Administration of USP7 inhibitor p22077 alleviates Angiotensin II (Ang II)-induced atrial fibrillation in Mice

Atrial fibrillation (AF), the most common cardiac arrhythmia, is an important contributor to mortality and morbidity. Ubquitin-specific protease 7 (USP7), one of the most abundant ubiquitin-specific proteases (USP), participated in many cellular events, such as cell proliferation, apoptosis, and tumourigenesis. However, its role in AF remains unknown. Here, the mice were treated with Ang II infusion to induce the AF model. Echocardiography was used to measure the atrial diameter. Electrical stimulation was programmed to measure the induction and duration of AF. The changes in atrial remodeling were measured using routine histologic analysis. Here, a significant increase in USP7 expression was observed in Ang II-stimulated atrial cardiomyocytes and atrial tissues, as well as in atrial tissues from patients with AF. The administration of p22077, the inhibitor of USP7, attenuated Ang II-induced inducibility and duration of AF, atrial dilatation, connexin dysfunction, atrial fibrosis, atrial inflammation, and atrial oxidase stress, and then inhibited the progression of AF. Mechanistically, the administration of p22077 alleviated Ang II-induced activation of TGF-β/Smad2, NF-κB/NLRP3, NADPH oxidases (NOX2 and NOX4) signals, the up-regulation of CX43, ox-CaMKII, CaMKII, Kir2.1, and down-regulation of SERCA2a. Together, this study, for the first time, suggests that USP7 is a critical driver of AF and revealing USP7 may present a new target for atrial fibrillation therapeutic strategies.

Can a best practice advisory improve anticoagulation prescribing to reduce stroke risk in patients with atrial fibrillation?

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac rhythm disorder and a risk factor for stroke. Randomized trials have demonstrated that anticoagulation can reduce strokes in AF patients. Yet, widespread underutilization of this therapy continues. To address this practice gap, we designed a study to implement and evaluate the effectiveness of a best practice advisory (BPA) for an Atrial Fibrillation Decision Support Tool (AFDST) embedded within our electronic health record.

METHODS

Our intervention is provider-facing, focused on decision support. Clinical setting is ambulatory patients being seen by primary care physicians. We prospectively enrolled 608 patients in our health system who are currently receiving less than optimal anticoagulation therapy as determined by the AFDST and randomized them to one of two arms - 1) usual care, in which the AFDST is available for use; or 2) addition of a BPA to the AFDST notifying clinicians that their patient stands to gain significant benefit from a change in current therapy. Primary outcome was effectiveness of the BPA measured by change to "appropriate thromboprophylaxis" based on the AFDST recommendation at 3 months post-enrollment. Secondary endpoints included Reach and Adoption from the RE-AIM (Reach, Effectiveness, Adoption, Implementation, & Maintenance) framework for implementation studies.

RESULTS

Among 562 patients with a minimum follow-up of 3 months, addition of a BPA to the AFDST resulted in significant improvement in anticoagulation therapy, 5 % (12/248) versus 11 % (33/314) p = 0.02, odds ratio 2.31 (95 % CI, 1.17-4.87).

CONCLUSIONS

A BPA added to an AF decision support tool improved anticoagulation therapy among AF patients in a primary care academic health system setting.

Cardiomyopathy in Patients With Acute Ischemic Stroke and Methamphetamine Use: Relevance for Cardioembolic Stroke and Outcome

BACKGROUND

Methamphetamine use has emerged as a major risk factor for cardiovascular and cerebrovascular disease in young adults. The aim of this study was to investigate a possible association of methamphetamine use with cardioembolic stroke.

METHODS AND RESULTS

We performed a retrospective study of patients with acute ischemic stroke admitted at our medical center between 2019 and 2022. All patients were screened for methamphetamine use and cardiomyopathy, defined as left ventricular ejection fraction ≤45%. Among 938 consecutive patients, 46 (4.9%) were identified as using methamphetamine. Compared with the nonmethamphetamine group (n=892), the methamphetamine group was significantly younger (52.8±9.6 versus 69.7±15.2 years; P<0.001), included more men (78.3% versus 52.8%; P<0.001), and had a significantly higher rate of cardiomyopathy (30.4% versus 14.0%; P<0.01). They were also less likely to have a history of atrial fibrillation (8.7% versus 33.4%; P<0.01) or hyperlipidemia (28.3% versus 51.7%; P<0.01). Compared with patients with cardiomyopathy without methamphetamine use, the patients with cardiomyopathy with methamphetamine use had significantly lower left ventricular ejection fraction (26.0±9.59% versus 32.47±9.52%; P<0.01) but better functional outcome at 3 months, likely attributable to significantly younger age and fewer comorbidities. In the logistic regression model of clinical variables, methamphetamine-associated cardiomyopathy was found to be significantly associated with cardioembolic stroke (odds ratio, 1.79 [95% CI, 1.04-3.06]; P<0.05).

CONCLUSIONS

We demonstrate that methamphetamine use is significantly associated with cardiomyopathy and cardioembolic stroke in young adults.

A phase 1 trial of AP30663, a KCa2 channel inhibitor in development for conversion of atrial fibrillation

AIMS

AP30663 is a novel compound under development for pharmacological conversion of atrial fibrillation by targeting the small conductance Ca2+ activated K+ (KCa2) channel. The aim of this extension phase 1 study was to test AP30663 at higher single doses compared to the first-in-human trial.

METHODS

Sixteen healthy male volunteers were randomized into 2 cohorts: 6- and 8-mg/kg intravenous single-dose administration of AP30663 vs. placebo. Safety, pharmacokinetic and pharmacodynamic data were collected.

RESULTS

AP30663 was associated with mild and transient infusion site reactions with no clustering of other adverse events but with an estimated maximum mean QTcF interval prolongation of 45.2 ms (95% confidence interval 31.5-58.9) in the 6 mg/kg dose level and 50.4 ms (95% confidence interval 36.7-64.0) with 8 mg/kg. Pharmacokinetics was dose proportional with terminal half-life of around 3 h.

CONCLUSION

AP30663 in doses up to 8 mg/kg was associated with mild and transient infusion site reactions and an increase of the QTcF interval. Supporting Information support that the QTc effect may be explained by an off-target inhibition of the IKr channel.

Age-related variation in coagulation factors in non-valvular atrial fibrillation patients receiving direct oral anticoagulants

Age is a significant risk factor for ischemic stroke. However, the influence of aging on coagulation parameters in non-valvular atrial fibrillation (NVAF) patients treated with direct oral anticoagulants (DOACs) remains unclear. A total of 775 samples were collected from 224 NVAF patients receiving apixaban, edoxaban or rivaroxaban. The samples were categorized into three age groups: (i) ≤ 64 years, (ii) 65-74 years, and (iii) ≥ 75 years (apixaban: N = 48, 108, 119; edoxaban: N = 63, 68, 126; rivaroxaban: N = 115, 90, 38, respectively). Coagulation parameters including fibrinogen (Fbg), factor II, factor V, factor VII, factor X, and D-dimer, were compared between the three age groups for each drug. The slopes in the correlation between drug concentrations and modified diluted prothrombin time (mdPT) were also assessed. Fbg and factor V increased with age, while factor II and factor X decreased. Factor VII and D-dimer showed no significant differences across age categories. The slope in response to drug concentrations was similar between the age groups. In NVAF patients treated with apixaban, edoxaban and rivaroxaban, some coagulation parameters exhibited age-related variation. However, the response of mdPT to drug concentration was consistent across age categories.

Percutaneous left atrial appendage occlusion and risk of stroke, hospitalized bleeding and death in Medicare beneficiaries

PURPOSE

Among patients with atrial fibrillation (AF), a nonpharmacologic option (e.g., percutaneous left atrial appendage occlusion [LAAO]) is needed for patients with oral anticoagulant (OAC) contraindications. Among beneficiaries in the Medicare fee-for-service coverage 20% sample databases (2015-18) who had AF and an elevated CHA2DS2-VASc score, we assessed the association between percutaneous LAAO versus OAC use and risk of stroke, hospitalized bleeding, and death.

METHODS

Patients undergoing percutaneous LAAO were matched to up to five OAC users by sex, age, date of enrollment, index date, CHA2DS2-VASc score, and HAS-BLED score. Overall, 17 156 patients with AF (2905 with percutaneous LAAO) were matched (average ± SD 78 ± 6 years, 44% female). Cox proportional hazards model were used.

RESULTS

Median follow-up was 10.3 months. After multivariable adjustments, no significant difference for risk of stroke or death was noted when patients with percutaneous LAAO were compared with OAC users (HRs [95% CIs]: 1.14 [0.86-1.52], 0.98 [0.86-1.10]). There was a 2.94-fold (95% CI: 2.50-3.45) increased risk for hospitalized bleeding for percutaneous LAAO compared with OAC use. Among patients 65 to <78 years old, those undergoing percutaneous LAAO had higher risk of stroke compared with OAC users. No association was present in those ≥78 years.

CONCLUSION

In this analysis of real-world AF patients, percutaneous LAAO versus OAC use was associated with similar risk of death, nonsignificantly elevated risk of stroke, and an elevated risk of bleeding in the post-procedural period. Overall, these results support results of randomized trials that percutaneous LAAO may be an alternative to OAC use for patients with contraindications.

Apixaban-Associated Intracranial Hemorrhage in a Patient With Elevated International Normalized Ratio

Apixaban has been associated with prolongation of the international normalized ratio (INR), but data surrounding the extent of elevation and its clinical significance are limited. Due to interaction between apixaban and the prothrombin assay, elevations in INR in patients receiving apixaban are common and not always grounds for concern. However, in high risk patients, elevations can represent a need for closer monitoring. This case summarizes an 82-year-old woman with a history of atrial fibrillation and left middle cerebral artery strokes with no residual deficits. She presented with right-sided hemiparesis and aphasia and underwent a mechanical thrombectomy with TICI 2b recanalization of a left M1 occlusion. Post-thrombectomy, she was found to have a left atrial thrombus and 10 days later was started on apixaban 5 mg twice daily. On the fourth day of apixaban therapy, she experienced an INR increase to 2.3, prompting initiation of a vitamin K challenge for nutritional deficiency. Despite initial improvement, her INR increased to 2.7 a week after apixaban was initiated, coinciding with a decline in mental status and an apixaban peak level of 435.6 ng/mL (reference range 91-321 ng/mL). A computed tomography (CT) scan of her head showed new intracranial hemorrhage in the area of her previous infarction, prompting apixaban reversal with andexanet alfa. Unfortunately, the patient expired. This case report highlights the importance and difficulty in performing therapeutic drug monitoring in patients receiving oral anti-factor Xa inhibitors, revealing a downside to administration of high-risk medications that do not have readily available monitoring.

Clot time ratio (CTR) and treatment outcomes in Apixaban-treated atrial fibrillation patients

There are clinical situations where information about the anticoagulant effects of Apixaban could be useful. Specialised methods for measuring Apixaban concentrations are not available at all medical laboratories while methods for measuring the functional effects of Apixaban, using clot time ratio (CTR), can be performed in most medical laboratories around the clock using well-established measurement procedures. The aim of this study was to investigate CTR in trough and peak samples during Apixaban treatment of atrial fibrillation and to correlate the findings to bleeds and thrombotic events. Three trough- and three peak samples from 61 patients (31 on Apixaban 5 mg twice daily and 30 on Apixaban 2.5 mg twice daily) were analysed with MRX PT DOAC. Patients were followed for 30 + /-15 months, and bleeds and thrombotic events were documented. The effect of Apixaban could be measured with MRX PT DOAC and there was a statistically significant difference between CTR in trough samples compared to peak samples (p < 0.001). A total of 21 patients suffered bleeds during follow-up; two patients suffered major bleeds, and 19 suffered minor bleeds. Patients with major bleeds had both mean peak- and mean trough CTR above the respective first to third quartile (Q1-Q3) range. Four patients suffered thromboembolic events. Generally, the peak CTRs were below or in the lower end of the peak Q1-Q3 for these patients. The new test MRX PT DOAC can be used to measure the effect of Apixaban during the treatment of atrial fibrillation. High mean peak- and mean trough CTR were seen in 2 patients with major bleeds, and low peak CTR was seen in 4 patients with thromboembolic events.

Efficacy and Safety of Non-Vitamin-K Antagonist Oral Anticoagulants Versus Warfarin Across the Spectrum of Body Mass Index and Body Weight: An Individual Patient Data Meta-Analysis of 4 Randomized Clinical Trials of Patients With Atrial Fibrillation

BACKGROUND

The efficacy and safety of non-vitamin-K antagonist oral anticoagulants (NOACs) across the spectrum of body mass index (BMI) and body weight (BW) remain uncertain.

METHODS

We analyzed data from COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation), which pooled patient-level data from the 4 pivotal randomized trials of NOAC versus warfarin in patients with atrial fibrillation. The primary efficacy and safety outcomes were stroke or systemic embolic events (stroke/SEE) and major bleeding, respectively; secondary outcomes were ischemic stroke/SEE, intracranial hemorrhage, death, and the net clinical outcome (stroke/SEE, major bleeding, or death). Each outcome was examined across BMI and BW. Because few patients had a BMI <18.5 kg/m2 (n=598), the primary analyses were restricted to those with a BMI ≥18.5 kg/m2.

RESULTS

Among 58 464 patients, the median BMI was 28.3 (interquartile range, 25.2-32.2) kg/m2, and the median BW was 81.0 (interquartile range, 70.0-94.3) kg. The event probability of stroke/SEE was lower at a higher BMI irrespective of treatment, whereas the probability of major bleeding was lower at a higher BMI with warfarin but relatively unchanged across BMI with NOACs. NOACs reduced stroke/SEE overall (adjusted hazard ratio [HRadj], 0.80 [95% CI, 0.73-0.88]; P<0.001), with a generally consistent effect across BMI (Ptrend across HRs, 0.48). NOACs also reduced major bleeding overall (HRadj, 0.88 [95% CI, 0.82-0.94]; P<0.001), but with attenuation of the benefit at a higher BMI (trend test across BMI [Ptrend], 0.003). The overall treatment effects of NOACs versus warfarin for secondary outcomes were consistent across BMI, with the exception of the net clinical outcome and death. While these outcomes were overall reduced with NOACs (net clinical outcome, HRadj, 0.91 [95% CI, 0.87-0.95]; P<0.001; death, HRadj, 0.91 [95% CI, 0.86-0.97]; P=0.003), these benefits were attenuated at higher BMI (Ptrend, 0.001 and 0.08, respectively). All findings were qualitatively similar when analyzed across BW.

CONCLUSIONS

The treatment effect of NOACs versus warfarin in atrial fibrillation is generally consistent for stroke/SEE across the spectrum of BMI and BW, whereas the reduction in major bleeding is attenuated in those with higher BMI or BW. Death and the net clinical outcome are overall reduced with NOACs over warfarin, although there remain uncertainties for these outcomes at a very high BMI and BW.

Lessons derived from post authorisation safety studies (ETNA-AF and XANTUS) on once daily direct oral anticoagulants for atrial fibrillation

BACKGROUND

Phase III trials should be integrated by post authorisation safety studies (PASS) to confirm their conclusions in real life. In this setting, comorbidities are commonly more prevalent, decisions about drugs and regimens are left to the attending physicians and therapy monitoring is not usually as strict as in pivotal trials.

AIMS AND METHODS

To evaluate real life safety and effectiveness of edoxaban and rivaroxaban, ETNA-AF Europe (ETNA-AF-Eu) and XANTUS studies were reviewed and compared. A further comparison between data collected in these studies and in the pivotal studies ENGAGE AF-TIMI 48 and ROCKET-AF was also performed.

RESULTS

ETNA-AF-Eu and XANTUS showed lower bleeding, stroke, cardiovascular- and all-cause mortality rates as compared to those observed in Phase 3 trials, even when including subgroups with lower comorbidities. Patients in ETNA-AF-Eu were older, with a larger proportion of octogenarians (≥85 years in 10.5%) and patients with impaired renal function as compared to patients in XANTUS (CrCl <50 ml/min in 18.2% vs 12.2%) and in ENGAGE AF-TIMI 48 and ROCKET-AF, without paying any excess tribute in terms of safety. Therapy persistence was very high in the two real life studies (91.9% in ETNA-AF-Eu and 79.9% in XANTUS), thus showing that edoxaban and rivaroxaban are well tolerated in real life.

CONCLUSION

The ETNA-AF-Eu and XANTUS confirmed the safety and effectiveness of edoxaban and rivaroxaban in real life.

Optimizing warfarin dosing for patients with atrial fibrillation using machine learning

While novel oral anticoagulants are increasingly used to reduce risk of stroke in patients with atrial fibrillation, vitamin K antagonists such as warfarin continue to be used extensively for stroke prevention across the world. While effective in reducing the risk of strokes, the complex pharmacodynamics of warfarin make it difficult to use clinically, with many patients experiencing under- and/or over- anticoagulation. In this study we employed a novel implementation of deep reinforcement learning to provide clinical decision support to optimize time in therapeutic International Normalized Ratio (INR) range. We used a novel semi-Markov decision process formulation of the Batch-Constrained deep Q-learning algorithm to develop a reinforcement learning model to dynamically recommend optimal warfarin dosing to achieve INR of 2.0-3.0 for patients with atrial fibrillation. The model was developed using data from 22,502 patients in the warfarin treated groups of the pivotal randomized clinical trials of edoxaban (ENGAGE AF-TIMI 48), apixaban (ARISTOTLE) and rivaroxaban (ROCKET AF). The model was externally validated on data from 5730 warfarin-treated patients in a fourth trial of dabigatran (RE-LY) using multilevel regression models to estimate the relationship between center-level algorithm consistent dosing, time in therapeutic INR range (TTR), and a composite clinical outcome of stroke, systemic embolism or major hemorrhage. External validation showed a positive association between center-level algorithm-consistent dosing and TTR (R2 = 0.56). Each 10% increase in algorithm-consistent dosing at the center level independently predicted a 6.78% improvement in TTR (95% CI 6.29, 7.28; p < 0.001) and a 11% decrease in the composite clinical outcome (HR 0.89; 95% CI 0.81, 1.00; p = 0.015). These results were comparable to those of a rules-based clinical algorithm used for benchmarking, for which each 10% increase in algorithm-consistent dosing independently predicted a 6.10% increase in TTR (95% CI 5.67, 6.54, p < 0.001) and a 10% decrease in the composite outcome (HR 0.90; 95% CI 0.83, 0.98, p = 0.018). Our findings suggest that a deep reinforcement learning algorithm can optimize time in therapeutic range for patients taking warfarin. A digital clinical decision support system to promote algorithm-consistent warfarin dosing could optimize time in therapeutic range and improve clinical outcomes in atrial fibrillation globally.

Patterns of Anticoagulation Use and All-Cause of Mortality in Cancer Patients with Atrial Fibrillation

BACKGROUND

There is uncertainty regarding the clinical benefit of anticoagulant (AC) treatment in patients with cancer with atrial fibrillation (AF). We aimed to evaluate the distribution and patterns of AC use and its impact on all-cause mortality in cancer patients with AF.

METHODS

A total of 1,653 patients with cancer diagnosed with AF were included in this retrospective cohort analysis. Multivariable logistic regression was applied to identify the clinical predictors of anticoagulant prescription. Kaplan-Meier curve with a log-rank test was used to compare the probability of survival between the AC and non-AC groups. Multivariate Cox proportional hazard regression models were implemented to evaluate the influences of various variables on all-cause death.

RESULTS

Of 1,653 patients with cancer with AF, 971 (58.7%) did not receive a prescription for AC. Among patients with CHA2DS2-VASC ≥2 in men or ≥3 in women and HAS-BLED <3, 56.5% were not prescribed AC. Rivaroxaban and warfarin are more frequently used than dabigatran, mainly in patients with lung and breast cancer. Over a median follow-up of 36 months, 776 deaths were identified. The Kaplan-Meier curve suggested that patients with AC prescriptions had better clinical outcomes. On multivariate Cox proportional risk regression analysis, AC prescription was significantly associated with a lower risk of all-cause mortality (hazard ratio, 0.78; 95% confidence interval, 0.66-0.91; P = 0.002).

CONCLUSIONS

The prescription of anticoagulants in patients with cancer with AF was suboptimal. AC prescription at discharge was associated with a decreased risk of all-cause mortality.

IMPACT

This study highlights the importance of AC prescriptions in patients with cancer with AF.

Clinical Outcomes in Older Patients with Atrial Fibrillation: Insights from the GARFIELD-AF Registry

BACKGROUND

Oral anticoagulants (OAC) are underutilized in older patients with atrial fibrillation, despite proven clinical benefits. Our objective was to investigate baseline characteristics, treatment patterns, and impact of anticoagulation upon clinical outcomes with respect to age.

METHODS

Adults with newly diagnosed atrial fibrillation were recruited into the prospective observational registry, GARFIELD-AF, and followed up for 24 months. Adjusted hazard ratios (HR) were obtained via Cox proportional-hazards models with applied weights, to quantify the association of age with clinical outcomes. Comparative effectiveness of OAC vs No OAC and non-vitamin K oral anticoagulants (NOAC) vs vitamin K antagonists (VKA) were assessed using a propensity score with an overlap weighting scheme.

RESULTS

Of 52,018 patients, 32.6% were 65-74 years of age, 29.3% were 75-84 years, and 7.9% were ≥85 years. OAC treatment was associated with a numerical reduction in all-cause mortality among those aged 65-74 years (HR; 95% confidence interval) (0.86; 0.69-1.06) and aged 75-84 years (0.89; 0.75-1.05) and a significant reduction in patients ≥85 years (0.77; 0.63-0.95) vs no OAC. Similarly, OACs were associated with a decrease in stroke: 65-74 (0.51; 0.35-0.76) and ≥85 years (0.58; 0.34-0.99) and a numerical decrease in 75-84 years (0.84; 0.59-1.18). No increase in major bleeding was observed in patients aged ≥85 treated with OACs. Compared with VKA, NOACs were associated with a significant reduction in all-cause mortality in patients aged <65 and 65-74, with numerical reductions in those aged 75-84 and ≥85 years.

CONCLUSIONS

Older patients using OACs saw lower all-cause mortality and stroke risk; NOACs had less mortality and major bleeding compared with VKAs.

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

Oral Anticoagulants Beyond Warfarin

Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists, mostly warfarin, for the main indications for oral anticoagulation, prevention and treatment of venous thromboembolism, and prevention of embolic stroke in atrial fibrillation. While DOACs offer practical, fixed-dose anticoagulation in many patients, specific restrictions or contraindications may apply. DOACs are not sufficiently effective in high-thrombotic risk conditions such as antiphospholipid syndrome and mechanical heart valves. Patients with cancer-associated thrombosis may benefit from DOACs, but the bleeding risk, particularly in those with gastrointestinal or urogenital tumors, must be carefully weighed. In patients with frailty, excess body weight, and/or moderate-to-severe chronic kidney disease, DOACs must be cautiously administered and may require laboratory monitoring. Reversal agents have been developed and approved for life-threatening bleeding. In addition, the clinical testing of potentially safer anticoagulants such as factor XI(a) inhibitors is important to further optimize anticoagulant therapy in an increasingly elderly and frail population worldwide.

An extension of biorelevant fed-state dissolution tests to clinical pharmacokinetics - A study on gastrointestinal factors influencing rivaroxaban exposure and efficacy in atrial fibrillation patients

A direct oral anticoagulant rivaroxaban fails to prevent stroke and systemic embolism in one-to-several percent of patients with nonvalvular atrial fibrillation (NVAF), but the reasons are unknown. The study used semi-mechanistic in vitro-in vivo prediction (IVIVP) modeling to explore the reasons for ineffective thrombosis prevention in NVAF patients. Steady-state drug concentrations in plasma were measured at 0 h (Ctrough), 3 h (C3h), and 12 h post-dosing in thirty-four patients treated with 20 mg rivaroxaban daily. The clinical data were compared against "virtual twins" generated with a novel IVIVP model that combined drug dissolution modeling, mechanistic description of gastric drug transit, and population pharmacokinetics defining the variability of drug disposition. The nonresponders had significantly lower C3h and Ctrough than the responders (p < 0.001) and the covariates included in the population pharmacokinetic submodel did not fully explain this difference. Simulations involving varied gastrointestinal parameters in the "virtual twins" revealed that lower small intestinal effective permeability (Peff), rather than a slower stomach emptying rate, could explain low rivaroxaban exposure in the nonresponders. IVIVP modeling was effectively used for exploring pharmacotherapy failure. Low Peff, found as a major determinant of ineffective rivaroxaban treatment, encourages further research to find (pato)physiological factors influencing suboptimal absorption.

Impact of Unhealthy Lifestyles on Patients with Atrial Fibrillation at Low Risk of Stroke: A Nationwide Cohort Study

BACKGROUND

The impact of unhealthy lifestyles on clinical outcomes among patients with atrial fibrillation (AF) who are at low risk of stroke remains uncertain. The study objective was to evaluate the association between unhealthy lifestyles and clinical outcomes among low-risk AF patients with 0-1 non-sex risk factor of the CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, prior Stroke or transient ischemic attack [TIA], Vascular disease, Age 65-74 years, female Sex;) score.

METHODS

A total of 52,451 low-risk AF patients (mean age 51.6 ± 10.4 years) were evaluated with the National Health Insurance Service of the Republic of Korea database between 2009 and 2016. Using the survey on health habits, an unhealthy lifestyle score (ULS) was calculated by adding one point each if a respondent had a sedentary lifestyle, drinking, or smoking. The primary outcome was the composite of myocardial infarction, ischemic stroke, heart failure, and all-cause death. Multivariable Cox regression analysis was used to estimate the risk of the study outcome according to the ULS.

RESULTS

There was a total of 12,792 (24.4%), 24,785 (47.3%), 11,602 (22.1%), and 3272 (6.2%) low-risk AF patients with 0 to 3 points of the ULS, respectively. The median follow-up period was 4.1 (2.1-6.1) years. Compared with the healthiest-lifestyle group (ULS 0), the other groups were associated with significantly higher risks of the primary outcome, with a gradually increasing trend according to the ULS (adjusted hazard ratio [95% confidence interval] =1.17 [1.05-1.31], 1.37 [1.21-1.56], 1.82 [1.53-2.17], for the groups with ULS 1, 2, and 3, respectively).

CONCLUSION

Unhealthy lifestyles, including a sedentary lifestyle, drinking, and smoking, may synergistically impact poor clinical outcomes in AF patients who are deemed to be at low risk of stroke.

Risk of ischemic stroke associated with direct oral anticoagulants discontinuation on patients with non-valvular atrial fibrillation

INTRODUCTION

Although direct oral anticoagulants' (DOACs) prescriptions have experienced immense growth in the last decade, the proportion of discontinuers is still common yielding an increased risk of ischemic stroke (IS) onset.

AIMS

We aimed to estimate the association between DOACs discontinuation and risk of IS among patients with non-valvular atrial fibrillation (NVAF).

METHODS

We used data from a cohort of new DOACs users, followed patients from the first DOAC prescription date up to IS (index date) and conducted a nested case-control analysis using conditional logistic regression. Adjusted odds ratios, 95% confidence intervals were calculated for discontinuation of DOACs (current use compared with past use). The latter, subdivided among those stopping treatment 3 to 2 months and 6 and 3 months prior to index date. The effect of naïve current users against IS onset compared with non-naïve current users was also evaluated.

RESULTS

DOACs discontinuation showed an OR of IS of 1.47 (95% CI: 1.02-2.12); estimates were 2.51 (95% CI: 1.84-3.42) for whom discontinued treatment within months 3 and 2 and 1.43 (95% CI: 0.96-2.13) for those between months 6 and 3 prior to index date. Analyzing DOACs individually, risk of IS associated with past users compared with current users: 1.98 (95% CI: 1.25-3.12) for apixaban, 1.38 (95% CI: 0.40-4.72) for edoxaban, 1.98 (95% CI: 1.24-2.65) for dabigatran and 1.87 (95% CI: 1.26-2.76) for rivaroxaban. Similar results were found when stratified by naïve and non-naïve users.

CONCLUSIONS

DOACs' discontinuation is associated with higher risk of IS, especially in the second and third months following interruption.

Costunolide ameliorates angiotensin II-induced atrial inflammation and fibrosis by regulating mitochondrial function and oxidative stress in mice: A possible therapeutic approach for atrial fibrillation

Atrial fibrillation (AF) is a cardiac disease characterized by disordered atrial electrical activity. Atrial inflammation and fibrosis are involved in AF progression. Costunolide (COS) is a sesquiterpene lactone containing anti-inflammatory and anti-fibrotic activities. This study aims to explore the underlying mechanisms by which COS protects against AF. Male C57BL/6 mice (8- to 10-week-old) were infused with angiotensin (Ang) II for 3 weeks. Meanwhile, different doses of COS (COS-L: 10 mg/kg, COS-H: 20 mg/kg) were administered to mice by intragastric treatment. The results showed irregular and rapid heart rates in Ang II-treated mice. Moreover, the levels of inflammatory cytokines and fibrotic factors were elevated in mice. COS triggered a reduction of Ang II-induced inflammation and fibrosis, which conferred a protective effect. Mechanistically, mitochondrial dysfunction with mitochondrial respiration inhibition and aberrant ATP levels were observed after Ang II treatment. Moreover, Ang-II-induced excessive reactive oxygen species caused oxidative stress, which was further aggravated by inhibiting Nrf2 nuclear translocation. Importantly, COS diminished these Ang-II-mediated effects in mice. In conclusion, COS attenuated inflammation and fibrosis in Ang-II-treated mice by alleviating mitochondrial dysfunction and oxidative stress. Our findings represent a potential therapeutic option for AF treatment.

Influence of thrombocytopenia on bleeding and vascular events in atrial fibrillation

Whether thrombocytopenia substantively increases the risk of hemorrhage associated with anticoagulation in patients with atrial fibrillation (AF) is not established. The purpose of this study was to compare rates of bleeding in patients with AF and thrombocytopenia (platelet count < 100 000/μL) to patients with AF and normal platelet counts (>150 000/μL). We performed a propensity score-matched, retrospective cohort study of adults (n = 1070) with a new diagnosis of AF who received a prescription for an oral anticoagulant between 2015 and 2020. The thrombocytopenia cohort was defined as having at least 2 platelet counts <100 000/μL on separate days in the period spanning the 12 weeks preceding the initiation of anticoagulation to 6 weeks after the initiation of anticoagulation. The primary end point was the 1-year cumulative incidence of major bleeding; secondary end points included clinically relevant bleeding, arterial and venous thrombotic events, and all-cause mortality. Patients with AF and thrombocytopenia experienced a higher 1-year cumulative incidence of major bleeding (13.3% vs 5.7%; P < .0001) and clinically relevant bleeding (24.5% vs 16.7%; P = .005) than the controls. Thrombocytopenia was identified as an independent risk factor for major bleeding (hazard ratio, 2.20; confidence interval, 1.36-3.58; P = .001), with increasing risk based on the severity of thrombocytopenia. The cumulative incidence of arterial thrombosis at 1 year was 3.6% in the group with thrombocytopenia and 1.5% in controls (Gray test, P = .08). These findings suggest that baseline platelet counts are an important biomarker for hemorrhagic outcomes in AF and that the degree of thrombocytopenia is an important factor in determining the level of risk.

Impact of P-glycoprotein and CYP3A4-interacting drugs on clinical outcomes in patients with atrial fibrillation using non-vitamin K antagonist oral anticoagulants: a nationwide cohort study

AIMS

The clinical relevance of common pharmacokinetic interactions with non-vitamin K antagonist oral anticoagulants (NOACs) often remains unclear. Therefore, the impact of P-glycoprotein (P-gp) and CYP3A4 inhibitors and inducers on clinical outcomes in NOAC-treated patients with atrial fibrillation (AF) was investigated.

METHODS AND RESULTS

AF patients were included between 2013 and 2019 using Belgian nationwide data. Concomitant use of P-gp/CYP3A4-interacting drugs at the time of NOAC initiation was identified. Among 193 072 NOAC-treated AF patients, 46 194 (23.9%) and 2903 (1.5%) subjects concomitantly used a P-gp/CYP3A4 inhibitor or inducer, respectively. After multivariable adjustment, concomitant use of P-gp/CYP3A4 inhibitors was associated with significantly higher major bleeding [adjusted hazard ratio (aHR) 1.24, 95% confidence interval (CI) (1.18-1.30)] and all-cause mortality risks [aHR 1.07, 95% CI (1.02-1.11)], but not with thromboembolism in NOAC-treated AF patients. A significantly increased risk of major bleeding was observed with amiodarone [aHR 1.27, 95% CI (1.21-1.34)], diltiazem [aHR 1.28, 95% CI (1.13-1.46)], verapamil [aHR 1.36, 95% CI (1.03-1.80)], ticagrelor [aHR 1.50, 95% CI (1.20-1.87)], and clarithromycin [aHR 1.55, 95% CI (1.14-2.11)]; and in edoxaban [aHR 1.24, 95% CI (1.06-1.45)], rivaroxaban [aHR 1.25, 95% CI (1.16-1.34)], and apixaban users [aHR 1.27, 95% CI (1.16-1.39)], but not in dabigatran users [aHR 1.07, 95% CI (0.94-1.23)]. Concomitant use of P-gp/CYP3A4 inducers (e.g. antiepileptic drugs like levetiracetam) was associated with a significantly higher stroke risk [aHR 1.31, 95% CI (1.03-1.68)], but not with bleeding or all-cause mortality.

CONCLUSION

Concomitant use of P-gp/CYP3A4 inhibitors was associated with higher bleeding and all-cause mortality risks in NOAC users, whereas the use of P-gp/CYP3A4 inducers was associated with higher stroke risks.

Efficacy and Safety of Direct Oral Anticoagulants for Stroke Prevention in Older Patients With Atrial Fibrillation: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Although older patients with atrial fibrillation are at heightened risk of thromboembolic and bleeding events, their optimal treatment choice remains uncertain.

METHODS AND RESULTS

This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, EMBASE, and Cochrane databases for randomized controlled trials that compared thromboembolic or bleeding outcomes between a direct oral anticoagulant (DOAC) and a vitamin K antagonist (VKA) and reported outcomes for patients aged ≥75 years with atrial fibrillation. The efficacy outcome was the composite of stroke and systemic embolism. Safety outcomes included major bleeding, any clinically relevant bleeding, and intracranial hemorrhage. Each DOAC and VKA was compared pairwise in a network meta-analysis. High- and low-dose regimens and factor IIa and Xa inhibitors were also compared. Seven randomized controlled trials were included in the analysis. Stroke and systemic embolism risks did not differ significantly among DOACs. There were no significant differences in major bleeding between each DOAC and VKA. Intracranial hemorrhage risk was significantly lower with dabigatran, apixaban, and edoxaban than with VKA and rivaroxaban, which had similar risks. High-dose regimens led to lower risks of stroke or systemic embolism compared with VKA and low-dose regimens, with both doses having similar bleeding risks.

CONCLUSIONS

In patients aged ≥75 years with atrial fibrillation, DOACs were associated with fewer thromboembolic events compared with VKA, whereas dabigatran, apixaban, and edoxaban were associated with lower risks of intracranial hemorrhage compared with VKA and rivaroxaban.

REGISTRATION

URL: www.crd.york.ac.uk/prospero/. Unique identifier: CRD42022329557.

Comparing Efficacy and Safety Between Patients With Atrial Fibrillation Taking Direct Oral Anticoagulants or Warfarin After Direct Oral Anticoagulant Failure

BACKGROUND

An increased risk of recurrent stroke is noted in patients with atrial fibrillation despite direct oral anticoagulant (DOAC) use. We investigated the efficacy and safety of treatment with each of 4 different DOACs or warfarin after DOAC failure.

METHODS AND RESULTS

We retrospectively analyzed patients with atrial fibrillation with ischemic stroke despite DOAC treatment between January 2002 and December 2016. The different outcomes of patients with DOAC failure were compared, including recurrent ischemic stroke, major cardiovascular events, intracranial hemorrhage and subarachnoid hemorrhage, mortality, and net composite outcomes according to switching to different DOACs or vitamin K antagonist after index ischemic stroke. We identified 3759 patients with DOAC failure. A total of 84 patients experienced recurrent ischemic stroke after switching to different oral anticoagulants, with a total follow-up time of 14 years. Using the vitamin K antagonist group as a reference, switching to any of the 4 DOACs was associated with a 69% to 77% reduced risk of major cardiovascular events (adjusted hazard ratio [aHR], 0.25 [95% CI, 0.16-0.39] for apixaban, 0.23 [95% CI, 0.14-0.37] for dabigatran, 0.23 [95% CI, 0.09-0.60] for edoxaban, and 0.31 [95% CI, 0.21-0.45] for rivaroxaban), and a 69% to 83% reduced risk of net composite outcomes (aHR, 0.25 [95% CI, 0.18-0.35] for apixaban, 0.17 [95% CI, 0.11-0.25] for dabigatran, 0.31 [95% CI, 0.17-0.56] for edoxaban, and 0.31 [95% CI, 0.23-0.41] for rivaroxaban).

CONCLUSIONS

In Asian patients with DOAC failure, continuing DOACs after index stroke was associated with fewer undesirable outcomes than switching to a vitamin K antagonist. Alternative pharmacologic and nonpharmacologic strategies warrant investigation.

Pinocembrin attenuates susceptibility to atrial fibrillation in rats with pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a disease characterized by pulmonary vascular remodeling that triggers fibrosis and excessive myocardium apoptosis, ultimately facilitating atrial fibrillation (AF). In various rat models, Pinocembrin has anti-fibrotic and anti-apoptotic effects, reducing arrhythmia vulnerability. However, whether pinocembrin alleviates to AF in a PAH model remains unclear. The experiment aims to investigate how pinocembrin affects AF susceptibility in PAH rats and the possible mechanisms involved.

METHODS

The PAH model was induced by monocrotaline (MCT; i. p. 60 mg/kg). Concurrently, rats received pinocembrin (i.p.50 mg/kg) or saline. Hemodynamics parameters, electrocardiogram parameters, lung H.E. staining, atrial electrophysiological parameters, histology, Western blot, and TUNEL assay were detected.

RESULTS

Compared to the control rats, MCT-induced PAH rats possessed prominently enhancive mPAP (mean pulmonary artery pressure), pulmonary vascular remodeling, AF inducibility, HRV, right atrial myocardial fibrosis, apoptosis, atrial ERP, APD, and P-wave duration. Additionally, there were lowered protein levels of Cav1.2, Kv4.2, Kv4.3, and connexin 40 (CX40) in the MCT group in right atrial tissue. However, pinocembrin reversed the above pathologies and alleviated the activity of the Rho A/ROCKs signaling pathway, including the expression of Rho A, ROCK1, ROCK2, and its downstream MYPT-1, LIMK2, BCL-2, BAX, cleaved-caspase3 in right atrial and HL-1 cells.

CONCLUSION

Present data exhibited pinocembrin attenuated atrial electrical, ion-channel, and autonomic remodeling, diminished myocardial fibrosis and apoptosis levels, thereby reducing susceptibility to AF in the MCT-induced PAH rats. Furthermore, we found that pinocembrin exerted inhibitory action on the Rho A/ROCK signaling pathway, which may be potentially associated with its anti-AF effects.

Anticoagulation in acute ischemic stroke patients with mechanical heart valves: To bridge or not with heparin. The ESTREM study

INTRODUCTION

The best therapeutic strategy for patients with mechanical heart valves (MHVs) having acute ischemic stroke during treatment with vitamin K antagonists (VKAs) remain unclear. Being so, we compared the outcomes for: (i) full dose heparin along with VKA (bridging therapy group) and (ii) restarting VKA without heparin (nonbridging group).

PATIENTS AND METHODS

For this multicenter observational cohort study, data on consecutive acute ischemic stroke patients with MHV was retrospectively collected from prospective registries. Propensity score matching (PSM) was adopted to adjust for any treatment allocation confounders. The primary outcome was the composite of stroke, systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding at 90 days.

RESULTS

Overall, 255 out of 603 patients (41.3%) received bridging therapy: 36 (14.1%) had combined outcome, compared with 28 (8.0%) in the nonbridging group (adjusted OR 1.83; 95% CI 1.05-3.18; p = 0.03). Within the bridging group, 13 patients (5.1%) compared to 12 (3.4%) in the nonbridging group had an ischemic outcome (adjusted OR 1.71; 95% CI 0.84-3.47; p = 0.2); major bleedings were recorded in 23 (9.0%) in the bridging group and 16 (4.6%) in the nonbridging group (adjusted OR 1.88; 95% CI 0.95-3.73; p = 0.07). After PSM, 36 (14.2%) of the 254 bridging patients had combined outcome, compared with 23 (9.1%) of 254 patients in the nonbridging group (OR 1.66; 95% CI 0.95-2.85; p = 0.07).

CONCLUSION

Acute ischemic stroke patients with MHV undergoing bridging therapy had a marginally higher risk of ischemic or hemorrhagic events, compared to nonbridging patients.

Medical cardioversion of atrial fibrillation and flutter with class IC antiarrhythmic drugs in young patients with and without congenital heart disease

INTRODUCTION

The use of flecainide and propafenone for medical cardioversion of atrial fibrillation (AF) and atrial flutter/intra-atrial reentrant tachycardia (IART) is well-described in adults without congenital heart disease (CHD). Data are sparse regarding their use for the same purpose in adults with CHD and in adolescent patients with anatomically normal hearts and we sought to describe the use of class IC drugs in this population and identify factors associated with decreased likelihood of success.

METHODS

Single center retrospective cohort study of patients who received oral flecainide or propafenone for medical cardioversion of AF or IART from 2000 to 2022. The unit of analysis was each episode of AF/IART. We performed a time-to-sinus rhythm analysis using a Cox proportional hazards model clustering on the patient to identify factors associated with increased likelihood of success.

RESULTS

We identified 45 episodes involving 41 patients. As only episodes of AF were successfully cardioverted with medical therapy, episodes of IART were excluded from our analyses. Use of flecainide was the only factor associated with increased likelihood of success. There was a statistically insignificant trend toward decreased likelihood of success in patients with CHD.

CONCLUSIONS

Flecainide was more effective than propafenone. We did not detect a difference in rate of conversion to sinus rhythm between patients with and without CHD and were likely underpowered to do so, however, there was a trend toward decreased likelihood of success in patients with CHD. That said, medical therapy was effective in >50% of patients with CHD with AF.

Amiodarone-Induced Nystagmus and Ataxia: Case Report and Systematic Review of Case Reports

Amiodarone is an antiarrhythmic drug with a significant adverse effect profile, including neurotoxicity. While ataxia, neuropathy, and tremors are more commonly seen forms of amiodarone neurotoxicity, very few cases of nystagmus are reported. We report the case of an 86-year-old man who presented with abrupt-onset ataxia, dizziness, and inability to ambulate, 10 days after initiating amiodarone for atrial fibrillation. His examination revealed gaze-evoked nystagmus along with features of cerebellar dysfunction. After excluding other etiologies, amiodarone was stopped. His nystagmus resolved, and his ataxia improved within 48 h of stopping amiodarone. Due to the rarity of this drug-induced adverse effect, we performed a systematic review of available case reports in the literature (PubMed and Scopus) using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and presented our findings. Nystagmus is a rarely reported adverse effect of amiodarone, which can occur within days to months of starting the medication. Treatment includes stopping the drug and monitoring for resolution of nystagmus.

Dapagliflozin attenuates the vulnerability to atrial fibrillation in rats with lipopolysaccharide-induced myocardial injury

BACKGROUND

Oxidative stress is an essential component participating in the development and maintenance of atrial fibrillation (AF). Dapagliflozin, a SGLT2 inhibitor, has been shown to exert cardioprotective effects by ameliorating oxidative stress in multiple heart disease models. However, its potential to attenuate lipopolysaccharide (LPS)-induced myocardial injury in rats remains unknown.

AIM

This study aims to investigate the role of dapagliflozin in LPS-induced myocardial injury and the potential mechanisms involved.

METHODS

Rats were intraperitoneally administered LPS to induce sepsis-like condition. The intervention was conducted with intraperitoneal injection of dapagliflozin or saline 1 h in advance. The effects of dapagliflozin were detected by electrophysiological recordings, western blot, qPCR, ELISA, HE staining, immunohistochemistry and fluorescence. We further validated the mechanism in vitro using HL-1 cells.

RESULTS

Dapagliflozin significantly improved LPS-induced myocardial injury, reduced susceptibility to AF, and mitigated atrial tissue inflammatory cell infiltration and atrial myocyte apoptosis. These were correlated with the Nrf2/HO-1 signaling pathway, which subsequently reduced oxidative stress. Subsequently, we used a specific inhibitor of the Nrf2/HO-1 pathway in vitro, reversed the anti-oxidative stress effects of dapagliflozin on HL-1 cells, further confirming the Nrf2/HO-1 pathway's pivotal role in dapagliflozin-mediated cardioprotection.

CONCLUSION

Dapagliflozin ameliorated myocardial injury and susceptibility to AF induced by LPS through anti-oxidative stress, which relied on upregulation of the Nrf2/HO-1 pathway.

Development and Feasibility of a Primary Care Provider Training Intervention to Improve Atrial Fibrillation Management

The disparities in atrial fibrillation (AF) care are partially attributed to inadequate access to providers with specialized training in AF. Primary care providers (PCPs) are often the sole providers of AF care in under-resourced regions. As such, we sought to create a virtual education intervention for PCPs and to evaluate its impact on the use of stroke risk reduction strategies in patients with AF. A multidisciplinary team mentored PCPs on AF management over 6 months using a virtual case-based training format. Surveys of participant knowledge and confidence in AF care were compared before and after the intervention. Hierarchical logistic regression modeling was used to evaluate change in oral anticoagulation (OAC) therapy in the patients seen by participants before or after training. Of 41 participants trained, 49% worked in family medicine, 41% internal medicine, and 10% general cardiology. Participants attended a mean of 14 1-hour sessions. Overall, the appropriate use of OAC (for CHA2DS2-VASc score ≥1 man, ≥2 women) increased from 37% to 46% (p <0.001) comparing the patients seen before (n = 1,739) versus after (n = 610) intervention. The factors independently associated with appropriate OAC use included participant training (odds ratio [OR] 1.4, p = 0.002) and participant competence in AF management. The factors associated with decreased OAC use included patient age (OR 0.8 per 10 year, p = 0.008) and nonwhite race (OR 0.7, p = 0.028). Provider knowledge and confidence in AF care improved (p <0.001). In conclusion, we show that a virtual PCP training intervention improves the use of stroke risk reduction therapy in outpatients with AF and could be a widely scalable intervention to improve AF care in under-resourced communities.

Identification of Brugada syndrome based on P-wave features: an artificial intelligence-based approach

AIMS

Brugada syndrome (BrS) is an inherited disease associated with an increased risk of ventricular arrhythmias. Recent studies have reported the presence of an altered atrial phenotype characterized by abnormal P-wave parameters. The aim of this study was to identify BrS based exclusively on P-wave features through an artificial intelligence (AI)-based model.

METHODS AND RESULTS

Continuous 5 min 12-lead ECG recordings were obtained in sinus rhythm from (i) patients with spontaneous or ajmaline-induced BrS and no history of AF and (ii) subjects with suspected BrS and negative ajmaline challenge. The recorded ECG signals were processed and divided into epochs of 15 s each. Within these epochs, P-waves were first identified and then averaged. From the averaged P-waves, a total of 67 different features considered relevant to the classification task were extracted. These features were then used to train nine different AI-based supervised classifiers. A total of 2228 averaged P-wave observations, resulting from the analysis of 33 420 P-waves, were obtained from 123 patients (79 BrS+ and 44 BrS-). Averaged P-waves were divided using a patient-wise split, allocating 80% for training and 20% for testing, ensuring data integrity and reducing biases in AI-based model training. The BrS+ patients presented with longer P-wave duration (136 ms vs. 124 ms, P < 0.001) and higher terminal force in lead V1 (2.5 au vs. 1.7 au, P < 0.01) compared with BrS- subjects. Among classifiers, AdaBoost model had the highest values of performance for all the considered metrics, reaching an accuracy of over 81% (sensitivity 86%, specificity 73%).

CONCLUSION

An AI machine-learning model is able to identify patients with BrS based only on P-wave characteristics. These findings confirm the presence of an atrial hallmark and open new horizons for AI-guided BrS diagnosis.

Chinese stroke patients with atrial fibrillation used Robert's age-adjusted warfarin loading protocol obtained good INR results within therapeutic range

To assess whether Roberts' age-adjusted warfarin loading protocol is effective in Chinese patients and whether the SAMeTT2R2 score can predict international normalized ratio (INR) control. Roberts' protocol for warfarin titration was applied to patients with non-valvular atrial fibrillation (NVAF) complicated with ischemic stroke at the Department of Neurology between 2014 and 2019. Clinical and sociodemographic variables were recorded. A minimum of 1-year follow-up was used to calculate the time in therapeutic range (TTR) of the INR. A total of 94 acute ischemic stroke patients with NVAF were included in the study. Seventy-seven (81.9%) of the patients had attained stable INR (2.0-3.0) at the fifth dose, and 90.0% of the patients had achieved stable INR on the ninth day. Seventeen (18.1%) of the patients had an INR > 4 during dose-adjustment period. Patients with INR > 4 had significantly lower body weight (53.8 vs. 63.1 kg, P = 0.014), lower rate of achievement of stable INR (35.3% vs. 92.2%, P = 0.000), and lower rate of TTR ≥ 65% (23.5% vs. 70.1%, P = 0.001), but with no significant increase in bleeding risk. A total of 89 patients underwent long-term INR follow-up, of which 58 (65.2%) patients achieved TTR ≥ 65%. Patients with poor TTR had significantly lower body weight (56.3 vs. 63.7 kg, P = 0.020) and lower rate of stable INR achievement (64.5% vs. 89.7%, P = 0.002). All 94 patients had SAMeTT2R2 score ≥ 2. There was no linear association between SAMeTT2R2 score and the rate of TTR ≥ 65% (Ptrend = 0.095). Chinese ischemic stroke patients with NVAF on warfarin can safely and quickly achieve therapeutic INR using Roberts' age-adjusted protocol and can obtain a good TTR. Lower body weight may be a predictor of poor TTR and INR > 4. Patients who have not attained stable INR after adjusting the dose five times are at high risk for poor TTR. SAMeTT2R2 score may not predict TTR in Chinese ischemic stroke patients with NVAF.

Associations of Life's Essential 8 and fine particulate matter pollution with the incidence of atrial fibrillation

Both unhealthy lifestyle factors and ambient air pollution have been closely linked with the risk of atrial fibrillation (AF). We retrieved 250,898 participants without AF at baseline from UK Biobank. LE8 was determined by 8 metrics, and was characterized as low, moderate and high cardiovascular health (CVH). Exposure to PM2.5 was estimated at the geocoded residential address of each participant. During a median follow-up of 12.46 years, we identified 14,743 (5.9%) incident AF cases. Participants with moderate and high CVH showed a decreased risk of incident AF compared to those with low CVH. Of the LE8 metrics, ideal body mass index (BMI) and blood pressure (BP) were associated with a decrease of 11.57% and 11.46% AF cases. High PM2.5 exposure was associated with an 8% increased risk of AF as compared to low PM2.5 exposure. Compared with those who had low CVH and high PM2.5 exposure, participants with a high CVH and low PM2.5 exposure had the lower AF incidence. Our study found higher CVH is protective, while higher PM2.5 might be one risk factor of AF. Adherence to the LE8 guidelines may help reduce the incidence of AF, especially in those with lower PM2.5 exposure.

COMP Improves Ang-II-Induced Atrial Fibrillation via TGF-β Signaling Pathway

Cartilage oligomeric matrix protein (COMP) regulates transforming growth factor-β (TGF-β) signaling pathway, which has been proved to be associated with skin fibrosis and pulmonary fibrosis. Atrial fibrosis is a major factor of atrial fibrillation (AF). Nevertheless, the interaction between COMP and TGF-β as well as their role in AF remains undefined. The purpose of this study is to clarify the role of COMP in AF and explore its potential mechanism. The hub gene of AF was identified from two datasets using bioinformatics. Furthermore, it was verified by the downregulation of COMP in angiotensin-II (Ang-II)-induced AF in mice. Moreover, the effect on AF was examined using CCK8 assay, ELISA, and western blot. The involvement of TGF-β pathway was further discussed. The expression of COMP was the most significant among all these hub genes. Our experimental results revealed that the protein levels of TGF-β1, phosphorylated Smad2 (P-Smad2), and phosphorylated Smad3 (P-Smad3) were decreased after silencing COMP, which indicated that COMP knockdown could inhibit the activation of TGF-β pathway in AF cells. However, the phenomenon was reversed when the activator SRI was added. COMP acts as a major factor and can improve Ang-II-induced AF via TGF-β signaling pathway. Thus, our research enriches the understanding of the interaction between COMP and TGF-β in AF, and provides reference for the pathogenesis and diagnosis of AF.

Effect of Carvedilol vs Metoprolol on Atrial and Ventricular Arrhythmias Among Implantable Cardioverter-Defibrillator Recipients

BACKGROUND

Both selective and nonselective beta-blockers are used to treat patients with heart failure (HF). However, the data on the association of beta-blocker type with risk of atrial arrhythmia and ventricular arrhythmia (VA) in HF patients with a primary prevention implantable cardioverter-defibrillator (ICD) are limited.

OBJECTIVES

This study sought to evaluate the effect of metoprolol vs carvedilol on the risk of atrial tachyarrhythmia (ATA) and VA in HF patients with an ICD.

METHODS

This study pooled primary prevention ICD recipients from 5 landmark ICD trials (MADIT-II, MADIT-CRT, MADIT-RIT, MADIT-RISK, and RAID). Fine and Gray multivariate regression models, stratified by study, were used to evaluate the risk of ATA, inappropriate ICD shocks, and fast VA (defined as ventricular tachycardia ≥200 beats/min or ventricular fibrillation) by beta-blocker type.

RESULTS

Among 4,194 patients, 2,920 (70%) were prescribed carvedilol and 1,274 (30%) metoprolol. The cumulative incidence of ATA at 3.5 years was 11% in patients treated with carvedilol vs 15% in patients taking metoprolol (P = 0.003). Multivariate analysis showed that carvedilol treatment was associated with a 35% reduction in the risk of ATA (HR: 0.65; 95% CI: 0.53-0.81; P < 0.001) when compared to metoprolol, and with a corresponding 35% reduction in the risk of inappropriate ICD shocks (HR: 0.65; 95% CI: 0.47-0.89; P = 0.008). Carvedilol vs metoprolol was also associated with a 16% reduction in the risk of fast VA. However, these findings did not reach statistical significance (HR: 0.84; 95% CI: 0.70-1.02; P = 0.085).

CONCLUSIONS

These findings suggests that HF patients with ICDs on carvedilol treatment experience a significantly lower risk of ATA and inappropriate ICD shocks when compared to treatment with metoprolol.

Comprehension of Nonvalvular Atrial Fibrillation and Anticoagulant Adherence in Elderly Patients in a Subcohort Study of the All Nippon Atrial Fibrillation in the Elderly Registry

In this subcohort study of the ANAFIE (All Nippon Atrial Fibrillation In the Elderly) Registry enrolling >30,000 Japanese elderly (aged ≥75 years) patients with nonvalvular atrial fibrillation (NVAF), we assessed the association between patient comprehension of NVAF and adherence to anticoagulant therapy with clinical outcomes. Data from 1,968 patients evaluated for NVAF comprehension by a questionnaire consisting of 4 key questions, and 2,362 patients who completed the Morisky Medication Adherence Scale-8 questionnaire were analyzed. Overall, NVAF comprehension was low (81.9% had <3 points), and compared with high comprehension (score ≥3), low comprehension (0 points: 42.1%) was associated with poor prognosis, nonsignificantly higher risk of stroke or systemic embolic event (adjusted hazard ratio [aHR] 2.60 [95% confidence interval 0.97 to 6.94, p = 0.057]), all-cause death (aHR 1.71 [0.96 to 3.04, p = 0.069]), and significantly higher risk of net clinical outcome (composite of stroke/systemic embolic events, major bleeding, and all-cause death) (aHR 1.63 [1.04 to 2.54, p = 0.032]). Adherence to anticoagulant therapy assessed by Morisky Medication Adherence Scale-8 was high (64.9% had high adherence; 29.2%, had medium adherence), but compared with high adherence (score 8), low adherence (score <6: 5.9%) was associated with poor prognosis, significantly higher risk of ischemic stroke (aHR 2.95 [1.08 to 8.04, p = 0.035]), all-cause death (aHR 1.93 [1.16 to 3.21, p = 0.011]), and net clinical outcome (aHR 1.75 [1.12 to 2.75, p = 0.015]). Overall, NVAF comprehension and adherence showed a weak correlation to anticoagulant therapy at baseline (correlation coefficient 0.049). In conclusion, low NVAF comprehension and low anticoagulant adherence were associated with poor clinical outcomes in elderly patients with NVAF.

Qi-Po-Sheng-Mai granule ameliorates Ach-CaCl2 -induced atrial fibrillation by regulating calcium homeostasis in cardiomyocytes

BACKGROUND

Atrial fibrillation (AF) is one of the most common arrhythmias encountered in clinical settings. Currently, the pathophysiology of AF remains unclear, which severely limits the effectiveness and safety of medical therapies. The Chinese herbal formula Qi-Po-Sheng-Mai Granule (QPSM) has been widely used in China to treat AF. However, its pharmacological and molecular mechanisms remain unknown.

PURPOSE

The purpose of this study was to investigate the molecular mechanisms and potential targets of QPSM for AF.

STUDY DESIGN AND METHODS

The AF model was induced by Ach (66 μg/ml) and CaCl2 (10 mg/kg), and the dose of 0.1 ml/100 g was injected into the tail vein for 5 weeks. QPSM was administered daily at doses of 4.42 and 8.84 g/kg, and amiodarone (0.18 g/kg) was used as the positive control. The effect of QPSM on AF was assessed by electrocardiogram, echocardiography, and histopathological analysis. Then, we employed network pharmacology with single nucleus RNA sequencing (snRNA-Seq) to investigate the molecular mechanisms and potential targets of QPSM for AF. Furthermore, high performance liquid chromatography (HPLC) method was used for component analysis of QPSM, and molecular docking was used to verify the potential targets. Using the IonOptix single cell contraction and ion synchronization test equipment, single myocyte length and calcium ion variations were observed in real time. The expression levels of calcium Transporter-related proteins were detected by western blot and immunohistochemistry.

RESULTS

Based on an Ach-CaCl2-induced AF model, we found that QPSM treatment significantly reduced atrial electrical remodeling-related markers, such as AF inducibility and duration, and attenuated atrial dilation and fibrosis. Network pharmacology identified 52 active ingredients and 119 potential targets for QPSM in the treatment of AF, and 45 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched, among which calcium pathway had the greatest impact. Using single nucleus sequencing (snRNA-seq), we identified cardiomyocytes as the most differentially expressed in response to drug treatment, with nine differentially expressed genes enriched in calcium signaling pathways. High performance liquid chromatography and molecular docking confirmed that the core components of QPSM strongly bind to the key factors in the calcium signaling pathway. Additional experiments have shown that QPSM increases calcium transients (CaT) and contractility in the individual cardiomyocyte. This was accomplished by increasing the expression of CACNA1C and SERCA2a and decreasing the expression of CAMK2B and NCX1.

CONCLUSION

The present study has systematically elucidated the role of QPSM in maintaining calcium homeostasis in cardiomyocytes through the regulation of calcium transporters, which could lead to new drug development ideas for AF.

Risk of osteoporosis in patients treated with direct oral anticoagulants vs. warfarin: an analysis of observational studies

Aims

Evidence on the association between the risk of new-onset osteoporosis and oral anticoagulants remains controversial. We aimed to compare the risk of osteoporosis associated with the use of direct oral anticoagulants (DOACs) with that associated with warfarin use.

Methods

Studies published up to 15 March 2023 that investigated the association between the use of DOACs and warfarin and the incidence of osteoporosis were identified by online searches in PubMed, Embase, the Cochrane Library, and Web of Science conducted by two independent investigators. Random-effects or fixed-effect models were employed to synthesize hazard ratios (HRs)/relative ratios (RRs) with 95% confidence intervals (CIs) for estimating the risk of osteoporosis correlated with DOAC and warfarin prescriptions (PROSPERO No. CRD42023401199).

Results

Our meta-analysis ultimately included four studies involving 74,338 patients. The results suggested that DOAC use was associated with a significantly lower incidence of new-onset osteoporosis than warfarin use (pooled HR: 0.71, 95% CI: 0.57 to 0.88, p < 0.001, I 2: 85.1%). Subanalyses revealed that rivaroxaban was associated with a lower risk of osteoporosis than both warfarin and dabigatran. In addition, DOACs were associated with a lower risk of developing osteoporosis than warfarin in both male and female patients, in patients with atrial fibrillation (AF), and in patients who underwent therapy for > 365 days.

Conclusion

DOAC users experienced a lower incidence of osteoporosis than warfarin users. This study may give us insight into safe anticoagulation strategies for patients who are at high risk of developing osteoporosis.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023401199.

Iodine-Induced Hyperthyroidism and Long-term Risks of Incident Atrial Fibrillation and Flutter

CONTEXT

Although iodine-induced hyperthyroidism is a potential consequence of iodinated radiologic contrast administration, its association with long-term cardiovascular outcomes has not been previously studied.

OBJECTIVE

To investigate the relationships between hyperthyroidism observed after iodine contrast administration and incident atrial fibrillation/flutter.

METHODS

Retrospective cohort study of the U.S. Veterans Health Administration (1998-2021) of patients age ≥18 years with a normal baseline serum thyrotropin (TSH) concentration, subsequent TSH <1 year, and receipt of iodine contrast <60 days before the subsequent TSH. Cox proportional hazards regression was employed to ascertain the adjusted hazard ratio (HR) with 95% CI of incident atrial fibrillation/flutter following iodine-induced hyperthyroidism, compared with iodine-induced euthyroidism.

RESULTS

Iodine-induced hyperthyroidism was observed in 2500 (5.6%) of 44 607 Veterans (mean ± SD age, 60.9 ± 14.1 years; 88% men) and atrial fibrillation/flutter in 10.4% over a median follow-up of 3.7 years (interquartile range 1.9-7.4). Adjusted for sociodemographic and cardiovascular risk factors, iodine-induced hyperthyroidism was associated with an increased risk of atrial fibrillation/flutter compared with those who remained euthyroid after iodine exposure (adjusted HR 1.19, 95% CI 1.06-1.33). Females were at greater risk for incident atrial fibrillation/flutter than males (females, HR 1.81, 95% CI 1.12-2.92; males, HR 1.15, 95% CI 1.03-1.30; P for interaction = .04).

CONCLUSION

Hyperthyroidism following a high iodine load was associated with an increased risk of incident atrial fibrillation/flutter, particularly among females. The observed sex-based differences should be confirmed in a more sex-diverse study sample, and the cost-benefit analysis of long-term monitoring for cardiac arrhythmias following iodine-induced hyperthyroidism should be evaluated.

Neutrophil-lymphocyte ratio and clinical outcomes in 19,697 patients with atrial fibrillation: Analyses from ENGAGE AF- TIMI 48 trial

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) is the ratio between neutrophil and lymphocyte counts measured in peripheral blood. NLR is easily calculable based on a routine blood test available worldwide and may reflect systemic inflammation. However, the relationship between NLR and clinical outcomes in atrial fibrillation (AF) patients is not well-described.

METHODS

We calculated NLR at baseline in ENGAGE AF-TIMI 48, a randomized trial comparing edoxaban versus warfarin in patients with AF followed for 2.8 years (median). The association of baseline NLR with major bleeding events, major adverse cardiac events (MACE), cardiovascular death, stroke/systemic embolism, and all-cause mortality were calculated.

RESULTS

The median baseline NLR in 19,697 patients was 2.53 (interquartile range 1.89-3.41). NLR was associated with major bleeding events (HR 1.60; 95% CI 1.41-1.80), stroke/systemic embolism (HR 1.25; 95% CI, 1.09-1.44), MI (HR 1.73; 95% CI 1.41-2.12), MACE (HR 1.70; 95% CI 1.56-1.84), CV (HR 1.93; 95% CI 1.74-2.13) and all-cause mortality (HR 2.00; 95% CI 1.83-2.18). The relationships between NLR and outcomes remained significant after adjustment for risk factors. Edoxaban consistently reduced major bleeding. MACE, and CV death across NLR groups vs. warfarin.

CONCLUSIONS

NLR represents a widely available, simple, arithmetic calculation that could be immediately and automatically reported during a white blood cell differential measurement to identify patients with AF at increased risk of bleeding, CV events, and mortality.

Effectiveness and Safety of Direct Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation Patients With Extreme Obesity

Direct oral anticoagulants (DOACs) are a favored treatment to prevent stroke in patients with atrial fibrillation (AF). There are limited data concerning the efficacy and safety of DOACs in obese. Obesity leads to wide structural and physiological changes that may affect the pharmacokinetics and pharmacodynamics of drugs. The optimal dosing strategies for DOACs in this significant and growing sub-group remain unknown. The study aimed to evaluate on a large scale the safety and efficacy of DOAC treatment in extreme obese patients with AF. In this retrospective cohort study, we included patients with AF treated with DOACs. Patients were divided according to body mass index (BMI). Study outcomes included stroke, major bleeding, and death. Between 2012 and 2017, 5183 patients with AF were included in the analysis (2,688, 2137, and 358 patients had a BMI <30, 30 to 40, and >40 accordingly). There was no significant difference in the prevalence of ischemic events (9.9%, 8.2%, and 7.5% of patients with BMI <30, 30 to 40, and >40, respectively, p = 0.088), major bleeding events (13%, 14.1%, and 11.2% of patients with BMI <30, 30 to 40, and >40, respectively, p value = 0.257) or net ischemic and major bleeding events (18.7%, 18.7%, and 15.4% of patients with BMI <30, 30 to 40, and >40 respectively, p = 0.297) between the BMI groups. In conclusion, DOACs treatment for prevention of ischemic events in AF is effective and safe through the BMI spectrum, including extreme obesity.

Air Pollution and Arrhythmias

Air pollution is commonly defined as the contamination of the air we breathe by any chemical, physical, or biological agent that is potentially threatening to human and ecosystem health. The common pollutants known to be disease-causing are particulate matter, ground-level ozone, sulphur dioxide, nitrogen dioxide, and carbon monoxide. Although the association between increasing concentrations of these pollutants and cardiovascular disease is now accepted, the association of air pollution and arrhythmias is less well established. In this review we provide an in-depth discussion of the association of acute and chronic air pollution exposure and arrhythmia incidence, morbidity, and mortality, and the purported pathophysiological mechanisms. Increases in concentrations of air pollutants have multiple proarrhythmic mechanisms including systemic inflammation (via increases in reactive oxygen species, tumour necrosis factor, and direct effects from translocated particulate matter), structural remodelling (via an increased risk of atherosclerosis and myocardial infarction or by affecting the cell-to-cell coupling and gap junction function), and mitochondrial and autonomic dysfunction. Furthermore, we describe the associations of air pollution and arrhythmias. There is a strong correlation of acute and chronic air pollutant exposure and the incidence of atrial fibrillation. Acute increases in air pollution increase the risk of emergency room visits and hospital admissions for atrial fibrillation and the risk of stroke and mortality in patients with atrial fibrillation. Similarly, there is a strong correlation of increases of air pollutants and the risk of ventricular arrhythmias, out-of-hospital cardiac arrest, and sudden cardiac death.

Predictors of ibrutinib-associated atrial fibrillation: 5-year follow-up of a prospective study

Ibrutinib-associated atrial fibrillation (IRAF) emerged among the adverse events of major interests in ibrutinib-treated patients as real-world studies showed a higher incidence compared to clinical trials. We prospectively analyzed predictors of IRAF in 43 single-center consecutive patients affected by chronic lymphocytic leukemia that started therapy with ibrutinib between 2015 and 2017. Key secondary endpoints were to describe the management of IRAF and survival outcomes. During a median follow-up period of 52 months, we registered 45 CV events, with a total of 23 AF events in 13 patients (CI 30.0% (95% CI: 16.5-43.9)). Pre-existent cardiovascular risk factors, in particular hypertension, a previous history of AF and a high Shanafelt risk score emerged as predictors of IRAF. Baseline echocardiographic evaluation of left atrial (LA) dimensions confirmed to predict IRAF occurrence and cut-off values were identified in our cohort: 32 mm for LA diameter and 18 cm2 for LA area. No difference in progression free survival and overall survival emerged in patients experiencing IRAF. Following AF, anticoagulation was started in all eligible patients, and cardioactive therapy was accordingly modified. Echocardiography represents a highly reproducible and widespread tool to be included in the work-up of ibrutinib candidates; the identification of IRAF predictors represents a useful guide to clinical practice.

The Arrhythmogenicity of Sotalol and its Role in Heart Failure: A Literature Review

ABSTRACT

According to the American Heart Association, approximately 6 million adults have been afflicted with heart failure in the United States in 2020 and are more likely to have sudden cardiac death accounting for approximately 50% of the cause of mortality. Sotalol is a nonselective β-adrenergic receptor antagonist with class III antiarrhythmic properties that has been mostly used for atrial fibrillation treatment and suppressing recurrent ventricular tachyarrhythmias. The use of sotalol in patients with left ventricular dysfunction is not recommended by the American College of Cardiology or American Heart Association because studies are inconclusive with conflicting results regarding safety. This article aims to review the mechanism of action of sotalol, the β-blocking effects on heart failure, and provide an overview of clinical trials on sotalol use and its effects in patients with heart failure. Small- and large-scale clinical trials have been controversial and inconclusive about the use of sotalol in heart failure. Sotalol has been shown to reduce defibrillation energy requirements and reduce shocks from implantable cardioverter-defibrillators. Torsades de Pointes is the most life-threatening arrhythmia that has been documented with sotalol use and occurs more commonly in women and heart failure patients. Thus far, mortality benefits have not been demonstrated with sotalol use and larger multicenter studies are required going forward.

Dronedarone Versus Sotalol in Antiarrhythmic Drug-Naive Veterans With Atrial Fibrillation

BACKGROUND

Sotalol and dronedarone are both used for maintenance of sinus rhythm for patients with atrial fibrillation. However, while sotalol requires initial monitoring for QT prolongation and proarrhythmia, dronedarone does not. These treatments can be used in comparable patients, but their safety and effectiveness have not been compared head to head. Therefore, we retrospectively evaluated the effectiveness and safety using data from a large health care system.

METHODS

Using Veterans Health Administration data, we identified 11 296 antiarrhythmic drug-naive patients with atrial fibrillation prescribed dronedarone or sotalol in 2012 or later. We excluded patients with prior conduction disease, pacemakers or implantable cardioverter-defibrillators, ventricular arrhythmia, cancer, renal failure, liver disease, or heart failure. We used natural language processing to identify and compare baseline left ventricular ejection fraction between treatment arms. We used 1:1 propensity score matching, based on patient demographics, comorbidities, and medications, and Cox regression to compare strategies. To evaluate residual confounding, we performed falsification analysis with nonplausible outcomes.

RESULTS

The matched cohort comprised 6212 patients (3106 dronedarone and 3106 sotalol; mean [±SD] age, 71±10 years; 2.5% female; mean [±SD] CHA2DS2-VASC, 2±1.3). The mean (±SD) left ventricular ejection fraction was 55±11 and 58±10 for dronedarone and sotalol users, correspondingly. Dronedarone, compared with sotalol, did not demonstrate a significant association with risk of cardiovascular hospitalization (hazard ratio, 1.03 [95% CI, 0.88-1.21]) or all-cause mortality (hazard ratio, 0.89 [95% CI, 0.68-1.16]). However, dronedarone was associated with significantly lower risk of ventricular proarrhythmic events (hazard ratio, 0.53 [95% CI, 0.38-0.74]) and symptomatic bradycardia (hazard ratio, 0.56 [95% CI, 0.37-0.87]). The primary findings were stable across sensitivity analyses. Falsification analyses were not significant.

CONCLUSIONS

Dronedarone, compared with sotalol, was associated with a lower risk of ventricular proarrhythmic events and conduction disorders while having no difference in risk of incident cardiovascular hospitalization and mortality. These observational data provide the basis for prospective efficacy and safety trials.

Balancing the risk of stroke and bleeding in atrial fibrillation patients with a history of falls

INTRODUCTION

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and can lead to serious consequences such as ischemic stroke and systemic thromboembolism. The risk of thromboembolism can be reduced by anticoagulation, however many patients with high falls risk do not receive oral anticoagulation.

AREAS COVERED

In this narrative literature review, performed with searches of the PubMed database, we discuss the factors predisposing AF patients to falls, ways to optimize bleeding risk with individualized assessment, and clarify misconceptions around falls risk and anticoagulation therapy.

EXPERT OPINION

In general, the advantages of stroke prevention with oral anticoagulation outweigh the risk of bleeding resulting from falls, especially with the increasing use of non-vitamin K oral anticoagulants, which are associated with fewer intracranial hemorrhages and thromboembolic complications than vitamin K anticoagulants. Most studies in this field are observational and randomized controlled studies would be beneficial.

Association between exposure to air pollution and incidence of atrial fibrillation

INTRODUCTION AND OBJECTIVE

Air pollution is the largest environmental health risk, estimated to cause over 5 million premature deaths per year worldwide, including half million deaths in Europe. It is associated with significant reductions in healthy life years and worker productivity. It may also be an important endocrine disrupter, contributing to the development of metabolic diseases such as obesity and diabetes mellitus and due to acute ischaemic/thrombotic cardiovascular events. Aim of the study was to present the current knowledge on short- and long-term exposure to air pollution, including particulate matter (PM2.5 and PM10) and the occurrence of atrial fibrillation (AF).

REVIEW METHODS

The review article was based on data obtained from articles published in the PubMed or related databases. We searched observational studies.

ABBREVIATED DESCRIPTION OF THE STATE OF KNOWLEDGE

Some of the studies demonstrated a triggering effect of exposure to air pollution on acute exacerbation of atrial fibrillation. Evidence for a long-term effect of air pollution exposure on AF episodes is even more scarce or limited.

SUMMARY

Data indicate that human exposure to air pollution is associated with an increased risk of atrial fibrillation. Studies confirmed that further efforts to reduce air pollution exposure should be undertaken to reduce the negative health effects in the general population. To better understand the effect of air pollution on incidence of AF and the related public health impact in the most polluted regions of the world, more high-quality studies are needed.