A Prospective Study Evaluating the Role of Obesity and Obstructive Sleep Apnea for Outcomes After Catheter Ablation of Atrial Fibrillation

Obesity as a risk factor in atrial fibrillation and heart failure

Objectives

The aim of this article is to provide an insight into the role of obesity as a risk factor, and as a potential etiologic agent of atrial fibrillation (AF) and heart failure (HF).

Methods

A narrative (non-systematic) review article summarizing currently available data regarding the interaction between obesity, AF and HF.

Results

Obesity is considered a risk factor of AF and chronic HF. Multiple recent studies indicate that obesity is also a potential causal factor in the development of AF and HF, the elucidation of pathological mechanisms of which could help devise new diagnostic and therapeutic modalities for these conditions. The discussion about obesity in relation to HF cannot omit the so-called obesity paradox, which represents a dilemma for clinicians, and it is still a source of irregularities regarding the strategy of weight reduction in obese patients with HF. Recently, the obesity paradox has also been assumed to play a role in the relationship between obesity and thromboembolic complications of AF.

Conclusions

Obesity is an independent and modifiable risk factor for AF and HF. In addition, there is an increasing volume of experimental and clinical data that suggests an important role of the epicardial adipose tissue in the pathophysiology of AF. However, several issues, such as the issue of optimal pharmacotherapy and weight reduction strategy in obese patients with HF remains still unanswered, and open for future investigation.

Obesity effect on newly diagnosed and recurrent post-ablation atrial fibrillation: a systematic review and meta-analysis

BACKGROUND AND AIMS

The role of overweight and obesity in the development of atrial fibrillation (AF) is well established; however, the differential effect on the occurrence and recurrence of AF remains uncertain. The aim of this review is to compare the effect of underweight and varying degrees of obesity on onset of AF and in recurrent post-ablation AF, and, when possible, in relation to sex.

METHODS

A systematic literature search was conducted in PubMed, Embase, and Cochrane Library from inception to January 31, 2023. Studies reporting frequency of newly-diagnosed AF and of recurrent post-ablation AF in different BMI categories, were included. 3400 records were screened and 50 met the inclusion criteria. Standardized data search and abstraction were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. Data were extracted from the manuscripts and were analyzed using a random effect model. The outcome was the occurrence of AF in population studies and in patients undergoing ablation.

RESULTS

Data from 50 studies were collected, of which 27 for newly-diagnosed AF and 23 for recurrent post-ablation AF, for a total of 15,134,939 patients, of which 15,115,181 in studies on newly-diagnosed AF and 19,758 in studies on recurrent post-ablation AF. Compared to normal weight, the increase in AF was significant (p < 0.01) for overweight, obese, and morbidly obese patients for newly-diagnosed AF, and for obese and morbidly obese patients for recurrent post-ablation AF. Newly-diagnosed AF was more frequent in obese female than obese male patients.

CONCLUSION

The effect of increased BMI was greater on the onset of AF, and obese women were more affected than men.

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.

Left atrial remodeling and voltage-guided ablation outcome in obese patients with persistent atrial fibrillation

Background

Obesity is a risk factor for atrial fibrillation (AF). Data regarding left atrial (LA) remodeling in obese patients are scarce. Whether obesity favors AF recurrence after catheter ablation (CA) is still controversial. We assessed the distribution of epicardial atrial fat on computed tomography (CT), LA bipolar voltage, low-voltage zone (LVZ) extent, and the outcome of voltage-guided ablation of persistent AF in obese and non-obese patients.

Methods

A total of 139 patients with persistent AF undergoing a first voltage-guided ablation were enrolled and divided into two groups: 74 were non-obese and 65 were obese. Epicardial adipose tissue (EAT) was assessed on a CT scanner. LA endocardial voltage maps were obtained using a 3D mapping system in sinus rhythm. LVZ was defined as a bipolar peak-to-peak voltage amplitude <0.5 mV.

Results

LA volume, voltage, and EAT amount were similar in the two groups. LVZ was less frequent in obese patients [12 (18.8%) vs. 26 (35.1%), p = 0.05], particularly on the anterior wall. The posterior and lateral EATs were correlated with posterior and lateral LVZ extent, respectively, in obese patients. After 36 months of follow-up, the AF-free survival rate was similar. Lateral EAT [odds ratio (OR) 1.21, 95% confidence interval (CI) 1-1.4, p = 0.04] and P-wave duration (OR 1.03, 95% CI 1-1.05, p = 0.03), but not body mass index (BMI), were predictors of AF recurrence after CA.

Conclusion

In obese patients, LVZ was less marked than in non-obese patients with similar LA volumes, voltage, and EAT amounts. In obese patients, posterior and lateral EATs were correlated with posterior and lateral LVZ extents. Obese patients had a similar and favorable 36-month outcome after AF ablation. BMI was not predictive of AF recurrence.

Recommended assessment and management of sleep disordered breathing in patients with atrial fibrillation, hypertension and heart failure: Taiwan Society of Cardiology/Taiwan Society of sleep Medicine/Taiwan Society of pulmonary and Critical Care Medicine joint consensus statement

Sleep disordered breathing (SDB) is highly prevalent and may be linked to cardiovascular disease in a bidirectional manner. The Taiwan Society of Cardiology, Taiwan Society of Sleep Medicine and Taiwan Society of Pulmonary and Critical Care Medicine established a task force of experts to evaluate the evidence regarding the assessment and management of SDB in patients with atrial fibrillation (AF), hypertension and heart failure with reduced ejection fraction (HFrEF). The GRADE process was used to assess the evidence associated with 15 formulated questions. The task force developed recommendations and determined strength (Strong, Weak) and direction (For, Against) based on the quality of evidence, balance of benefits and harms, patient values and preferences, and resource use. The resulting 11 recommendations are intended to guide clinicians in determining which the specific patient-care strategy should be utilized by clinicians based on the needs of individual patients.

Index and Repeat Ablation for Atrial Fibrillation in Older versus Younger Patients: A Propensity-Score Matching Analysis

Catheter ablation is a well-established rhythm control therapy in atrial fibrillation (AF). Although the prevalence of AF increases dramatically with age, the prognosis and safety profile of index and repeat ablation procedures remain unclear in the older population. The primary endpoint of this study was to assess the arrhythmia recurrence, reablation and complication rates in older patients. Secondary endpoints were the identification of independent predictors of arrhythmia recurrence and reablation, including information on pulmonary vein (PV) reconnection and other atrial foci. Older (n=129, ≥70 years) and younger (n=129, <70 years) patients were compared using a propensity-score matching analysis based on age, gender, obesity, hypertension, dyslipidemia, diabetes mellitus, dilated left atrium, severe obstructive sleep apnea, cardiac disease, left systolic ventricular function, AF pattern and ablation technique. Arrhythmia recurrence and reablation were evaluated in both groups using a Cox regression analysis in order to identify predictors. During a 30-month follow-up period, there were no significant differences between older and younger patients in the arrhythmia-free survival (65.1% and 59.7%; log-rank test p=0.403) and complication (10.1% and 10.9%; p>0.999) rates after the index ablation. However, the reablation rate was significantly different (46.7% and 69.2%; p<0.05, respectively). In those patients who underwent reablation procedure (redo subgroups), there were no differences in the incidence of PV reconnection (38.1% redo-older and 27.8% redo-younger patients; p=0.556). However, the redo-older patients had lower reconnected PVs per patient (p<0.01) and lower atrial foci (2.3 and 3.7; p<0.01) than the redo-younger patients. A further important finding was that age was not an independent predictor of arrhythmia recurrence or reablation. Our data reveal that the AF index ablation in older patients had a similar efficacy and safety profile to younger patients. Therefore, age alone must not be considered a prognostic factor for AF ablation but the presence of limiting factors such as frailty and multiple comorbidities.

Obesity-Related Atrial Fibrillation: Cardiac Manifestation of a Systemic Disease

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with increased morbidity and mortality. The mechanisms underlying AF are complex and multifactorial. Although it is well known that obesity is a strong risk factor for AF, the mechanisms underlying obesity-related AF are not completely understood. Current evidence proposes that in addition to overall hemodynamic changes due to increased body weight, excess adiposity raises systemic inflammation and oxidative stress, which lead to adverse atrial remodeling. This remodeling includes atrial fibrosis, atrial dilation, decreased electrical conduction between atrial myocytes, and altered ionic currents, making atrial tissue more vulnerable to both the initiation and maintenance of AF. However, much remains to be learned about the mechanistic links between obesity and AF. This knowledge will power the development of novel diagnostic tools and treatment options that will help combat the rise of the global AF burden among the obesity epidemic.

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.

Association between obstructive sleep apnea (OSA) and atrial fibrillation (AF): A dose-response meta-analysis

BACKGROUND

Refractory hypoxemia episodes are characteristic of obstructive sleep apnea (OSA). Patients with OSA suffer from oxidative stress in all systems. Atrial fibrillation (AF) is a type of arrhythmia that may be induced by OSA. In this study, we explored the dose-response relationship between OSA and AF. Our research provides the basis for a novel approach to AF prevention.

METHODS

We screened four databases (PubMed, Embase, the Cochrane Library, and Web of Science) for observational studies on OSA and AF. Studies were collected from database establishment to November 2020. We performed a traditional subgroup meta-analysis. Linear and spline dose-response models were applied to assess the association between the apnea-hypopnea index, an indicator of OSA severity, and the risk of AF. Review Manager version 5.3 software and Stata 16.0 were used for the analysis.

RESULTS

Sixteen observational studies were included in the study. We excluded a study from the conventional meta-analysis. In the subgroup analysis, the odds ratios for new onset AF for no obvious reason, new onset AF after surgical operations, such as coronary artery bypass grafting, and AF after ablation treatment were 1.71 (95% CI 1.37-2.13, P < .05), 2.65 (95% CI 2.32-3.01, P < .05), and 2.93 (95% CI 2.47-3.49, P < .05), respectively. Linear dose-response meta-analysis results revealed that the risk of AF increased with increasing apnea-hypopnea index value.

CONCLUSION

Through dose-response meta-analysis, we found a potential dose-response relationship between OSA severity and the risk of AF. This relationship should be considered in interventions aimed at AF prevention in the future.

Lifestyle Modification and Atrial Fibrillation: Critical Care for Successful Ablation

Management of atrial fibrillation (AF) requires a comprehensive approach due to the limited success of medical or procedural approaches in isolation. Multiple modifiable risk factors contribute to the development and progression of the underlying substrate, with a heightened risk of progression evident with inadequate risk factor management. With increased mortality, stroke, heart failure and healthcare utilisation linked to AF, international guidelines now strongly support risk factor modification as a critical pillar of AF care due to evidence demonstrating the efficacy of this approach. Effective lifestyle management is key to arrest and reverse the progression of AF, in addition to increasing the likelihood of freedom from arrhythmia following catheter ablation.

Risk factor management of atrial fibrillation using mHealth: The Atrial Fibrillation – Helping Address Care with Remote Technology (AF-HEART) Pilot Study

Background

Personalized treatment of atrial fibrillation (AF) risk factors using mHealth and telehealth may improve patient outcomes.

Objective

The purpose of this study was to assess the feasibility of the Atrial Fibrillation Helping Address Care with Remote Technology (AF-HEART) intervention on the following patient outcomes: (1) heart rhythm tracking; (2) weight, alcohol, blood pressure (BP), and sleep apnea reduction; (3) AF symptom reduction; and (4) quality-of-life (QOL) improvement.

Methods

A total of 20 patients with AF undergoing antiarrhythmic therapy, cardioversion, and/or catheter ablation were enrolled and followed for 6 months. The AF-HEART intervention included remote heart rhythm, weight, and BP tracking; televisits with a dietician focusing on AF risk factors; and referrals for sleep apnea and hypertension treatment.

Results

Patients transmitted a median of 181 rhythm recordings during the 6-month follow-up period. Patients lost an average of 3.5 kilograms at 6 months (P = .005). Patients had improved SF-12 scores (P = .01), AFSS score (P = .01), EQ-5D score (P = .006), and AFEQT Global Score (P = .03). There was significant correlation between weight loss and decrease in symptom severity (r = -0.45, P = .05), and between % weight loss and decrease in symptom severity (r = -0.49, P = .03).

Conclusion

This study described the feasibility of the AF-HEART intervention for (1) consistent remote tracking of heart rhythm, weight, and BP; (2) achievement of weight loss; (3) reduction of symptoms; and (4) improvement in QOL. Expansion to a larger randomized study is planned.

Impact of Obesity on Atrial Fibrillation Recurrence Following Stand-Alone Cox Maze IV Procedure

OBJECTIVE

Obesity is a strong and independent factor for the development of atrial fibrillation (AF), and adversely impacts the success of catheter ablation procedures for AF. This study evaluated the impact of body mass index (BMI) on the outcomes following surgical ablation of AF.

METHODS

Between 2003 and 2019, 236 patients underwent a stand-alone biatrial Cox maze IV procedure (CMP-IV) for refractory AF. Obesity was defined as BMI ≥30 kg/m². Patients were divided into two groups: BMI <30 kg/m² (n = 100) and BMI ≥30 kg/m² (n = 136). Freedom from atrial tachyarrhythmia (ATA) was determined using electrocardiography, Holter, or pacemaker interrogation at 1 year and annually thereafter. Recurrence was defined as any documented ATA lasting ≥30 s. Predictors of recurrence were determined using multivariable logistic regression. Preoperative and procedural outcomes were compared between groups.

RESULTS

Obese patients had a higher rate of diabetes (16% vs 7%, P = 0.044) and larger left atrial diameter (4.9 ± 1.1 cm vs 4.6 ± 1.0 cm, P = 0.021) when compared to non-obese patients. There was no difference in major complication rate between the groups (4% vs 7%, P = 0.389). There was no operative mortality in either group. During 4.1 ± 2.4 years of follow-up, there was no significant difference in freedom from ATA with or without antiarrhythmic drugs in obese patients when compared to the non-obese group (P > 0.05). Absence of sinus rhythm at discharge predicted AF recurrence up to 7 years postoperatively.

CONCLUSIONS

As opposed to catheter ablation, obesity did not adversely impact the short and long-term outcomes of stand-alone surgical ablation with CMP-IV, and BMI was not a predictor of AF recurrence. Additionally, there was no significant increase in major complications in obese patients.

Subjective assessment of complexity and prognosis after pulmonary vein isolation as significant predictor for procedural success

PURPOSE

Subjective estimation of recurrence after atrial fibrillation ablation is an important tool in clinical use. The aim of this study is to evaluate (1) if the subjective complexity of an atrial fibrillation ablation procedure is correlated with rhythm stability and (2) if the subjective prognosis of the operator has a predictive value.

METHODS

We prospectively enrolled patients admitted for ablation of atrial fibrillation. Two scores were given immediately after the procedure by the operator: the complexity and the prognosis scores. With routine follow-ups, we tried to evaluate the correlation between the subjective scores and measured outcome.

RESULTS

The study population included 611 patients (63 ± 10 years, 37% females, 61% persistent AF). During follow-up (FU) (median 24, IQR 7-36 months), recurrences occurred in 44% patients. Both scores (prognosis and complexity) correlated significantly with age, persistent AF, LA diameter, procedural characteristics, and recurrences. On multivariable analysis, complexity (OR 1.304, 95%CI 1.016-1.675, p = 0.037) and prognosis (OR 1.443, 95%CI 1.080-1.982, p = 0.013) scores remained significant predictors for arrhythmia recurrences. On ROC analysis, both scores showed significant predictive value for rhythm outcomes after catheter ablation (AUC 0.599 and 0.613, both p < 0.001 for complexity and prognosis scores, respectively).

CONCLUSIONS

Complexity and prognosis scores are significant predictors for arrhythmia recurrences after AF catheter ablations and even independent when competing with simple risk factors.

BMI and atrial fibrillation recurrence post catheter ablation: A dose-response meta-analysis

INTRODUCTION

The evidence on the association between obesity and atrial fibrillation (AF) recurrence was equivocal. We aimed to evaluate the dose-response relationship between body mass index (BMI) and AF recurrence and adverse events.

METHODS

A systematic literature search was conducted using PubMed, Europe PMC, EBSCO, ProQuest and Cochrane Library. Obesity was defined as BMI ≥28 kg/m² . The primary outcome was AF recurrence, and the secondary outcome was adverse events. Adverse events were defined as procedure-related complications and cardio-cerebrovascular events.

RESULTS

There were a total of 52,771 patients from 20 studies. Obesity was associated with higher AF recurrence (Odds ratio [OR] 1.30 [95% confidence interval [CI] 1.16-1.47], P < .001; I² : 72.7%) and similar rate of adverse events (OR 1.21 [95% CI 0.87-1.67], P = .264; I² : 23.9%). Meta-regression showed that the association varies by age (coefficient: -0.03, P = .024). Meta-analysis of highest versus lowest BMI showed that the highest group had higher AF recurrence (OR 1.37 [95% CI 1.18-1.58], P < .001; I² : 64.9%) and adverse events (OR 2.02 [95% CI 1.08-3.76], P = .028; I² : 49.5%). The linear association analysis for AF recurrence was not significant (P = .544). The dose-response relationship for BMI and AF recurrence was nonlinear (p_nonlinearity  < 0.001), the curve became steeper at 30-35 kg/m² . For adverse events, an increase of 1% for every 1 kg/m² increase in BMI (OR 1.01 [95% CI 1.00-1.02], P = .001), the relationship was nonlinear (p_nonlinearity  = 0.001).

CONCLUSION

Obesity was associated with higher AF recurrence in patients undergoing catheter ablation. High BMI might be associated with a higher risk for adverse events.

PROSPERO ID

CRD42020198787.

Impact of body mass index on procedural complications, procedure duration, and radiation dose in patients with atrial fibrillation undergoing radiofrequency ablation: A systematic review and meta-analysis

Background

The association of body mass index (BMI) and procedure‐related factors in patients with atrial fibrillation (AF) after radiofrequency ablation (RFA) is still unclear.

Hypothesis

BMI is associated with increased the radiation dose, procedure duration, and procedural complications.

Methods

Prospective studies assessing BMI and procedure duration, radiation dose, and procedural complications in patients with AF after RFA were identified through electronic searches of PubMed, Embase, and the Cochrane Library database.

Results

Ten studies with 14 735 participants undergoing RFA were included. Procedure duration was significantly longer in patients with overweight or obesity than in patients with normal BMI, with a mean difference (MD) of 0.95. Patients with overweight and obesity were exposed to a larger radiation dose, with standard MD of 1.71 and 1.98, respectively. There was no significant association between overweight or obesity and the risk of procedural complications (RR of 0.91 for overweight, 1.01 for obesity, 0.89 for stage I obesity, 1.00 for stage II obesity, and 0.94 for stage III obesity). Further analysis showed there was no significant difference regarding stroke or transient ischemic attack (overweight, RR: 0.92; obesity, RR: 1.02); cardiac tamponade (overweight, RR: 0.92; obesity, RR: 1.02); groin hematoma (overweight, RR: 0.62; obesity, RR: 0.40); or pulmonary vein stenosis (overweight, RR: 0.49; obesity, RR: 0.40) among BMI groups.

Conclusion

Based on available evidence, we first showed that patients with overweight/obesity undergoing RFA experienced a significantly increased procedure duration and received a larger radiation dose than patients with normal BMI; however, there was no significant difference in procedural complications between patients with overweight/obesity and patients with normal BMI.

Clinical Factors Associated with a Successful Catheter Ablation Outcome in Elderly Patients with Atrial Fibrillation

Catheter ablation is currently an established treatment for symptomatic paroxysmal atrial fibrillation (AF). We focused on elderly patients with a high prevalence of AF and attempted to identify the clinical factors associated with unsuccessful ablation outcomes.Among 735 consecutive patients who underwent AF ablation procedures, 108 (14.7%, 66 men) aged ≥ 75 years were included. Of them, 80 had paroxysmal AF, and the remaining 28 non-paroxysmal AF. All patients underwent pulmonary vein (PV) isolation and occasionally additional ablation. When AF recurred, redo ablation procedures were performed if the patient so desired.The mean number of ablation procedures was 1.1 ± 0.4 times per patient. During a mean follow-up of 38.7 ± 21.7 months, sinus rhythm was maintained in 100 patients (92.6%) without any antiarrhythmic drugs, but not in the remaining 8 (7.4%). Left atrial diameter (LAD, P < 0.001), left ventricular (LV) systolic diameter (P < 0.001), LV diastolic diameter (P = 0.001), non-PV AF foci (P = 0.036), and diabetes (P = 0.045) were associated with unsuccessful ablation procedures. Multivariate logistic regression analysis revealed a large LAD and non-PV AF foci were significant independent predictors of AF recurrences, with odds ratios of 0.76 (P = 0.019) and 0.04 (P = 0.023), respectively. In a total of 124 procedures, one major (0.8%) and 11 minor (8.9%) complications occurred.In elderly AF patients, catheter ablation of AF is effective and safe. Non-PV AF foci and a large LAD were independent clinical predictors of unsuccessful AF ablation outcomes.

Impact of Body Mass Index on the Outcomes of Catheter Ablation of Atrial Fibrillation: A European Observational Multicenter Study

Background Outcomes of catheter ablation of atrial fibrillation (AF) are variable and the predictors of success require further elucidation since the identification of correctable risk factors could help to optimize therapy. We aimed to assess the impact of body mass index (BMI) in the overall safety and efficacy of catheter ablation of AF, with emphasis on the use of cryoballoon ablation and novel oral anticoagulants. Methods and Results There were 2497 consecutive patients undergoing catheter ablation of AF in 7 European high volume centers were stratified according to BMI (normal weight <25 kg/m2, pre-obese 25-30 kg/m2, obesity 30-35 kg/m2, and morbid obesity ≥35 kg/m2) and comparisons of procedural outcomes evaluated. Pre-obese and obese patients presented more comorbidities (hypertension, diabetes mellitus, and sleep apnea), and had higher rates of non-paroxysmal AF ablation procedures. The rate of atrial 12-month arrhythmia relapse increased alongside with BMI (35.2%, 35.7%, 43.6%, and 48.0% P<0.001). During a median follow-up of 18.8 months (interquartile range 11-28), after adjusting for all baseline differences, BMI was an independent predictor of relapse (hazard ratio=1.01 per kg/m2; 95% CI 1.01-1.02; P=0.002), adding incremental predictive value to obstructive sleep apnea. BMI was not a predictor for any of the reported complications. Using novel oral anticoagulants and cryoballoon ablation was safe and efficacy was comparable with vitamin-K antagonists and radiofrequency ablation. Conclusions Obese patients present with a more adverse comorbidity profile, more advanced forms of AF, and have lower chances of being free from AF relapse after ablation. Use of novel oral anticoagulants and cryoballoon ablation may be an option in this patient group.

Assessment of obesity prevalence and validity of obesity diagnoses coded in claims data for selected surgical populations: A retrospective, observational study

In many types of surgery, obesity may influence patient selection, prognosis, and/or management. Quantifying the accuracy of the coding of obesity and other prognostic factors is important for the design and interpretation of studies of surgical outcomes based on administrative healthcare data. This study assessed the validity of obesity diagnoses recorded in insurance claims data in selected surgical populations.This was a retrospective, observational study. Deidentified electronic health record (EHR) and linked administrative claims data were obtained for US patients age ≥20 years who underwent a qualifying surgical procedure (bariatric surgery, total knee arthroplasty [TKA], cardiac ablation, or hernia repair) in 2014Q1-2017Q1 (first = index). Patients' body mass index (BMI) as coded in the claims data (error-prone measure) during the index procedure or 180d pre-index was compared with their measured BMI as recorded in the EHR (criterion standard) to estimate the sensitivity and positive predictive value (PPV) of obesity diagnosis codes.Among patients who underwent bariatric surgery (N = 1422), TKA (N = 8670), cardiac ablation (N = 167), or hernia repair (N = 5450), obesity was present in 98%, 63%, 52%, and 54%, respectively, based on measured BMI. PPVs of obesity diagnosis codes were high: 99.3%, 96.0%, 92.8%, and 94.1% in bariatric surgery, TKA, cardiac ablation, and hernia repair, respectively. The sensitivity of obesity diagnoses was: 99.8%, 46.2%, 41.3%, and 42.3% in bariatric surgery, TKA, cardiac ablation, and hernia repair, respectively. Among false-positive patients diagnosed as obese but with measured BMI <30, the proportion with a BMI ≥28 was 40.0%, 67.6%, 60.7%, and 65.8% for bariatric surgery, TKA, cardiac ablation, and hernia repair, respectively.Our data indicate that obesity is highly prevalent in many surgical populations, obesity diagnosis codes have high PPVs, but also obesity is generally undercoded in claims data. Quantifying the validity of diagnosis codes for obesity and other important prognostic factors is important for the design and interpretation of studies of surgical outcomes based on administrative data. Further research is needed to determine the extent to which undercoding of BMI and obesity can be addressed through the use of proxies that may be better documented in claims data.

Patient characteristics as predictors of recurrence of atrial fibrillation following cryoballoon ablation

BACKGROUND

While several studies have evaluated predictors for atrial fibrillation (AF) recurrence following catheter ablation, there are limited data specific to cryoballoon ablation (CBA).

METHODS

We analyzed a prospective registry of patients at a single institution who underwent CBA. Recurrence of AF (RAF) was defined as recurrence of AF by 12-month follow-up, excluding the 3-month blanking period. Univariate analysis was performed to evaluate predictors of RAF. Receiver operating characteristic analysis was used to compare and evaluate the performance of various risk scores for discriminating risk of RAF.

RESULTS

There were 542 patients included in the analysis with mean age 61.3 ± 10.6 years, 67.9% male, and 51.6% paroxysmal AF (PAF). Overall, only left atrial diameter (LAD) > 40 mm and ERAF (early recurrence of AF within 0-3 month blanking period) were significant predictors of RAF. In the PAF specific subgroup, LAD > 40 mm, AF duration > 12 months, prior stroke or transient ischemic attack, ERAF, and having previously failed an antiarrhythmic drug were significant predictors of RAF. In persistent AF (PeAF) subgroup, obstructive sleep apnea (OSA) and ERAF were significant predictors of RAF. Out of clinical risk scores tested, BASEAF2 had the highest performance with area under the curve of 0.646 (95% confidence interval [0.548, 0.708]; P < .01).

CONCLUSIONS

In this single-center retrospective study of CBA, we found only LAD > 40 mm and ERAF to be predictors of RAF. We identified OSA as a potential targetable risk factor in PeAF patients undergoing CBA. Out of risk scores tested for discriminating risk of RAF, BASEAF2 had the best performance.

Clinical Overview of Obesity and Diabetes Mellitus as Risk Factors for Atrial Fibrillation and Sudden Cardiac Death

The epidemics of obesity and diabetes mellitus are associated with an increased incidence of both atrial fibrillation (AF), the most common sustained arrhythmia in adults, and sudden cardiac death (SCD). Obesity and DM are known to have adverse effects on cardiac structure and function. The pathologic mechanisms are thought to involve cardiac tissue remodeling, metabolic dysregulation, inflammation, and oxidative stress. Clinical data suggest that left atrial size, epicardial fat pad thickness, and other modifiable risk factors such as hypertension, glycemic control, and obstructive sleep apnea may mediate the association with AF. Data from human atrial tissue biopsies demonstrate alterations in atrial lipid content and evidence of mitochondrial dysfunction. With respect to ventricular arrhythmias, abnormalities such as long QT syndrome, frequent premature ventricular contractions, and left ventricular hypertrophy with diastolic dysfunction are commonly observed in obese and diabetic humans. The increased risk of SCD in this population may also be related to excessive cardiac lipid deposition and insulin resistance. While nutritional interventions have had limited success, perhaps due to poor long-term compliance, weight loss and improved cardiorespiratory fitness may reduce the frequency and severity of AF.

Impact of body mass index on the outcome of catheter ablation of atrial fibrillation

Objectives

The association between obesity and atrial fibrillation (AF) is well-established. We aimed to evaluate the impact of index body mass index (BMI) on AF recurrence at 12 months following catheter ablation using propensity-weighted analysis. In addition, periprocedural complications and fluoroscopy details were examined to assess overall safety in relationship to increasing BMI ranges.

Methods

Baseline, periprocedural and follow-up data were collected on consecutive patients scheduled for AF ablation. There were no specific exclusion criteria. Patients were categorised according to baseline BMI in order to assess the outcomes for each category.

Results

Among 3333 patients, 728 (21.8%) were classified as normal (BMI <25.0 kg/m2), 1537 (46.1%) as overweight (BMI 25.5–29.0 kg/m2) and 1068 (32.0%) as obese (BMI ≥30.0 kg/m2). Procedural duration and radiation dose were higher for overweight and obese patients compared with those with a normal BMI (p=0.002 and p<0.001, respectively). An index BMI ≥30 kg/m2 led to a 1.2-fold increased likelihood of experiencing recurrent AF at 12-months follow-up as compared with overweight patients (HR 1.223; 95% CI 1.047 to 1.429; p=0.011), while no significant correlation was found between overweight and normal BMI groups (HR 0.954; 95% CI 0.798 to 1.140; p=0.605) and obese versus normal BMI (HR 1.16; 95% CI 0.965 to 1.412; p=0.112).

Conclusions

Patients with a baseline BMI ≥30 kg/m2 have a higher recurrence rate of AF following catheter ablation and therefore lifestyle modification to target obesity preprocedure should be considered in these patients.

Effect of obstructive sleep apnea and its treatment of atrial fibrillation recurrence after radiofrequency catheter ablation: A meta-analysis

BACKGROUND/OBJECTIVES

Patients with obstructive sleep apnea (OSA) have an increased the risk of developing atrial fibrillation (AF). However, it remains unclear if patients with OSA carry a higher risk of recurrent AF after successful catheter ablation. This meta-analysis was conducted (1) to evaluate the association between OSA and recurrent AF after catheter ablation, and (2) to assess the effect of continuous positive airway pressure (CPAP) on the risk of recurrent AF in patients with OSA.

METHODS

A comprehensive literature review was conducted using MEDLINE, EMBASE, Cochrane databases from inception through July 2017 to identify studies that evaluated the risk of recurrent AF after successful catheter ablation in patients with OSA were included. Effect estimates from the individual study were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Seven observational studies with a total of 4572 patients AF after successful catheter ablation were enrolled. Compared to patients without OSA, the pooled OR of recurrent AF in patients with OSA was 1.70 (95% CI, 1.40-2.06, I²  = 0). Among OSA patients with AF after successful catheter ablation, the use of CPAP was significantly associated with decreased risk of recurrent AF with pooled OR of 0.28 (0.19-0.40, I²  = 0). Egger's regression asymmetry test was performed and showed no publication bias for the associations of OSA and CPAP with recurrent AF.

CONCLUSIONS

Our meta-analysis suggested a significant association between OSA and recurrent AF after catheter ablation. The use of CPAP in patients with OSA is associated with reduced risk of recurrent AF after catheter ablation.

Obstructive Sleep Apnea Is Closely Related to Cardiovascular Risk Factors, but Not to Clinical Recurrence of Atrial Fibrillation after Catheter Ablation: An Analysis of Atrial Fibrillation Patients

Background

Obstructive sleep apnea (OSA) is a well-known predictor of atrial fibrillation (AF). However, OSA usually accompanies other risk factors of AF. We tried to investigate whether OSA is related to AF recurrence after catheter ablation.

Methods

A total of 378 patients (mean age 59.9 ± 10.7 years, 72.5$ male) who underwent catheter ablation of AF were enrolled and underwent overnight ambulatory polysomnography before the ablation procedure. These patients were examined once every 3 months at the outpatient clinic to determine AF recurrence.

Results

Based on the apnea-hypopnea index (AHI), we divided the study subjects into 3 groups defined as mild (AHI < 10), moderate (10 <AHI < 30), or severe (AHI > 30) OSA. Patients with severe OSA had a higher prevalence of hypertension, diabetes mellitus, and coronary artery disease (CAD). However, AF recurrence was not different between the three groups. The Kaplan-Meier analysis also showed no significant difference in AF recurrence according to the degree of severity of OSA. Multivariate logistic regression analysis revealed that OSA might be a predictor of CAD; however, Cox regression analysis showed that only early recurrence is closely related to AF recurrence after catheter ablation, rather than the severity of OSA.

Conclusion

This study shows that the severity of OSA is not associated with the recurrence of AF after catheter ablation in Korean patients. Treatment of OSA for the sole indication of lowering AF recurrence may need to be reconsidered.

Atrial Fibrillation Burden: Moving Beyond Atrial Fibrillation as a Binary Entity: A Scientific Statement From the American Heart Association

Our understanding of the risk factors and complications of atrial fibrillation (AF) is based mostly on studies that have evaluated AF in a binary fashion (present or absent) and have not investigated AF burden. This scientific statement discusses the published literature and knowledge gaps related to methods of defining and measuring AF burden, the relationship of AF burden to cardiovascular and neurological outcomes, and the effect of lifestyle and risk factor modification on AF burden. Many studies examine outcomes by AF burden classified by AF type (paroxysmal versus nonparoxysmal); however, quantitatively, AF burden can be defined by longest duration, number of AF episodes during a monitoring period, and the proportion of time an individual is in AF during a monitoring period (expressed as a percentage). Current guidelines make identical recommendations for anticoagulation regardless of AF pattern or burden; however, a review of recent evidence suggests that higher AF burden is associated with higher risk of stroke. It is unclear whether the risk increases continuously or whether a threshold exists; if a threshold exists, it has not been defined. Higher burden of AF is also associated with higher prevalence and incidence of heart failure and higher risk of mortality, but not necessarily lower quality of life. A structured and comprehensive risk factor management program targeting risk factors, weight loss, and maintenance of a healthy weight appears to be effective in reducing AF burden. Despite this growing understanding of AF burden, research is needed into validation of definitions and measures of AF burden, determination of the threshold of AF burden that results in an increased risk of stroke that warrants anticoagulation, and discovery of the mechanisms underlying the weak temporal correlations of AF and stroke. Moreover, developments in monitoring technologies will likely change the landscape of long-term AF monitoring and could allow better definition of the significance of changes in AF burden over time.

Effectiveness and safety of simultaneous hybrid thoracoscopic endocardial catheter ablation of atrial fibrillation in obese and non-obese patients

Background

We evaluated the safety and effectiveness of the hybrid thoracoscopic endocardial epicardial ablation technique for the treatment of atrial fibrillation (AF) in obese versus non-obese patients.

Methods

Between January 2010 and January 2015, a cohort of 61 patients were retrospectively identified to undergo ablation of AF as a stand-alone procedure using a thoracoscopic, hybrid epicardial-endocardial technique. All patients underwent continuous 7-day Holter monitoring at 3, 6 months, 1 year and yearly thereafter.

Results

A total of 40% of the obese cohort had persistent or long-standing AF, compared to 54.9% of the non-obese cohort. There were no deaths or conversion to cardiopulmonary bypass required. At 3-year follow-up, 60% of the obese group were in sinus rhythm (SR) with no episode of AF, atrial flutter or atrial tachycardia lasting 30 s off anti-arrhythmic drugs. This was compared to 70.6% in the non-obese group, with no significant difference between the groups (P=0.468). For success rates on anti-arrhythmic drugs, this was 80% in the obese group compared to 86% in the non-obese group at 3-year follow-up (P=0.637). No patient died and no thromboembolic/bleeding events or procedure-related complications occurred during the follow-up.

Conclusions

In a retrospective cohort with approximately half with persistent or long-standing AF, thoracoscopic hybrid epicardial endocardial ablation proved to be equally effective and safe in obese versus non-obese patients. Current preliminary findings require further validation in multi-institutional prospective studies with larger sample sizes.

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.

Clinical significance of nutritional status in patients with atrial fibrillation: An overview of current evidence

BACKGROUND

Obesity is a well-known atherosclerosis risk factor; however, its role and the importance of undernutrition in atrial fibrillation (AF) pathogenesis are still not well understood. The aim of this study was to present the current state of knowledge on this issue in different groups of patients.

METHODS

Systematic review of papers published between 1980 and 2016.

RESULTS

The literature shows contradicting views regarding the impact of nutritional status on the risk, course, and complications of AF. On the one hand, it has been revealed that overweight, obesity, and high birth mass increase the risk of AF, and that their reduction is linked to an improved course of AF and reduced all-cause and cardiovascular mortality. On the other hand, a so-called obesity paradox has been found, which shows lower all-cause mortality in overweight patients with AF compared to those of normal weight or who are underweight. It has also been shown, although based on a small number of studies, that the relationship between nutritional status and risk of AF and its complication may be U-shaped, which means that not only patients with obesity, but also individuals with underweight, cachexia, and low birth weight may have an increased risk and poor outcome of AF.

CONCLUSIONS

The relationship between patients' nutritional status and the course of AF has become clearer but it requires further studies examining the importance of weight reduction on AF course.

Obstructive Sleep Apnea Treatment and Atrial Fibrillation: A Need for Definitive Evidence

Prevalence rates of atrial fibrillation (AF) and obstructive sleep apnea (OSA) are rising on a global scale. Epidemiological data have consistently demonstrated an independent association between the 2 conditions. Investigators pose that pathophysiologic features of OSA enable progression of the AF substrate; these features include abnormalities of gas exchange, autonomic remodeling, atrial stretch, and inflammation. Furthermore, many of the mechanistic perturbations that impact the AF substrate in OSA can be substantially attenuated by effective treatment with continuous positive airway pressure (CPAP). Clear associations of OSA treatment and improved AF control have been observed across multiple clinical contexts. However, the precision and generalizability of these findings are unclear in view of the data's observational nature. Although risk factor management has emerged as a critical component of AF treatment, effective control of many AF risk factors can be challenging in the longer term. In view of the efficacy and sustainability of CPAP therapy, OSA raises its profile as a prime candidate for intervention. However, translation of this strategy to the broader framework for AF management requires robust data from randomized controlled trials.

Analysis of Bipolar Radiofrequency Ablation in Treatment of Atrial Fibrillation Associated with Rheumatic Heart Disease

Background

Among patients with rheumatic heart disease (RHD), 45% to 60% present with atrial fibrillation (AF), which is associated with increased rates of thromboembolism, heart failure, and even death. The bipolar radiofrequency ablation (BRFA) combining with mitral valve procedure has been adopted in patients of AF associated with RHD, but evaluations about its effectiveness are still limited.

Methods

A total of 87 patients with RHD and long persistent AF who had accepted mitral valve replacement concomitant with BRFA were studied. Clinical data were collected to analyze the midterm results of BRFA and evaluate its efficiency. Univariate and multivariate analyses were used to identify the independent factors associated with late AF recurrence.

Results

Sixty-six (75.9%) patients maintained sinus rhythm after a mean follow-up of 13.4 ± 5.2 months. Late AF recurrence had been detected in 21 (24.1%) patients, 11 (12.6%) patients were confirmed to be AF, 8 (9.2%) patients were atrial flutter and 2 (2.3%) patients were junctional rhythm. In Multivariate logistic regression analysis, body mass index (BMI) (OR = 1.756, 95% CI = 1.289–2.391, p = 0.000) and early AF recurrence (OR = 5.479, 95% CI = 1.189–25.254, p = 0.029) were independent predictors of late AF recurrence. In addition, left ventricular ejection fraction (LVEF) and New York Heart Association class showed a greater improvement in patients who maintained sinus rhythm than those who experienced late AF recurrence.

Conclusion

BRFA is an effective technique for the treatment of long persistent AF associated with RHD during mitral valve replacement. The BMI and early AF recurrence are independent predictors for late AF recurrence. Patients with long-term restoration of sinus rhythm experienced a greater improvement of left ventricular function after BRFA.

Cardiovascular benefits of bariatric surgery

The prevalence of obesity is increasing in the United States and worldwide, bringing with it an excess of morbidity and premature death. Obesity is strongly associated with both traditional cardiovascular risk factors as well as direct effects on hemodynamics and cardiovascular structure and function. In fact, cardiovascular disease is one of the major causes of morbidity and mortality in obese patients. Often, lifestyle and pharmacological weight-loss interventions are of limited efficacy in severely obese patients. Bariatric surgery has been shown to be a feasible option to achieve substantial and sustained weight loss in this group of patients. It is a safe procedure with low in-hospital and 30-day mortality rates even in groups that are considered higher risk for surgery (e.g., the elderly), especially if performed in high-volume centers. There is observational evidence that bariatric surgery in severely obese patients is associated with both a reduction of traditional cardiovascular risk factors as well as improvement in cardiac structure and function. Marked decreases in the levels of inflammatory and prothrombotic markers, as well as markers of subclinical atherosclerosis and endothelial dysfunction, are seen after bariatric surgery. This article summarizes the existing evidence regarding the cardiovascular benefits in patients following bariatric surgery.

Prevalence and predictors of atrial fibrillation among patients undergoing bariatric surgery

BACKGROUND

While AF is a disease of the elderly, it can occur earlier in the presence of risk factors such as obesity. Bariatric surgery patients are significantly younger and more obese than previously described populations with AF. Therefore, it remains to be determined whether current estimates of the prevalence and predictors for AF remain true in the bariatric surgery population.

METHODS

We performed a cross-sectional analysis of 1,341 consecutive patients who underwent bariatric surgery from January 2008 to October 2012. Baseline characteristics were compared between patients with and without AF. For additional comparison, 176 patients with AF and body mass index (BMI) >40 kg/m(2) were identified from the Vanderbilt AF Registry. A multivariable logistic regression was performed to identify predictors of AF within the bariatric surgery cohort.

RESULTS

The prevalence of AF in the bariatric surgery cohort was 1.9 % (25/1,341). Patients with AF were older (median 56 years (interquartile range [52-64) vs.46 [38-56] years, p < 0.001), were more often male (48 vs. 23 %, p = 0.004), had more comorbidities, but had no difference in BMI (50 kg/m(2) [44-58] vs. 48 [43-54], p = 0.4). In multivariable analysis, the odds of AF increased 2.2-fold by age per decade (95 % CI, 1.4-3.5; p < 0.001) and 2.4-fold by male gender (1.1-5.4, p = 0.03) when adjusted for BMI. BMI was not independently associated with AF (OR 1.15 [95 % CI, 0.98-1.41], p = 0.09).

CONCLUSIONS

The prevalence of AF is 1.9 % among patients undergoing bariatric surgery. Risk of AF was found to increase with age and male gender, but not with higher BMI.

Effects of body mass index on risks for ischemic stroke, thromboembolism, and mortality in Chinese atrial fibrillation patients: a single-center experience

Background

Obesity is considered to be related to recurrence of atrial fibrillation (AF), left atrial thrombus formation, and atrial remodeling. However, whether obesity is an independent risk factor for stroke and other thromboembolic events is still controversial.

Objective

This study aimed to investigate the effects of body mass index (BMI) on the risks of stroke, thromboembolism, and mortality in AF patients.

Methods

Patients who were diagnosed with nonvalvular AF were included in this observational, retrospective study. The study population was stratified by BMI at baseline. The Cox proportional hazard model was adopted to calculate adjusted hazard ratios of risk factors for adverse clinical events (stroke, thromboembolism, and mortality).

Results

A total of 1286 AF patients (males, 78.30%; mean age, 74.50 years; 94.48% paroxysmal AF) were followed up for a median of 2.1 years (IQR: 1.5–2.9 years). Overall, 159 patients died. A total of 84 strokes and 35 thromboembolic events occurred. Multivariate analysis showed that overweight (25.0≤BMI<30.0 kg/m²) and age ≥75 years were independent risk factors for ischemic stroke (both P<0.01). Obesity (BMI ≥30.0 kg/m²), age ≥75 years, persistent/permanent AF, and prior thromboembolism were independent risk factors for thromboembolism (all P<0.05). Underweight (BMI <18.5 kg/m²), age ≥75 years, prior ischemic stroke/transient ischemic attack, renal dysfunction, and heart failure were independent risk factors for all-cause deaths (all P<0.05).

Conclusions

Overweight or obesity may be a risk factor of ischemic stroke and thromboembolism in AF patients. Excessive low weight is significantly associated with increased all-cause mortality.