A U-shaped relationship of body mass index on atrial fibrillation recurrence post ablation: A report from the Guangzhou atrial fibrillation ablation registry

Physical frailty, genetic predisposition, and incident arrhythmias

BACKGROUND

Cross-sectional evidence suggests a possible link between frailty and atrial fibrillation (AF). It remains unclear whether frailty and incident arrhythmias are longitudinally associated. This study aimed to determine whether the frailty phenotype is longitudinally associated with incident arrhythmias, especially AF.

METHODS

In this prospective cohort of UK Biobank, individuals with arrhythmias at baseline, those without data for frailty phenotype, and no genetic data were excluded. Five domains of physical frailty, including weight loss, exhaustion, low physical activity, low grip strength, and slow gait speed, were assessed. A total of 142 single-nucleotide polymorphisms was used to calculate the polygenic risk score (PRS) for AF. Hospital inpatient records and death records were used to identify incident arrhythmias.

RESULTS

This study included 464 154 middle-aged and older adults (mean age 56.4 ± 8.1 years, 54.7% female) without arrhythmia at baseline. During a median follow-up of 13.4 years (over 5.9 million person-years), 46 454 new-onset arrhythmias cases were recorded. In comparison with non-frailty, the multivariable-adjusted hazard ratios (HRs) of AF were 1.12 (95% CI: 1.09, 1.15, P < 0.0001) and 1.44 (95% CI: 1.36, 1.51, P < 0.0001) for participants with pre-frailty and frailty, respectively. Similar associations were observed for other arrhythmias. We found that slow gait speed presented the strongest risk factor in predicting all arrhythmias, including AF (HR 1.34, 95% CI: 1.30, 1.39), bradyarrhythmias (HR 1.30, 95% CI: 1.22, 1.37), conduction system diseases (HR 1.29, 95% CI: 1.22, 1.36), supraventricular arrhythmias (HR 1.32, 95% CI: 1.19, 1.47), and ventricular arrhythmias (HR 1.37, 95% CI: 1.25, 1.51), with all P values <0.0001. In addition to slow gait speed, weight loss (HR 1.13, 95% CI: 1.09, 1.16, P < 0.0001) and exhaustion (HR 1.11, 95% CI: 1.07, 1.14, P < 0.0001) were significantly associated with incident AF, whereas insignificant associations were observed for physical activity (HR 1.03, 95% CI: 0.996, 1.08, P = 0.099) and low grip strength (HR 1.00, 95% CI: 0.97, 1.03, P = 0.89). We observed a significant interaction between genetic predisposition and frailty on incident AF (P for interaction <0.0001), where those with frailty and the highest tertile of PRS had the highest risk of AF (HR 3.34, 95% CI: 3.08, 3.61, P < 0.0001) compared with those with non-frailty and the lowest tertile of PRS.

CONCLUSIONS

Physical pre-frailty and frailty were significantly and independently associated with incident arrhythmias. Although direct causal inference still needs to be further validated, these results suggested the importance of assessing and managing frailty for arrhythmia prevention.

Multidisciplinary management strategies for atrial fibrillation

There has been a significant increase in the prevalence of atrial fibrillation (AF) over the past 30 years. Pulmonary vein isolation (PVI) is an effective treatment for AF, but research investigations have shown that AF recurrence still occurs in a significant number of patients after ablation. Heart rhythm outcomes following catheter ablation are correlated with numerous clinical factors, and researchers developed predictive models by integrating risk factors to predict the risk of recurrence of atrial fibrillation. The purpose of this article is to outline the risk scores for predicting cardiac rhythm outcomes after PVI and to discuss the modifiable factors that increase the risk of recurrence of AF, with the hope of further improving catheter ablation efficacy through preoperative identification of high-risk populations and postoperative management of modifiable risk factors.

Association between body mass index and results of cryoballoon ablation in Korean patients with atrial fibrillation: an analysis from the Korean Heart Rhythm Society Cryoablation registry

AIMS

Pulmonary vein isolation using cryoablation is effective and safe in patients with atrial fibrillation (AF). Although both obesity and underweight are associated with a higher risk for incident AF, there is limited data on the efficacy and safety following cryoablation according to body mass index (BMI) especially in Asians.

METHODS AND RESULTS

Using the Korean Heart Rhythm Society Cryoablation registry, a multicentre registry of 12 tertiary hospitals, we analysed AF recurrence and procedure-related complications after cryoablation by BMI (kg/m2) groups (BMI < 18.5, underweight, UW; 18.5-23, normal, NW; 23-25, overweight, OW; 25-30, obese Ⅰ, OⅠ; ≥30, obese Ⅱ, OⅡ). A total of 2648 patients were included (median age 62.0 years; 76.7% men; 55.6% non-paroxysmal AF). Patients were categorized by BMI groups: 0.9% UW, 18.7% NW, 24.8% OW, 46.1% OI, and 9.4% OII. Underweight patients were the oldest and had least percentage of non-paroxysmal AF (33.3%). During a median follow-up of 1.7 years, atrial arrhythmia recurred in 874 (33.0%) patients (incidence rate, 18.9 per 100 person-years). After multivariable adjustment, the risk of AF recurrence was higher in UW group compared with NW group (adjusted hazard ratio, 95% confidence interval; 2.55, 1.18-5.50, P = 0.02). Procedure-related complications occurred in 123 (4.7%) patients, and the risk was higher for UW patients (odds ratio, 95% confidence interval; 2.90, 0.94-8.99, P = 0.07), mainly due to transient phrenic nerve palsy.

CONCLUSION

Underweight patients showed a higher risk of AF recurrence after cryoablation compared with NW patients. Also, careful attention is needed on the occurrence of phrenic nerve palsy in UW patients.

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.

Influence of body mass index on recurrence of atrial fibrillation after electrical cardioversion

BACKGROUND

Several studies have shown an independent relationship between body mass index (BMI) and the incidence of atrial fibrillation (AF). However, little is known about the influence of BMI on AF recurrence after electrical cardioversion (ECV).

METHODS

We selected 1121 patients who reverted to sinus rhythm after scheduled ECV and were included in three prospective Spanish registries of ECV in persistent AF. The patients were classified according to baseline BMI into three categories (normal weight, overweight, obesity). We assessed the influence of BMI on the rate of AF recurrence at 3 months.

RESULTS

We identified 538 patients (48%) who had AF recurrence in the first 3 months after successful ECV. The patients who suffered AF recurrence had a higher BMI than those who remained in sinus rhythm (29.66±4.57 vs. 28.87±4.64 Kg/m2, respectively; p = 0.004). We observed a higher incidence of AF recurrence in the overweight and obese patients (BMI ≥25 kg/m2) than in those classified as normal weight (50.5% vs. 35.6%, respectively; p<0,001). BMI≥25 Kg/m2 was shown to be independently related to of AF recurrence in the multivariate analysis (OR = 1.75, 95% confidence interval = 1.20-2.58; p = 0.004).

CONCLUSIONS

Increased BMI is independently related to AF recurrence after ECV. BMI should also be taken into account when making decisions about the indication for ECV in persistent AF.

Prevalence and Impact of Poorly Controlled Modifiable Risk Factors Among Patients Who Underwent Atrial Fibrillation Ablation

Managing atrial fibrillation (AF) risk factors (RFs) improves ablation outcomes in obese patients. However, real-world data, including nonobese patients, are limited. This study examined the modifiable RFs of consecutive patients who underwent AF ablation at a tertiary care hospital from 2012 to 2019. The prespecified RFs included body mass index (BMI) ≥30 kg/m², >5% fluctuation in BMI, obstructive sleep apnea with continuous positive airway pressure noncompliance, uncontrolled hypertension, uncontrolled diabetes, uncontrolled hyperlipidemia, tobacco use, alcohol use higher than the standard recommendation, and a diagnosis-to-ablation time (DAT) >1.5 years. The primary outcome was a composite of arrhythmia recurrence, cardiovascular admissions, and cardiovascular death. In this study, a high prevalence of preablation modifiable RFs was observed. More than 50% of the 724 study patients had uncontrolled hyperlipidemia, a BMI ≥30 mg/m², a fluctuating BMI >5%, or a delayed DAT. During a median follow-up of 2.6 (interquartile range 1.4 to 4.6) years, 467 patients (64.5%) met the primary outcome. Independent RFs were a fluctuation in BMI >5% (hazard ratio [HR] 1.31, p = 0.008), diabetes with A_1c ≥6.5% (HR 1.50, p = 0.014), and uncontrolled hyperlipidemia (HR 1.30, p = 0.005). A total of 264 patients (36.46%) had at least 2 of these predictive RFs, which was associated with a higher incidence of the primary outcome. Delayed DAT over 1.5 years did not alter the ablation outcome. In conclusion, substantial portions of patients who underwent AF ablation have potentially modifiable RFs that were not well controlled. Fluctuating BMI, diabetes with hemoglobin A_1c ≥6.5%, and uncontrolled hyperlipidemia portend an increased risk of recurrent arrhythmia, cardiovascular hospitalizations, and mortality after ablation.

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.

Weight loss and atrial fibrillation: a review

PURPOSE OF REVIEW

Despite technological advancements in catheter ablation, patients with atrial fibrillation often require multiple ablations, with diminishing returns depending on duration and persistence. Although early ablation is vital, modification of atrial fibrillation disease can be achieved with modification of existing risk factors. Obesity is an important modifiable risk factor, but there does not appear to be a consensus on the best method or goal for weight reduction.

RECENT FINDINGS

The relationship between atrial fibrillation and obesity has been acknowledged. This review examines the clinical evidence demonstrating the benefit of weight reduction in the management of atrial fibrillation. In particular, this review compares the different approaches of recent studies.

SUMMARY

On the basis of the literature, the authors recommend a structured weight loss programme with dietary and behavioural modifications individualized to each patient and including the implementation of physical activity. Consideration of bariatric surgery is appropriate in certain patients with obesity.

Metabolic Inflexibility as a Pathogenic Basis for Atrial Fibrillation

Atrial fibrillation (AF), the most common sustained arrhythmia, is closely intertwined with metabolic abnormalities. Recently, a metabolic paradox in AF pathogenesis has been suggested: under different forms of pathogenesis, the metabolic balance shifts either towards (e.g., obesity and diabetes) or away from (e.g., aging, heart failure, and hypertension) fatty acid oxidation, yet they all increase the risk of AF. This has raised the urgent need for a general consensus regarding the metabolic changes that predispose patients to AF. “Metabolic flexibility” aptly describes switches between substrates (fatty acids, glucose, amino acids, and ketones) in response to various energy stresses depending on availability and requirements. AF, characterized by irregular high-frequency excitation and the contraction of the atria, is an energy challenge and triggers a metabolic switch from preferential fatty acid utilization to glucose metabolism to increase the efficiency of ATP produced in relation to oxygen consumed. Therefore, the heart needs metabolic flexibility. In this review, we will briefly discuss (1) the current understanding of cardiac metabolic flexibility with an emphasis on the specificity of atrial metabolic characteristics; (2) metabolic heterogeneity among AF pathogenesis and metabolic inflexibility as a common pathological basis for AF; and (3) the substrate-metabolism mechanism underlying metabolic inflexibility in AF pathogenesis.

Obesity and Body Mass Components Influence Exercise Tolerance and the Course of Hypertension in Perimenopausal Women

The aim of this study was to identify the potential influence of obesity and body mass components on exercise tolerance assessed in cardiopulmonary exercise testing (CPET), biochemical and echocardiographic parameters and factors correlated with oxygen absorption at the anaerobic threshold in hypertensive women with low levels of physical activity in the perimenopausal period. The study comprised 188 hypertensive women divided, based on body mass index (BMI), into an obesity group and a non-obesity group. Women with BMI ≥ 30 kg/m2 had significantly higher parameters of left ventricular diastolic dysfunction in echocardiography, lower total body water (TBC) in percentage assessed by bioimpedance and significantly worse exercise capacity assessed by CPET. In the study group, VO2 AT (mL/kg/min) correlated positively with TBW (r = 0.4, p < 0.0001) and with the ratio of extracellular water to total body water (ECW/TBW) (r = 0.4, p < 0.00001) and negatively with fat (% and kg) (r = −0.4, p < 0.0001 for both). Obesity negatively affects parameters of diastolic left ventricular function, as well as exercise tolerance in CPET in hypertensive females during the perimenopausal period. The oxygen uptake at anaerobic threshold correlates positively with total body water and ECW/TBW and negatively with body fat; this connection is more pronounced in women without obesity. ClinicalTrials.gov Identifier: NCT04802369.

Epicardial adipose tissue, obesity and the occurrence of atrial fibrillation: an overview of pathophysiology and treatment methods

INTRODUCTION

Obesity is a chronic disease, which has significant health consequences and is a staggering burden to health care systems. Obesity can have harmful effects on the cardiovascular system, including heart failure, hypertension, coronary heart disease, and atrial fibrillation (AF). One of the possible substrates might be epicardial adipose tissue (EAT), which can be the link between AF and obesity. EAT is a fat deposit located between the myocardium and the visceral pericardium. Numerous studies have demonstrated that EAT plays a pivotal role in this relationship regarding atrial fibrillation.

AREAS COVERED

This review will focus on the role of obesity and the occurrence of atrial fibrillation (AF) and examine the connection between these and epicardial adipose tissue (EAT). The first part of this review will explain the pathophysiology of EAT and its association with the occurrence of AF. Secondly, we will review bariatric and metabolic surgery and its effects on EAT and AF.

EXPERT COMMENTARY

In this review, the epidemiology, pathophysiology, and treatments methods of AF are explained. Secondly the effects on EAT were elucidated. Due to the complex pathophysiological link between EAT, AF, and obesity, it is still uncertain which treatment strategy is superior.

Impact of Preoperative Nutritional Status on the Outcome of Catheter Ablation for Atrial Fibrillation

BACKGROUND

The relationship between nutritional status and the incidence or prognosis of atrial fibrillation (AF) has been reported, but no studies have described the relationship between the outcomes of AF catheter ablation (CA) and nutritional status as assessed by various scoring tools. We aimed to verify the hypothesis that preoperative nutritional status is associated with arrhythmia recurrence after CA for AF.

METHODS AND RESULTS

We evaluated 913 patients (age, 67±10 years; men, 72%; paroxysmal AF, 56%) who underwent CA for AF between November 2011 and November 2017. Patients were systematically followed with an endpoint of atrial tachyarrhythmia recurrence, the predictive value of which was compared among 3 scoring tools (Controlling Nutritional Status [CONUT] score / Geriatric Nutritional Risk Index [GNRI] / Prognostic Nutritional Index [PNI]). Patients were divided into normal nutrition (CONUT <2 [n=637] / GNRI >98 [n=836] / PNI >38 [n=910]) and undernutrition (CONUT ≥2 [n=276] / GNRI ≤98 [n=77] / PNI ≤3 [n=3]) groups. AF recurred in 274 patients (mean follow-up, 2.3±0.8 years). The AF recurrence rate was higher in patients with undernutrition than in those with normal nutrition (CONUT/GNRI) status. Multivariate Cox regression analysis identified undernutrition status (GNRI ≤98) as an independent predictor of atrial tachyarrhythmia recurrence.

CONCLUSIONS

The AF recurrence rate after CA was higher in patients with undernutrition than in those with normal nutrition as stratified by the nutrition scoring tools.

Underweight is a major risk factor for atrial fibrillation in Asian people with type 2 diabetes mellitus

BACKGROUND

Atrial fibrillation (AF) is prevalent in patients with type 2 diabetes mellitus (T2DM). Obesity commonly accompanies T2DM, and increases the risk of AF. However, the dose-relationship between body mass index (BMI) and AF risk has seldom been studied in patients with diabetes.

METHODS

This cohort study utilized a database from National Taiwan University Hospital, a tertiary medical center in Taiwan. Between 2014 and 2019, 64,339 adult patients with T2DM were enrolled for analysis. BMI was measured and categorized as underweight (BMI < 18.5), normal (18.5 ≤ BMI < 24), overweight (24 ≤ BMI < 27), obesity class 1 (27 ≤ BMI < 30), obesity class 2 (30 ≤ BMI < 35), or obesity class 3 (BMI ≥ 35). Multivariate Cox regression and spline regression models were employed to estimate the relationship between BMI and the risk of AF in patients with T2DM.

RESULTS

The incidence of AF was 1.97 per 1000 person-years (median follow-up, 70.7 months). In multivariate Cox regression, using normal BMI as the reference group, underweight (HR 1.52, 95% CI 1.25-1.87, p < 0.001) was associated with a significantly higher risk of AF, while overweight was associated with significantly reduced risk of AF (HR 0.82, 95% CI 0.73-0.89, p < 0.001). Kaplan-Meier analysis showed AF risk was highest in the underweight group, followed by obesity class 3, while the overweight group had the lowest incidence of AF (log-rank test, p < 0.001). The cubic restrictive spline model revealed a "J-shaped" or "L-shaped" relationship between BMI and AF risk.

CONCLUSIONS

Underweight status confers the highest AF risk in Asian patients with T2DM.

Subclinical Atrial Fibrillation: A Silent Threat with Uncertain Implications

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Implantable and wearable cardiac devices have enabled the detection of asymptomatic AF episodes-termed subclinical AF (SCAF). SCAF, the prevalence of which is likely significantly underestimated, is associated with increased cardiovascular and all-cause mortality and a significant stroke risk. Recent advances in machine learning, namely artificial intelligence-enabled ECG (AI-ECG), have enabled identification of patients at higher likelihood of SCAF. Leveraging the capabilities of AI-ECG algorithms to drive screening protocols could eventually allow for earlier detection and treatment and help reduce the burden associated with AF. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Malnutrition and Risk of Procedural Complications in Patients With Atrial Fibrillation Undergoing Catheter Ablation

Background: Little is known about the prognostic value of nutritional status among patients undergoing atrial fibrillation (AF) catheter ablation (AFCA). We compared the risk of procedure-related complications and long-term rhythm outcomes of AFCA according to nutritional status.

Methods: We included 3,239 patients undergoing de novo AFCA in 2009-2020. Nutritional status was assessed using the controlling nutritional status (CONUT) score. The association between malnutrition and the risk of AFCA complications or long-term rhythm outcomes was evaluated. We validated the effects of malnutrition using an external cohort of 360 patients undergoing AFCA in 2013-2016.

Results: In the study population (26.8% women, median age: 58 years), 1,005 (31.0%) had malnutrition (CONUT scores ≥ 2); 991 (30.6%) had mild (CONUT 2–4) and 14 (0.4%) had moderate-to-severe (CONUT ≥ 5) malnutrition. The overall complication rates after AFCA were 3.3% for normal nutrition, 4.2% for mild malnutrition, and 21.4% for moderate-to-severe malnutrition. Moderate-to-severe malnutrition [odds ratio (OR) 6.456, 95% confidence interval (CI) 1.637-25.463, compared with normal nutrition], older age (OR 1.020 per 1-year increase, 95% CI 1.001-1.039), female sex (OR 1.915, 95% CI 1.302-2.817), and higher systolic blood pressure (OR 1.013 per 1-mmHg increase, 95% CI 1.000-1.026) were independent predictors for the occurrence of complications. In the validation cohort, malnutrition (CONUT ≥ 2) was associated with a 2.87-fold higher risk of AFCA complications (95% CI 1.174-7.033). The association between malnutrition and a higher risk of AFCA complications was consistently observed regardless of body mass index and sex. Malnutrition did not affect rhythm outcomes during the median follow-up of 40 months (clinical recurrence: 37.0% in normal nutrition vs. 36.5% in malnutrition).

Conclusion: Malnutrition, which is common in patients undergoing AFCA, was associated with a substantially higher risk for complications after AFCA.

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.

The Relationship of Dehydration and Body Mass Index With the Occurrence of Atrial Fibrillation in Heart Failure Patients

Purpose: The aim of the study was to assess the relationship of dehydration, body mass index (BMI) and other indices with the occurrence of atrial fibrillation (AF) in heart failure (HF) patients. Methods: The study included 113 patients [median age 64 years; 57.52% male] hospitalized due to HF. Baseline demographics, body mass analysis, echocardiographic results, key cardiopulmonary exercise test (CPET) parameters, 6 min walk distance (6MWD) and Kansas City Cardiomyopathy Questionnaire (KCCQ) score were assessed. Results: Of all patients, 23 (20.35%) had AF, and 90 (79.65%) had sinus rhythm (SR). Patients with AF were older (med. 66 vs. 64 years; p = 0.039), with higher BMI (32.02 vs. 28.51 kg/m2; p = 0.017) and percentage of fat content (37.0 vs. 27.9%, p = 0.014). They were more dehydrated, with a lower percentage of total body water (TBW%) (45.7 vs. 50.0%; p = 0.022). Clinically, patients with AF had more often higher New York Heart Association (NYHA) class (III vs. II; p < 0.001), shorter 6MWD (median 292.35 vs. 378.4 m; p = 0.001) and a lower KCCQ overall summary score (52.60 vs. 73.96 points; p = 0.002). Patients with AF had significantly lower exercise capacity as measured by peak oxygen consumption (peak VO2) (0.92 vs. 1.26 mL/min, p = 0.016), peak VO2/kg (11 vs. 15 mL/kg/min; p < 0.001), and percentage of predicted VO2max (pp-peak VO2) (62.5 vs 70.0; p=0.010). We also found VE/VCO2 (med. 33.85 vs. 32.20; p = 0.049) to be higher and peak oxygen pulse (8.5 vs. 11 mL/beat; p = 0.038) to be lower in patients with AF than in patients without AF. In a multiple logistic regression model higher BMI (OR 1.23 per unit increase, p < 0.001) and higher left atrial volume index (LAVI) (OR 1.07 per unit increase, p = 0.03), lower tricuspid annular plane systolic excursion (TAPSE) (OR 0.74 per unit increase, p =0.03) and lower TBW% in body mass analysis (OR 0.90 per unit increase, p =0.03) were independently related to AF in patients with HF. Conclusion: Increased volume of left atrium and right ventricular systolic dysfunction are well-known predictors of AF occurrence in patients with HF, but hydration status and increased body mass also seem to be important factors of AF in HF patients.

The impact of underweight and obesity on outcomes in anticoagulated patients with atrial fibrillation: A systematic review and meta-analysis on the obesity paradox

Although obesity is associated with the development and progression of atrial fibrillation (AF), an obesity paradox may be present, illustrated by seemingly protective effects of obesity on AF-related outcomes. Body mass index (BMI) has an impact on outcomes in AF patients using oral anticoagulants. After searching Medline and Embase, meta-analysis of results of four randomized and five observational studies demonstrated significantly lower risks of stroke or systemic embolism (RR 0.80, 95%CI [0.73-0.87]; RR 0.63, 95%CI [0.57-0.70]; and RR 0.42, 95%CI [0.31-0.57], respectively) and all-cause mortality (RR 0.73, 95%CI [0.64-0.83]; RR 0.61, 95%CI [0.52-0.71]; and RR 0.56, 95%CI [0.47-0.66], respectively) in overweight, obese and morbidly obese anticoagulated AF patients (BMI 25 to <30, ≥30 and ≥40 kg/m2 , respectively) compared to normal BMI anticoagulated AF patients (BMI 18.5 to <25 kg/m2 ). In contrast, thromboembolic (RR 1.92, 95%CI [1.28-2.90]) and mortality (RR 3.57, 95%CI [2.50-5.11]) risks were significantly increased in underweight anticoagulated AF patients (BMI <18.5 kg/m2 ). In overweight and obese anticoagulated AF patients, the risks of major bleeding (RR 0.86, 95%CI [0.76-0.99]; and RR 0.88, 95%CI [0.79-0.98], respectively) and intracranial bleeding (RR 0.75, 95%CI [0.58-0.97]; and RR 0.57, 95%CI [0.40-0.80], respectively) were also significantly lower compared to normal BMI patients, while similar risks were observed in underweight and morbidly obese patients. This meta-analysis demonstrated lower thromboembolic and mortality risks with increasing BMI. However, as this paradox was driven by results from randomized studies, while observational studies rendered more conflicting results, these seemingly protective effects should still be interpreted with caution.

The impact of malnutrition on atrial fibrillation recurrence post ablation

BACKGROUND AND AIMS

Both malnutrition and atrial fibrillation (AF) are the major health problems in modern society. Only a few studies focused on the relationship between malnutrition and recurrence of atrial arrhythmias post AF ablation (AF recurrence), which used body mass index (BMI) as nutrition assessment tool. However, BMI can't credibly reflect body composition and has limitation in patients with water-sodium retention. In this study, we used controlling nutritional status score (CONUT score) and geriatric nutritional risk index (GNRI) to identify the malnutrition patients and explored the effect of malnutrition on AF recurrence.

METHODS AND RESULTS

This retrospective study included 246 patients who underwent AF ablation. During a median 11-month follow-up, 77 patients (31.3%) experienced AF recurrence. The recurrence group had higher CONUT score (2.3 ± 1.5 vs. 0.9 ± 1.0, P < 0.001) and lower GNRI (99.9 ± 7.6 vs. 103.9 ± 5.6, P < 0.001). After balancing the traditional risk factors, both CONUT score (OR: 2.614, 95%CI: 1.831-3.731, P < 0.001) and GNRI (OR: 0.884, 95%CI: 0.828-0.944, P < 0.001) were the independent predictors for AF recurrence. Pre-ablation CONUT score ≥1 and GNRI≥95.66 are indicative of AF recurrence. Adding CONUT score or GNRI to the base prediction model for AF recurrence significantly improved the discrimination and calibration. However, adding BMI to the base prediction model did not improve the model performance.

CONCLUSIONS

CONUT score and GNRI are ideal tools to evaluate the nutrition status of AF patients. Undernourished patients are more likely to suffer from AF recurrence. Improving nutrition status may be a potential target for reducing the postoperative recurrence rate.

The obesity paradox for outcomes in atrial fibrillation: Evidence from an exposure-effect analysis of prospective studies

The impact of obesity on the prognosis of atrial fibrillation (AF) remains controversial. We conducted an exposure-effect meta-analysis of prospective studies to clarify the relationship between body mass index (BMI) and outcomes in patients with AF. The Cochrane Library, PubMed, and Embase databases were searched through May 1, 2019. Summary relative risks (RRs) were calculated using random-effects models. Nonlinear associations were explored using restricted cubic spline models. Twenty publications involving 161,922 individuals were included. Categorical variable analysis showed that underweight was associated with an increased risk of all-cause mortality (RR: 2.6), cardiovascular death (RR: 2.91), major bleeding (RR: 1.57), stroke or systemic embolism (RR: 1.62), and a composite endpoint (RR: 2.23). In exposure-effect analysis, the risk per 5 BMI increase was reduced for adverse outcomes (RR=0.86, 95% CI: 0.80-0.92 for all-cause death; RR=0.82, 95% CI: 0.71-0.95 for cardiovascular death; RR=0.89, 95% CI: 0.84-0.95 for stroke or systemic embolism; and RR=0.78, 95% CI: 0.67-0.92 for a composite endpoint). There was a significant "U"-shaped exposure-effect relationship with all-cause death, and the nadir of the curve was observed at a BMI of approximately 28. Our results showed that underweight is associated with a worse prognosis, but that overweight and obesity are associated with improved adverse outcomes in patients with AF.

Association of Obesity Measures with Atrial Fibrillation Recurrence After Cryoablation in Patients with Paroxysmal Atrial Fibrillation

BACKGROUND Obesity increases the risk of atrial fibrillation (AF) recurrence after ablation. This study explored the relationship between various obesity indexes and risk of recurrence after cryoablation of paroxysmal AF (PAF). MATERIAL AND METHODS Our prospective study included 100 patients with PAF who underwent first cryoablation. Physical examination and fasting blood lipids levels were measured at baseline. Seven obesity indexes were determined: body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-hip ratio (WHR), cardiometabolic index (CMI), lipid accumulation product (LAP), and body adiposity index (BAI). AF recurrence was confirmed by electrocardiograms and Holter monitor at follow-up visits after the initial 3-month blanking period. Receiver operating characteristic (ROC) curves were drawn to assess the abilities of obesity indicators in predicting AF recurrence. Multivariable Cox regression analysis was used to examine independent predictors of AF recurrence. RESULTS During a mean follow-up of 13.4 months, 31 patients (31.0%) had recurrent AF. Patients with recurrence had higher BMI, WC, WHtR, LAP, and BAI compared with those without recurrence. ROC analysis indicated the potential predictive value of BAI with an AUC of 0.657 (95% confidence interval [CI]: 0.534-0.779), followed by WC, WHtR, LAP, and BMI (all P<0.05). Diagnosis-to-ablation time (HR 1.034, 95% CI: 1.002-1.068), left atrial diameter (HR 1.147, 95% CI: 1.026-1.281), and WC (HR 1.026, 95% CI: 1.000-1.053) were independent predictive factors for AF recurrence after multivariable adjustment. CONCLUSIONS In this study population, WC appears to be a potential indicator for the prediction of recurrence in patients with PAF after cryoablation.

Obesity and atrial fibrillation: making inroads through fat

The global prevalence of obesity has reached epidemic proportions, paralleled by a rise in cases of atrial fibrillation (AF). Data from epidemiological cohorts support the role of obesity as an independent risk factor for AF. Increasing evidence indicates that obesity may contribute to the AF substrate through a number of pathways including by altering epicardial adipose tissue biology, inflammatory pathways, structural cardiac remodelling, and inducing atrial fibrosis. Due to changes in pharmacokinetics and pharmacodynamics, specific therapeutic considerations are required to guide management of patients with AF including anticoagulation and rhythm control. Also, weight loss in patients with AF has been associated with reduced progression from paroxysmal to persistent AF and indeed regression from persistent to proximal AF. However, the role of dietary intervention in AF control remains to be fully elucidated and hard prospective outcome data to support weight loss are required in AF to determine its role as part of a comprehensive risk factor management strategy for AF in obese patients.