Study on the Effect of Irbesartan on Atrial Fibrillation Recurrence in Kumamoto: Atrial Fibrillation Suppression Trial (SILK study)

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.

Meta-analysis of renin angiotensin aldosterone modulators mitigating Atrial Fibrillation risk in hypertensive patients

INTRODUCTION

Hypertension is associated with left ventricular hypertrophy/enlargement/fibrosis and atrial ectopic rhythm, leading to an increased risk of Atrial Fibrillation (AF). We aimed to stratify the effect of Angiotensin Converting Enzyme Inhibitors (ACEi) and Angiotensin Receptor Blockers (ARB) on the risk of AF.

METHODS

PubMed, Scopus, and Google Scholar databases were screened, and cross-citation was conducted for studies reporting AF in hypertensive patients on ACEi and ARB. Of 145 studies found till May 2023, 19 were included in this study. Binary random-effects models estimated the pooled odds ratios, I2 statistics assessed heterogeneity and sensitivity analysis was assessed using the leave-one-out method.

RESULTS

153,559 hypertensive patients met the inclusion criteria. For incidental AF, ACEi and ARB showed a significant decrease in both unadjusted (OR 0.75, 95% CI [0.66-0.85], I² = 20.79%, p=0.29) and adjusted risks (OR 0.76, 95% CI [0.62-0.93], I² = 88.41%, p<0.01). In recurrent AF, the unadjusted analysis showed no significant effect (OR 0.89, 95% CI [0.55-1.42], I² = 78.44%, p<0.01), while the adjusted analysis indicated a reduced risk (OR 0.62, 95% CI [0.50-0.76], I² = 65.71%, p<0.01). Leave-one-out sensitivity analysis confirmed these results.

CONCLUSIONS

ACEi and ARB considerably decrease the risk of incidental and recurrent AF in hypertensive patients, emphasizing the importance of treating clinical hypertension with these drugs.

A Systematic Review and Meta-analysis of Renin-angiotensin System Inhibitors and Angiotensin Receptor Neprilysin Inhibitors in Preventing Recurrence After Atrial Fibrillation Ablation

ABSTRACT

To systematically evaluate the efficacy and safety of renin-angiotensin system inhibitors (RASIs) and angiotensin receptor neprilysin inhibitors in preventing the recurrence of atrial fibrillation after atrial fibrillation ablation, we have written this meta-analysis. We systematically searched randomized controlled trials or cohort studies on RASIs and angiotensin receptor neprilysin inhibitor-sacubitril/valsartan (SV) in preventing the recurrence of atrial fibrillation. Two researchers independently screened the literature, extracted the data, and assessed the risk of bias in the included studies. Afterward, the meta-analysis was performed using RevMan 5.3 software. This meta-analysis results showed that the recurrence rate of atrial fibrillation after ablation in subjects using RASIs was lower than that in subjects not using them [relative risk = 0.85, 95% confidence interval (CI) (0.72-0.99), P = 0.03]; the recurrence rate in subjects using SV was lower than that in subjects using RASIs [RR= 0.50, 95% CI (0.37-0.68), P < 0.00001]. These results show that both the use of RASIs and SV can prevent the recurrence of after atrial fibrillation ablation, among which the use of SV is more effective.

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.

Comprehensive metabolomic characterization of atrial fibrillation

Background

Using human humoral metabolomic profiling, we can discover the diagnostic biomarkers and pathogenesis of disease. The specific characterization of atrial fibrillation (AF) subtypes with metabolomics may facilitate effective and targeted treatment, especially in early stages.

Objectives

By investigating disturbed metabolic pathways, we could evaluate the diagnostic value of biomarkers based on metabolomics for different types of AF.

Methods

A cohort of 363 patients was enrolled and divided into a discovery and validation set. Patients underwent an electrocardiogram (ECG) for suspected AF. Groups were divided as follows: healthy individuals (Control), suspected AF (Sus-AF), first diagnosed AF (Fir-AF), paroxysmal AF (Par-AF), persistent AF (Per-AF), and AF causing a cardiogenic ischemic stroke (Car-AF). Serum metabolomic profiles were determined by gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Metabolomic variables were analyzed with clinical information to identify relevant diagnostic biomarkers.

Results

The metabolic disorders were characterized by 16 cross-comparisons. We focused on comparing all of the types of AF (All-AFs) plus Car-AF vs. Control, All-AFs vs. Car-AF, Par-AF vs. Control, and Par-AF vs. Per-AF. Then, 117 and 94 metabolites were identified by GC/MS and LC-QTOF-MS, respectively. The essential altered metabolic pathways during AF progression included D-glutamine and D-glutamate metabolism, glycerophospholipid metabolism, etc. For differential diagnosis, the area under the curve (AUC) of specific metabolomic biomarkers ranged from 0.8237 to 0.9890 during the discovery phase, and the predictive values in the validation cohort were 78.8–90.2%.

Conclusions

Serum metabolomics is a powerful way to identify metabolic disturbances. Differences in small–molecule metabolites may serve as biomarkers for AF onset, progression, and differential diagnosis.

Angiotensin Receptor Blocker and Calcium Channel Blocker Preventing Atrial Fibrillation Recurrence in Patients with Hypertension and Atrial Fibrillation: A Meta-analysis

Background

Atrial fibrillation (AF) is the most common serious cardiac rhythm disturbances and is responsible for substantial morbidity and mortality in general population. Hypertension is the most prevalent and potentially modifiable risk factor for AF. This study is aimed at evaluating the effect of angiotensin receptor blocker (ARB) or calcium channel blocker (CCB) on AF recurrence among patients with hypertension and AF.

Methods

The PubMed, EMBASE, Medline, and Cochrane Collaboration of Controlled Clinical Trials registry databases were searched from their inception to September 2020.

Results

A total of 7 randomized controlled trials (RCTs) enrolling 1495 patients were included in our study. This finding showed that ARB had a statistically significant superiority in preventing AF recurrence (OR: 0.43, 95% CI: 0.30-0.72, P = 0.0006) and persistent AF (OR: 0.41, 95% CI: 0.24-0.71, P = 0.001) compared to CCB. Subgroup analysis showed that there was a significant difference in telmisartan subgroup (OR: 0.54, 95% CI: 0.23-1.29, P = 0.17) and nontelmisartan subgroup (OR: 0.42, 95% CI: 0.23-0.77, P = 0.005). Subgroup analysis indicated that nifedipine subgroup did not show a statistically significant difference on AF recurrence between ARB and CCB (OR: 0.88, 95% CI: 0.46-1.68, P = 0.69), but amlodipine subgroup showed that ARB had a significant superiority in prevention of AF recurrence (OR: 0.39, 95% CI: 0.27-0.56, P < 0.0001) compared with CCB.

Conclusions

This study suggests that ARB is superior to CCB for preventing the AF recurrence and persistent AF among patients with hypertension and AF.

Do age-associated changes of voltage-gated sodium channel isoforms expressed in the mammalian heart predispose the elderly to atrial fibrillation?

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. The prevalence of the disease increases with age, strongly implying an age-related process underlying the pathology. At a time when people are living longer than ever before, an exponential increase in disease prevalence is predicted worldwide. Hence unraveling the underlying mechanics of the disease is paramount for the development of innovative treatment and prevention strategies. The role of voltage-gated sodium channels is fundamental in cardiac electrophysiology and may provide novel insights into the arrhythmogenesis of AF. Na_v1.5 is the predominant cardiac isoform, responsible for the action potential upstroke. Recent studies have demonstrated that Na_v1.8 (an isoform predominantly expressed within the peripheral nervous system) is responsible for cellular arrhythmogenesis through the enhancement of pro-arrhythmogenic currents. Animal studies have shown a decline in Na_v1.5 leading to a diminished action potential upstroke during phase 0. Furthermore, the study of human tissue demonstrates an inverse expression of sodium channel isoforms; reduction of Na_v1.5 and increase of Na_v1.8 in both heart failure and ventricular hypertrophy. This strongly suggests that the expression of voltage-gated sodium channels play a crucial role in the development of arrhythmias in the diseased heart. Targeting aberrant sodium currents has led to novel therapeutic approaches in tackling AF and continues to be an area of emerging research. This review will explore how voltage-gated sodium channels may predispose the elderly heart to AF through the examination of laboratory and clinical based evidence.

Combinational Biomarkers for Atrial Fibrillation Derived from Atrial Appendage and Plasma Metabolomics Analysis

Atrial fibrillation (AF) is one of the most common types of arrhythmias and often leads to clinical complications. The objectives of this study were to offer insights into the metabolites of AF and to determine biomarkers for AF diagnosis or prediction. Sixty atrial appendage samples (AF group: 30; non-AF group: 30) and 163 plasma samples (AF group: 48; non-AF group: 115) from 49 AF patients and 116 non-AF patients were subjected to liquid chromatography positive ion electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) metabolomics analysis. Consequently, 24 metabolites in atrial appendage samples and 24 metabolites in plasma samples were found to reflect metabolic differences between AF and non-AF patients (variable importance in projection (VIP) ≥ 1, P ≤ 0.05). Five identical metabolites including creatinine, D-glutamic acid, choline, hypoxanthine, and niacinamide (VIP ≥ 1.5, P < 0.01, FDR < 0.05) in atrial appendage and plasma samples were considered prominent features of AF patients, and the D-glutamine and D-glutamate metabolic pathway was also identified as a feature of AF patients. Finally, in plasma samples, the combination of D-glutamic acid, creatinine, and choline had an AUC value of 0.927 (95% CI: 0.875-0.979, P < 0.001) and displayed 90.5% sensitivity and 83.3% specificity; this group of metabolites was thus defined as a combinational biomarker for the recognition of AF and non-AF patients.

Oxidative stress and atrial fibrillation: an update

Atrial remodelling involves electrophysiological and structural abnormalities that promote the development and perpetuation of atrial fibrillation. Experimental and clinical data indicate that oxidative stress is implicated in the pathophysiology of atrial remodelling. The mechanistic links between atrial remodelling and oxidative stress are complex with several underlying diseases and conditions may affect these pathways. Therefore, the development of antioxidant interventions in this setting remains difficult. Besides classical antioxidant compounds, several agents with pleiotropic effects, including anti-inflammatory and antioxidant, have been tested in experimental and clinical settings with variable results. Strategies applying conventional antioxidants in specific situations such as postoperative atrial fibrillation show beneficial effects, especially the two-step regimen of antioxidants combination. Of note, there are limited data on the development of strategies that target specific sources of reactive oxygen species implicated in atrial remodelling. Lifestyle, diet, and risk factors modification is a complementary promising approach. This updated review provides a concise and critical overview of all available data regarding oxidative stress and its modulation in atrial fibrillation. Future directions on this exciting field are also discussed.