Nine-Year Trends in Prevention of Thromboembolic Complications in Elderly Patients with Atrial Fibrillation Treated with NOACs

BACKGROUND

Atrial fibrillation (AF) is the most common disease in elderly patients and thromboembolic complication prophylaxis significantly improves the prognosis in these patients. The study assessed the frequency of individual non-vitamin K antagonist oral anticoagulant (NOAC) use among patients ≥75 years and attempted to identify factors predisposing to their prescription.

METHODS

The data of patients with non-valvular AF hospitalized in the reference cardiology center between 2011 and 2019 were analyzed.

RESULTS

Out of 1443 analyzed patients, 329 (22.8%) received apixaban, 618 (42.8%) dabigatran, and 496 (34.4%) rivaroxaban. The entire population mean age was 82.3 ± 5 years, and 57.9% were females. Independent predictors of apixaban use were age, and bleeding history. Hospitalization for the implantation/reimplantation of a cardiac implantable electronic device (CIED) reduced the chance of apixaban use. Hypertension was a predictor of dabigatran prescription. The chance of using dabigatran decreased with age. Hypertension and bleeding history decreased the chance of rivaroxaban application.

CONCLUSIONS

In hospitalized AF patients ≥75 years, dabigatran was the most frequently used NOAC. Age, comorbidities and bleeding risk determined the selection of individual NOACs.

More obvious association between short-term ambient nitrogen dioxide and atrial fibrillation outpatient visits in cool seasons: A hospital-based study in northwestern China

Atrial fibrillation (AF) is the most common sustained heart rhythm disorder associated with high mortality and morbidity. Limited studies have been conducted to assess the relationship between short-term exposure to ambient air pollution and AF attacks. This study aimed to explore the association between short-term ambient nitrogen dioxide (NO₂) exposure and outpatient visits for AF in Xi'an, China. Data on daily AF outpatient visits and air pollutants from 2013 to 2019 (2555 days) were obtained. A time-series approach using over-dispersed Poisson generalized additive model (GAM) was employed, and stratified analyses were performed to investigate the potential modifying effects by season, age, and gender. A total of 8307 outpatient visits for AF were recorded. Increased levels of NO₂ were associated with increased AF outpatient visits, and the most significant effect estimates were observed at lag 03: A 10 μg/m³ increase of NO₂ at lag 03 was related to an elevation of 5.59% (95% CI: 2.67%, 8.51%) in daily outpatient visits for AF. Stratified analyses showed that there were no gender and age difference in the effect of NO₂, while more obvious association was observed in cool seasons (October to March) than in warm seasons (April to September). In summary, short-term ambient NO₂ exposure can be positively associated with daily outpatient visits for AF, especially in cool seasons. This work provided novel data that the association between air pollutants and AF can vary by seasons, further supporting that the prevention of cardiovascular health effects should be strengthened in winter.

Clinical outcomes of gastrointestinal bleeding management during anticoagulation therapy

Background

Acute gastrointestinal (GI) bleeding is not an uncommon complication of oral anticoagulation (OAC) therapy that requires medication cessation. However, drug cessation may cause fatal stroke or systemic embolization in patients at high thromboembolic risk. Here we sought to find an appropriate anticoagulation cessation strategy in cases of GI bleeding during OAC therapy.

Methods

This single-center retrospective cohort analysis was performed between 2010 and 2018. Patients were enrolled if the following three consecutive conditions were met: 1) electrocardiography electrocardiography-proven atrial fibrillation; 2) OAC therapy; and 3) GI bleeding. We divided the drug cessation strategy into the continuation and discontinuation groups. During 1-year follow-up, the rates of major thromboembolic and rebleeding events were calculated.

Results

One hundred and forty-six patients (continuation [n = 54] vs. discontinuation [n = 92] group) were enrolled. Patients in the discontinuation group were more likely to be older (69.8 ± 9.0 yrs vs. 74.9 ± 8.9 yrs, p = 0.001), while patients in the continuation group were more likely to have undergone cardiac valve surgery (51.9% vs. 20.7%, p<0.001). The presence of a mechanical mitral valve was a determinant of continuation strategy (38.9% vs. 7.5%, p<0.001). However, the mean CHA₂DS₂-VASc (3.4±1.3 vs. 4.1±1.6, p = 0.010) and Glasgow-Blatchford (8.0±2.4 vs. 8.9±2.5, p = 0.037) scores were higher in the discontinuation group.

Two major embolic strokes occurred in each group (3.7% vs. 2.2%, p = 0.585). Four of 54 (7.4%) and five of 92 (5.4%) patients had rebleeding events during follow-up (p = 0.632). One embolic event in the continuation group and one rebleeding event in the discontinuation group were fatal. The Glasgow-Blatchford score was a predictor of 1-year rebleeding events (odds ratio [OR], 1.36; 95% confidence interval [CI], 0.68–2.20; p = 0.028). The high CHA₂DS₂-VASc score showed a strong trend (OR, 1.71; 95% CI, 0.92–3.20; p = 0.089) in 1-year thromboembolic events.

Conclusion

No single risk factor or drug cessation strategy was attributed to adverse clinical events after GI bleeding. The risk of future thrombotic or rebleeding events should be individualized and controlled for based on a pre-existing stratification system.

Practical "1-2-3-4-Day" Rule for Starting Direct Oral Anticoagulants After Ischemic Stroke With Atrial Fibrillation: Combined Hospital-Based Cohort Study

BACKGROUND

The "1-3-6-12-day rule" for starting direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation after acute ischemic stroke or transient ischemic attack recommends timings that may be later than used in clinical practice. We investigated more practical optimal timing of DOAC initiation according to stroke severity.

METHODS

The combined data of prospective registries in Japan, Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-nonvalvular atrial fibrillation (September 2011 to March 2014) and RELAXED (February 2014 to April 2016) were used. Patients were divided into transient ischemic attack and 3 stroke subgroups by the National Institutes of Health Stroke Scale score: mild (0-7), moderate (8-15), and severe (≥16). The early treatment group was defined as patients starting DOACs earlier than the median initiation day in each subgroup. Outcomes included a composite of recurrent stroke or systemic embolism, ischemic stroke, and severe bleeding within 90 days. Six European prospective registries were used for validation.

RESULTS

In the 1797 derivation cohort patients, DOACs were started at median 2 days after transient ischemic attack and 3, 4, and 5 days after mild, moderate, and severe strokes, respectively. Stroke or systemic embolism was less common in Early Group (n=785)-initiating DOACS within 1, 2, 3, and 4 days, respectively-than Late Group (n=1012) (1.9% versus 3.9%; adjusted hazard ratio, 0.50 [95% CI, 0.27-0.89]), as was ischemic stroke (1.7% versus 3.2%, 0.54 [0.27-0.999]). Major bleeding was similarly common in the 2 groups (0.8% versus 1.0%). On validation, both ischemic stroke (2.4% versus 2.2%) and intracranial hemorrhage (0.2% versus 0.6%) were similarly common in Early (n=547) and Late (n=1483) Groups defined using derivation data.

CONCLUSIONS

In Japanese and European populations, early DOAC initiation within 1, 2, 3, or 4 days according to stroke severity seemed to be feasible to decrease the risk of recurrent stroke or systemic embolism and no increase in major bleeding. These findings support ongoing randomized trials to better establish the optimal timing of DOAC initiation.

Chronic kidney disease and atrial fibrillation: A dangerous combination

Background

Chronic kidney disease (CKD) and atrial fibrillation (AF) are both risk factors for bleeding, stroke and mortality. The aim of our study was to investigate the interaction between CKD and atrial fibrillation and outcomes.

Methods

We included 12,394 subjects referred to the University Medical Center Utrecht (the Netherlands) from September 1996 to February 2018 for an out-patient visit (Utrecht Cardiovascular Cohort Second Manifestation of Arterial disease cohort). Hazard ratios (HRs) with 95% confidence intervals (CIs) for bleeding, ischemic stroke or mortality were calculated with Cox proportional hazard analyses. Presence of interaction between AF and CKD was examined by calculating the relative excess risk due to interaction (RERI), the attributable proportion (AP) due to interaction and the synergy index (S).

Results

Of the 12,394 patients, 699 patients had AF, 2,752 patients had CKD and 325 patients had both AF and CKD. Patients with both CKD and AF had a 3.0-fold (95% CI 2.0–4.4) increased risk for bleeding, a 4.2-fold (95% CI 3.0–6.0) increased ischemic stroke risk and a 2.2-fold (95% CI 1.9–2.6) increased mortality risk after adjustment as compared with subjects without atrial fibrillation and CKD. We did not find interaction between AF and CKD for bleeding and mortality. However, we found interaction between AF and CKD for ischemic stroke risk (RERI 1.88 (95% CI 0.31–3.46), AP 0.45 (95% CI 0.17–0.72) and S 2.40 (95% CI 1.08–5.32)).

Conclusion

AF and CKD are both associated with bleeding, ischemic stroke and mortality. There is a positive interaction between AF and CKD for ischemic stroke risk, but not for bleeding or mortality.

Early initiation of rivaroxaban after reperfusion therapy for stroke patients with nonvalvular atrial fibrillation

Background

The optimal timing of initiating oral anticoagulants after reperfusion therapy for ischemic stroke is unknown. Factors related to early initiation of rivaroxaban and differences in clinical outcomes of stroke patients with nonvalvular atrial fibrillation (NVAF) who underwent reperfusion therapy was investigated.

Methods

From data of 1,333 NVAF patients with ischemic stroke or transient ischemic attack (TIA) in a prospective multicenter study, patients who started rivaroxaban after intravenous thrombolysis and/or mechanical thrombectomy were included. The clinical outcomes included the composite of ischemic events (recurrent ischemic stroke, TIA, or systemic embolism) and major bleeding at 3 months.

Results

Among the 424 patients, the median time from index stroke to starting rivaroxaban was 3.2 days. On multivariable logistic regression analysis, infarct size (odds ratio [OR], 0.99; 95%CI, 0.99–1.00) was inversely and successful reperfusion (OR, 2.13; 95%CI, 1.24–3.72) was positively associated with initiation of rivaroxaban within 72 hours. 205 patients were assigned to the early group (< 72 hours) and 219 patients (≥ 72 hours) to the late group. Multivariable Cox regression models showed comparable hazard ratios between the two groups at 3 months for ischemic events (hazard ratio [HR], 0.18; 95%CI, 0.03–1.32) and major bleeding (HR, 1.80; 95%CI, 0.24–13.54).

Conclusions

Infarct size and results of reperfusion therapy were associated with the timing of starting rivaroxaban. There were no significant differences in the rates of ischemic events and major bleeding between patients after reperfusion therapy who started rivaroxaban < 72 hours and ≥ 72 hours after the index stroke.

Clinical trial registration

Unique identifier: NCT02129920; URL: https://www.clinicaltrials.gov.

Determinants of Atrial Fibrillation Development among Patients undergoing Ibrutinib Therapy

Objective: Within the last decade, the use of ibrutinib, a first-generation, non-selective, irreversible Burton's tyrosine kinase inhibitor for the treatment of hematological malignancies has proven highly effective in improving patient outcomes.Background: Ibrutinib has been associated with an increase in atrial fibrillation (AF). The predisposing factors are thought to be pre-existing cardiovascular risk factors, but these have not been directly evaluated.Methods: We conducted a nested case-control study, recruiting consecutive ibrutinib treated subjects to evaluate cardiovascular risk factors associated with the development of AF in patients diagnosed with hematological B-cell malignancies.Results: Of the 189 patients treated with ibrutinib and without AF at baseline, 54 (29%) developed AF. Cardiovascular risk factors associated with AF development were, older age, prior hypertension (HTN), history of heart failure (HF) and congenital heart disease. A patient with HF at baseline had a 1, 2, 6, and 12 month cumulative hazard of AF of 40%, 48%, 64%, and 71%, respectively. Patients with prior HTN without HF at baseline had a 1, 2, 6, and 12 month cumulative hazard of AF of 5%, 10%, 23%, and 31%, respectively while on ibrutinib therapy.Conclusions: The relationship between ibrutinib, cardiovascular comorbidities, and AF is through pre-existing cardiovascular disease. An individualized, multidisciplinary approach involving cardiologists should be considered when initiating ibrutinib, particularly when there is a history of HTN, HF or congenital heart disease. In such patients, there should be close cardiovascular monitoring and prompt intervention when AF develops to improve patient outcomes.

Hip fractures risks in edoxaban versus warfarin users: A propensity score-matched population-based cohort study with competing risk analyses

OBJECTIVE

The three direct oral anticoagulants (DOAC), rivaroxaban, apixaban and dabigatran have been associated with lower risks of fractures compared to warfarin. However, no large scale studies have explored the associations with the newest DOAC, edoxaban, with fracture risk. The present study aims to elucidate the effects of edoxaban on the risk of hip fracture amongst elderly patients by comparing the incidence of new onset hip fracture between edoxaban and warfarin users in a Chinese population.

METHODS

This was a retrospective population-based cohort study of patients with edoxaban or warfarin use between January 1st, 2016 and December 31st, 2019 in Hong Kong, China. Patients with less than one-month exposure, medication switching between warfarin and edoxaban, those who died within 30 days after drug exposure, prior human immunodeficiency virus infection, age <50 years old, and those with prior hip fractures were excluded. Propensity score matching (1:2) between edoxaban and warfarin users using the nearest neighbour method was performed based on demographics, prior comorbidities, and use of different medications. The study outcomes were new onset hip fractures, medically attended falls and all-cause mortality.

RESULTS

A total of 5014 patients including 579 edoxaban users and 4435 warfarin users (median age: 70 years old [interquartile range (IQR): 62-79], 56.66% males) with a median follow-up of 637.5 (IQR: 320-1073) days were included. In the matched cohort, edoxaban users had significantly lower rates of new onset hip fractures, medically attended falls and all-cause mortality. The protective value of edoxaban use against new onset hip fracture (hazard ratio [HR]: 0.13, 95% confidence interval [CI]: [0.03-0.54], p = 0.0051), medically attended falls (HR: 0.47, [0.29-0.75], p = 0.0018) and all-cause mortality (HR: 0.61, [0.42-0.87], p = 0.0059) in comparison to warfarin use persisted after matching. The significant relationship between edoxaban use and lower fracture risk was preserved in all sensitivity analyses using different approaches using the propensity score.

CONCLUSIONS

Edoxaban use is associated with lower risks of new onset hip fractures, medically attended falls and mortality risks compared to warfarin after propensity score matching.

The Rate of Clinical Outcomes in Atrial Fibrillation according to Antithrombotic Strategy: The COOL-AF Registry

Background

Ischemic stroke/transient ischemic attack (TIA), major bleeding, and death are common outcomes in atrial fibrillation (AF) patients, so appropriate antithrombotic therapy is crucial. The objective of this study was to investigate the rate of ischemic stroke/TIA, major bleeding, and death compared among AF patients who received oral anticoagulant (OAC) alone, antiplatelet alone, or OAC plus antiplatelet.

Methods

Prospective data from the COOL-AF Registry (Thailand's largest multicenter nationwide AF registry) were analyzed. Clinical, laboratory, and medication data were collected at baseline and during follow-up. Clinical outcomes, including ischemic stroke/TIA, major bleeding, and death, were collected.

Results

There were 3,148 patients included. Mean age was 68.1 ± 10.8 years and 1,826 (57.7%) were male. AF was paroxysmal in 998 (31.7%), persistent in 603 (19.2%), and permanent in 1,547 (49.1%). The mean follow-up duration was 25.7 ± 10.6 months. The median rates of ischemic stroke/TIA, major bleeding, and death were 1.49 (1.21-1.81), 2.29 (1.94-2.68), and 3.89 (3.43-4.40) per 100 person-years. Antiplatelet alone, OAC plus antiplatelet, and OAC alone were used in 582 (18.5%), 308 (9.8%), and 2,258 (71.7%) patients, respectively. Antiplatelet alone significantly increased the risk of ischemic stroke/TIA and death compared to OAC alone. OAC plus antiplatelet significantly increased the risk of death compared to OAC alone.

Conclusions

Antiplatelet was used in 890 (28.3%) AF, of whom 582 (18.5%) received antiplatelet alone, and 308 (9.8%) received antiplatelet and OAC. OAC plus antiplatelet significantly increased the risk of death without additional stroke prevention benefit. Antiplatelet alone should not be used in patients with AF.

Inhibition of ferroptosis reduces susceptibility to frequent excessive alcohol consumption-induced atrial fibrillation

Both long-term and short-term alcohol consumption can cause internal homeostasis imbalance, and they have been proved to be related to the initiation and development of atrial fibrillation (AF). Ferroptosis is an iron-dependent form of non-apoptotic oxidative death which also regulate the cell death homeostasis, but whether it involves in AF induced by alcohol consumption remains unclear. Here, we report a study on the effect of ferroptosis on susceptibility to AF at different alcohol consumption frequencies. We divided the mice into single or frequent excessive alcohol consumption group which given sterile drinking water or alcohol by gavage at different frequencies. Meanwhile, the experimental group was given an intraperitoneal injection of ferroptosis inhibitor (Fer-1) before alcohol drinking. It was found that once exposure to 5 g/kg/d frequent excessive alcohol consumption, compared with the single excessive alcohol consumption group, the mice serum non-heme iron concentration, accumulation of iron and oxidative stress reaction in atrial tissues were increased, while the body weight, heart weight and heart weight to tibia length (HW/TL) ratio were decreased. In addition, the inducibility rate of AF increased, while RR interval, effective refractory periods (ERPs) and 90 % action potential duration (APD90) shortened, as well as QTc interval prolonged. Furthermore, the protein and mRNA expression levels of GPx4, FTL, FTH1, Kv1.5, Kv2.1, Kv4.3, Cav1.2, Serca2α, p-PLB were down-regulated, while PTGS2 was up-regulated. Most of the changes can be partially or completely reversed by Fer-1. These results suggest that frequent excessive alcohol consumption activates ferroptosis and increases the inducibility rate of AF. Nevertheless, inhibition of ferroptosis can balance iron overload disorders and reduce the generation of reactive oxygen species (ROS), eventually decrease the susceptibility to AF. Our results highlight the importance of guidance and warnings for unhealthy alcohol-abuse lifestyle.

Ambient nitrogen dioxide is associated with emergency hospital visits for atrial fibrillation: a population-based case-crossover study in Reykjavik, Iceland

BACKGROUND

In Iceland air quality is generally good; however, previous studies indicate that there is an association between air pollution in Reykjavik and adverse health effects as measured by dispensing of medications, mortality, and increase in health care utilisation. The aim was to study the association between traffic-related ambient air pollution in the Reykjavik capital area and emergency hospital visits for heart diseases and particularly atrial fibrillation and flutter (AF).

METHODS

A multivariate time-stratified case-crossover design was used to study the association. Cases were those patients aged 18 years or older living in the Reykjavik capital area during the study period, 2006-2017, who made emergency visits to Landspitali University Hospital for heart diseases. In this population-based study, the primary discharge diagnoses were registered according to International Classification of Diseases, 10th edition (ICD-10). The pollutants studied were NO₂, PM₁₀, PM_2.5, and SO_2, with adjustment for H₂S, temperature, and relative humidity. The 24-h mean of pollutants was used with lag 0 to lag 4.

RESULTS

During the study period 9536 cases of AF were identified. The 24-h mean NO₂ was 20.7 μg/m³. Each 10 μg/m³ increase in NO₂ was associated with increased risk of heart diseases (ICD-10: I20-I25, I44-I50), odds ratio (OR) 1.023 (95% CI 1.012-1.034) at lag 0. Each 10 μg/m³ increase in NO₂ was associated with an increased risk of AF (ICD-10: I48) on the same day, OR 1.030 (95% CI: 1.011-1.049). Females were at higher risk for AF, OR 1.051 (95% CI 1.019-1.083) at lag 0, and OR 1.050 (95% CI 1.019-1.083) at lag 1. Females aged younger than 71 years had even higher risk for AF, OR 1.077 (95% CI: 1.025-1.131) at lag 0. Significant associations were found for other pollutants and emergency hospital visits, but they were weaker and did not show a discernable pattern.

CONCLUSIONS

Short-term increase in NO₂ concentrations was associated with heart diseases, more precisely with AF. The associations were stronger among females, and among females at younger age. This is the first study in Iceland that finds an association between air pollution and cardiac arrhythmias, so the results should be interpreted with caution.

Activation of PKG-CREB-KLF15 by melatonin attenuates Angiotensin II-induced vulnerability to atrial fibrillation via enhancing branched-chain amino acids catabolism

Mitochondrial reactive oxygen species (ROS) damage and atrial remodeling serve as the crucial substrates for the genesis of atrial fibrillation (AF). Branched-chain amino acids (BCAAs) catabolic defect plays critical roles in multiple cardiovascular diseases. However, the alteration of atrial BCAA catabolism and its role in AF remain largely unknown. This study aimed to explore the role of BCAA catabolism in the pathogenesis of AF and to further evaluate the therapeutic effect of melatonin with a focus on protein kinase G (PKG)-cAMP response element binding protein (CREB)-Krüppel-like factor 15 (KLF15) signaling. We found that angiotensin II-treated atria exhibited significantly elevated BCAA level, reduced BCAA catabolic enzyme activity, increased AF vulnerability, aggravated atrial electrical and structural remodeling, and enhanced mitochondrial ROS damage. These deleterious effects were attenuated by melatonin co-administration while exacerbated by BCAA oral supplementation. Melatonin treatment ameliorated BCAA-induced atrial damage and reversed BCAA-induced down-regulation of atrial PKGIα expression, CREB phosphorylation as well as KLF15 expression. However, inhibition of PKG partly abolished melatonin-induced beneficial actions. In summary, these data demonstrated that atrial BCAA catabolic defect contributed to the pathogenesis of AF by aggravating tissue fibrosis and mitochondrial ROS damage. Melatonin treatment ameliorated Ang II-induced atrial structural as well as electrical remodeling by activating PKG-CREB-KLF15. The present study reveals additional mechanisms contributing to AF genesis and highlights the opportunity of a novel therapy for AF by targeting BCAA catabolism. Melatonin may serve as a potential therapeutic agent for AF intervention.

Effect of Long-Term Marine ɷ-3 Fatty Acids Supplementation on the Risk of Atrial Fibrillation in Randomized Controlled Trials of Cardiovascular Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

Some, but not all, large-scale randomized controlled trials (RCTs) investigating the effects of marine ɷ-3 fatty acids supplementation on cardiovascular outcomes have reported increased risks of atrial fibrillation (AF). The potential reasons for disparate findings may be dose-related.

METHODS

The MEDLINE and Embase databases were searched for articles and abstracts published between January 1, 2012, and December 31, 2020, in addition to a meta-analysis of large cardiovascular RCTs published in 2019. RCTs of cardiovascular outcomes of marine ɷ-3 fatty acids that reported results for AF, either as a prespecified outcome, an adverse event, or a cause for hospitalization, with a minimum sample size of 500 patients and a median follow-up of at least 1 year were included. RCTs specifically examining shorter-term effects of ɷ-3 fatty acids on recurrent AF in patients with established AF or postoperative AF were not included. The hazard ratio (HR) for the reported AF outcomes within each trial was meta-analyzed using random effects model with Knapp-Hartung adjustment and evaluated a dose-response relationship with a meta-regression model.

RESULTS

Of 4049 screened records, 7 studies were included in the meta-analysis. Of those, 5 were already detected in a previous meta-analysis of cardiovascular RCTs. Among the 81 210 patients from 7 trials, 58 939 (72.6%) were enrolled in trials testing ≤1 g/d and 22 271 (27.4%) in trials testing >1 g/d of ɷ-3 fatty acids. The mean age was 65 years, and 31 842 (39%) were female. The weighted average follow-up was 4.9 years. In meta-analysis, the use of marine ɷ-3 fatty acid supplements was associated with an increased risk of AF (n=2905; HR, 1.25 [95% CI, 1.07-1.46]; P=0.013). In analyses stratified by dose, the HR was greater in the trials testing >1 g/d (HR, 1.49 [95% CI, 1.04-2.15]; P=0.042) compared with those testing ≤1 g/d (HR, 1.12 [95% CI, 1.03-1.22]; P=0.024; P for interaction <0.001). In meta-regression, the HR for AF increased per 1 g higher dosage of ɷ-3 fatty acids dosage (HR, 1.11 [95% CI, 1.06-1.15]; P=0.001).

CONCLUSIONS

In RCTs examining cardiovascular outcomes, marine ɷ-3 supplementation was associated with an increased risk of AF. The risk appeared to be greater in trials testing >1 g/d.

Association between magnesium in drinking water and atrial fibrillation incidence: a nationwide population-based cohort study, 2002-2015

BACKGROUND

Atrial fibrillation (AF) is a common heart rhythm disorder and a risk factor of adverse cardiovascular diseases. Established causes do not fully explain the risk of AF and unexplained risk factors might be related to the environment, e.g. magnesium in drinking water. Low magnesium levels in drinking water might be associated with higher risk of cardiovascular diseases including AF. With detailed individual data from nationwide registries and long-term magnesium exposure time series, we had a unique opportunity to investigate the association between magnesium in drinking water and AF.

OBJECTIVE

We evaluated the association between magnesium concentration in drinking water and AF risk.

METHODS

A nationwide register-based cohort study (2002-2015) was used including individuals aged ≥30 years. Addresses were linked with water supply areas (n = 2418) to obtain time-varying drinking water magnesium exposure at each address. Five exposure groups were defined based on a 5-year rolling time-weighted average magnesium concentration. AF incidence rate ratios (IRRs) between exposure groups were calculated using a Poisson regression of incidence rates, adjusted for sex, age, and socioeconomic position. Robustness of results was investigated with different exposure definitions.

RESULTS

The study included 4,264,809 individuals (44,731,694 person-years) whereof 222,998 experienced an incident AF. Magnesium exposure ranged from 0.5 to 62.0 mg/L (mean = 13.9 mg/L). Estimated IRR (95% CI) compared to the referent exposure group (< 5 mg/L) was 0.98 (0.97-1.00) for the second lowest exposure group (5-10 mg/L), and 1.07 (1.05-1.08) for the two highest exposure groups (15-62 mg/L). Strongest positive associations were observed among those aged ≥80 years and with lowest education group. An inverse association was found among individuals with highest education group.

CONCLUSION

There might be a small beneficial effect on AF of an increase in magnesium level in drinking water up to 10 mg/L, though an overall positive association was observed. The unexpected positive association and different associations observed for subgroups suggest a potential influence of unaccounted factors, particularly in vulnerable populations. Future research on magnesium in drinking water and cardiovascular diseases needs to focus on contextual risk factors, especially those potentially correlating with magnesium in drinking water.

A proposed interval for evaluation of renal function during anticoagulation therapy using direct oral anticoagulants in patients with atrial fibrillation

BACKGROUND

Direct oral anticoagulants (DOACs) have been used to prevent cardiogenic embolism in patients with atrial fibrillation (AF). No evidence has been established for the follow-up renal function evaluation intervals. We hypothesized that a proposed follow-up interval of renal function can be estimated by patient's baseline characteristics including creatinine clearance (CCr).

METHODS

We conducted a single-center retrospective study at Kindai University Hospital from May 2011 to December 2017. Patients were screened and they were enrolled if baseline CCr of ≥50 mL/min. To provide a periodical synchronization for measurements of CCr in all patients, these were evaluated at four different time points (approximately at 3, 6, 9, and 12 months). Primary endpoint was defined as a CCr value of <50 mL/min during the follow-up period. We analyzed associations between the cumulative risk for renal endpoint and baseline characteristics by the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

Renal endpoint was associated with age (95% CI: 0.07 to 0.21, p<0.01), body weight (95% CI: -0.09 to -0.01, p<0.01), CCr (95% CI: -0.18 to -0.07, p<0.01), and CHA2DS2-VASc score (95% CI: 0.14 to 0.63, p<0.01). Combining baseline CCr of <60 mL/min and other risk factors, acceptable intervals for 5% risk levels were 78 days (age ≥75 years old), 100 days (CHA2DS2-VASc score of> 4 points), and 90 days (body weight <60kg), respectively. Under conditions of baseline CCr of <60 mL/min, age ≥75 years old, CHA2DS2-VASc score of> 4 points, or body weight <60 kg, an increased risk of renal endpoints is 4.85, 3.29, 1.24, 2.44 fold, respectively.

CONCLUSIONS

We propose a risk-stratified follow-up interval for renal evaluation in patients with AF and DOACs therapy according to a combination of baseline CCr and other risk factors.

miR‑101a‑3p overexpression prevents acetylcholine‑CaCl2‑induced atrial fibrillation in rats via reduction of atrial tissue fibrosis, involving inhibition of EZH2

Atrial fibrillation (AF), a clinically common heart arrhythmia, can result in left ventricular hypofunction, embolism and infarction. MicroRNA (miR)‑101a‑3p is lowly expressed in atrial tissues of patients with AF, but its role in AF remains unknown. In the present study, an AF model in rats was established via intravenous injection of acetylcholine (Ach)‑CaCl2. The downregulation of miR‑101a‑3p and upregulation of enhancer of zeste 2 homolog 2 (EZH2) were observed in AF model rats, indicating the involvement of miR‑101a‑3p and EZH2 in AF development. To study the effect of miR‑101a‑3p on AF in vivo, AF model rats were intramyocardially injected with lentivirus expressing miR‑101a‑3p. Electrocardiogram analysis identified that miR‑101a‑3p overexpression restored disappeared P wave and R‑R interphase changes in Ach‑CaCl2‑induced rats. Overexpression of miR‑101a‑3p also increased the atrial effective refractory period, reduced AF incidence and shortened duration of AF. Histological changes in atrial tissues were observed after H&E and Masson staining, which demonstrated that miR‑101a‑3p reduced atrial remodeling and fibrosis in AF model rats. Moreover, EZH2 expression was downregulated in atrial tissues by miR‑101a‑3p induction. Immunohistochemistry for collagen Ⅰ and collagen III revealed a reduction in atrial collagen synthesis following miR‑101a‑3p overexpression in AF model rats. Additionally, miR‑101a‑3p lowered the expression of pro‑fibrotic biomarkers, including TGF‑β1, connective tissue growth factor, fibronectin and α‑smooth muscle actin. The luciferase reporter assay results also indicated that EZH2 was a target gene of miR‑101a‑3p. Taken together, it was found that miR‑101a‑3p prevented AF in rats possibly via inhibition of collagen synthesis and atrial fibrosis by targeting EZH2, which provided a potential target for preventing AF.

Long-Term Exposures to Air Pollution and the Risk of Atrial Fibrillation in the Women's Health Initiative Cohort

BACKGROUND

Atrial fibrillation (AF) is associated with substantial morbidity and mortality. Short-term exposures to air pollution have been associated with AF triggering; less is known regarding associations between long-term air pollution exposures and AF incidence.

OBJECTIVES

Our objective was to assess the association between long-term exposures to air pollution and distance to road on incidence of AF in a cohort of U.S. women.

METHODS

We assessed the association of high resolution spatiotemporal model predictions of long-term exposures to particulate matter (PM 10 and PM 2.5 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), and distance to major roads with incidence of AF diagnosis, identified through Medicare linkage, among 83,117 women in the prospective Women's Health Initiative cohort, followed from enrollment in Medicare through December 2012, incidence of AF, or death. Using time-varying Cox proportional hazards models adjusted for age, race/ethnicity, study component, body mass index, physical activity, menopausal hormone therapy, smoking, diet quality, alcohol consumption, educational attainment, and neighborhood socioeconomic status, we estimated the relative risk of incident AF in association with each pollutant.

RESULTS

A total of 16,348 incident AF cases were observed over 660,236 person-years of follow-up. Most exposure-response associations were nonlinear. NO 2 was associated with risk of AF in multivariable adjusted models [Hazard Ratio  ( HR ) = 1.18 ; 95% confidence interval (CI): 1.13, 1.24, comparing the top to bottom quartile, p -for-trend = < 0.0001 ]. Women living closer to roadways were at higher risk of AF (e.g., HR = 1.07 ; 95% CI: 1.01, 1.13 for living within 50 m of A3 roads, compared with ≥ 1,000  m , p -for-trend = 0.02 ), but we did not observe adverse associations with exposures to PM 10 , PM 2.5 , or SO 2 . There were adverse associations with PM 10 (top quartile HR = 1.10 ; 95% CI: 1.05, 1.16, p -for-trend = < 0.0001 ) and PM 2.5 (top quartile HR = 1.09 ; 95% CI: 1.03, 1.14, p -for-trend = 0.002 ) in sensitivity models adjusting for census region.

DISCUSSION

In this study of postmenopausal women, NO 2 and distance to road were consistently associated with higher risk of AF. https://doi.org/10.1289/EHP7683.

The relationship between exposure to PM2.5 and atrial fibrillation in older adults: A systematic review and meta-analysis

Fine particle matter (PM_2.5) is recognized as atrial fibrillation (AF) risk factor, especially for older adults. However, studies on the relationship between PM_2.5 and AF were inconsistent. Herein, we present a systematic review to further assess the correlation between PM_2.5 and AF in older adults (average age > 50 years old). A comprehensive search was conducted with the keywords in PubMed (675 records), Web of Science (1130 records), Embase (82 records), and the Cochrane Library (42 records). Using Stata12.0 software to test the heterogeneity between studies, and select the corresponding model to calculate the comprehensive effect value, odds ratio (OR, odds ratio), the pooled %-change (percentage change) and its 95% confidence interval (CL, confidence interval). A total of 16 observational studies were included, involving 10,580,394 participants, the results showed that PM_2.5 had an adverse effects on AF in older adults. An association was found between exposure to PM_2.5 (per 10 μg/m³ increase) and AF in older adults, with the corresponding pooled OR (1.11, 95% CI: 1.03-1.19) and pooled %-change (1.01%, 95% CI: 0.14%-1.88%). Our study indicated that PM_2.5 exposure was significantly related to increased incidence of AF in older adults. Both the pooled OR and %-change value were higher in areas with higher levels of PM_2.5(≥25 μg/m³).

Sex-related difference in bleeding and thromboembolic risks in patients with atrial fibrillation treated with direct oral anticoagulants

BACKGROUND

Sex-related difference in non-valvular atrial fibrillation (NVAF) patients treated with direct oral anticoagulants (DOACs) is still to be investigated. We aimed to investigate sex difference in patient characteristics and clinical outcomes of the NVAF patients treated with DOAC in the real-world Japanese clinical practice.

METHODS AND RESULTS

We conducted a single-center prospective observational registry of NVAF patients treated with DOACs: the DIRECT registry (women, N = 806; men, N = 1410; follow-up duration, 407 ± 388 days). In the present study, all patients were stratified by sex. Women had significantly higher age, lower body weight, lower hemoglobin, lower creatinine clearance, and a higher bleeding risk estimate (ORBIT score) and higher thromboembolic risk estimates (CHADS₂ score and CHA₂DS₂VAS score) than men. Albeit the different bleeding risk estimates by the ORBIT score between both sexes, the Kaplan-Meier estimates of bleeding events were similar between both sexes (Log-rank test P = 0.152 for clinically significant bleeding, and P = 0.122 for major bleeding). The Kaplan-Meier estimated 2 year rate of stroke/systemic embolism was higher in women than in men (4.9 ± 1.3% vs. 2.3 ± 0.6%, Log-rank test P = 0.048).

CONCLUSIONS

Our real-world study of patients treated with DOAC showed that Japanese women experienced comparable bleeding events as compared to men despite the higher bleeding risk estimates. The higher thromboembolic risk estimates in women than in men translated into the higher thromboembolic event rates.Clinical trials identifier: UMIN000033283.

Quercetin prevents isoprenaline-induced myocardial fibrosis by promoting autophagy via regulating miR-223-3p/FOXO3

Atrial fibrillation (AF) is the common arrhythmias. Myocardial fibrosis (MF) is closely related to atrial remodeling and leads to AF. MF is the main cause of cardiovascular diseases and a pathological basis of AF. Thus, the underlying mechanism in MF and AF development should be fully elucidated for AF therapeutic innovation. Autophagy is a highly conserved lysosomal degradation pathway, and the relationship between autophagy and MF has been previously shown. Moreover, research reported that quercetin (Que) could ameliorate MF. The current study aimed to explore the mechanism of Que in MF. The results in this study showed that in clinical AF patients and in aged rats, miR-223-3p was high-expressed, while FOXO3 and autophagy pathway related proteins, such as ATG7, p62/SQSTM1 and the ratio of LC3B-II/LC3B-I were significantly inhibited. In vivo and in vitro studies, we found that Que can effectively inhibit the expression of miR-223-3p in AF model cells and rats myocardial tissues, and meanwhile enhance the expression of FOXO3 and activate the autophagy pathway, and significantly inhibit myocardial fibrosis, and improve myocardial remodeling in atrial fibrillation. All in all, in this study, we found that Que prevents isoprenaline-induced MF by increasing autophagy via regulating miR-223-3p/FOXO3.

Risk of Severe Abnormal Uterine Bleeding Associated with Rivaroxaban Compared with Apixaban, Dabigatran and Warfarin

INTRODUCTION

There have been reports of clinically relevant uterine bleeding events among women of reproductive age exposed to rivaroxaban.

OBJECTIVE

The aim of this study was to compare the risk of severe abnormal uterine bleeding (SAUB) resulting in transfusion or surgical intervention among women on rivaroxaban versus apixaban, dabigatran and warfarin.

METHODS

We conducted a retrospective cohort study in the FDA's Sentinel System (10/2010-09/2015) among females aged 18+ years with venous thromboembolism (VTE), or atrial flutter/fibrillation (AF) who newly initiated a direct oral anticoagulant (DOAC; rivaroxaban, apixaban, dabigatran) or warfarin. We followed women from dispensing date until the earliest of transfusion or surgery following vaginal bleeding, disenrollment, exposure or study end date, or recorded death. We estimated hazard ratios (HRs) using Cox proportional hazards regression via propensity score stratification. Four pairwise comparisons were conducted for each intervention.

RESULTS

Overall, there was an increased risk of surgical intervention with rivaroxaban when compared with dabigatran (HR 1.19; 95% CI 1.03-1.38), apixaban (1.23; 1.04-1.47), and warfarin (1.34; 1.22-1.47). No difference in risk for surgical intervention was observed for dabigatran-apixaban comparisons. Increased risk of transfusion was observed for rivaroxaban compared with dabigatran (1.49; 1.03-2.17) only. For patients with no gynecological history, rivaroxaban was associated with risk of surgical intervention compared with dabigatran (1.22; 1.05-1.42), apixaban (1.25; 1.04-1.49), and warfarin (1.36; 1.23-1.50).

CONCLUSION

Our study found increased SAUB risk with rivaroxaban use compared with other DOACs or warfarin. Increased risk with rivaroxaban was present among women without underlying gynecological conditions. Women on anticoagulant therapy should be aware of a risk of SAUB.

Vascular Impact of Cancer Therapies: The Case of BTK (Bruton Tyrosine Kinase) Inhibitors

Novel targeted cancer therapies have revolutionized oncology therapies, but these treatments can have cardiovascular complications, which include heterogeneous cardiac, metabolic, and vascular sequelae. Vascular side effects have emerged as important considerations in both cancer patients undergoing active treatment and cancer survivors. Here, we provide an overview of vascular effects of cancer therapies, focusing on small-molecule kinase inhibitors and specifically inhibitors of BTK (Bruton tyrosine kinase), which have revolutionized treatment and prognosis for B-cell malignancies. Cardiovascular side effects of BTK inhibitors include atrial fibrillation, increased risk of bleeding, and hypertension, with the former 2 especially providing a treatment challenge for the clinician. Cardiovascular complications of small-molecule kinase inhibitors can occur through either on-target (targeting intended target kinase) or off-target kinase inhibition. We will review these concepts and focus on the case of BTK inhibitors, highlight the emerging data suggesting an off-target effect that may provide insights into development of arrhythmias, specifically atrial fibrillation. We believe that cardiac and vascular sequelae of novel targeted cancer therapies can provide insights into human cardiovascular biology.

Sacubitril/Valsartan Decreases Atrial Fibrillation Susceptibility by Inhibiting Angiotensin II-Induced Atrial Fibrosis Through p-Smad2/3, p-JNK, and p-p38 Signaling Pathways

Sacubitril/valsartan (SAC/VAL) prevents angiotensin II (AngII) from binding AT1-R and blocks degradation of natriuretic peptides. Despite its efficacy in reducing ventricular fibrosis and preserving cardiac functions, which has been extensively demonstrated in myocardial infarction or pressure overload models, few studies have been conducted to determine whether SAC/VAL could attenuate atrial fibrosis and decrease atrial fibrillation (AF) susceptibility. Our study provided evidence for the inhibition of atrial fibrosis and reduced susceptibility to AF by SAC/VAL. After 28 days of AngII continuous subcutaneous stimulation, rats in SAC/VAL group exhibited reduced extent of atrial fibrosis, inhibited proliferation, migration, and differentiation of atrial fibroblasts, and decreased susceptibility to AF. We further found that inhibition of p-Smad2/3, p-JNK, and p-p38MAPK pathways is involved in the role of SAC/VAL on AngII-induced atrial fibrosis in vivo. These results emphasize the importance of SAC/VAL in the prevention of AngII-induced atrial fibrosis and may help to enrich the options for AF pharmacotherapy.

Effects of the L/N-Type Ca2+ Channel Blocker Cilnidipine on the Cardiac Histological Remodelling and Inducibility of Atrial Fibrillation in High-Salt-Fed Rats

High salt intake has been shown to induce hypertrophy and fibrosis in the atria and ventricles, which could result in the development of atrial fibrillation (AF). Whereas the development of AF is suggested to be prevented by renin-angiotensin system (RAS) inhibitors, recent findings have indicated that this prevention is closely associated with their antihypertensive effects. In this study, we investigated whether the L/N-type Ca2+ channel blocker cilnidipine counteracts salt-induced atrial and ventricular remodelling and the inducibility of AF. Cilnidipine was orally administered to Dahl salt-sensitive rats fed with an 8% NaCl diet at 10 mg/kg for 5 weeks, and then electrophysiological evaluation and histological analyses were performed. The effects were compared with those of the L-type Ca2+ channel blocker amlodipine at 3 mg/kg. Following the intake of the 8% NaCl diet, the blood pressure (BP) increased, and fibrosis was induced in the atria and ventricles. Cilnidipine decreased BP, and the extent of the decrease in the cilnidipine group was similar to those in the amlodipine group. Cilnidipine produced a greater decrease in the fibrotic area in the atria and ventricles than amlodipine. The cilnidipine group shortened the AF duration from 7.43 ± 3.16 to 2.95 ± 1.73 s, which had been increased by NaCl intake. Plasma noradrenaline levels in the cilnidipine group were lower than those in the amlodipine group. Thus, the suppressive effects of cilnidipine on the salt-induced atrial and ventricular remodelling, fibrosis, and AF sustainability might be closely associated with its N-type Ca2+ channel-blocking actions.