Comparison of outcome in catheter ablation of atrial fibrillation in patients with versus without the metabolic syndrome

Correlates of sleep-disordered breathing and Cheyne-Stokes respiration in patients with atrial fibrillation who have undergone pulmonary vein isolation

Sleep disordered breathing (SDB) is a common comorbidity in patients with atrial fibrillation (AF). Patients undergoing pulmonary vein isolation (PVI) for AF have a high prevalence of SDB. In previous studies, some patients with AF had Cheyne-Stokes respiration (CSR). The aim of the present study was to assess the prevalence of SDB and the correlates of SDB severity and CSR in AF patients who have undergone PVI. The study was conducted using a single-center observational design. All participants underwent a home sleep apnea test (ApneaLink Air, ResMed, Australia), which could determine the severity of SDB as assessed by the apnea-hypopnea index (AHI) and the percentage of CSR (%CSR) pattern. 139 AF patients who underwent PVI were included in the study. Overall, 38 (27.3%) patients had no SDB (AHI < 5), 53 (38.1%) had mild SDB (5 ≤ AHI < 15), 33 (23.7%) had moderate SDB (15 ≤ AHI < 30), and 15 (10.8%) had severe SDB (AHI ≥ 30). Correlates of the increased AHI included male sex (β = 0.23, p = 0.004), age (β = 0.19, p = 0.020), high body mass index (β = 0.31, p < 0.001), and β blockers usage (β = 0.18, p = 0.024). Conversely, correlates with the %CSR rate included male sex (β = 0.18, p = 0.020), age (β = 0.19, p = 0.015), non-paroxysmal AF (β = 0.22, p = 0.008), and high glycohemoglobin A1c (β = 0.36, p < 0.001) and N-terminal pro-brain natriuretic peptide (β = 0.24, p = 0.005) levels. SDB is prevalent in patients with AF who have undergone PVI; predisposing factors for SDB include male sex, older age, and obesity. CSR occurs in patients with AF who have undergone PVI; predisposing factors for CSR include male sex, older age, high left ventricular filling pressure, and abnormal blood glucose level.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

Prognostic importance of ischemic heart disease for patients with atrial fibrillation undergoing catheter ablation

BACKGROUND

Ischemic heart disease (IHD) has been linked to an increased risk of atrial fibrillation (AF). However, data are sparse regarding the role of IHD in AF recurrence after catheter ablation.

OBJECTIVE

We sought to investigate whether preexisting or new-onset IHD is associated with a greater risk of AF recurrence after ablation.

METHODS

With use of Danish nationwide registries, all patients undergoing first-time AF ablation in Denmark from 2010 to 2020 were identified. The primary outcome was AF recurrence defined by AF-related hospital admission or antiarrhythmic drug use within 1 year after ablation excluding a 3-month blanking period. IHD was defined as an International Classification of Diseases, Tenth Revision diagnosis of IHD or prior coronary revascularization.

RESULTS

Of 12,162 patients undergoing first-time ablation for AF (mean age, 62 years; 30% female), 20% had preexisting IHD. Preexisting IHD was associated with an increased risk of AF recurrence in univariable log-binomial logistic regression (relative risk, 1.09; 95% CI, 1.04-1.14; P < .001). However, after multivariable adjustment including procedural year, preexisting IHD was no longer associated with an increased risk of AF recurrence (relative risk, 1.02; 95% CI, 0.97-1.06; P = .42). In a nested case-control study of those without preexisting IHD before ablation (n = 9778), newly diagnosed IHD after ablation was associated with an increased risk of AF recurrence in multivariable analysis (hazard ratio, 3.03; 95% CI, 1.84-4.99; P < .001).

CONCLUSION

The presence of IHD does not appear to reduce the effectiveness of AF ablation procedures. However, the emergence of IHD after AF ablation may serve as a trigger for AF that is insufficiently suppressed by prior ablation.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Clinical implication of the patient's disease awareness and adherence to medications in patients undergoing atrial fibrillation ablation

Background

The effects of the patient's disease awareness on the management of postablation of atrial fibrillation (AF) are unknown.

Methods

One hundred thirty-three AF patients undergoing an initial ablation were given a disease awareness questionnaire with a score of 16 points (8 points about AF in general and 8 points about oral anticoagulants) for the Jessa Atrial Fibrillation Knowledge Questionnaire (JAKQ) before and 1-year-after ablation. We divided them into the poor disease awareness group and good disease awareness group according to the median value (75%) of the total JAKQ score about AF in general, and compared the baseline patient characteristics and the 1-year changes in the JAKQ score, medication adherence, blood pressure, laboratory data, echocardiographic parameters, and AF/atrial tachycardia (AT) recurrence rate between the two groups.

Results

Forty-two (31.6%) patients were classified as having poor disease awareness (<75% of the total JAKQ score), which was closely associated with poor medication adherence, hypertension, diabetes, dyslipidemia, and greater left atrial volume (LAV). These trends in the poor disease awareness group remained unchanged 1 year after the ablation. During the 25.3-month follow-up, the AF/AT recurrence rate was significantly higher in the poor disease awareness than the good disease awareness group (23.8% vs. 7.7%; p = .003 by the log-rank test).

Conclusions

Poor disease awareness was linked to poor medication adherence, lifestyle-related diseases, and greater LAV before and even 1 year after the ablation, making it a potential surrogate marker for AF/AT recurrence. These findings highlight the clinical significance of disease awareness in AF management.

Predictors of recurrence after catheter ablation and electrical cardioversion of atrial fibrillation: an umbrella review of meta-analyses

AIMS

The recurrence rates after catheter ablation (CA) and direct current (DC) cardioversion remain high, although they have been established treatments of rhythm control of atrial fibrillation (AF). This umbrella review systematically appraises published meta-analyses of both observational and randomized controlled trials (RCTs) for the association of risk and protective factors for arrhythmia recurrence after CA and DC cardioversion of AF.

METHODS AND RESULTS

Three bibliographic databases were searched up to June 2021. Evidence of association was rated as convincing, highly suggestive, suggestive, weak, or not significant with respect to observational studies and as high, moderate, low, or very low with respect to RCTs, according to established criteria. Thirty-one meta-analyses were included. Of the 28 associations between CA and the risk of arrhythmia recurrence, none presented convincing evidence, and only the time from diagnosis to ablation over 1 year provided highly suggestive evidence. The association between hypertension and metabolic profile provided suggestive evidence. The associations of Class IC and III antiarrhythmic drugs use with the recurrence after DC cardioversion were supported by an intermediate level of evidence.

CONCLUSION

Although AF is a major health issue, few risk- and protective factors for AF recurrence have been identified. None of these factors examined were supported by convincing evidence, whereas established factors such as female gender and left atrial volume showed only weak association. An early CA strategy combined with treatment of metabolic syndrome and hypertension prior to CA may reduce the risk of arrhythmia recurrence. The use of antiarrhythmics can increase the success rate of DC cardioversion.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registry number: CRD42021270613.

Body mass index and atrial fibrillation recurrence post ablation: A systematic review and dose-response meta-analysis

Objectives

The aim of this study was to evaluate the shape of the dose-response relationship between body mass index (BMI) and atrial fibrillation (AF) recurrence in patients who have undergone radiofrequency ablation.

Methods

Studies investigating BMI and AF recurrence in patients with AF after ablation were identified through electronic searches in the PubMed, EMBASE, and Cochrane Library databases. The potential non-linear relationship was fitted using robust error meta-regression. Our study was registered with PROSPERO (CRD42019121373).

Results

Twenty-six cohort studies with 7,878 cases/26,450 individuals were included, and a linear dose-response relationship between BMI and AF recurrence (P _{non-linearity} = 0.12) was found. The risk of AF recurrence in patients with a BMI over 28 was significantly increased. Specifically, for each 5 kg/m² increase in BMI, the risk of AF recurrence increased by 15% (95% CI: 1.08-1.22) with moderate heterogeneity (I ² = 53%). Subgroup analyses showed that the pooled risk ratio was not significantly changed in subgroup analysis adjustment for the following important potential intermediate factors: left atrial diameter and obstructive sleep apnea.

Conclusion

This study showed that there is a borderline positive linear association between BMI and AF recurrence post ablation. Overweight and obesity are significantly associated with AF recurrence.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42019128770.

[Rhythm and metabolic control]

Diabetes mellitus and atrial fibrillation show a steady increase in their prevalence. Diabetes mellitus is a relevant risk factor for the development and maintenance of atrial fibrillation, which should not be underestimated. Fluctuations in blood glucose levels occurring in diabetes, inflammatory processes and oxidative stress lead to structural, electromechanical, electrical and autonomic remodelling processes in the myocardium that promote atrial fibrillation. When atrial fibrillation and diabetes mellitus coincide, this is often associated with more pronounced symptoms, lower quality of life, more frequent hospitalization and a higher mortality rate. Can early and consistent euglycemic blood glucose monitoring effectively influence atrial remodelling processes, cardiovascular end points and the occurrence of atrial fibrillation? Are there new and combined drug treatment approaches for diabetes mellitus and atrial fibrillation? What ablation strategy should be adopted for the interventional treatment of atrial fibrillation in patients with diabetes mellitus? This review article attempts to find answers to these questions.

Epicardial Fat Volume as a New Imaging-Based Feature Associated with Risk of Recurrence after Pulmonary Veins Ablation in Atrial Fibrillation

Background: Atrial fibrillation (AF), a common arrhythmia in clinical practice, is associated with a high rate of complications and an increased risk for thromboembolic events. Pulmonary vein ablation is a new therapeutic option to cure AF; however, it remains associated with a high rate of recurrence. In this study we aimed to identify the clinical characteristics and imaging-based features that may predict the risk of recurrence after pulmonary veins ablation in atrial fibrillation.

Materials and method: Twenty-four patients with paroxysmal and persistent AF, who underwent radiofrequency catheter ablation and a 12-month follow-up were included in the study. Group 1 included 8 patients with AF recurrence, and group 2 included 16 patients with no AF recurrence. In all cases, cardiovascular risk factors, ejection fraction, left atrial diameter, atrial volumes, and epicardial fat volume were analyzed.

Results: CT analysis revealed that patients with AF recurrence presented a significantly larger mean index of left atrial volume (59.57 ± 8.52 mL/m2 vs. 49.99 ± 10.88 mL/m2, p = 0.04), right atrial volume (58.94 ± 8.37 mL/m2 vs. 43.21 ± 6.4 mL/m2, p<0.0001), and indexed bi-atrial volume (118.5 ± 15.82 mL/m2 vs. 93.19 ± 16.42 mL/m2, p = 0.005). At the same time, CT analysis of the epicardial adipose tissue volume indicated that patients with AF recurrence have a larger amount of epicardial fat than those without AF recurrence (176.4 ± 100.8 mL vs. 109.8 ± 40.73 mL, p = 0.02).

Conclusion: Left atrial diameter, indexed atrial volumes, and epicardial fat volume may be used as factors to identify patients at risk for developing recurrence after pulmonary vein ablation.

Association of metabolic syndrome with non-thromboembolic adverse cardiac outcomes in patients with atrial fibrillation

Aims

Evidence suggests an excess risk of non-thromboembolic major adverse cardiac events (MACE) associated with atrial fibrillation (AF), particularly in individuals free of overt coronary artery disease (CAD). Metabolic syndrome (MetS) increases cardiovascular risk in the general population, but less is known how it influences outcomes in AF patients. We aimed to assess whether MetS affects the risk of MACE in AF patients without overt CAD.

Methods and results

This prospective, observational study enrolled 843 AF patients (mean-age, 62.5 ± 12.1 years, 38.6% female) without overt CAD. Metabolic syndrome was defined according to the National Cholesterol Education Program. The 5-year composite MACE included myocardial infarction (MI), coronary revascularization, and cardiac death. Metabolic syndrome was present in 302 (35.8%) patients. At 5-year follow-up, 118 (14.0%) patients experienced MACE (2.80%/year). Metabolic syndrome conferred a multivariable adjusted hazard ratio (aHR) of 1.98 for MACE [95% confidence interval (CI), 1.23-3.16; P = 0.004], and for individual outcomes: MI (aHR, 2.00; 95% CI, 1.69-5.11; P < 0.001), revascularization (aHR, 2.33; 95% CI, 1.40-3.87; P = 0.001), and cardiac death (aHR, 2.59; 95% CI, 1.25-5.33; P = 0.011). Following the propensity score (PS)-adjustment for MetS, the association between MetS and MACE (PS-aHR, 1.87; 95% CI, 1.21-3.01; P = 0.012), MI (PS-aHR, 1.72; 95% CI, 1.54-5.00; P = 0.008), revascularization (PS-aHR, 2.18; 95% CI, 1.69-3.11; P = 0.015), and cardiac death (PS-aHR, 2.27; 95% CI, 1.14-5.11; P = 0.023) remained significant.

Conclusion

Metabolic syndrome is common in AF patients without overt CAD, and confers an independent, increased risk of MACE, including MI, coronary revascularization, and cardiac death. Given its prognostic implications, prevention and treatment of MetS may reduce the burden of non-thromboembolic complications in AF.

Echocardiography Evaluation of Left Ventricular Diastolic Function in Elderly Women with Metabolic Syndrome

To date, we found no published reports on the effects of metabolic syndrome and physical activity levels on left ventricular (LV) diastolic function in elderly women aged over 65 years. Our study involved patients with echocardiographically normal LV ejection fractions (≥50%) and normal LV dilatation diameters (≤55 mm). Elderly women with metabolic syndrome (n = 20) and healthy elderly women (n = 17) were selected and assessed with the National Cholesterol Education Program Adult Treatment Panel III, a metabolic syndrome diagnostic instrument. We compared the LV function indices and physical activity levels according to the presence (metabolic syndrome group) or absence (normal group) of metabolic syndrome. The LV end-systolic (LVES) diameter was significantly smaller (p = 0.037) and LV outflow tract (LVOT) diameter was significantly larger (p = 0.030) in the metabolic syndrome group. The left arterial dimension at end-systole (p = 0.024), left arterial volume (LAV) index (p = 0.015), early peak mitral inflow velocity (E, p = 0.031), early diastolic mitral annulus motion velocity (E'-septal, p = 0.044), (E'-lateral, p = 0.008), and E/late peak mitral inflow velocity ratio (E/A, p = 0.006) values were significantly lower and physical activity levels (p = 0.034) were significantly higher in the metabolic syndrome group. These results indicated that the metabolic syndrome group had relatively high physical activity levels compared to the normal group, which may have positively affected the LVES, LVOT, left atrial volume index, E, E', and E/A values.

Catheter Ablation of Paroxysmal Atrial Fibrillation Originating from Non-pulmonary Vein Areas

Pulmonary veins (PVs) are a major source of ectopic beats that initiate AF. PV isolation from the left atrium is an effective therapy for the majority of paroxysmal AF. However, investigators have reported that ectopy originating from non-PV areas can also initiate AF. Patients with recurrent AF after persistent PV isolation highlight the need to identify non-PV ectopy. Furthermore, adding non-PV ablation after multiple AF ablation procedures leads to lower AF recurrence and a higher AF cure rate. These findings suggest that non-PV ectopy is important in both the initiation and recurrence of AF. This article summarises current knowledge about the electrophysiological characteristics of non-PV AF, suitable mapping and ablation strategies, and the safety and efficacy of catheter ablation of AF initiated by ectopic foci originating from non-PV areas.

Atrial Fibrillation and Myocardial Infarction: A Systematic Review and Appraisal of Pathophysiologic Mechanisms

BACKGROUND

A growing body of evidence suggests that atrial fibrillation (AF) is associated with myocardial infarction (MI). However, incidence and management of MI in AF is still undefined.

METHODS AND RESULTS

We searched MEDLINE via PubMed and Cochrane database between 1965 and 2015. All observational clinical studies and interventional trials reporting 1-year incidence of MI in AF were included. We also discussed pathophysiological mechanisms, predictors, and therapeutic approaches to reduce the risk of MI in AF. Twenty-one observational studies and 10 clinical trials were included. The annual rate of MI in observational studies including AF patients ranged from 0.4% to 2.5%. Higher rates of MI were reported in AF patients with stable coronary artery disease (11.5%/year), vascular disease (4.47%/year), heart failure (2.9%/year), and in those undergoing coronary artery interventions (6.3%/year). However, lower annual rates have been described in AF patients from Eastern countries (0.2-0.3%/year), and in those enrolled in clinical trials (from 0.4 to 1.3%/year).

CONCLUSIONS

AF patients had a significant residual risk of MI despite anticoagulant treatment. Coexistence of atherosclerotic risk factors and platelet activation account for the increased risk of MI in AF. Identification of high-risk AF patients is a needed first step to develop cost-effective approaches for prevention. A new score, the 2MACE score, has been recently developed to stratify MI risk in AF, and may help not only in allocating resources to high-risk groups, but also in design of studies examining novel therapies for prevention of MI in AF.

Incidence of myocardial infarction and vascular death in elderly patients with atrial fibrillation taking anticoagulants: relation to atherosclerotic risk factors

BACKGROUND

Recent findings suggest that patients with atrial fibrillation (AF), in addition being at thromboembolic risk, are at risk of myocardial infarction (MI). Our aim was to investigate predictors of MI and cardiovascular death in a cohort of patients with AF who were taking anticoagulants.

METHODS

We prospectively followed up 1,019 patients with AF for a median of 33.7 months (3,223 person-years). All patients were treated with oral vitamin K antagonists. Primary outcome was a composite end point of cardiovascular events (CVEs) including fatal/nonfatal MI, cardiac revascularization, and cardiovascular death.

RESULTS

The mean age of the patients was 73.2 years, and 43.8% were women. At follow-up, 111 CVEs (3.43%/y) had occurred: 47 fatal-nonfatal MI/revascularization and 64 cardiovascular deaths. In addition, 31 stroke/transient ischemic attacks (0.96%/y) were recorded. Patients experiencing CVEs were older (P < .001) and had a higher prevalence of metabolic syndrome (MetS) (P = .005), heart failure (P = .001), and prior cardiac (P < .001) and cerebrovascular events (P < .001). On a Cox proportional hazard analysis, age (hazard ratio [HR], 1.083; 95% CI, 1.053-1.113; P < .001), smoking (HR, 2.158; 95% CI, 1.193-3.901; P = .011), history of cerebrovascular (HR, 1.704; 95% CI, 1.119-2.597; P = .013) and cardiac (HR, 1.658; 95% CI, 1.105-2.489; P = .015) events, MetS (HR, 1.663; 95% CI, 1.107-2.499; P = .014), heart failure (HR, 1.584; 95% CI, 1.021-2.456; P = .040), and male sex (HR, 1.499; 95% CI, 1.010-2.223; P = .044) predicted CVEs.

CONCLUSIONS

Patients with AF still experience a high rate of CVEs despite receiving anticoagulant treatment. MetS is a common clinical feature in patients with AF, which increases the risk of CVEs. A holistic approach is needed to reduce the cardiovascular risk in patients with AF.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01882114; URL: www.clinicaltrials.gov.

Interatrial septal thickness is associated with the extent of left atrial complex fractionated atrial electrograms and acute procedural outcome in patients with persistent atrial fibrillation

AIMS

The interatrial septal thickness (IAST) reflects the changes of the atrial wall in patients with atrial fibrillation (AF). Complex fractionated atrial electrograms (CFAEs) were consistently positioned on the interatrial septum, especially in the remodelled left atrium (LA). We sought to characterize the relationship between IAST and LA CFAE area, as well as the acute procedural and clinical outcomes of catheter ablation in persistent AF patients.

METHODS AND RESULTS

This study included 71 patients who underwent catheter ablation for drug-refractory persistent AF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by LA and right atrial CFAE-guided ablation. Interatrial septal thickness was measured 1 cm inferior to the fossa ovalis on cardiac computed tomography (CT). The extent of LA CFAEs was assessed by CFAE area and index (CFAE area/LA surface area × 100). Patients were grouped into tertiles according to the value of IAST. The mean IAST of the first, second, and third tertile was 4.69 ± 0.79, 6.44 ± 0.45, and 9.12 ± 1.42 mm, respectively (P < 0.001). The mean CFAE areas (5.6 ± 6.9, 18.5 ± 20.3, and 24.3 ± 26.6 mm(2), P = 0.005) and CFAE indexes (3.1 ± 4.2, 9.2 ± 10.7, and 11.8 ± 15.3, P = 0.025) in LA were significantly different among the three groups. More patients in the highest IAST tertile did not terminate AF during catheter ablation (12.5% vs. 26.1% vs. 37.5%, P = 0.048).

CONCLUSIONS

Interatrial septal thickness measured by cardiac CT is associated with the extent of CFAE area within the LA and is related to acute procedural success of catheter ablation. These findings suggest that IAST reflects the degree of atrial substrate and remodelling in patients with persistent AF.

Impact of Metabolic Syndrome on Left Atrial Electroanatomical Remodeling and Outcomes After Radiofrequency Ablation of Nonvalvular Atrial Fibrillation

Background—

Recent studies reported worse outcomes after atrial fibrillation (AF) ablation in patients with metabolic syndrome (MetS). However, mechanisms of AF recurrence in MetS remain unclear.

Method and Results—

We performed pulmonary vein isolation and voltage mapping in 236 patients with AF (age 61±9.6 years; persistent AF 64%; MetS 54%). Left atrial (LA) low voltage areas were semiquantitatively estimated and presented as low voltage index. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III. Follow-up for AF recurrence ≤12 months was performed. LA low voltage areas were observed in 46% of patients with MetS versus 8.2% patients without MetS ; P <0.0001. MetS was an independent predictor of LA low voltage areas: odds ratio, 11.64; 95% confidence interval, 4.381–30.903; P <0.0001. Observed AF recurrence at 12 months was 42.7% in MetS versus 36.1% in the non-MetS group ( P =0.303). The presence of LA low voltage areas was a predictor of 12-month AF recurrence: odds ratio, 2.99; 95% confidence interval, 1.36–6.56; P =0.006. Probability of 12-month AF recurrence increased with 84.5% for every unit of low voltage Index.

Conclusions—

MetS was not associated with worse outcomes after radiofrequency catheter ablation of AF, but LA low voltage areas were more frequently observed in patients with MetS. The presence and extent of LA low voltage areas may influence the long-term outcomes after catheter ablation.

Impact of metabolic syndrome on the risk of atrial fibrillation recurrence after catheter ablation: systematic review and meta-analysis

PURPOSE

The impact of metabolic syndrome (MetS) on recurrence of atrial fibrillation (AF) after catheter ablation remains uncertain. We conducted a meta-analysis to summarize the relative risks (RR) of AF recurrence after catheter ablation in patients with vs. without MetS and its components.

METHODS

Among 839 articles identified from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, we included 23 studies with a total of 12,924 patients (7,594 with paroxysmal AF and 5,330 with nonparoxysmal AF) for analysis. Five of these had complete information on MetS components. Variables assessed comprised study design and population characteristics, AF ablation methods, use of anti-arrhythmic drugs, AF recurrence ascertainment methods, adjustment variables, and other quality indicators.

RESULTS

Our meta-analysis found an elevated risk of AF recurrence after ablation in patients with vs. without MetS (pooled RR, 1.63; 95 % confidence interval (CI), 1.25-2.12). Among components of MetS, hypertension was a predictor of AF post-ablation recurrence in studies without adjustment for other MetS components (RR, 1.62; 95 % CI, 1.23-2.13) but not in those adjusting for two or more additional MetS components (RR, 1.03; 95 % CI, 0.88-1.20). There was a borderline association between overweight/obesity and AF recurrence after ablation (RR, 1.27; 95 % CI, 0.99-1.64).

CONCLUSIONS

MetS is associated with an increased risk of AF recurrence after catheter ablation. Further study of the MetS and its components as determinants of AF risk could help refine patient selection and improve procedural outcomes.

What do we currently know about metabolic syndrome and atrial fibrillation?

Metabolic syndrome represents a cluster of atherogenic risk factors including hypertension, insulin resistance, obesity, and dyslipidemia. Considering that all of these risk factors could influence the development of atrial fibrillation, an association between atrial fibrillation and the metabolic syndrome has been suggested. Additionally, oxidative stress and inflammation have been involved in the pathogenesis of both metabolic syndrome and atrial fibrillation. The mechanisms that relate metabolic syndrome to the increased risk of atrial fibrillation occurrence are not completely understood. Metabolic syndrome and atrial fibrillation are associated with increased cardiovascular morbidity and mortality. Because atrial fibrillation is the most common arrhythmia, and along with the prevalence of metabolic syndrome constantly increasing, it would be very important to determine the relationship between these 2 entities, especially due to the fact that the risk factors of metabolic syndrome are mainly correctable. This review focused on the available evidence supporting the association between metabolic syndrome components and metabolic syndrome as a clinical entity with atrial fibrillation.

Cause of very late recurrence of atrial fibrillation or flutter after catheter ablation for atrial fibrillation

The major mechanism underlying the early recurrence of atrial fibrillation (AF) after ablation is mainly reconnection of the isolated pulmonary vein (PV); however, the mechanism responsible for very late recurrence (VLR) has not been fully elucidated. The purpose of the present study was to investigate the mechanism underlying VLR. The study population included 150 consecutive patients with AF who underwent a second session of catheter ablation because of recurrence. We divided them into 2 groups according to the point of initial AF recurrence: the late recurrence group (LR group, initial recurrence 3 to 12 months after ablation, n = 124) and the VLR group (initial recurrence >12 months after ablation, n = 26). We identified PVs with ectopic foci (trigger PVs) in the first procedure and checked their electrical reconnection in the second procedure. The prevalence of PV reconnection and trigger PV reconnection were significantly lower in the VLR group than in LR group (LR vs VLR, 90% vs 69% and 48% vs 27%, p = 0.007 and p = 0.045, respectively). In the VLR group, left ventricular systolic and diastolic function were significantly worse than in the LR group, and more patients in the VLR group required non-PV trigger ablation in the second session than did those in the LR group (30% vs 54%, p = 0.034). In conclusion, electrical PV reconnection contributed less to VLR than to LR. Progression of the AF substrate might be an important mechanism responsible for VLR.

Predictors of Recurrence After Radiofrequency Ablation of Persistent Atrial Fibrillation

Radiofrequency catheter ablation that targets the pulmonary veins is well established as a mainstay for drug-refractory, paroxysmal atrial fibrillation (AF). However, in patients with persistent AF, the ideal approach remains elusive. Further, despite the various additional ablation strategies that have been investigated in patients with persistent AF, the rate of recurrent atrial tachyarrhythmias after ablation remains relatively high. In this review, the predictors of recurrent atrial tachyarrhythmias after catheter ablation of persistent AF will be discussed.

Atrial Fibrillation and Metabolic Syndrome: Understanding the Connection

Metabolic syndrome, a constellation of conditions including obesity, dyslipidemia, hypertension and insulin resistance, has increased to epidemic proportions. Metabolic syndrome has been recognized as a risk factor for cardiovascular morbidity and is likely related to the epidemic of cardiovascular diseases. Perhaps not coincidentally, its growth in incidence has paralleled that of atrial fibrillation. Various components of metabolic syndrome have been known to have a role in the pathogenesis of atrial fibrillation. With the conglomeration of components seen in the metabolic syndrome, the risk for atrial fibrillation increases greatly. Several studies have elucidated the role of metabolic syndrome in the development of atrial fibrillation. Its role on the atrial substrate makes it an important determinant of progression of disease and failure of therapeutic strategies such as catheter ablation. Control of the various components of metabolic syndrome may ultimately lead to better outcomes in atrial fibrillation patients.

Atrial Fibrillation Ablation in Obese Patients

Despite the increased burden of atrial fibrillation (AF), obese patients have similar, if not slightly improved, mortality, described as the "obesity paradox." Catheter ablation for AF in obese patients is a reasonable option, but patients should be screened for sleep apnea and counseled about the possibility of longer procedure times and repeat procedures to achieve similar success rates. Quality of life will likely improve after successful ablation. Although no statistically significant increases in procedural complications have occurred in obese subjects, patients should be counseled about the increased radiation dose and higher incidence of left atrial thrombus preablation.

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.