and major depressive disorder demonstrated significant mediation effects on the causal pathway linking GERD and any stroke. This study demonstrates that GERD is associated with seven CVD outcomes and nine cardiovascular risk factors. Importantly, GERD treatment may help prevent common CVD events.

Resveratrol protects against doxorubicin-induced cardiotoxicity by attenuating ferroptosis through modulating the MAPK signaling pathway.

Doxorubicin (Dox) is a widely used antitumor agent with dose-dependent and cumulative cardiotoxic effects. Resveratrol (Res) is a natural non-flavonoid polyphenol that can potentially provide cardiovascular benefits. We aimed to estimate the protective effect of Res on Dox-induced cardiotoxicity (DIC) and explore whether it was related to attenuating ferroptosis. We established DIC models in C57BL/6 J mice, H9C2 cardiomyoblasts, and neonatal rat cardiomyocytes (NRCMs). We further treated H9C2 cells with RSL3, a ferroptosis agonist, to investigate whether Res exerted protective effects through inhibiting ferroptosis. Ferrostatin-1 (Fer-1) was applied to suppress ferroptosis. Dox treatment caused cardiac dysfunction and resulted in apparent ferroptotic damage in cardiac tissue, involving increased iron accumulation, glutathione depletion, increased expression of ferroptosis-related proteins, and decreased expression of glutathione peroxidase 4, which were alleviated by Fer-1 and Res administration. These findings were also confirmed in Dox-treated H9C2 cells and NRCMs, with Fer-1 and Res effectively attenuating Dox-induced cytotoxicity and ferroptosis. Furthermore, Res protected H9C2 cells from RSL3-induced ferroptotic cell death, and the protective effect was similar to that of Fer-1. Both Dox and RSL3 treatment increased the phosphorylation levels of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinases; however, these changes were hindered by Res. This study demonstrates that Res effectively alleviates DIC by suppressing ferroptosis possibly through modulating the MAPK signaling pathway. Our results highlight that targeting ferroptosis can be a potential cardioprotective strategy for DIC.

Genetically predicted visceral adipose tissue and risk of nine non-tumour gastrointestinal diseases: evidence from a Mendelian randomization study.

BACKGROUND: Numerous studies have linked visceral adipose tissue (VAT) to gastrointestinal diseases. However, it remains unclear whether these associations reflect causal relationships. METHODS: We used a two-sample Mendelian randomization (MR) approach to elucidate the causal effect of VAT on nine non-tumour gastrointestinal diseases. The inverse-variance weighted method was used to perform the MR analyses. Complementary and multivariable MR analyses were performed to confirm the results. RESULTS: Genetically predicted higher VAT was associated with an increased risk of gastro-oesophageal reflux disease (GORD) (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.09-1.34; P = 3.06 × 10-4), duodenal ulcer (DU) (OR, 1.40; 95% CI, 1.10-1.77; P = 0.005), cholelithiasis (OR, 1.75; 95% CI, 1.53-2.00; P = 1.14 × 10-16), and non-alcoholic fatty liver disease (NAFLD) (OR, 2.68; 95% CI, 1.87-3.82; P = 6.26 × 10-8). There were suggestive associations between VAT and gastric ulcer (GU) (OR, 1.22; 95% CI, 1.01-1.48; P = 0.035) and acute pancreatitis (AP) (OR, 1.26; 95% CI, 1.05-1.52; P = 0.013). However, there was little evidence to support the associations between VAT and inflammatory bowel disease, irritable bowel syndrome, or chronic pancreatitis. The associations with GORD, GU, and NAFLD remained in the multivariable MR analyses with adjustment for body mass index (BMI). CONCLUSIONS: This study provided evidence in support of causal associations between VAT and GORD, GU, DU, cholelithiasis, AP, and NAFLD. Moreover, the associations between GORD, GU, and NAFLD were independent of the effect of BMI.

CCL24/CCR3 axis plays a central role in angiotensin II-induced heart failure by stimulating M2 macrophage polarization and fibroblast activation.

AIMS: We aimed to investigate the effect and mechanism of pleiotropic chemokine CCL24 in heart failure. METHODS AND RESULTS: Compared with normal donators, the expression of CCL24 and number of cardiac M2 macrophages in heart were higher in heart failure patients, the same as plasma CCL24. Treatment with CCL24 antibody hindered Ang II (1500 ng/kg/min)-induced cardiac adverse remodeling through preventing cardiac hypertrophy and fibrosis. RNA-seq showed that CCL24/CCR3 axis was involved in immune and inflammatory responses. Single-cell analysis of cytometry by time of flight (CyTOF) revealed that CCL24 antibody decreased the M2 macrophage and monocyte polarization during Ang II stimulation. Immunofluorescence co-localization analysis confirmed the expression of CCR3 in macrophage and fibroblasts. Then, in vitro experiments confirmed that CCL24/CCR3 axis was also involved in cardiac primary fibroblast activation through its G protein-coupled receptor function. CONCLUSION: CCL24/CCR3 axis plays a crucial part in cardiac remodeling by stimulating M2 macrophage polarization and cardiac fibroblast activation. Cardiac M2 macrophages, CCL24 and circulation CCL24 increased in heart failure patients. Treatment with CCL24 Ab hindered Ang II induced cardiac structural dysfunction and electrical remodeling. In CCL24 Ab group RNA-seq found that it was related to immune responses and hypertrophic cardiomyopathy, CytoF revealed M2 macrophages and monocytes decreased obviously. In vitro,CCL24 promoted activation and migration of cardiac fibroblast.

Arrhythmogenesis of surgical atrial incisions and lesions in Maze procedure: insights from high-resolution mapping of atrial tachycardias.

BACKGROUND: Atrial tachycardias (ATs) frequently develop after a surgical Maze procedure. We aimed to elucidate the electrophysiologic mechanisms and their arrhythmogenic substrates of these ATs. METHODS AND RESULTS: We retrospectively reviewed 20 patients (14 females, mean age of 55.5 ± 8.6 years) with post-Maze ATs who underwent high-resolution mapping at three institutions. The slow conduction areas, reentry circuits, voltage signals, complex electrograms, and their correlation with the surgical incisions and lesions placed in the surgical Maze procedures were analyzed. Thirty-six ATs with a mean cycle length of 260.0 ± 67.6 ms were mapped in these patients. Among them, 22 (61.1%) were anatomical macro-reentrant ATs (AMAT), 12 (33.3%) non-AMATs (localized ATs), and 2 (5.6%) focal ATs, respectively. Epicardial conduction bridges were observed in 6/20 (30.0%) patients and 7/36 (19.4%) ATs. Different arrhythmogenic substrates were identified in these ATs, including slow conduction regions within the previous lesion areas or between the incisions and anatomical structures, the prolonged activation pathways caused by the short lesions connecting the tricuspid annulus, and the circuits around the long incisions and/or lesions. CONCLUSIONS: Reentry is the main mechanism of the post-Maze ATs. The pro-arrhythmic substrates are most likely caused by surgical incisions and lesions. The slow conduction regions and the protected channels yielded from these areas are the major arrhythmogenic factors.

Sacubitril/Valsartan Can Reduce Atrial Fibrillation Recurrence After Catheter Ablation in Patients with Persistent Atrial Fibrillation.

PURPOSE: This study compared the effectiveness of sacubitril/valsartan (SV) vs. valsartan (V) for treating persistent atrial fibrillation (AF) after radio-frequency catheter ablation (RFCA). METHODS: Patients with persistent AF who received RFCA were randomly assigned to the SV or V treatment group with the intervention lasting for 12 months. The primary outcome included any atrial arrhythmia episode lasting ≥ 30 s after a 3-month blanking period. The secondary outcome included any atrial arrhythmia episode lasting ≥ 24 h or requiring cardioversion after a 3-month blanking period. The H2FPEF score was used to assess the possibility of patients suffering from heart failure with preserved ejection fraction. RESULTS: A total of 143 patients with persistent AF who received RFCA were randomized for the study, with 5 patients failing to follow-up. Among them, 29 (42%) out of 69 patients receiving V and 15 (21.7%) out of 69 patients receiving SV reached the primary endpoint (P < 0.001). A total of 26 (37.7%) out of 69 patients receiving V and 7 (10.1%) out of 69 patients receiving SV reached the secondary endpoint (P < 0.001). A decrease in the H2FPEF score after a 1-year follow-up seemed to be related to the recurrence of AF (OR, 0.065; 95% CI: 0.018-0.238, P < 0.001). CONCLUSIONS: SV can decrease AF recurrence after catheter ablation in patients with persistent AF at the 1-year follow-up. The mechanism for this process may be related to the reduction in the H2FPEF score in patients with preserved ejection fraction heart failure.

Recurrent pacemaker-mediated arrhythmia with a right bundle branch block pattern in a patient with a cardiac resynchronization therapy device.

Under certain conditions, cardiovascular implantable electronic devices can be directly involved in initiating and sustaining pacemaker-mediated arrhythmias (PMA), of which repetitive reentrant ventriculoatrial synchrony (RRVAS) is the most well-known and common type. RRVAS, also known as pacemaker-mediated tachycardia, was commonly secondary to atrioventricular (AV) dissociation and subsequent ventriculoatrial (VA) conduction. RRVAS in a biventricular system is rare due to its less predisposition to the appearance of AV dissociation and subsequent VA conduction, but urgent in its adverse impact on cardiac resynchronization therapy (CRT), which may predispose to exacerbated heart failure. We present a rare case of recurrent PMA manifested as a right bundle branch block pattern in a patient with a CRT device. Notably, most episodes of PMA were triggered by a premature atrial contraction accompanied by the appearance of VA conduction with no prolongation of AV delay. In this study, we have demonstrated the impact of the appearance of VA conduction due to the loss of capture of right ventricular lead and its potential risk for inducing RRVAS in a CRT device.

Spinal Cord Stimulation Attenuates Neural Remodeling, Inflammation, and Fibrosis After Myocardial Infarction.

OBJECTIVES: Spinal cord stimulation (SCS) is an established neuromodulation method that regulates the cardiac autonomic system. However, the biological mechanisms of the therapeutic effects of SCS after myocardial infarction (MI) remain unclear. MATERIALS AND METHODS: Twenty-five rabbits were divided into five groups: SCS-MI (voltage: 0.5 v; pulse width: 0.2 ms; 50 Hz; ten minutes on and 30 minutes off; two weeks; n = 5), MI (n = 5), sham SCS-MI (voltage: 0 v; two weeks; n = 5), sham MI (n = 5), and blank control (n = 5) groups. MI was induced by permanent left anterior descending artery ligation. SCS-MI and sham SCS-MI rabbits received the corresponding interventions 24 hours after MI. Autonomic remodeling was evaluated using enzyme-linked immunosorbent assay and immunohistochemistry. Inflammation and myocardial fibrosis were assessed using immunohistochemistry, quantitative polymerase chain reaction, hematoxylin and eosin staining, Masson staining, and Western blot. RESULTS: SCS improved the abnormal systemic autonomic activity. Cardiac norepinephrine decreased after MI (p < 0.01) and did not improve with SCS. Cardiac acetylcholine increased with SCS compared with the MI group (p < 0.05). However, no difference was observed between the MI and blank control groups. Growth-associated protein 43 (p < 0.001) and tyrosine hydroxylase (p < 0.001) increased whereas choline acetyltransferase (p < 0.05) decreased in the MI group compared with the blank control group. These changes were attenuated with SCS. SCS inhibited inflammation, decreased the ratio of phosphorylated-Erk to Erk (p < 0.001), and increased the ratio of phosphorylated-STAT3 to STAT3 (p < 0.001) compared with the MI group. Myocardial fibrosis was also attenuated by SCS. CONCLUSIONS: SCS improved abnormal autonomic activity after MI, leading to reduced inflammation, reactivation of STAT3, and inhibition of Erk. Additionally, SCS attenuated myocardial fibrosis. Our results warrant future studies of biological mechanisms of the therapeutic effects of SCS after MI.

Thymoquinone ameliorates pressure overload-induced cardiac hypertrophy by activating the AMPK signalling pathway.

Prolonged pathological myocardial hypertrophy leads to end-stage heart failure. Thymoquinone (TQ), a bioactive component extracted from Nigella sativa seeds, is extensively used in ethnomedicine to treat a broad spectrum of disorders. However, it remains unclear whether TQ protects the heart from pathological hypertrophy. This study was conducted to examine the potential utility of TQ for treatment of pathological cardiac hypertrophy and if so, to elucidate the underlying mechanisms. Male C57BL/6J mice underwent either transverse aortic constriction (TAC) or sham operation, followed by TQ treatment for six consecutive weeks. In vitro experiments consisted of neonatal rat cardiomyocytes (NRCMs) that were exposed to phenylephrine (PE) stimulation to induce cardiomyocyte hypertrophy. In this study, we observed that systemic administration of TQ preserved cardiac contractile function, and alleviated cardiac hypertrophy, fibrosis and oxidative stress in TAC-challenged mice. The in vitro experiments showed that TQ treatment attenuated the PE-induced hypertrophic response in NRCMs. Mechanistical experiments showed that supplementation of TQ induced reactivation of the AMP-activated protein kinase (AMPK) with concomitant inhibition of ERK 1/2, p38 and JNK1/2 MAPK cascades. Furthermore, we demonstrated that compound C, an AMPK inhibitor, abolished the protective effects of TQ in in vivo and in vitro experiments. Altogether, our study disclosed that TQ provides protection against myocardial hypertrophy in an AMPK-dependent manner and identified it as a promising agent for the treatment of myocardial hypertrophy.

Matr3 reshapes m6A modification complex to alleviate macrophage inflammation during atherosclerosis.

Atherosclerosis, characterized as the chronic inflammation of the arterial wall, is one of the leading causes of coronary artery disease (CAD), and macrophages are found to play essential roles in the initiation and progression of inflammation in atherosclerosis. N6-methyladenosine (m6A) modification, as the most abundant epi-transcriptomic modification in mRNA, is found to mediate the atherogenic inflammatory cascades in vascular endothelium. The detailed molecular mechanism of m6A methylation regulating inflammatory response during atherosclerosis is still not fully known. In this study, we find oxidized low-density lipoprotein (oxLDL) stimulation increases methyltransferases Mettl3 and Mettl14 expressions in macrophages, whereas the total m6A modification level in macrophages decreases under oxLDL stimulation. Matrin-3 (Matr3), an RNA binding protein, is identified to play a suppressive role on oxLDL-mediated macrophage inflammatory responses through inhibiting activation of pro-inflammatory signaling, mitogen-activated protein kinase (Mapk) by m6A-mediated mRNA decay via regulating the formation of Mettl3-Mettl14 complex. Moreover, we find that Matr3 expression decreases in the oxLDL-stimulated macrophages, and the peripheral blood-derived monocytes from patients with CAD, and overexpression of Matr3 significantly alleviates atherosclerosis development in vivo. Our study for the first time clarifies the role of Matr3 on macrophage inflammatory responses during atherosclerotic development, and supplies deep understanding on the relationship of m6A modification and inflammatory responses in atherosclerosis.

A sudden change in pacing rate: Normal or malfunction?

A woman with a dual-chamber pacemaker was examined for recurrent chest discomfort and palpitations at our hospital. The Holter monitor test recorded recurrent episodes of a sudden increase in pacing rate from 60 to 105 bpm, which corresponded to the symptoms. Orthodromic pacemaker-mediated arrhythmia (OPMA), caused by ventricular lead dislodgement and atrial far-field sensing, caused the recurrent episodes of a sudden change in pacing rate. The occurrence of OPMA may represent a rare but noteworthy pacemaker problem. To our knowledge, our study reports the first case of PMA that only occurs, and is maintained, in the DDI mode.

Catheter ablation of premature ventricular contractions originating from periprosthetic aortic valve regions.

BACKGROUND: Little is known about the ablation outcomes of premature ventricular contractions (PVCs) that originate from the periprosthetic aortic valve (PPAV) regions of patients with aortic valve replacement (AVR). METHODS AND RESULTS: Our study had 11 patients who underwent catheter ablation for PVCs arising from the PPAV regions (bioprosthetic aortic valve, n = 5; mechanical aortic valve, n = 6). The PVC characteristics, procedure characteristics, and efficacy of ablation were compared with the control group (n = 33). At baseline, the PPAV group had a lower left ventricular ejection fraction (mean [SD], 41% [12%] vs. 51% [8%]; p = .002). The rate of acute ablation success was 90.9% in the PPAV group. Ablation sites were identified above the left coronary cusp (LCC) and right coronary cusp commissure (LRCC) in one PVC, below the prosthetic valve in eight PVCs (four below LCC and four below LRCC), and within the distal coronary sinus in two PVCs. The mean procedure time, fluoroscopy time, and radiation in the PPAV group were all significantly greater than those in the control group (all p < .05). However, the number of radiofrequency ablation energy deliveries was not different. The PPAV group had a long-term success rate compared with the control group (72.7% vs. 87.9%, p = .48) and an increase of left ventricular ejection fraction from 43% to 49% after successful PVC ablation at follow-up (p < .001). Echocardiography showed no significant change in valve regurgitation after ablation. No new atrioventricular block occurred. CONCLUSION: PVCs arising from PPAV regions can be successfully ablated in patients with prior AVR, without damaging the prosthetic aortic valve and atrioventricular conduction.

High-Normal Thyroid Function and Recurrence of Atrial Fibrillation after Catheter Ablation: A Prospective Observational Study.

BACKGROUND: Thyroid function is increasingly recognized as an important modifiable factor for atrial fibrillation (AF); however, it is unclear if the changes in thyroid hormones, even within the normal range, are associated with AF recurrence after catheter ablation. METHODS: Consecutive paroxysmal AF patients who underwent catheter ablation were enrolled. Patients with abnormal thyroid hormones or previous thyroid illnesses were excluded. Patients were followed for 12 months or until they presented with the first episode of atrial tachyarrhythmia after a blanking period. RESULTS: The study included 448 patients with a mean age of 61 (14) years, and 46% were women. After a 1-year follow-up, 104 (23.2%) patients experienced atrial tachyarrhythmia recurrences after an ablation procedure. Recurrence was significantly different among quartile groups of thyroid function, with highest FT4 and FT3 levels associated with the greatest risk of recurrence (p < 0.001 and p = 0.024, respectively). FT4 and FT3 levels were independent predictors of atrial tachyarrhythmia recurrence (hazard ratio 1.07 per 1 pmol/L increase in FT4, 95% confidence interval [CI] 1.01-1.15, p = 0.036 and 1.31 per 1 pmol/L increase in FT3, 95% CI 1.01-1.71, p = 0.032). CONCLUSIONS: High-normal FT3 and FT4 levels are associated with AF recurrence after catheter ablation in this Chinese population. Attention to thyroid hormones could be valuable to assist in the management of AF.

No causal association between plasma homocysteine levels and atrial fibrillation: A Mendelian randomization study.

BACKGROUND AND AIMS: Although several studies have shown an association between plasma homocysteine (Hcy) levels and atrial fibrillation (AF), the causality remains unclear. We undertook a Mendelian randomization (MR) study to investigate the causal association between Hcy and AF. METHODS AND RESULTS: Single-nucleotide polymorphisms (SNPs) which genome-wide significantly associated with plasma Hcy levels were obtained from a genome-wide meta-analysis (N = 44 147). MR analyses including the random-effect inverse variance-weighted (IVW) meta-analysis, weighted median analysis, and MR-Egger regression were used to estimate the associations between the selected SNPs and AF based on a meta-analysis of genome-wide association study for AF (N = 588 190). The MR analyses revealed no causal role of genetically elevated plasma Hcy levels with AF risk (random-effect IVW, odds ratio per 1 SD increase in Hcy levels = 0.972, 95% confidence interval = 0.919 to 1.027, P = 0.308). The results were consistent with the weighted median method, MR-Egger and the analysis after excluding the pleiotropic SNPs. No heterogeneity and directional pleiotropy were observed in sensitivity analyses. CONCLUSION: The findings suggested that plasma Hcy levels were not causally associated with AF.

Gene polymorphisms of insulin secretion signaling pathway associated with clopidogrel resistance in Han Chinese population.

BACKGROUND: Due to the loss of responsiveness to insulin, diabetes mellitus (DM) patients develop increased platelet reactivity and reduced response to antiplatelet agents. Nevertheless, the relationship between the single-nucleotide polymorphisms (SNP) of the signal pathway gene of insulin secretion and the effect of clopidogrel is elusive. METHODS: Blood samples were collected from patients administered with dual-antiplatelet therapy (clopidogrel, 75 mg, once daily and aspirin, 100 mg, once daily) after 5 days and completed test within 4 h. The VerifyNow P2Y12 assay was used to measure the platelet functions, and the results were expressed as a P2Y12 reaction unit (PRU). Notably, the selected SNPs were analyzed to demonstrate the functionality of genetic variants. RESULTS: Analysis of the study population showed that old age, lower plasma albumin (ALB) level, higher creatinine (CREA) level, higher uric acid (UA) level, lower platelet (PLT) count, and lower plateletcrit (PCT) potentially increased the risk of clopidogrel resistance. In a single-nucleotide polymorphism rs6056209 of the PCLB1 gene, the AG genotype was a risk factor for clopidogrel resistance (p < 0.05, OR = 1.574). Similarly, the CC and AG genotype in GNAS rs7121 and CCKAR rs1800857 were protective factors (p < 0.05, OR = 0.094; p <0.05, OR = 0.491). TT was a protective factor in rs10814274 of the CREB3 gene (p < 0.05, OR = 0.444). In the RAPGEF4 gene polymorphism rs17746510, TG was the protective genotype, and the TT genotype was a risk factor for clopidogrel resistance. GCG rs5645 was confirmed; there was a relationship between genotypes containing A or G and clopidogrel resistance. CONCLUSION: Single-nucleotide polymorphisms of insulin secretion signaling pathway genes trigger clopidogrel resistance.

The Association Between Ambient Air Pollution and Atrial Fibrillation.

Atrial fibrillation (AF) is the most common cardiac arrhythmia; it has been known to increase the risk of stroke and heart failure. The association between air pollutants and AF has remained to be controversial. Thus, in this study, we sought to undertake a systematic review and meta-analysis in order to assess the short- and long-term effects of ambient air pollution on AF.We searched PubMed, Web of Science, Embase, and Ovid for all related studies up to October 2019. We used the random-effects model to estimate the excess risk percentage (ER%) and confidence intervals (CI) for particulate matter with diameter ≤ 2.5 (PM2.5) and ≤ 10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO). Results were further analyzed by subgroups according to location, age, outcome, and gender.In total, 18 studies were included in our meta-analysis: 5 evaluated for long-term effects, 12 for short-term effects, and 1 for both long- and short-term effects. For the short term, ER per 10 µg/m3 increase of pollutants was 1.8% (0%-3.7%) for PM2.5 and 1.1% (-0.2%-2.4%) for PM10; per 10 parts per billion (ppb) increment of gaseous pollutions was 3.2% (0.6%-5.8%) for NO2, 2.9% (0.3%-5.7%) for SO2, 0.5% (-3.4%-4.7%) for O3, and 2.0% (-1.3%-5.4%) for CO per 1000 ppb change. The subgroup analysis showed the short-term effect was significantly different by region, gender, outcome, and age. Meanwhile, in the long term, except for O3, a statistically significant association was noted between AF incidence and all pollutants.Our meta-analysis suggests that short-term exposure to part of pollutants (PM2.5, SO2, and NO2) increases AF attack. Further, long-term exposure to air pollution can significantly contribute to the incidence of AF in a healthy population.

Distinct origins and functions of cardiac orthotopic macrophages.

Macrophages are one cell type in the innate immune system. Recent studies involving macrophages have overturned the conventional concept that circulating bone marrow-derived blood mononuclear cells in the adult body continuously replace macrophages residing in the tissues. Investigations using refined technologies have suggested that embryonic hematopoiesis can result in the differentiation into macrophage subgroups in some tissues. In adulthood, these macrophages are self-sustaining via in situ proliferation, with little contribution of circulating bone marrow-derived blood mononuclear cells. Macrophages are integral component of the heart, accounting for 8% of the non-cardiac cells. The use of innovative molecular techniques in paradigm shifting researches has revealed the complexity of cardiac macrophages, including their heterogeneity and ontological diversity. Resident cardiac macrophages modulate the physiological and pathophysiological processes of the cardiovascular system, with distinct and crucial roles in healthy and injured hearts. Their functions include sensing of pathogens, antigen presentation, digesting cell debris, regulating inflammatory responses, generating distinct cytokines, and secreting some regulatory factors. More recent studies have revealed further functions of cardiac macrophages. This review focuses on macrophages within the cardiovascular system. We discuss evidence that has changed our collective view of cardiac macrophage subgroups, and improved our understanding of the different phenotypes, cell surface markers, heterogeneities, origins, developments, and the dynamic and separate roles of these cardiac macrophage subgroups in the steady state and injured hearts. This review may provide novel insights concerning the pathophysiology of cardiac-resident macrophages in cardiovascular diseases and innovative therapeutic strategies that could include the modulation of the role of macrophages in cardiovascular injuries.

The Effect of Renin-Angiotensin System Inhibitors on the Recurrence of Atrial Fibrillation After Catheter Ablation.

Atrial fibrillation (AF) is the most common sustained arrhythmia. Renin-angiotensin system (RAS) inhibitors were reported to modify the arrhythmia substrate and reverse atrial remodeling. However, the role of RAS inhibitors on AF recurrence after catheter ablation remains much more controversial. In this study, a meta-analysis was performed to explore the effect of RAS inhibitors on AF recurrence after catheter ablation.We searched PubMed, Cochrane Library, EMBASE, and Web of Science for all articles published up to July 2019 on the effect of RAS inhibitors on AF recurrence rate after ablation. We used the random-effects model to estimate the odds ratios (ORs) and confidence intervals (CI). The I2 statistic was used to evaluate statistical heterogeneity. A two-tailed P value of <0.05 was considered statistically significant. Results were further analyzed by subgroup according to the type of study design.We included 13 studies, including 3661 patients with AF, in this analysis, of which 4 were randomized controlled trials (RCTs) and the others were cohort studies. Overall, treatment with RAS inhibitors showed a significant reduction of AF recurrence after catheter ablation (OR, 0.61; 95% CI, 0.45-0.82). Additionally, both the RCT (OR, 0.35; 95% CI, 0.24-0.49) and non-RCT (OR, 0.76; 95% CI, 0.57-1.00) groups demonstrated that RAS inhibitors could reduce the AF recurrence rate after catheter ablation in the subgroup analysis.Our meta-analysis suggests that RAS inhibitors had significant benefit in reducing the recurrence rate of AF after catheter ablation.

[Clinical practice guidelines for hereditary cardiomyopathy].

Cardiomyopathies are a group of heterogeneous diseases which can be caused by various factors (often genetic) and can lead to heart failure, arrhythmia and sudden death. Primary cardiomyopathies includes hereditary hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, mitochondrial cardiomyopathy, mixed (hereditary and acquired) dilated cardiomyopathy and restrictive cardiomyopathy, left ventricular densification insufficiency, and other unclassified cardiomyopathies. With the help of genomic technology, common mutations in the population have been identified. In vivo and in vitro study of such mutations has provided insight into the pathogenesis and treatment of these diseases. The compilation of this guideline is based on the consensus of basic and clinical research and guidelines from other countries, and has summarized the phenotype, diagnosis, treatment and consultation of various types of genetic cardiomyopathies with an aim to standardize the clinical management of patients.

U-Shaped Relationship Between Left Atrium Size on Echocardiography and 1-Year Recurrence of Atrial Fibrillation After Radiofrequency Catheter Ablation　- Prognostic Value Study.

BACKGROUND: The larger the left atrium anteroposterior dimension (LAD) and left atrium volume (LAV), the stronger the association with recurrent atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). Patients with a smaller left atrium (LA) size, however, also have increased AF recurrence.Methods and Results:In 521 patients, routine 48-h Holter electrocardiogram and echocardiography were obtained at each outpatient visit every 3 months for 12 months. On multivariate analysis, AF type, LAD, and LAV calculated using the ellipsoid model/body surface area (LAVe/BSA) were independent predictors of AF recurrence. Patients were divided into 7 groups at 0.4-cm increments of LAD: ≤3 cm, LAD≤3 cm, 3.05.0 cm. Compared with the 3.4-3.8-cm group, the adjusted HR were 3.88 (95% CI: 2.02-7.46, P<0.001), 1.03 (95% CI: 0.50-2.12, P=0.939), 0.96 (95% CI: 0.52-1.77, P=0.901), 1.36 (95% CI: 0.72-2.57, P=0.347), 3.04 (95% CI: 1.67-5.53, P<0.001), and 4.07 (95% CI: 1.93-8.60, P<0.001), respectively. Similarly, we divided LAVe/BSA into 8 groups and also observed a U-shaped curve for AF recurrence. CONCLUSIONS: Both larger and smaller LAD and LAVe/BSA were associated with a higher risk of AF recurrence 1 year after RFCA. The association of LA size and AF recurrence after RFCA is represented by a U-shaped curve.