Valsartan for prevention of recurrent atrial fibrillation

Long-Term Statin Use Is Associated With Reduced Rates of Adverse Events in Patients With Newly Diagnosed Atrial Fibrillation

BACKGROUND

The effectiveness of statin use in preventing adverse cardiovascular events in individuals with atrial fibrillation (AF) has remained uncertain. This study aimed to assess whether statin use could lead to better outcomes among individuals with AF.

METHODS AND RESULTS

We enrolled 397 787 patients with AF from January 1, 2012 to December 31, 2020. Patients with AF were divided into 2 groups (statin user and statin nonuser), and the risks of composite outcomes (including ischemic stroke, hemorrhagic stroke, and transient ischemic attack), all-cause death, and major adverse cardiovascular events (which encompassed cardiovascular death, myocardial infarction, stroke, and heart failure hospitalization) were analyzed. We analyzed 288 958 patients with newly diagnosed AF (mean age, 73 years; 44% women; mean CHA2DS2-VASc score, 3.5). Compared with patients without statin use, statin users had lower risks of composite end points (adjusted hazard ratio [HR], 0.91 [95% CI, 0.87-0.94]; P<0.01). In regard to all-cause death, statin users exhibited a 67% risk reduction compared with statin nonusers (adjusted HR, 0.33 [95% CI, 0.32-0.33]; P<0.01). Statin use was also associated with reduced incidence of major adverse cardiovascular events (adjusted HR, 0.64 [95% CI, 0.63-0.66]; P<0.01). In the subgroups stratified by CHA2DS2-VASc score, statin therapy was particularly effective for patients with CHA2DS2-VASc scores 0 to 3 for composite end points but consistently reduced all-cause mortality and major adverse cardiovascular events across all score categories.

CONCLUSIONS

Among patients with newly diagnosed AF, statin use was associated with lower risk of ischemic stroke, hemorrhagic stroke, transient ischemic attack, all-cause mortality, and major adverse cardiovascular events.

A real-world pharmacovigilance analysis of adverse events associated with irbesartan using the FAERS and JADER databases

Objective

Hypertension is a leading global risk factor for disability and death. Irbesartan, a potent angiotensin II receptor blocker, requires continuous safety monitoring. We conducted a disproportionality analysis of irbesartan-related adverse drug events (ADEs) using the FDA's FAERS and Japan's JADER databases.

Methods

We extracted irbesartan-related ADE reports from FAERS (Q1 2004 to Q1 2024) and JADER (Q2 2008 to Q4 2023). We used Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM) for signal detection. Sensitivity analyses were conducted to exclude comorbid medications, and subgroup analyses by age and gender were performed to explore ADE occurrence in specific populations. Th time to onset (TTO) of ADEs was assessed using Weibull distribution test and Kaplan-Meier curves.

Results

A total of 5,816 (FAERS) and 366 (JADER) reports were analyzed, with irbesartan-related preferred terms (PTs) involving 27 System Organ Classes (SOCs) in FAERS and 22 in JADER. Three SOCs met detection thresholds in both databases: "metabolism and nutrition disorders," "cardiac disorders," and "renal and urinary disorders." We identified 219 positive signals in FAERS and 20 in JADER, including known signals like hyperkalemia, hypotension, and acute kidney injury. Notably, newly identified signals such as acute pancreatitis (n = 50, ROR: 7.76 [5.88-10.25]) and rhabdomyolysis (n = 50, ROR: 7.76 [5.88-10.25]) in FAERS and respiratory failure (n = 7, ROR: 6.76 [3.20-14.26]) in JADER could have significant clinical implications, as they may lead to severe outcomes if not recognized and managed promptly. Subgroup analyses revealed both similarities and differences in signal detection across gender and age groups. Sensitivity analyses, excluding concomitant medications, confirmed the persistence of key positive signals, including hyperkalemia, angioedema, acute pancreatitis, and agranulocytosis. ADEs mainly occurred within 1 month (34.14%) and after 1 year (32.32%) after dosing, with a median onset of 107 days.

Conclusion

This study provides valuable real-world evidence on the safety profile of irbesartan. The identification of new safety signals underscores the necessity of updating drug labels, particularly for assessing and managing high-risk patients. Additionally, the TTO analysis emphasizes the importance of sustained vigilance for adverse events over time. In conclusion, our findings contribute to a more comprehensive understanding of irbesartan's safety, aiding healthcare professionals in optimizing its use in clinical practice.

Metabolic remodelling in atrial fibrillation: manifestations, mechanisms and clinical implications

Atrial fibrillation (AF) is a continually growing health-care burden that often presents together with metabolic disorders, including diabetes mellitus and obesity. Current treatments often fall short of preventing AF and its adverse outcomes. Accumulating evidence suggests that metabolic disturbances can promote the development of AF through structural and electrophysiological remodelling, but the underlying mechanisms that predispose an individual to AF are aetiology-dependent, thus emphasizing the need for tailored therapeutic strategies to treat AF that target an individual's metabolic profile. AF itself can induce changes in glucose, lipid and ketone metabolism, mitochondrial function and myofibrillar energetics (as part of a process referred to as 'metabolic remodelling'), which can all contribute to atrial dysfunction. In this Review, we discuss our current understanding of AF in the setting of metabolic disorders, as well as changes in atrial metabolism that are relevant to the development of AF. We also describe the potential of available and emerging treatment strategies to target metabolic remodelling in the setting of AF and highlight key questions and challenges that need to be addressed to improve outcomes in these patients.

Hypertension and atrial fibrillation: the clinical impact of hypertension on perioperative outcomes of atrial fibrillation ablation and its optimal control for the prevention of recurrence

Hypertension (HTN) is one of the major risk factors for developing atrial fibrillation (AF), and it has been estimated that approximately 70% of hypertensive patients are at risk of developing AF. On the other hand, 60-80% of AF patients have HTN. These two diseases share many risk factors such as diabetes mellitus, obesity, alcohol consumption, and sleep apnea syndrome during their onset and disease progression. The mutual presence of these diseases has the potential to create a negative spiral, exacerbating each other's impact and ultimately leading to cardiovascular events such as heart failure and cerebrovascular disorders, thereby increasing mortality rates. With regard to the treatment of HTN, the variety of antihypertensive drugs and treatment options have significantly increased. Alongside the widespread adoption of antihypertensive therapy, a certain level of efficacy has been recognized in suppressing the incidence of new-onset AF. Catheter ablation is an established and effective treatment for AF. However, a notable recurrence rate persists. In recent years, management of these multiple risk factors has been recognized to be essential for suppressing AF recurrence, and recent guidelines for AF underscore the significance of proactively managing these risks before treatment. Notably, effective HTN management assumes paramount importance given its impact on the morbidity of AF patients. This review summarizes the correlation between HTN control before and after ablation and the risk of AF recurrence. The focus is on elucidating the pathophysiological background and its impact on clinical outcomes.

Atrial Fibrillation and Underlying Structural and Electrophysiological Heterogeneity

As atrial fibrillation (AF) progresses from initial paroxysmal episodes to the persistent phase, maintaining sinus rhythm for an extended period through pharmacotherapy and catheter ablation becomes difficult. A major cause of the deteriorated treatment outcome is the atrial structural and electrophysiological heterogeneity, which AF itself can exacerbate. This heterogeneity exists or manifests in various dimensions, including anatomically segmental structural features, the distribution of histological fibrosis and the autonomic nervous system, sarcolemmal ion channels, and electrophysiological properties. All these types of heterogeneity are closely related to the development of AF. Recognizing the heterogeneity provides a valuable approach to comprehending the underlying mechanisms in the complex excitatory patterns of AF and the determining factors that govern the seemingly chaotic propagation. Furthermore, substrate modification based on heterogeneity is a potential therapeutic strategy. This review aims to consolidate the current knowledge on structural and electrophysiological atrial heterogeneity and its relation to the pathogenesis of AF, drawing insights from clinical studies, animal and cell experiments, molecular basis, and computer-based approaches, to advance our understanding of the pathophysiology and management of AF.

Primary cilia suppress the fibrotic activity of atrial fibroblasts from patients with atrial fibrillation in vitro

Atrial fibrosis serves as an arrhythmogenic substrate in atrial fibrillation (AF) and contributes to AF persistence. Treating atrial fibrosis is challenging because atrial fibroblast activity is multifactorial. We hypothesized that the primary cilium regulates the profibrotic response of AF atrial fibroblasts, and explored therapeutic potentials of targeting primary cilia to treat fibrosis in AF. We included 25 patients without AF (non-AF) and 26 persistent AF patients (AF). Immunohistochemistry using a subset of the patients (non-AF: n = 10, AF: n = 10) showed less ciliated fibroblasts in AF versus non-AF. Acetylated α-tubulin protein levels were decreased in AF, while the gene expressions of AURKA and NEDD9 were highly increased in AF patients' left atrium. Loss of primary cilia in human atrial fibroblasts through IFT88 knockdown enhanced expression of ECM genes, including FN1 and COL1A1. Remarkably, restoration or elongation of primary cilia by an AURKA selective inhibitor or lithium chloride, respectively, prevented the increased expression of ECM genes induced by different profibrotic cytokines in atrial fibroblasts of AF patients. Our data reveal a novel mechanism underlying fibrotic substrate formation via primary cilia loss in AF atrial fibroblasts and suggest a therapeutic potential for abrogating atrial fibrosis by restoring primary cilia.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Lifestyle changes in atrial fibrillation management and intervention

Atrial fibrillation (AF) is one of the most common arrhythmias in adults, and its continued rise in the United States is complicated by the increased incidence and prevalence of several AF risk factors, such as obesity, physical inactivity, hypertension, obstructive sleep apnea, diabetes mellitus, coronary artery disease, and alcohol, tobacco, or caffeine use. Lifestyle and risk factor modification has been proposed as an additional pillar of AF therapy, added to rhythm control, rate control, and anticoagulation, to reduce AF burden and risk. Although emerging evidence largely supports the integration of lifestyle and risk factor management in clinical practice, randomized clinical trials investigating the long-term sustainability and reproducibility of these benefits remain sparse. The purpose of this review is to discuss potentially reversible risk factors on AF, share evidence for the impact on AF by modification of these risk factors, and then provide an overview of the effects of reversing or managing these risk factors on the success of various AF management strategies, such as antithrombotic, rate control, and rhythm control therapies.

Randomised controlled trials of antihypertensive therapy: does exclusion of orthostatic hypotension alter treatment effect? A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Management of antihypertensive therapy is challenging in patients with symptomatic orthostatic hypotension, a population often excluded from randomised controlled trials of antihypertensive therapy. In this systematic review and meta-analysis, we sought to determine whether the association of antihypertensive therapy and adverse events (e.g. falls, syncope), differed among trials that included or excluded patients with orthostatic hypotension.

METHODS

We performed a systematic review and meta-analysis of randomised controlled trials comparing blood pressure lowering medications to placebo, or different blood pressure targets on falls or syncope outcomes and cardiovascular events. A random-effects meta-analysis was used to estimate a pooled treatment-effect overall in subgroups of trials that excluded patients with orthostatic hypotension and trials that did not exclude patients with orthostatic hypotension, and tested P for interaction. The primary outcome was fall events.

RESULTS

46 trials were included, of which 18 trials excluded orthostatic hypotension and 28 trials did not. The incidence of hypotension was significantly lower in trials that excluded participants with orthostatic hypotension (1.3% versus 6.2%, P < 0.001) but not incidences of falls (4.8% versus 8.8%; P = 0.40) or syncope (1.5% versus 1.8%; P = 0.67). Antihypertensive therapy was not associated with an increased risk of falls in trials that excluded (OR 1.00, 95% CI; 0.89-1.13) or included (OR 1.02, 95% CI; 0.88-1.18) participants with orthostatic hypotension (P for interaction = 0.90).

CONCLUSIONS

The exclusion of patients with orthostatic hypotension does not appear to affect the relative risk estimates for falls and syncope in antihypertensive trials.

Gq-Mediated Arrhythmogenic Signaling Promotes Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is promoted by various stimuli like angiotensin II, endothelin-1, epinephrine/norepinephrine, vagal activation, or mechanical stress, all of which activate receptors coupled to G-proteins of the Gα_q/Gα₁₁-family (G_q). Besides pro-fibrotic and pro-inflammatory effects, G_q-mediated signaling induces inositol trisphosphate receptor (IP₃R)-mediated intracellular Ca²⁺ mobilization related to delayed after-depolarisations and AF. However, direct evidence of arrhythmogenic G_q-mediated signaling is absent.

METHODS AND RESULTS

To define the role of G_q in AF, transgenic mice with tamoxifen-inducible, cardiomyocyte-specific Gα_q/Gα₁₁-deficiency (G_q-KO) were created and exposed to intracardiac electrophysiological studies. Baseline electrophysiological properties, including heart rate, sinus node recovery time, and atrial as well as AV nodal effective refractory periods, were comparable in G_q-KO and control mice. However, inducibility and mean duration of AF episodes were significantly reduced in G_q-KO mice-both before and after vagal stimulation. To explore underlying mechanisms, left atrial cardiomyocytes were isolated from G_q-KO and control mice and electrically stimulated to study Ca²⁺-mobilization during excitation-contraction coupling using confocal microscopy. Spontaneous arrhythmogenic Ca²⁺ waves and sarcoplasmic reticulum content-corrected Ca²⁺ sparks were less frequent in G_q-KO mice. Interestingly, nuclear but not cytosolic Ca²⁺ transient amplitudes were significantly decreased in G_q-KO mice.

CONCLUSION

G_q-signaling promotes arrhythmogenic atrial Ca²⁺-release and AF in mice. Targeting this pathway, ideally using G_q-selective, biased receptor ligands, may be a promising approach for the treatment and prevention of AF. Importantly, the atrial-specific expression of the G_q-effector IP₃R confers atrial selectivity mitigating the risk of life-threatening ventricular pro-arrhythmic effects.

Epidemiology and modifiable risk factors for atrial fibrillation

The global prevalence of atrial fibrillation (AF) has increased substantially over the past three decades and is currently approximately 60 million cases. Incident AF and its clinical consequences are largely the result of risk factors that can be modified by lifestyle changes. In this Review, we provide evidence that the lifetime risk of AF is modified not only by sex and race but also through the clinical risk factor and comorbidity burden of individual patients. We begin by summarizing the epidemiology of AF, focusing on non-modifiable and modifiable risk factors, as well as targets and strategies for the primary prevention of AF. Furthermore, we evaluate the role of modifiable risk factors in the secondary prevention of AF as well as the potential effects of risk factor interventions on the frequency and severity of subsequent AF episodes. We end the Review by proposing strategies that require evaluation as well as global policy changes that are needed for the prevention of incident AF and the management of recurrent episodes in patients already affected by AF.

Hypertension and atrial fibrillation

Hypertension is the most prevalent cardiovascular risk factor underlying atrial fibrillation and is present in up to 40% of patients with atrial fibrillation. Furthermore, attributable risk studies have shown that a history of hypertension contributes to up to 24% of incident atrial fibrillation. New data suggest that even early forms of hypertension (prehypertension and aortic stiffness) are associated with an increased risk of atrial fibrillation development. Hypertension and prehypertension are therefore critical mediators for the development of atrial fibrillation. Mechanisms for the association between hypertension and atrial fibrillation include diffuse electro-structural changes to the left atrium, driven by the haemodynamic and neurohormonal influences of hypertension and other, frequently coexisting, cardiovascular risk factors. Management of hypertension in atrial fibrillation should focus not only on blood pressure reduction but also on a comprehensive risk factor modification strategy. Such strategies have been shown to be associated with significant improvements in atrial fibrillation symptom burden as well as improved arrhythmia-free survival and reversal of the progression of atrial fibrillation. These strategies should focus on dietary modifications as well as prescribed exercise programmes involving a multidisciplinary team and patient-centred atrial fibrillation care. Risk factor management, supplemented by antihypertensive medications as needed, provides the optimum strategy for improving outcomes and even reversing the natural progression of atrial fibrillation in patients with hypertension.

Benefits and risks of antihypertensive medication in adults with different systolic blood pressure: A meta-analysis from the perspective of the number needed to treat

Background

The blood pressure (BP) threshold for initial pharmacological treatment remains controversial. The number needed to treat (NNT) is a significant indicator. This study aimed to explore the benefits and risks of antihypertensive medications in participants with different systolic BPs (SBPs), and cardiovascular disease status from the perspective of the NNT.

Methods

We conducted a meta-analysis of 52 randomized placebo-controlled trials. The data were extracted from published articles and pooled to calculate NNTs. The participants were divided into five groups, based on the mean SBP at entry (120–129.9, 130–139.9, 140–159.9, 160–179.9, and ≥180 mmHg). Furthermore, we stratified patients into those with and without cardiovascular disease. The primary outcomes were the major adverse cardiovascular events (MACEs), and adverse events (AEs) leading to discontinuation.

Results

Antihypertensive medications were not associated with MACEs, however, it increased AEs, when the SBP was <140 mmHg. For participants with cardiovascular disease or at a high risk of heart failure and stroke, antihypertensive treatment reduced MACEs when SBP was ≥130 mmHg. Despite this, only 2–4 subjects had reduced MACEs per 100 patients receiving antihypertensive medications for 3.50 years. The number of individuals who needed to treat to avoid MACEs declined with an increased cardiovascular risk.

Conclusion

Pharmacological treatment could be activated when SBP reaches 140 mmHg. For people with cardiovascular disease or at a higher risk of stroke and heart failure, 130 mmHg may be a better therapeutic threshold. It could be more cost-effective to prioritize antihypertensive medications for people with a high risk of developing cardiovascular disease.

Effects of Sacubitril/Valsartan on the Expression of CaMKII/Cav1.2 in Atrial Fibrillation Stimulation Rabbit Model

Background and Objective. Atrial fibrillation (AF) is linked to high morbidity and death rates throughout the world due to limited therapeutic options and thus presents a major challenge to the developed and developing countries. In this study, we aim to investigate the influence of sacubitril/valsartan (sac/val) treatment on the calmodulin-dependent protein kinase II (CaMKII)/Cav1.2 expression in AF models. Methods. Overall, 18 rabbits were randomly divided into control, pacing (600 beats/min), and pacing+sac/val groups. The rabbits in the pacing+sac/val cohort received oral sac/val (10 mg/kg twice daily) across the 21-day investigation period. After three weeks, the atrial effective refractory period (AERP) and AF induction rate were compared. HL-1 cultures were exposed to fast pacing (24 h) with and without LBQ657 (active sacubitril form)/valsartan. Western blots were used for detecting Cav1.2 and CaMKII expression within atrial muscles of the rabbits and HL-1 cultures of AF model. Results. In comparison to the sham cohort, the AF induction rate was markedly increased together with AERP reduction within pacing cohort. Such changes were markedly rescued through sac/val treatment in pacing+sac/val cohort. The proteomic expression profiles of CaMKII and Cav1.2 showed that the CaMKII expression was markedly upregulated, while Cav1.2 expression was downregulated in the pacing cohort. Importantly, these effects were absent in pacing+sac/val cohort. Conclusion. Results of this study show that sac/val treatment regulates the expression of CaMKII/Cav1.2 and could alter this pathway in atrial rapid electrical stimulation models. Therefore, this investigation could contribute to a novel strategy in AF therapeutics in clinical settings.

Sacubitril/valsartan attenuates atrial structural remodelling in atrial fibrillation patients

Aims

Radiofrequency catheter ablation (RFCA) is now an established therapeutic option for patients with atrial fibrillation (AF), but the long‐term recurrence rate of AF is still high. Sacubitril/valsartan (Sac/Val) is superior to valsartan in attenuating ventricular remodelling and improving clinical outcomes in heart failure patients, but whether this additional benefit exists in reversing atrial remodelling and reducing AF recurrence of RFCA‐treated AF patients remains uncovered.

Methods and results

Patients that had undergone RFCA were enrolled and randomly assigned 1:1 to valsartan (160 mg/day) or Sac/Val (200 mg/day) treatment group, in addition to other standard treatment of AF. Patients were followed up for 24 weeks. Echocardiography and ambulatory Holter monitoring for 24 h was performed at 24 weeks after RFCA. The primary end point was the change of atrial diameter from baseline to 24 weeks after RFCA. Second end points included the recurrence rate of AF, all‐cause hospitalization and all‐cause death. A total of 64 AF patients were enrolled, 32 of which received Sac/Val and 32 received valsartan treatment. There was no difference in the age (64.8 ± 9.8 vs. 63.7 ± 9.0, P = 0.634), gender (per cent of male: 59.4% vs. 50.0%, P = 0.616), heart rate (84.7 ± 4.1 b.p.m. vs. 80.9 ± 2.6 b.p.m., P = 0.428), systolic (127.5 ± 15.4 mmHg vs. 130.0 ± 17.8 mmHg, P = 0.549) or diastolic (81.7 ± 9.8 mmHg vs. 79.9 ± 12.6, P = 0.537) blood pressure upon admission between valsartan and Sac/Val treatment groups. The percentage of persistent AF was also comparable (43.8% vs. 53.1%, P = 0.617) in both treatment groups. Patients receiving Sac/Val treatment displayed significant decrease in the left atrial diameter (4.3 ± 0.5 cm to 3.8 ± 0.5 cm, P < 0.001), volume index (48.0 ± 6.4 mL/m² to 41.7 ± 7.0 mL/m², P < 0.001), and right atrial diameter (4.4 ± 0.8 cm to 3.9 ± 0.7 cm, P = 0.017) from baseline to 24 weeks after RFCA. This effect was not observed in valsartan treatment group. There was a numerical decrease in AF recurrence rate in the Sac/Val group compared with valsartan group (9.4% vs. 15.6%), although this difference did not reach a statistical significance (P = 0.708). No difference in all‐cause hospitalization rate (6.3% in each group) or all‐cause death rate (0% in each group) was observed.

Conclusions

Our data indicate that Sac/Val is superior to valsartan in attenuating atrial structural remodelling in catheter ablation‐treated AF patients.

Role of Inflammation in the Pathogenesis of Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common arrhythmias encountered in clinical practice. AF is a major risk factor for stroke, which is associated with high mortality and great disability and causes a significant burden on society. With the development of catheter ablation, AF has become a treatable disease, but its therapeutic outcome has been limited so far. In persistent and long-standing AF, the expanded AF substrate is difficult to treat only by ablation, and a better understanding of the mechanism of AF substrate formation will lead to the development of a new therapeutic strategy for AF. Inflammation is known to play an important role in the substrate formation of AF. Inflammation causes and accelerates the electrical and structural remodeling of the atria via pro-inflammatory cytokines and other inflammatory molecules, and enhances the AF substrate, leading to the maintenance of AF and further inflammation, which forms a vicious spiral, so-called "AF begets AF". Breaking this vicious cycle is expected to be a key therapeutic intervention in AF. In this review, we will discuss the relationship between AF and inflammation, the inflammatory molecules included in the AF-related inflammatory process, and finally the potential of those molecules as a therapeutic target.

Hypertension and Arrhythmias: A Clinical Overview of the Pathophysiology-Driven Management of Cardiac Arrhythmias in Hypertensive Patients

Because of demographic aging, the prevalence of arterial hypertension (HTN) and cardiac arrhythmias, namely atrial fibrillation (AF), is progressively increasing. Not only are these clinical entities strongly connected, but, acting with a synergistic effect, their association may cause a worse clinical outcome in patients already at risk of ischemic and/or haemorrhagic stroke and, consequently, disability and death. Despite the well-known association between HTN and AF, several pathogenetic mechanisms underlying the higher risk of AF in hypertensive patients are still incompletely known. Although several trials reported the overall clinical benefit of renin–angiotensin–aldosterone inhibitors in reducing incident AF in HTN, the role of this class of drugs is greatly reduced when AF diagnosis is already established, thus hinting at the urgent need for primary prevention measures to reduce AF occurrence in these patients. Through a thorough review of the available literature in the field, we investigated the basic mechanisms through which HTN is believed to promote AF, summarising the evidence supporting a pathophysiology-driven approach to prevent this arrhythmia in hypertensive patients, including those suffering from primary aldosteronism, a non-negligible and under-recognised cause of secondary HTN. Finally, in the hazy scenario of AF screening in hypertensive patients, we reviewed which patients should be screened, by which modality, and who should be offered oral anticoagulation for stroke prevention.

Impact of renin-angiotensin-aldosterone-system inhibitor drugs on mortality in patients with atrial fibrillation and hypertension

BACKGROUND

Renin-angiotensin-aldosterone-system inhibitors markedly play an active role in the primary prevention of atrial fibrillation (AF), but the impact of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) on the mortality of patients with AF remains unclear. This study aimed to examine the relationship between treatment with ACEIs or ARBs and mortality in emergency department (ED) patients with AF and hypertension.

METHODS

This multicenter study enrolled 2016 ED patients from September 2008 to April 2011; 1110 patients with AF and hypertension were analyzed. Patients were grouped according to whether they were treated with ACEI/ARB or not and completed a 1-year follow-up to evaluate outcomes including all-cause death, cardiovascular death, stroke, and major adverse events (MAEs).

RESULTS

Among the 1110 patients with AF and hypertension, 574 (51.7%) received ACEI/ARB treatment. During the 1-year follow-up, 169 all-cause deaths (15.2%) and 100 cardiovascular deaths (9.0%) occurred, while 98 strokes (8.8%) and 255 MAEs (23.0%) occurred. According to the multivariate Cox regression analysis, ACEI/ARB therapy was significantly associated with a reduced risk of all-cause death (HR, 0.605; 95% CI 0.431-0.849; P = 0.004). Moreover, ACEI/ARB therapy was independently associated with a reduced risk of cardiovascular death (HR 0.585; 95% CI 0.372-0.921; P = 0.020) and MAEs (HR 0.651, 95% CI 0.496-0.855, P = 0.002) after adjusting for other risk factors.

CONCLUSIONS

Our results revealed that ACEI/ARB therapy was independently associated with a reduced risk of all-cause death, cardiovascular death, and MAEs in ED patients with AF and hypertension. These results provide evidence for a tertiary preventive treatment for patients with AF and hypertension.

Atrial Fibrillation and Hypertension: "Quo Vadis"

Hypertension is one of the most well-established risk factors for atrial fibrillation. Long-standing untreated hypertension leads to structural remodeling and electrophysiologic alterations causing an atrial myopathy that forms a vulnerable substrate for the development and maintenance of atrial fibrillation. Hypertension-induced hemodynamic, inflammatory, hormonal, and autonomic changes all appear to be important contributing factors. Furthermore, hypertension is also associated with several atrial fibrillation-related comorbidities. As such, hypertension may represent an important target for therapy in atrial fibrillation. Clinicians should be aware of pitfalls of the blood pressure measurement in atrial fibrillation. While the auscultatory method is preferred, the use of automated devices appears to be an acceptable method in the ambulatory setting. There are pathophysiologic bases and emerging clinical evidence suggesting the benefit of renin-angiotensin system inhibition in risk reduction of atrial fibrillation development particularly in patients with left ventricular hypertrophy or left ventricular dysfunction. A better understanding of hypertension's pathophysiologic link to atrial fibrillation may lead to the development of novel therapies for the primary prevention of atrial fibrillation. Finally, future studies are needed to address optimal blood pressure goal to minimize the risk of atrial fibrillation-related complications.

Total NT-proBNP, a novel biomarker related to recurrent atrial fibrillation

Background

Novel circulating biomarkers may help in understanding the underlying mechanisms of atrial fibrillation (AF), a challenge for AF management and prevention of cardiovascular (CV) events. Whether glycosylation affects the prognostic value of N-terminal pro-B type natriuretic peptide (NT-proBNP) in AF is still unknown.

Objectives

To test how deglycosylated total NT-proBNP, NT-proBNP and a panel of biomarkers are associated with: (1) recurrent AF, (2) first hospitalization for CV reasons.

Methods

A total of 382 patients of the GISSI-AF trial in sinus rhythm with a history of AF, echocardiographic variables, total NT-proBNP, NT-proBNP and nine additional biomarkers [Total N-terminal pro-B type natriuretic peptide (Total NT proBNP), N-terminal pro-B type natriuretic peptide (NTproBNP), Angiopoietin 2 (Ang2), Bone morphogenic protein-10 (BMP10), Dickkopf-related protein-3 (DKK3), Endothelial cell specific molecule-1 (ESM1), Fatty acid-binding protein 3 (FABP3), Fibroblast growth factor 23 (FGF23), Growth differentiation factor-15 (GDF15), Insulin-like growth factor-binding protein-7 (IGFBP7) and Myosin binding protein C3 (MYPBC3)]. were assayed at baseline, 6 and 12 months under blind conditions in a laboratory at Roche Diagnostics, Penzberg, Germany. The associations between circulating biomarkers and AF at the 6- and 12-month visits, and their predictive value, were assessed in multivariable models with logistic regression analysis and Cox proportional hazards regression analysis. Biomarkers associations were modelled for 1SD increase in their level.

Results

Over a median follow-up of 365 days, 203/382 patients (53.1%) had at least one recurrence of AF and 16.3% were hospitalized for CV reasons. Total NT-proBNP, NT-proBNP, Ang2 and BMP10 showed the strongest associations with ongoing AF. Natriuretic peptides also predicted recurrent AF (total NT-proBNP: HR:1.19[1.04–1.36], p = 0.026; NT-proBNP: HR:1.19[1.06–1.35], p = 0.016; Ang2: HR:1.07[0.95–1.20], p = 0.283; BMP10: HR:1.09[0.96–1.25], p = 0.249) and CV hospitalization (total NT-proBNP: HR:1.57[1.29–1.90], p < 0.001 1.63], p = 0.097).

Conclusions

The association of total NT-proBNP with the risk of AF first recurrence was similar to that of NT-proBNP, suggesting no influence of glycosylation. Analogous results were obtained for the risk of first hospitalization for CV reasons. Natriuretic peptides, Ang2 and BMP10 were associated with ongoing AF. Findings from the last two biomarkers point to a pathogenic role of cardiac extracellular matrix and cardiomyocyte growth in the myocardium of the right atrium and ventricle.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02358-y.

Effect of Perindopril on Atrial Fibrillation Recurrence and Burden: Results of the Canadian Trial of Atrial Fibrillation (CTAF)-2

Background

Hypertension is a risk factor for the development and exacerbation of atrial fibrillation (AF). Angiotensin-converting enzyme inhibitors are a standard-of-care treatment option for patients with hypertension; however, there is conflicting evidence about their effects on AF recurrence. Therefore, our objective was to assess the efficacy of perindopril, compared with placebo, to reduce AF recurrence in patients with hypertension and AF.

Methods

In a multicenter, double-blind, placebo-controlled trial, patients with hypertension and symptomatic AF were randomly assigned (1:1) to perindopril or placebo based on a stratification factor of antiarrhythmic drug use. Patients with terminated AF were followed up from 30 days after randomization to 7 to 13 months. The primary endpoint was AF recurrence. Secondary endpoints included AF hospitalization, cardioversion, and blood pressure control. Recurrent events, AF burden, and safety endpoints were also investigated.

Results

A total of 315 patients were randomly assigned, and 301 patients were included in the modified intent-to-treat analysis (155 vs 146 patients in the perindopril and placebo groups, respectively). The mean follow-up was 336 ± 70 days, and 91.1% of patients were compliant to the treatment medication throughout the study. After adjustment for baseline antiarrhythmic drugs, there was no statistically significant difference in the hazards of AF recurrence (hazard ratio, 1.22; 95% confidence interval, 0.92-1.61), with similar blood pressure. The incidence of secondary endpoints and adverse events also did not differ between treatment arms.

Conclusions

Perindopril does not reduce recurrence or the number of AF episodes in patients with hypertension and AF.

Angiotensin II and angiotensin 1-7: which is their role in atrial fibrillation?

Atrial fibrillation (AF) is a significant cause of morbidity and mortality as well as a public health burden considering the high costs of AF-related hospitalizations. Pre-clinical and clinical evidence showed a potential role of the renin angiotensin system (RAS) in the etiopathogenesis of AF. Among RAS mediators, angiotensin II (AII) and angiotensin 1-7 (A1-7) have been mostly investigated in AF. Specifically, the stimulation of the pathway mediated by AII or the inhibition of the pathway mediated by A1-7 may participate in inducing and sustaining AF. In this review, we summarize the evidence showing that both RAS pathways may balance the onset of AF through different biological mechanisms involving inflammation, epicardial adipose tissue (EAT) accumulation, and electrical cardiac remodeling. EAT is a predictor for AF as it may induce its onset through direct (infiltration of epicardial adipocytes into the underlying atrial myocardium) and indirect (release of inflammatory adipokines, the stimulation of oxidative stress, macrophage phenotype switching, and AF triggers) mechanisms. Classic RAS blockers such as angiotensin converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB) may prevent AF by affecting the accumulation of the EAT, representing a useful therapeutic strategy for preventing AF especially in patients with heart failure and known left ventricular dysfunction. Further studies are necessary to prove this benefit in patients with other cardiovascular diseases. Finally, the possibility of using the A1-7 or ACE2 analogues, to enlarge current therapeutic options for AF, may represent an important field of research.

Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards

Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. However, current therapeutic interventions for atrial fibrillation have limited clinical efficacy as a consequence of major knowledge gaps in the mechanisms sustaining atrial fibrillation. From a mechanistic perspective, there is increasing evidence that atrial fibrosis plays a central role in the maintenance and perpetuation of atrial fibrillation. Electrophysiologically, atrial fibrosis results in alterations in conduction velocity, cellular refractoriness, and produces conduction block promoting meandering, unstable wavelets and micro-reentrant circuits. Clinically, atrial fibrosis has also linked to poor clinical outcomes including AF-related thromboembolic complications and arrhythmia recurrences post catheter ablation. In this article, we review the pathophysiology behind the formation of fibrosis as AF progresses, the role of fibrosis in arrhythmogenesis, surrogate markers for detection of fibrosis using cardiac magnetic resonance imaging, echocardiography and electroanatomic mapping, along with their respective limitations. We then proceed to review the current evidence behind therapeutic interventions targeting atrial fibrosis, including drugs and substrate-based catheter ablation therapies followed by the potential future use of electro phenotyping for AF characterization to overcome the limitations of contemporary substrate-based methodologies.

Implications of Inflammation and Fibrosis in Atrial Fibrillation Pathophysiology

Inflammation and fibrosis have been implicated in the pathophysiology of atrial fibrillation. Atrial fibrosis causes conduction disturbances and is a central component of atrial remodeling in atrial fibrillation. Cardiac fibroblasts, the cells responsible for fibrosis formation, are activated by inflammatory mediators and growth factors associated with systemic inflammatory conditions. Thus, inflammation contributes to atrial fibrosis; the complex interplay of these maladaptive components creates a vicious cycle of atrial remodeling progression, maintaining atrial fibrillation and increasing thrombogenicity. This review provides up-to-date knowledge regarding inflammation and fibrosis in atrial fibrillation pathophysiology and their potential as therapeutic targets.

Atrial Fibrillation (Part 1): Pathophysiology, Risk Factors, and Therapeutic Basis

A fibrilação atrial é a arritmia sustentada mais comum na prática clínica com predileção pelas faixas etárias mais avançadas. Com o envelhecimento populacional, as projeções para as próximas décadas são alarmantes. Além de sua importância epidemiológica, a fibrilação atrial é destacada por suas repercussões clínicas, incluindo fenômenos tromboembólicos, hospitalizações e maior taxa de mortalidade. Seu mecanismo fisiopatológico é complexo, envolvendo uma associação de fatores hemodinâmicos, estruturais, eletrofisiológicos e autonômicos. Desde os anos 1990, o estudo Framingham em análises multivariadas já demonstrou que, além da idade, a presença de hipertensão, diabetes, insuficiência cardíaca e doença valvar é preditor independente dessa normalidade do ritmo. Entretanto, recentemente, vários outros fatores de risco estão sendo implicados no aumento do número de casos de fibrilação atrial, tais como sedentarismo, obesidade, anormalidades do sono, tabagismo e uso excessivo de álcool. Além disso, as mudanças na qualidade de vida apontam para uma redução na recorrência de fibrilação atrial, tornando-se uma nova estratégia para o tratamento de excelência dessa arritmia cardíaca. A abordagem terapêutica envolve um amplo conhecimento do estado de saúde e hábitos do paciente, e compreende quatro pilares principais: mudança de hábitos de vida e tratamento rigoroso de fatores de risco; prevenção de eventos tromboembólicos; controle da frequência; e controle do ritmo. Pela dimensão de fatores envolvidos no cuidado ao paciente portador de fibrilação atrial, ações integradas com equipes multiprofissionais estão associadas aos melhores resultados clínicos.

Renin-Angiotensin System Inhibitors Prognostic Benefit in Older Patients with Atrial Fibrillation

OBJECTIVES

Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin-receptor blockers (ARB) have shown antiarrhythmic effects that are useful as part of the upstream therapy for atrial fibrillation (AF), both for primary and secondary prevention. Nevertheless, the potential prognosis value of these drugs in terms of mortality and major cardiovascular events is unclear, especially in older population with AF. Scientific evidence is scarce in this population and shows contradictory results. The aim of this study was to assess the potential benefit of ACEi and ARB in terms of mortality and major cardiovascular outcomes (hospitalization for heart failure, acute myocardial infarction and stroke) in older patients with AF, based on a real-world data analysis.

DESIGN

Observational: analysis of a retrospective registry.

SETTINGS AND PARTICIPANTS

The study included 9365 patients of 75 years or older diagnosed with AF, from CardioCHUVI-AF_75 registry: ClinicalTrials.gov Identifier: NCT04364516. Date of registration: November 26, 2018.

METHODS

We performed propensity score matching techniques to obtain 2 comparable groups of 3601 patients with and without ACEi or ARB treatment. We compared survival and cardiovascular outcomes in both groups of patients using Cox proportional hazards models.

RESULTS

We did not find significant differences in terms of survival between using or not using ACEi or ARB for the older population (hazard ratio for mortality: 0.959, 95% confidence interval 0.872-1.054). There were no significant differences regarding cardiovascular major events between the 2 groups.

CONCLUSIONS AND IMPLICATIONS

Treatment with ACEi or ARB did not improve outcomes in terms of survival and cardiovascular events in older patients with AF. These results should prompt the conduct of randomized clinical trials specifically in the older AF patient population to robustly address this issue.

Association between antihypertensive treatment and adverse events: systematic review and meta-analysis

OBJECTIVE

To examine the association between antihypertensive treatment and specific adverse events.

DESIGN

Systematic review and meta-analysis.

ELIGIBILITY CRITERIA

Randomised controlled trials of adults receiving antihypertensives compared with placebo or no treatment, more antihypertensive drugs compared with fewer antihypertensive drugs, or higher blood pressure targets compared with lower targets. To avoid small early phase trials, studies were required to have at least 650 patient years of follow-up.

INFORMATION SOURCES

Searches were conducted in Embase, Medline, CENTRAL, and the Science Citation Index databases from inception until 14 April 2020.

MAIN OUTCOME MEASURES

The primary outcome was falls during trial follow-up. Secondary outcomes were acute kidney injury, fractures, gout, hyperkalaemia, hypokalaemia, hypotension, and syncope. Additional outcomes related to death and major cardiovascular events were extracted. Risk of bias was assessed using the Cochrane risk of bias tool, and random effects meta-analysis was used to pool rate ratios, odds ratios, and hazard ratios across studies, allowing for between study heterogeneity (τ2).

RESULTS

Of 15 023 articles screened for inclusion, 58 randomised controlled trials were identified, including 280 638 participants followed up for a median of 3 (interquartile range 2-4) years. Most of the trials (n=40, 69%) had a low risk of bias. Among seven trials reporting data for falls, no evidence was found of an association with antihypertensive treatment (summary risk ratio 1.05, 95% confidence interval 0.89 to 1.24, τ2=0.009). Antihypertensives were associated with an increased risk of acute kidney injury (1.18, 95% confidence interval 1.01 to 1.39, τ2=0.037, n=15), hyperkalaemia (1.89, 1.56 to 2.30, τ2=0.122, n=26), hypotension (1.97, 1.67 to 2.32, τ2=0.132, n=35), and syncope (1.28, 1.03 to 1.59, τ2=0.050, n=16). The heterogeneity between studies assessing acute kidney injury and hyperkalaemia events was reduced when focusing on drugs that affect the renin angiotensin-aldosterone system. Results were robust to sensitivity analyses focusing on adverse events leading to withdrawal from each trial. Antihypertensive treatment was associated with a reduced risk of all cause mortality, cardiovascular death, and stroke, but not of myocardial infarction.

CONCLUSIONS

This meta-analysis found no evidence to suggest that antihypertensive treatment is associated with falls but found evidence of an association with mild (hyperkalaemia, hypotension) and severe adverse events (acute kidney injury, syncope). These data could be used to inform shared decision making between doctors and patients about initiation and continuation of antihypertensive treatment, especially in patients at high risk of harm because of previous adverse events or poor renal function.

REGISTRATION

PROSPERO CRD42018116860.

Atrial fibrosis underlying atrial fibrillation (Review)

Atrial fibrillation (AF) is one of the most common tachyarrhythmias observed in the clinic and is characterized by structural and electrical remodelling. Atrial fibrosis, an emblem of atrial structural remodelling, is a complex multifactorial and patient-specific process involved in the occurrence and maintenance of AF. Whilst there is already considerable knowledge regarding the association between AF and fibrosis, this process is extremely complex, involving intricate neurohumoral and cellular and molecular interactions, and it is not limited to the atrium. Current technological advances have made the non-invasive evaluation of fibrosis in the atria and ventricles possible, facilitating the selection of patient-specific ablation strategies and upstream treatment regimens. An improved understanding of the mechanisms and roles of fibrosis in the context of AF is of great clinical significance for the development of treatment strategies targeting the fibrous region. In the present review, a focus was placed on the atrial fibrosis underlying AF, outlining its role in the occurrence and perpetuation of AF, by reviewing recent evaluations and potential treatment strategies targeting areas of fibrosis, with the aim of providing a novel perspective on the management and prevention of AF.

Impact of renin-angiotensin system inhibitors on outcomes after transcatheter aortic valve replacement: A meta-analysis

OBJECTIVES

We aimed to evaluate the impact of renin-angiotensin system (RAS) inhibitors on outcomes after transcatheter aortic valve replacement (TAVR).

BACKGROUND

The impact of RAS inhibitors on outcomes after TAVR was unclear.

METHODS

A systematic review of articles comparing outcomes of patients using and not using RAS inhibitors after TAVR was performed through PubMed, Embase, and Cochrane. Primary outcome was midterm all-cause mortality. Risk ratios (RRs) were calculated with the corresponding 95% confidence interval using random effect models.

RESULTS

Five studies with 23,319 patients were included. Patients treated with RAS inhibitors had lower midterm all-cause mortality after TAVR than those without RAS inhibitors in both the unmatched (13.3 vs. 17.2%, RR 0.77, p = .005) and propensity score matched cohorts (13.5 vs 16.2%, RR 0.83, p < .001). Cardiovascular mortality (10.4 vs. 15.6%, RR 0.68, p < .001), rate of heart failure readmission (12.2 vs. 14.5%, RR 0.80, p = .006), and new-onset atrial fibrillation (14.0 vs. 23.7%, RR 0.73, p = .003) were also lower with RAS inhibitors. No difference was found between two groups regarding cerebrovascular events, myocardial infarction, major bleeding, major vascular complications, acute kidney injury, permanent pacemaker implantation, and moderate/severe paravalvular aortic regurgitation.

CONCLUSIONS

RAS inhibitors were associated with lower midterm all-cause mortality after TAVR.

Apelin Inhibits Angiotensin II-Induced Atrial Fibrosis and Atrial Fibrillation via TGF-β1/Smad2/α-SMA Pathway

BACKGROUND

Angiotensin II (Ang II) could promote the development of atrial fibrosis in atrial fibrillation (AF). Apelin can inhibit the occurrence of myocardial fibrosis. However, the effect of apelin on Ang II-induced atrial fibrosis and subsequent AF still remains unknown.

OBJECTIVE

In the present study, we examined the effect of apelin on the suppression of atrial fibrosis and subsequent AF, and investigated its underlying mechanisms.

METHODS

Sprague-Dawley rats were treated for 2 weeks with Ang II (1080 μg/kg/24 h) and apelin-13 (140 μg/kg/24 h) using implantable mini-pumps. The incidence of AF induced by atrial pacing was determined. Atrial electrophysiological mapping was recorded by a 32-electrode microelectrode array. Blood was collected to measure the levels of Ang II and apelin. Atrial tissue samples were preserved to assess the pathohistological changes, DDR2 and α-SMA co-staining were performed, and the protein expression of Smad2 phosphorylation was evaluated.

RESULTS

Apelin significantly inhibited Ang II-induced atrial fibrosis (HE:1.45 ± 0.11 vs 6.12 ± 0.16, P < 0.001; Masson:1.49 ± 0.25 vs 8.15 ± 0.23, P < 0.001; Picrosirius Red:1.98 ± 0.64 vs 9.59 ± 0.56, P < 0.001, respectively) and decreased the vulnerability of AF (inducibility of AF: z = -4.40, P < 0.001; total AF duration: z = -4.349, P < 0.001). Left atrial epicardial mapping studies demonstrated preservation of atrial conduction homogeneity by apelin. The protective effects of apelin from fibrotic remodeling were mediated by suppression of Smad2-dependent fibrosis.

CONCLUSION

Apelin potently inhibited Ang II-induced atrial fibrosis and subsequent vulnerability to AF induction via suppression TGF-β/Smad2/α-SMA pathway. Our results indicated that apelin might be an effective up-stream therapy for atrial fibrosis and AF.

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

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

A traditional herbal medicine rikkunshito prevents angiotensin II-Induced atrial fibrosis and fibrillation

BACKGROUND

Rikkunshito (RKT), a traditional herbal medicine, has been demonstrated to exert anti-inflammatory, anti-apoptotic, and anti-fibrotic effects in several organs. This study tested the hypothesis that RKT can suppress angiotensin II (AngII)-induced inflammatory atrial fibrosis and ameliorate enhanced vulnerability to atrial fibrillation (AF).

METHODS

Eight-week-old male C57BL/6 mice were subcutaneously infused with either vehicle or AngII (2.0 mg/kg/day) for 2 weeks. Water or RKT at a dose of 1000 mg/kg/day were orally administered once daily for 2 weeks. Morphological, histological, and biochemical analyses were performed. AF was induced either by transesophageal burst pacing in vivo or by burst/extrastimuli in isolated perfused hearts using a Langendorff apparatus.

RESULTS

RKT at a dose of 1000 mg/kg/day for 2 weeks attenuated atrial interstitial fibrosis and profibrotic and proinflammatory signals induced by continuous infusion of AngII. RKT attenuated AngII-induced enhanced vulnerability to AF in in vivo experiments and in isolated perfused hearts. Atractylodin, an active component of RKT, exhibited antifibrotic activity comparable to that of RKT. RKT reversed AngII-induced suppression of sirtuin 1 (Sirt1) translocation to the nuclei. RKT suppressed AngII-induced phosphorylation of IκB, overexpression of p53, and cellular apoptotic signals and apoptosis. All of the antagonizing effects of RKT against AngII were attenuated by a concomitant treatment with a growth hormone secretagogue receptor (GHSR)-inhibitor.

CONCLUSION

Our results demonstrated that RKT prevented atrial fibrosis and attenuated enhanced vulnerability to AF induced by AngII. The results also suggested that potentiating the GHSR-Sirt1 pathway is involved in these processes.

A New Therapeutic Framework for Atrial Fibrillation Drug Development

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia and cause of significant morbidity and mortality. Its increasing prevalence in aging societies constitutes a growing challenge to global healthcare systems. Despite substantial unmet needs in AF prevention and treatment, drug developments hitherto have been challenging, and the current pharmaceutical pipeline is nearly empty. In this review, we argue that current drugs for AF are inadequate because of an oversimplified system for patient classification and the development of drugs that do not interdict underlying disease mechanisms. We posit that an improved understanding of AF molecular pathophysiology related to the continuous identification of novel disease-modifying drug targets and an increased appreciation of patient heterogeneity provide a new framework to personalize AF drug development. Together with recent innovations in diagnostics, remote rhythm monitoring, and big data capabilities, we anticipate that adoption of a new framework for patient subsegmentation based on pathophysiological, genetic, and molecular subsets will improve success rates of clinical trials and advance drugs that reduce the individual patient and public health burden of AF.

Upstream Therapy for Atrial Fibrillation Prevention: The Role of Sacubitril/Valsartan

The therapy or prevention of atrial fibrillation (AF) is defined as upstream therapy when conducted with the use of drugs, e.g., angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor antagonists, statins, and omega-3 fatty acids, not included in the classes of antiarrhythmic drugs recognized by the Vaughan Williams classification. In our review, we illustrate the rational bases of upstream AF therapy, which encompasses drugs having the property to reduce hemodynamic congestion and cardiac overload, as in the case of ACEIs or angiotensin receptor blockers, as well as drugs able to prevent atrial fibrosis or reduce oxidative stress, such as statins or omega-3 fatty acids, respectively. In this review, randomized controlled trials (RCTs) conducted with the abovementioned drugs are examined. Really, these RCTs have generated mixed results. In the context of the prevention and therapy of AF, our experience is then presented, relating to a patient with heart failure and reduced left ventricular ejection fraction, with a history of relapsing episodes of paroxysmal AF. In this patient, administration of sacubitril/valsartan at appropriate doses allowed recovery of the sinus rhythm. Therefore this case testifies how the upstream therapy of AF might have good results when conducted with sacubitril/valsartan. Thus, RCTs with adequate statistical power are warranted in order to confirm the preliminary encouraging result of our case report, and validate a useful role of sacubitril/valsartan as an upstream therapy of AF.

Anti-arrhythmic properties of non-antiarrhythmic medications

Traditional anti-arrhythmic drugs are classified by the Vaughan-Williams classification scheme based on their mechanisms of action, which includes effects on receptors and/or ion channels. Some known anti-arrhythmic drugs do not perfectly fit into this classification scheme. Other medications/molecules with established non-anti-arrhythmic indications have shown anti-arrhythmic properties worth exploring. In this narrative review, we discuss the molecular mechanisms and evidence base for the anti-arrhythmic properties of traditional non-antiarrhythmic drugs such as inhibitors of the renin angiotensin system (RAS), statins and polyunsaturated fatty acids (PUFAs). In summary, RAS antagonists, statins and PUFAs are 'upstream target modulators' that appear to have anti-arrhythmic roles. RAS blockers prevent the downstream arrhythmogenic effects of angiotensin II - the main effector peptide of RAS - and the angiotensin type 1 receptor. Statins have pleiotropic effects including anti-inflammatory, immunomodulatory, modulation of autonomic nervous system, anti-proliferative and anti-oxidant actions which appear to underlie their anti-arrhythmic properties. PUFAs have the ability to alter ion channel function and prevent excessive accumulation of calcium ions in cardiac myocytes, which might explain their benefits in certain arrhythmic conditions. Clearly, whilst a number of anti-arrhythmic drugs exist, there is still a need for randomised trials to establish whether additional agents, including those already in clinical use, have significant anti-arrhythmic effects.

Sacubitril/valsartan attenuates atrial electrical and structural remodelling in a rabbit model of atrial fibrillation

Atrial structural and electrical remodelling play important roles in atrial fibrillation (AF). Sacubitril/valsartan attenuates cardiac remodelling in heart failure. However, the effect of sacubitril/valsartan on AF is unclear. The aim of this study was to evaluate the effect of sacubitril/valsartan on atrial electrical and structural remodelling in AF and investigate the underlying mechanism of action. Thirty-three rabbits were randomized into sham, RAP, and sac/val groups. HL-1 cells were subjected to control treatment or rapid pacing with or without LBQ657 and valsartan. Echocardiography, atrial electrophysiology, and histological examination were performed. The concentration of Ca²⁺ and expression levels of calcineurin, NFAT, p-NFAT, Cav1.2, collagen Ⅰ and Ⅲ, ANP, BNP, CNP, NT-proBNP, and ST2 in HL-1 cells, and I_caL in left atrial cells, were determined. We observed that compared to that in the sham group, the atrium and right ventricle were enlarged, myocardial fibrosis was markedly higher, AF inducibility was significantly elevated, and atrial effective refractory periods were shortened in the RAP group. These effects were significantly reversed by sacubitril/valsartan. Compared to that in the sham group, collagen Ⅰ and Ⅲ, NT-proBNP, ST2, calcineurin, and NFAT were significantly up-regulated, while p-NFAT and Ca_v1.2 were down-regulated in the RAP group, and sacubitril/valsartan inhibited these changes. Ca²⁺ concentration increased and I_CaL density decreased in in vivo and in vitro AF models, reversed by sacubitril/valsartan. Sacubitril/valsartan attenuates atrial electrical remodelling and ameliorates structure remodelling in AF. This study paves the way for the possibility of clinical use of sacubitril/valsartan in AF patients.

Assessing the risk of angiotensin receptor blockers on major cardiovascular events: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Angiotensin receptor blockers (ARBs) are commonly used as a treatment for many cardiovascular diseases, but their safety has been called into question. The VALUE trial found an increased risk of myocardial infarction in participants receiving ARBs compared to other antihypertensive. The aim of the meta-analysis was to synthetize the available evidence of randomised controlled trials (RCTs) and elucidate if ARBs increase the risk of cardiovascular events.

METHODS

A comprehensive search was conducted to identify RCTs that assessed the safety of ARBs. Titles and abstracts of all papers were independently screened by two authors. Data extraction and quality assessment were also performed independently. The relative risk (RR) of all-cause mortality, myocardial infarction, and stroke were pooled using the IVhet model. Multiple sensitivity analyses were conducted to assess the effect of ARBs by restricting the analysis to different participants' characteristics.

RESULTS

Forty-five RCTs comprising of 170,794 participants were included in the analysis. The pooled estimates revealed that ARBs do not increase the risk of all-cause mortality (RR 1.00; 95%CI 0.97-1.04), myocardial infarction (RR 1.01; 95%CI 0.96-1.06), and stroke (RR 0.92; 95%CI 0.83-1.01). The sensitivity analysis did not yield a particular group of patients at increased risk of cardiovascular events with ARBs. Risk of all-cause mortality and stroke decreased with ARB when the proportion of smokers in a population was < 25% (RR 0.91; 95%CI 0.84-0.98) and in females (RR 0.76; 95%CI 0.68-0.84), respectively.

CONCLUSIONS

ARBs do not increase the risk of major cardiovascular events and are safe for use in patients.

Elevated chymase-dependent angiotensin II-forming activity in circulating mononuclear leukocytes was observed in the patient of atrial fibrillation

Chymase is an angiotensin II-forming serine proteinase and elevation of its tissue activity occurs in various cardiovascular diseases. Several authors have suggested that there is an association between the renin-angiotensin system and atrial fibrillation (AF). Chymase-dependent angiotensin II-forming activity in circulating mononuclear leukocytes (CML chymase dAIIFA) was investigated in patients with AF and patients in sinus rhythm. Consecutive outpatients were recruited at our hospital. CML chymase dAIIFA was measured using a Nma/Dnp-type fluorescence-quenching substrate of modified angiotensin I in the presence or absence of a specific serine proteinase inhibitor. To search the independent contributing factor of existence of AF, the analysis between groups was carried out using multivariate analysis after univariate analysis. The patients were classified into a sinus rhythm (SR) group (n = 459) or an AF group (n = 48). CML chymase dAIIFA was significantly higher in the AF group (622 pmol/min/mg) compared with the SR group (488 pmol/min/mg) (p < 0.001). Logistic regression analysis revealed that high CML chymase dAIIFA was an independent determinant of the existence of AF (p < 0.001). Elevation of CML chymase dAIIFA was associated with AF. Activation of chymase might be linked to atrial structural and electrical remodeling.

Atrial Fibrillation: Development Mechanisms, Approaches and Prospects of Therapy

Atrial fibrillation (AF) is the most common arrhythmia. It is diagnosed in more than 33 million people worldwide and is the leading cause of hospitalization for arrhythmias. AF is characterized by fast and irregular atrial activation without discrete P-waves at a surface electrocardiography. AF pathophysiological mechanisms are very complex and include the dynamic interaction between arrhythmia substrate and triggers. Consequently, the clinical search for effective therapeutic targets should include the entire process of the onset and progression of the disease: from the first paroxysms to the development of a stable permanent form of AF.

Do most patients with obesity or type 2 diabetes, and atrial fibrillation, also have undiagnosed heart failure? A critical conceptual framework for understanding mechanisms and improving diagnosis and treatment

Obesity and diabetes can lead to heart failure with preserved ejection fraction (HFpEF), potentially because they both cause expansion and inflammation of epicardial adipose tissue and thus lead to microvascular dysfunction and fibrosis of the underlying left ventricle. The same process also causes an atrial myopathy, which is clinically evident as atrial fibrillation (AF); thus, AF may be the first manifestation of HFpEF. Many patients with apparently isolated AF have latent HFpEF or subsequently develop HFpEF. Most patients with obesity or diabetes who have AF and exercise intolerance have increased left atrial pressures at rest or during exercise, even in the absence of diagnosed HFpEF. Among patients with AF, those who also have latent HFpEF have increased risk for systemic thromboembolism and death. The identification of HFpEF in patients with obesity or diabetes alters the risk-to-benefit relationship of commonly prescribed treatments. Bariatric surgery and statins can ameliorate AF and reduce the risk for HFpEF. Conversely, antihyperglycaemic drugs that promote adipogenesis or cause sodium retention (insulin and thiazolidinediones) may increase the risk for heart failure in patients with an underlying ventricular myopathy. Patients with obesity and diabetes who undergo catheter ablation for AF are at increased risk for AF recurrence and for post-ablation increases in pulmonary venous pressures and worsening heart failure, especially if HFpEF coexists. Therefore, AF may be the earliest indicator of HFpEF in patients with obesity or type 2 diabetes, and recognition of HFpEF alters the management of these patients.

Effects of blood pressure-lowering treatment on cardiovascular outcomes and mortality: 14 - effects of different classes of antihypertensive drugs in older and younger patients: overview and meta-analysis

BACKGROUND AND OBJECTIVES

The five major classes of blood pressure (BP)-lowering drugs have all been shown to significantly reduce the risk of major cardiovascular events when compared with placebo, and when directly (head-to-head) compared, no significant differences in their overall effectiveness have been detected, except for minor differences in cause-specific events. It is unknown, however, whether age-related differences exist and if some classes of drugs are differently effective in older or younger individuals. This clinically relevant question has been the object of a systematic search and meta-analysis of all available data.

METHODS

Two databases we had previously identified [72 placebo-controlled BP-lowering randomized clinical trials (RCTs) in 260 210 individuals and 50 RCTs head-to-head comparing treatments with BP-lowering drugs of different classes in 247 006 individuals) were searched for separately reported data on patients older or younger than 65 years, and the data were further stratified according to the class of drug [diuretics, beta-blockers, calcium antagonists, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers] compared with placebo or with other drug classes. Seven fatal and nonfatal outcomes were considered for benefits. Adverse events were investigated as permanent treatment discontinuations for adverse events. Risk ratios and absolute risk changes were calculated by a random effects model. Effects at older and younger ages were compared by heterogeneity test.

RESULTS

We identified 20 placebo-controlled RCTs on 55 645 older individuals and 21 on 99 621 younger individuals, and 21 head-to-head drug comparison RCTs on 94 228 older individuals and 27 on 100 232 younger individuals (for a total of 349 726 individuals). When compared with placebo, all five classes of BP-lowering drugs significantly reduced the risk of major cardiovascular events or stroke, with no significant difference between older and younger patients. However, in head-to-head comparisons, no significant difference was found between older and younger patients in the effects of diuretics, calcium antagonists, ACE inhibitors and angiotensin receptor blockers on all cardiovascular outcomes, whereas beta-blockers revealed an age-dependent effectiveness, being equally effective as the other agents at an age below 65 years, but less effective at an older age.

CONCLUSION

Most BP-lowering classes are equally effective in preventing risk of fatal and nonfatal cardiovascular events both in older and younger patients, whereas beta-blockers, though being equally effective as the other agents in patients younger than 65, loose some of their effectiveness at an older age.

Effects of blood pressure-lowering treatment on cardiovascular outcomes and mortality: 13 - benefits and adverse events in older and younger patients with hypertension: overview, meta-analyses and meta-regression analyses of randomized trials

BACKGROUND

There is overwhelming evidence that blood pressure (BP)-lowering treatment can reduce cardiovascular outcomes also in the elderly, but some important aspects influencing medical practice are controversial as sufficient evidence has not been provided by single randomized controlled trials (RCTs), whereas evidence may result from a systematic search and meta-analysis of all available data.

OBJECTIVES

The following clinically relevant issues concerning the effects of BP lowering in older and younger individuals have been investigated: differences in benefits; the oldest and the youngest age range for which evidence of BP-lowering effects is available; the SBP level at which BP-lowering treatment should be initiated; the SBP and DBP levels treatment should be aimed at; differences in treatment burdens and harms.

METHODS

A database we previously identified of 72 BP-lowering RCTs in 260 210 patients was searched for separately reported data on older and younger individuals [cutoffs of 65 (primary analyses), 70, 75, 80, 60 and 55 years). The data were further stratified according to the levels of baseline (untreated) BP, and of on-treatment achieved SBP or DBP. Seven fatal and nonfatal outcomes were considered for benefits. Burdens and harms were investigated as permanent treatment discontinuations for adverse events, and hypotension/syncope. Risk ratios and absolute risk changes were calculated by a random effects model. Effects at older and younger ages were compared by heterogeneity test.

RESULTS

Thirty-two RCTs provided data on 96 549 patients older than 65 years, and 31 RCTs on 114 009 patients younger than 65 years. All cardiovascular outcomes were significantly reduced by treatment both in older and younger individuals, without significant age-dependent differences in relative risk reduction but with significantly higher absolute risk reductions in older individuals. The extreme age ranges for which evidence of significant benefits of treatment were available was greater than 80 and less than 55 years. Only one RCT provided data on benefits of BP-lowering at age greater than 65 when treatment was initiated at SBP values in the grade 1 range, but more consistent evidence was provided when age was greater than 60 years. Both in patients older and younger than 65 years, significant reductions of cardiovascular outcomes were found at on-treatment SBP less than 140 mmHg and DBP less than 80 mmHg. There was no evidence that treatment discontinuations for adverse events or hypotension/syncope were more frequent at age greater than 65.

CONCLUSION

Antihypertensive treatment should be recommended to all individuals with elevated BP, independent of age. The prudent recommendation to initiate treatment at SBP values 140-159 mmHg is supported at older age defined as greater than 60 years. SBP and DBP values lower than 140 mmHg and, respectively, 80 mmHg can be aimed at with incremental benefits without disproportionate burdens until age 80 years, above which available evidence is for benefits at on-treatment SBP 140-149 mmHg.