Impact of angiotensin-converting enzyme-inhibitors and angiotensin receptor blockers on long-term outcome of catheter ablation for atrial fibrillation

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.

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.

Sacubitril/valsartan reduces susceptibility to atrial fibrillation by improving atrial remodeling in spontaneously hypertensive rats

AIM

Sacubitril/valsartan (Sac/Val, LCZ696), the world's first angiotensin receptor-neprilysin inhibitor (ARNi), has been widely used in the treatment of heart failure. However, the use of Sac/Val in the treatment of atrial fibrillation (AF), especially AF with hypertension, has been less reported. We investigated the effect of Sac/Val on atrial remodeling and hypertension-related AF.

METHODS

The AF induction rate and electrophysiological characteristics of spontaneously hypertensive rats (SHRs) treated with Sac/Val or Val were detected by rapid atrial pacing and electrical mapping/optical mapping. The whole-cell patch-clamp and western blot were used to observe electrical/structural remodeling of atrial myocytes/tissue of rats and atrium-derived HL-1 cells cultured under 40 mmHg in vitro.

RESULTS

Sac/Val was superior to Val in reducing blood pressure, myocardial hypertrophy and susceptibility of AF in SHRs. The shorten action potentials duration (APD), decreased L type calcium channel current (I_Ca,L) and Cav1.2, increased ultrarapid delayed rectified potassium current (I_kur) and Kv1.5 in atrial myocytes/tissue of SHRs could be better improved by Sac/Val, as well as the levels of atrial fibrosis. While the protein expression of angiotensin-converting enzyme-1 (ACE-1), angiotensin, angiotensin II type I AT1 receptor (AT1R) and neprilysin (NEP) were increased, which could be more effective ameliorated by Sac/Val than Val. Furthermore, Val + Sacubitrilat (LBQ657) (an active NEP inhibitor) was also superior to LBQ657 or Val in improving the electrical and structural remodeling of HL-1 cells through inhibiting NEP.

CONCLUSION

Sac/Val can improve atrial structural and electrical remodeling induced by hypertension and reduce the AF susceptibility by inhibiting RAS and NEP. The above effects of Sac/Val were superior to Val alone.

Predictors of outcome after catheter ablation for atrial fibrillation: Group analysis categorized by age and type of atrial fibrillation

BACKGROUND

The outcome of catheter ablation could probably differ among patients with atrial fibrillation (AF), depending on age and AF type. We aimed to investigate the difference in predictors of outcome after catheter ablation for AF among the patient categories divided by age and AF type.

METHODS AND RESULTS

A total of 396 patients with AF (mean age 65.69 ± 11.05 years, 111 women [28.0%]) who underwent catheter ablation from January 2018 to December 2019 were retrospectively analyzed. We divided the patients into four categories: patients with paroxysmal AF (PAF) or persistent AF (PeAF) who were 75 years or younger (≤75 years) or older than 75 years (>75 years). Kaplan-Meier survival analysis demonstrated that patients with PAF aged ≤75 years had the lowest AF recurrence among the four groups (log-rank test, p = .0103). In the patients with PAF aged ≤75 years (N = 186, 46.7%), significant factors associated with recurrence were female sex (p = .008) and diabetes (p = .042). In the patients with PeAF aged ≤75 years (N = 142, 35.9%), the only significant factor associated with no recurrence was medication with a renin-angiotensin system inhibitor (p = .044). In the patients with PAF aged >75 years (N = 53, 14.4%), diabetes was significantly associated with AF recurrence (p = .021). No significant parameters were found in the patients with PeAF aged >75 years (N = 15, 4.1%).

CONCLUSIONS

Our findings indicate that the risk factors for AF recurrence after catheter ablation differed by age and AF type.

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.

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.

Renin-Angiotensin System Inhibitors for the Prevention of Atrial Fibrillation Recurrence After Ablation - A Meta-Analysis

BACKGROUND

Atrial fibrillation (AF) recurrence remains a tricky problem in patients undergoing ablation. This meta-analysis aimed to summarize the current literature to clarify whether renin-angiotensin system inhibitors (RASIs) prevent AF recurrence after ablation.Methods and Results:Relevant studies were searched on Pubmed and EMBASE through December 2019. Pooled relative risk (RR) of AF recurrence was calculated. Subgroup analyses according to study design, race, and follow-up duration were further performed. A total of 15 studies examining 4,300 patients were included, with 3 randomized controlled trials and 12 cohort studies. Overall analysis showed that RASIs significantly reduced AF recurrence after ablation (RR=0.83; 95% confidence interval (CI) 0.70-0.98, P=0.028; I²=68.9%). Subgroup analysis further indicated that positive results were found in randomized controlled trials (RR=0.51, 95% CI 0.37-0.70, P<0.001; I²=4%), studies conducted in Asia (RR=0.59, 95% CI 0.46-0.76, P<0.001; I²=30.7%), and studies with follow-up duration ≥1 year (RR=0.82, 95% CI 0.70-0.95, P=0.01; I²=59.1%); negative results were found in cohort studies, studies conducted in Europe or the USA, and studies with follow-up duration <1 year.

CONCLUSIONS

RASIs can potentially prevent AF recurrence after ablation under selected conditions. However, more studies are required to confirm this finding due to the variation in current evidence.

Data Linking Diabetes Mellitus and Atrial Fibrillation-How Strong Is the Evidence? From Epidemiology and Pathophysiology to Therapeutic Implications

According to estimates, around 5% of the world population has hazel eyes. And there are about as many people with diabetes mellitus (DM). Red hair occurs naturally in up to 2% of the human population. And about as many people are estimated to have atrial fibrillation (AF). If a hazel eyed person with red hair does not surprise us, should a diabetic patient with AF? Accumulating epidemiologic data suggest, however, that the DM-AF association may be more than a simple coincidence. But, how strong is this evidence? Experimental studies bring evidence for a DM-induced atrial proarrhythmic remodelling. But how relevant are these data for the clinical setting? In this review, we aim to provide a critical analysis of the existing clinical and experimental, epidemiologic, and mechanistic data that bridge DM and AF, we emphasize a number of questions that remain to be answered, and we identify hotspots for future research. The therapeutic implications of the DM-AF coexistence are also discussed, with a focus on rhythm control and on conventional and DM-specific upstream therapies for AF management.

Mid-Term Results of Surgical Treatment of Atrial Fibrillation in Valvular Heart Disease Assesed by Speckle Tracking Echocardiography

Background

Atrial fibrillation frequently affects patients with valvular heart disease. Ablation of atrial fibrillation during valvular surgery is an alternative for restoring sinus rhythm.

Objectives

This study aimed to evaluate mid-term results of successful atrial fibrillation surgical ablation during valvular heart disease surgery, to explore left atrium post-ablation mechanics and to identify predictors of recurrence.

Methods

Fifty-three consecutive candidates were included. Eligibility criteria for ablation included persistent atrial fibrillation <10 years and left atrium diameter < 6.0 cm. Three months after surgery, echocardiogram, 24-hour Holter monitoring and electrocardiograms were performed in all candidates who maintained sinus rhythm (44 patients). Echo-study included left atrial deformation parameters (strain and strain rate), using 2-dimensional speckle-tracking echocardiography. Simultaneously, 30 healthy individuals (controls) were analyzed with the same protocol for left atrial performance. Significance was considered with a P value of < 0.05.

Results

After a mean follow up of 17 ± 2 months, 13 new post-operative cases of recurrent atrial fibrillation were identified. A total of 1,245 left atrial segments were analysed. Left atrium was severely dilated in the post-surgery group and, mechanical properties of left atrium did not recover after surgery when compared with normal values. Left atrial volume (≥ 64 mL/m²) was the only independent predictor of atrial fibrillation recurrence (p = 0.03).

Conclusions

Left atrial volume was larger in patients with atrial fibrillation recurrence and emerges as the main predictor of recurrences, thereby improving the selection of candidates for this therapy; however, no differences were found regarding myocardial deformation parameters. Despite electrical maintenance of sinus rhythm, left atrium mechanics did not recover after atrial fibrillation ablation performed during valvular heart disease surgery.

Clinical, electrophysiological and imaging predictors of atrial fibrillation ablation outcome

INTRODUCTION

Significant technological advances for catheter ablation of atrial fibrillation (AF) have occurred over the last decade, with a consequent increase in numbers of patients referred for AF ablation worldwide. Despite this, long-term success rates, particularly in those with persistent AF, remain modest. The patient population presenting for AF ablation are heterogeneous with regard to age, type of AF and presence of associated cardiovascular disease. Improved understanding of factors predicting response to AF ablation may therefore help to improve patient selection for ablation procedures. Areas covered: This review outlines the clinical, electrophysiological and imaging predictors of response to radiofrequency ablation for AF in contemporary practice. Recently developed scoring systems incorporating these parameters are examined, as are factors identified thus far which may predict the outcome of cryoballoon ablation. Expert commentary: Traditional clinical factors associated with ablation outcomes serve as surrogates rather than direct measures of the underlying arrhythmia substrate. An improved understanding of this substrate could improve the prediction of response to radiofrequency ablation. Continued development of methods for characterising the arrhythmia substrate, including atrial cardiac magnetic resonance imaging and invasive voltage mapping, may inform patient risk assessment and help guide selection for catheter ablation on an increasingly individualistic basis.

Fluvastatin combined with benazepril may contribute to the favorable prognosis of patients with atrial fibrillation

The aim of this study was to observe the clinical efficacy of fluvastatin combined with benazepril in the treatment of patients with atrial fibrillation (AF). A total of 92 patients with AF were randomly assigned to the case group (n=46), in which the patients were treated with fluvastatin (80mg) plus benazepril (10mg), or to the control group (n=46), in which the patients were treated with fluvastatin (80mg). The conversion rate of sinus rhythm was higher in the case group than in the control group (P<0.05). The case group had more treatment-effective patients than the control group, with fewer treatment-ineffective patients (P<0.05). The LVEDd, LVESd, LAD, and LVEF indexes in the case group were lower than in the control group after 6 months of treatment (all P<0.05). Levels of hs-CRP were also lower in patients in the case group than in patients in the control group after 1 month of treatment (P<0.05). After 12 months, renin and Ang II concentrations were lower in patients in the case group than in the control group (both P<0.05). Significant differences in IL-6 and TNF-α expression were found between the two groups after 1 month, 6 months, and 12 months of treatment (all P<0.05). Compared to patients in the control group, the levels of total cholesterol (TC), triglycerides, and LDL-C in the case group were lower after 6 and 12 months of treatment (all P<0.05), while the HDL level was higher (P<0.05). Treatment with fluvastatin combined with benazepril further increased the conversion rate of sinus rhythm and significantly improved the quality of life and prognosis of AF patients.

Effect of valsartan on atrial fibrillation recurrence following pulmonary vein isolation in patients

Pulmonary venous isolation has emerged as an effective therapy for atrial fibrillation (AF); however, AF recurrence is common. The aim of the present study was to investigate the effect of angiotensin receptor blockers (ARBs) on the recurrence rate of AF following ablation therapy. In total, 120 patients, who were scheduled for ablation, were randomly selected. The patients were randomly divided into three groups, which received treatment with a placebo (n=40), 80 mg valsartan daily (n=40) or with 160 mg valsartan daily (n=40). The demographic characteristics, comorbidities, AF type and information regarding treatment with ARBs were recorded and analyzed. Following a mean follow-up period of 13.8±8.6 months, 66.7% of patients were found to be free of AF. Kaplan-Meier analysis of the time until the first recurrence during the follow-up period revealed that patients treated with 160 mg/day valsartan presented a higher probability of remaining free of AF (88%, vs. 47% for the control and 65% for the 80 mg/day valsartan groups). In addition, multivariate analysis demonstrated that treatment with ARB was associated with lower AF recurrence rates (hazard ratio, 0.46; 95% confidence interval, 0.20–0.93] P=0.01). In conclusion, treatment with 160 mg/day valsartan markedly reduced the risk of recurrence of AF in a dose-dependent manner in AF patients following ablation.

How To Follow Atrial Fibrillation Ablation Patients?

Catheter ablation is an established treatment option for symptomatic atrial fibrillation (AF), with circumferential pulmonary vein isolation being considered the cornerstone of the procedure. However, this is a complex intervention with potential major complications and with common arrhythmia recurrences. There is consensus among experts that all patients should be seen in follow-up regularly after AF ablation. To date there are limited data regarding the best methodology for routine clinical follow-up of this population. This review summarizes a contemporary insight into management of late complications following AF ablation, post-procedural anticoagulation and arrhythmia monitoring strategies, in order to prevent thromboembolic events, detect and treat arrhythmia recurrences, and discuss the use of upstream therapies after AF ablation.

Antiarrhythmic therapy following ablation of atrial fibrillation

Antiarrhythmic drugs (AADs) are often used after ablation for atrial fibrillation (AF); the drugs employed vary, but most common are the drugs that were unsuccessful prior to ablation since it seems that the efficacy of AADs might substantially increase after catheter ablation of AF. AADs reduce early recurrences of atrial tachyarrhythmias after AF catheter ablation, whereas they did not prevent arrhythmia recurrences occurring later. Several upstream therapies (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statins, corticosteroids and colchicine) have been tested with conflicting results. To date, there is no sufficient evidence to support the use of any upstream therapy after AF catheter ablation. Larger registries and controlled clinical trials in well-defined patient groups and with well-defined outcome parameters are required to further elucidate the role of AADs after AF ablation.

Renin Angiotenin Blocker Pre-treatment and Recurrence After Pulmonary Vein Isolation in Patients with Paroxysmal and Persistent Atrial Fibrillation

Introduction: Pulmonary venous isolation has emerged as an effective method for preventing atrial fibrillation (AF) recurrence. Yet, recurrence is common. Angiotensin-receptor-blockers (ARBs) and angiotensin-converting-enzyme-inhibitors (ACEI) are effective in reducing the extent of myocardial remodeling and fibrosis. Our aim was to study whether pretreatment with ARBs and ACEI was effective in decreasing recurrence after pulmonary vein isolation for patients with AF. Methods: Three hundred and twelve consecutive patients who underwent ablation from 12/2006 until 7/2010 were followed for at least one year. All patients underwent MRI before ablation to assess atrial fibrosis. Data include demographic characteristics, comorbidities, AF type and information regarding treatment with ACEI or ARBs. Results: Most patients were men (62%), mean age was 64. Hypertension (HTN) was present in 60%. Their mean ejection fraction was 60%. There were 104 patients (33.3%) treated with ACEI, and 13.5 % were treated with ARBs prior to ablation. Ninety seven patients (31.1%) had AF recurrence. AF type was a significant predictor for recurrence (recurrence with paroxysmal, persistent and long-standing persistent: 23.75, 37.3 and 60%, respectively, p=0.005). The most important factor predicting recurrence was increased pre-ablation atrial fibrosis (p<0.0001). Recurrence was more frequent in patients treated with ACEI (40.4% vs 26.4% untreated patients, p=0.012). In the ARB treated group, 38.1% vs 30.0% untreated experienced recurrence (p=0.3). After multivariable adjustment for demographics, risk factors and atrial fibrosis, treatment with ACEI was associated with increased rate of recurrence in patients with persistent AF (hazard ratio: 2.6, p=0.003). There was no significant relation between ACEI pretreatment and recurrence in patients with paroxysmal AF (HR- 0.83, p=0.7), or between ARB pre-treatment and recurrence in patients with paroxysmal as well as persistent AF (p=0.2 and 0.53, respectively). Conclusions: Pretreatment with ACEI or ARBs is not associated with reduced recurrence rate in patients with paroxysmal or persistent AF undergoing ablation.

Diabetes, Obesity and Atrial Fibrillation: Epidemiology, Mechanisms and Interventions

Body mass index (BMI) is a powerful predictor of death, type 2 diabetes (T2DM) and cardiovascular (CV) morbidity and mortality. Over the last few decades, we have witnessed a global rise in adult obesity of epidemic proportions. Similarly, there has been a parallel increase in the incidence of atrial fibrillation (AF), itself a significant cause of cardiovascular morbidity and mortality. This may be partly attributable to advances in the treatment of coronary heart disease (CHD) and heart failure (HF) improving life expectancy, however, epidemiological studies have demonstrated an independent association between obesity, diabetes and AF, suggesting possible common pathophysiological mechanisms and risk factors. Indeed, cardiac remodeling, haemodynamic alterations, autonomic dysfunction, and diastolic dysfunction have been reported in obese and diabetic cohorts. Moreover, diabetic cardiomyopathy is characterized by an adverse structural and functional cardiac phenotype, which may predispose to the development of AF. In this review, we discuss the pathophysiological and mechanistic relationships between obesity, diabetes and AF, and some of the challenges posed in the management of this high-risk group of individuals.

During ablation for atrial fibrillation, is simultaneous renal artery ablation appropriate?

Over the past few decades, the mainstay of hypertension management has been pharmacological therapy; however, there is now a growing body of evidence that drug-resistant hypertension can be managed effectively by renal artery ablation. Several studies have documented the feasibility and safety of this treatment, although data regarding long-term outcomes are still emerging. Atrial fibrillation (AF) and hypertension commonly coexist, and recent work has demonstrated improved outcomes from catheter ablation of AF with concomitant renal artery denervation at little extra cost in terms of time and resource. The aim of this review is to explore the link between hypertension and AF, the synergistic effect of renal artery ablation on AF ablation, explain how this may work and address unanswered questions.

Obesity, diabetes and atrial fibrillation; epidemiology, mechanisms and interventions

The last few decades have witnessed a global rise in adult obesity of epidemic proportions. The potential impact of this is emphasized when one considers that body mass index (BMI) is a powerful predictor of death, type 2 diabetes (T2DM) and cardiovascular (CV) morbidity and mortality [1, 2]. Similarly we have witnessed a parallel rise in the incidence of atrial fibrillation (AF), the commonest sustained cardiac arrhythmia, which is also a significant cause of cardiovascular morbidity and mortality. Part of this increase is attributable to advances in the treatment of coronary heart disease (CHD) and heart failure (HF) improving life expectancy and consequently the prevalence of AF. However, epidemiological studies have demonstrated an independent association between obesity and AF, possibly reflecting common pathophysiology and risk factors for both conditions. Indeed, weight gain and obesity are associated with structural and functional changes of the cardiovascular system including left atrial and ventricular remodeling, haemodynamic alterations, autonomic dysfunction, and diastolic dysfunction. Moreover, diabetic cardiomyopathy is characterized by an adverse structural and functional cardiac phenotype which may predispose to the development of AF [3]. In this review, we discuss the pathophysiological and mechanistic relationships between obesity, diabetes and AF, and the challenges posed in the management of this high-risk group of individuals.

Association of angiotensin-converting enzyme gene I/D and CYP11B2 gene -344T/C polymorphisms with lone atrial fibrillation and its recurrence after catheter ablation

The renin-angiotensin-aldosterone system (RAAS) plays a key role in atrial structural and electrical remodeling. The aim of this study was to investigate the potential associations of angiotensin-converting enzyme (ACE) gene insertion/ deletion (I/D) and aldosterone synthase (CYP11B2) gene −344T/C polymorphisms with the risk and recurrence of lone atrial fibrillation (AF). One hundred and ninety-three patients who underwent successful catheter ablation for lone AF were recruited. Two hundred and ninety-seven sinus rhythm subjects without a history of arrhythmia served as controls. The subjects were genotyped for ACE gene I/D and CYP11B2 gene −344T/C polymorphisms. Results showed that the ACE gene DD genotype and D allele were associated with a greater prevalence of lone AF (both P<0.01). In addition, the ACE gene DD genotype had a significantly larger left atrial dimension (LAD; 41.6±5.7 mm vs. 39.6±5.2 mm; P=0.043) and higher risk of AF recurrence [44.7% vs. 23.2%; odds ratio (OR), 2.68; 95% confidence interval (CI), 1.28–5.61; P=0.008] compared with the II+ID genotype in lone AF patients. After adjustment for a variety of risk factors, the ACE gene DD genotype had a 1.97-fold increased risk for lone AF (OR, 1.97; 95% CI, 1.15–3.37; P= 0.013) and 2.35-fold increased risk for AF recurrence (RR, 2.35; 95% CI, 1.10–5.04; P=0.028) compared with the ACE gene II+ID genotype. However, no correlation between the CYP11B2 gene −344T/C polymorphism and lone AF or its recurrence was observed in this cohort. In conclusion, the ACE gene DD genotype was associated with an increased incidence of lone AF and its recurrence following ablation, which was partly mediated by LAD.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.

Renin-Angiotensin System and AtrialFibrillation:Understanding the Connection

Atrial fibrillation (AF) arises as a result of a complex interaction of triggers, perpetuators and the substrate. The recurrence of AF may be partially related to a biologic phenomenon known as remodeling, in which the electrical, mechanical, and structural properties of the atrial tissue and cardiac cells are progressively altered,creating a more favorable substrate. Atrial remodeling is in part a consequence of arrhythmia itself. Therefore,to prevent and to treat AF, much attention has been directed to upstream therapies to alter the arrhythmia substrate and to reduce atrial remodeling. The renin-angiotensin-aldosterone system (RAAS) plays a keyrole in these strategies. In this review we analyze the experimental and clinical evidence regarding the efficacy of RAAS inhibitors in AF treatment. In the primary prevention of AF, meta-analyses have shown that risk of new-onset AF in patients with congestive heart failure and left ventricular dysfunction is reduced by RAAS inhibitors, whereas in hypertensive and post-myocardial infarction patients, the results are less evident. In the secondary prevention of AF, some large, prospective, randomized, placebo-controlled studieswith angiotensin II-receptor blockers returned negative results. Unfortunately, the approach of using RAASinhibitors as antiarrhythmic drugs to prevent both new-onset and recurrent AF is in decline because negativetrial results are accumulating, with the exception of the results in patients with congestive heart failure.

Upstream therapies for management of atrial fibrillation: review of clinical evidence and implications for European Society of Cardiology guidelines. Part II: secondary prevention

Fundamental research into molecular mechanisms of atrial fibrillation (AF) and improved understanding of processes involved in the initiation and maintenance of AF have transformed the traditional approach to its management by targeting only the electrical aspects, usually with antiarrhythmic drugs and, recently, by ablation. The antiarrhythmic potential of upstream therapies, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers (ARBs), statins, and n-3 (ω-3) polyunsaturated fatty acids, extends beyond the benefit of treating underlying heart disease to modifying the atrial substrate and intervening in specific mechanisms of AF. The key target is structural remodelling of the atria, particularly inflammation and fibrosis, although there is evidence to suggest the direct involvement at the ion channel level. Positive clinical reports supported by robust experimental data have suggested that upstream therapies can be valuable strategies for primary prevention of AF in selected patients and have resulted in several class IIA recommendations in the new European guidelines on AF. However, these results have not been consistently replicated in the secondary prevention setting, and several recent randomized controlled studies failed to demonstrate any effect of upstream therapies on AF burden or on major cardiovascular outcomes. Part II of the review summarizes the evidence base for the use of upstream therapies for secondary prevention of AF.