Association of pretreatment with angiotensin-converting enzyme inhibitors with improvement in ablation outcome in atrial fibrillation patients with low left ventricular ejection fraction

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.

Detection and modification of biomarkers of inflammation determining successful rhythm control in patients with atrial fibrillation

INTRODUCTION

Multiple pathophysiological mechanisms are involved in the pathogenesis of atrial fibrillation (AF). Growing evidence suggests that both local and systemic inflammation plays a key role even in early stages and its progression towards persisting and permanent AF. Rhythm control therapy via pulmonary vein isolation or cardioversion is the cornerstone of AF therapy for most symptomatic patients, yet arrhythmia recurrence after treatment is still common, especially in patients with persistent AF.

MATERIAL AND METHODS

In this review, we summarize the current state of knowledge of biomarkers of inflammation with prognostic value in patients with atrial fibrillation as well as anti-inflammatory medication with potential benefits after rhythm control therapy.

RESULTS AND DISCUSSION

Both onset of AF, progression and arrhythmia recurrence after rhythm control therapy can be caused by local and systemic inflammation. Various inflammatory biomarkers have been established to predict treatment success. Furthermore, additional anti-inflammatory therapy may significantly improve success rates.

Small molecule angiotensin converting enzyme inhibitors: A medicinal chemistry perspective

Angiotensin-converting enzyme (ACE), a zinc metalloprotein, is a central component of the renin-angiotensin system (RAS). It degrades bradykinin and other vasoactive peptides. Angiotensin-converting-enzyme inhibitors (ACE inhibitors, ACEIs) decrease the formation of angiotensin II and increase the level of bradykinin, thus relaxing blood vessels as well as reducing blood volume, lowering blood pressure and reducing oxygen consumption by the heart, which can be used to prevent and treat cardiovascular diseases and kidney diseases. Nevertheless, ACEIs are associated with a range of adverse effects such as renal insufficiency, which limits their use. In recent years, researchers have attempted to reduce the adverse effects of ACEIs by improving the selectivity of ACEIs for structural domains based on conformational relationships, and have developed a series of novel ACEIs. In this review, we have summarized the research advances of ACE inhibitors, focusing on the development sources, design strategies and analysis of structure-activity relationships and the biological activities of ACE inhibitors.

Role of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in cryoballoon ablation outcomes for paroxysmal atrial fibrillation

BACKGROUND

Cryoballoon ablation (CBA) is recommended for patients with paroxysmal atrial fibrillation (AF) refractory to antiarrhythmic drugs. However, only 80% of patients benefit from initial CBA. There is growing evidence that pretreatment with angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) decreases the recurrence of AF postablation, particularly in nonparoxysmal AF undergoing radiofrequency ablation. The role of ACEIs and ARBs in patients with paroxysmal AF in CBA remains unknown. We decided to investigate the role of ACEIs and ARBs in preventing the recurrence of atrial arrhythmia (AA) following CBA for paroxysmal AF.

AIM

To investigate the role of ACEIs and ARBs in preventing recurrence of AA following CBA for paroxysmal AF.

METHODS

We followed 103 patients (age 60.6 ± 9.1 years, 29% women) with paroxysmal AF undergoing CBA 1-year post procedure. Recurrence was assessed by documented AA on electrocardiogram or any form of long-term cardiac rhythm monitoring. A multivariable Cox proportional hazard model was used to assess if ACEI or ARB treatment predicted the risk of AA recurrence.

RESULTS

After a 1-year follow-up, 19 (18.4%) participants developed recurrence of AA. Use of ACEI or ARB therapy was noted in the study population. Patients on ACEI/ARB had a greater prevalence of hypertension and coronary artery disease. On a multivariate model adjusted for baseline demographics and risk factors for AF, ACEI or ARB therapy did not prevent recurrence of AA following CBA (P = 0.72). Similarly, on Kaplan–Meier analysis pretreatment with ACEI/ARB did not predict the time to first recurrence of AA (P = 0.2173).

CONCLUSION

In our study population, preablation treatment with an ACEI or ARB had no influence on the recurrence of AA following CBA for paroxysmal 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.

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.

Quantification of peripheral whole blood, cell-free plasma and exosome encapsulated mitochondrial DNA copy numbers in patients with atrial fibrillation

Mitochondrial DNA (mtDNA) copy number changes have been associated with various diseases. Several studies showed that mtDNA content in peripheral blood was associated with oxidative stress and cardiovascular disease. Atrial fibrillation (AF) is one of the severe cardiovascular diseases. We aimed to determine the mtDNA copy numbers in peripheral blood, in cell-free plasma and in exosomes of AF patients and healthy controls. Peripheral blood was drawn from 60 AF patients and 72 healthy controls. DNA was isolated from EDTA blood and plasma. Exosomes were isolated from cell-free plasma and then exosome encapsulated DNA (exoDNA) was extracted. Quantitative-real-time PCR was performed with Human Mitochondrial DNA (mtDNA) Monitoring Primer Set. Statistical analysis of the data was performed. We found statistically significant difference in mtDNA copy numbers in DNA isolated from peripheral whole blood, cell-free plasma and exosome samples of controls' (44.4 ± 18.0, 27.2 ± 30.1, 11.5 ± 8.7), and patients' group (43.4 ± 13.6, 26.2 ± 26.4, 14.5 ± 12.3). However there was no significant difference in mtDNA copy number between the two study groups either in peripheral blood, in cell-free plasma and in exosomes, and even in different sexes and ages. We found the highest copy number of mtDNA in peripheral blood, followed by plasma and exosomes. We did not find differences between patients and controls, neither age nor gender had effect on the mtDNA copy number. According to our results the mtDNA copy numbers did not differ in AF patients.

Influence of Inflammation and Atherosclerosis in Atrial Fibrillation

BACKGROUND

Inflammation markers have been associated with cardiovascular diseases including atrial fibrillation. This arrhythmia is the most frequent, with an incidence of 38/1000 person-years.

PURPOSE OF REVIEW

The aims of this study are to discuss the association between inflammation, atherosclerosis and atrial fibrillation and its clinical implications. Atherosclerosis is a chronic inflammatory disease and inflammation is a triggering factor of atherosclerotic plaque rupture. In addition to coronary artery disease, clinical conditions identified as risk factors for atrial fibrillation (AF) are also associated with the inflammatory state such as obesity, diabetes mellitus, hypertension, heart failure, metabolic syndrome and sedentary lifestyle. Biomarkers of inflammation, oxidative stress, coagulation, and myocardial necrosis have been identified in patients with atrial fibrillation and these traditional risk factors. Some markers of inflammation were identified as predictors of recurrence of this arrhythmia, subsequent myocardial infarction, stroke by embolism, and death. Thus, approaches to manipulate the inflammatory pathways may be therapeutic interventions, benefiting patients with AF and increased inflammatory markers.

Atrial Fibrillation in Heart Failure: a Therapeutic Challenge of Our Times

Atrial fibrillation (AF) and heart failure (HF) are growing cardiovascular disease epidemics worldwide. There has been an exponential increase in the prevalence of AF and HF correlating with an increased burden of cardiac risk factors and improved survival rates in patients with structural heart disease. AF is associated with adverse prognostic outcomes in HF and is most evident in mild-to-moderate left ventricular (LV) dysfunction where the loss of "atrial kick" translates into poorer quality of life and increased mortality. In the absence of underlying structural heart disease, arrhythmia can independently contribute to the development of cardiomyopathy. Together, these 2 conditions carry a high risk of thromboembolism due to stasis, inflammation and cellular dysfunction. Stroke prevention with oral anticoagulation (OAC) remains a mainstay of treatment. Pharmacologic rate and rhythm control remain limited by variable efficacy, intolerance and adverse reactions. Catheter ablation for AF has resulted in a paradigm shift with evidence indicating superiority over medical therapy. While its therapeutic success is high for paroxysmal AF, it remains suboptimal in persistent AF. A better mechanistic understanding of AF as well as innovations in ablation technology may improve patient outcomes in the future. Refractory cases may benefit from atrioventricular junction ablation and biventricular pacing. The value of risk factor modification, especially with regard to obesity, sleep apnea, hypertension and diabetes, cannot be emphasized enough. Close interdisciplinary collaboration between HF specialists and electrophysiologists is an essential component of good long-term outcomes in this challenging population.

Redefining the Blanking Period After Catheter Ablation for Paroxysmal Atrial Fibrillation: Insights From the ADVICE (Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination) Trial

BACKGROUND

Early recurrences (ERs) of atrial tachyarrhythmia are common after catheter ablation of atrial fibrillation. A 3-month blanking period is recommended by current guidelines. This study sought to investigate the significance of ER during the first 3 months post ablation in predicting late recurrences and determine whether it varies according to timing.

METHODS AND RESULTS

A total of 401 patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation were followed for 12 months with transtelephonic monitoring in the ADVICE (Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination) trial. Patients with atrial tachyarrhythmia ≥30 s within the 3-month blanking period were stratified according to the timing of ER. A total of 179 patients (44.6%) experienced their last episode of ER during the first (n=53), second (n=44), or third (n=82) month of the 3-month blanking period. One-year freedom from symptomatic atrial tachyarrhythmia was 77.2% in patients without ER compared with 62.6%, 36.4%, and 7.8% in patients with ER 1, 2, and 3 months post ablation, respectively (P<0.0001). Receiver operating curve analyses revealed a strong correlation between the timing of ER and late recurrence (area under the curve 0.82, P<0.0001). Corresponding hazard ratios for ER during the first, second, and third months were 1.84, 4.45, and 9.64, respectively.

CONCLUSIONS

This study validates the use of a blanking period after catheter ablation for paroxysmal atrial fibrillation but calls into question the 90-day cut-off value. In particular, >90% of patients with ER during the third month post ablation experience late recurrence by 1 year. However, pending further study, repeat ablation before 90 days cannot be routinely advocated.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01058980.

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.

Prevalence of right atrial non-pulmonary vein triggers in atrial fibrillation patients treated with thyroid hormone replacement therapy

BACKGROUND

Thyroid hormone (TH) is known to enhance arrhythmogenicity, and high-normal thyroid function is related with an increased recurrence of atrial fibrillation (AF) after catheter ablation. However, the impact of thyroid hormone replacement (THR) on AF ablation is not well known.

METHODS

This study evaluated 1163 consecutive paroxysmal AF patients [160 (14%) on THR and 1003 (86%) without THR] undergoing their first catheter ablation. A total of 146 patients on THR and 146 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model (age, sex, body mass index, and left atrium size). The presence of non-pulmonary vein (PV) triggers was disclosed by a high-dose isoproterenol challenge (up to 30 μg/min) after PV isolation.

RESULTS

Clinical characteristics were not different between the groups. When compared to the control, non-PV triggers were significantly greater in the THR patients [112 (77%) vs. 47 (32%), P < 0.001], and most frequently originated from the right atrium (95 vs. 56%, P < 0.001). Other sources of non-PV triggers were the interatrial septum (25 vs. 11%, P = 0.002), coronary sinus (70 vs. 52%, P = 0.01), left atrial appendage (47 vs. 34%, P = 0.03), crista terminalis/superior vena cava (11 vs. 8%, P = 0.43), and mitral valve annulus (7 vs. 5%, P = 0.45) (THR vs. control), respectively. After mean follow-up of 14.7 ± 5.2 months, success rate was lower in patients on THR therapy [94 (64.4%)] compared to patients not receiving THR therapy [110 (75.3%), log-rank test value = 0.04].

CONCLUSIONS

Right atrial non-PV triggers were more prevalent in AF patients treated with THR. Elimination of non-PV triggers provided better arrhythmia-free survival in the non-THR group.