Impact of Body Mass Index on Cryoablation of atrial fibrillation: Patient characteristics, procedural data and long-term outcomes

Cryoballoon Pulmonary Vein Isolation in Obese Patients with Atrial Fibrillation Compared to Non-Obese Counterparts: A Meta-Analysis

Introduction: Obesity is an important risk factor for atrial fibrillation (AF) development. Data on cryoballoon ablation (CBA) outcomes in obese patients have so far been scarce. We reviewed the existing literature to compare the efficacy and safety of CBA in obese versus non-obese AF patients. Methods: A systematic literature search was conducted for studies comparing clinical outcomes (arrhythmia recurrence and/or procedural data and/or safety outcomes) between obese and non-obese patients undergoing CBA for AF. Statistical pooling was performed according to a random-effects model with generic inverse-variance weighting of relative risks (RRs) and standardised mean differences (SMDs) computing risk estimates with 95% confidence intervals (CIs). Results: Obese and non-obese patients had comparable arrhythmia recurrence rates (normal versus overweight, RR = 0.95, 95% CI: 0.82-1.11, p = 0.55, I2% = 91%; normal versus class I obesity, RR = 0.97, 95% CI: 0.82-1.13, p = 0.68, I2% = 87%; normal versus class II obesity, RR = 0.98, 95% CI: 0.91-1.07, p = 0.29, I2% = 65%). Procedure time was marginally increased in obese patients compared to non-obese counterparts (normal versus overweight, SMD = 0.05, 95% CI: -0.15-0.26, p = 0.62, I2% = 74%; normal versus class I obesity, SMD = 0.10, 95% CI: -0.00-0.19, p = 0.06, I2% = 2%; overweight versus class I obesity, SMD = 0.11, 95% CI: 0.01-0.21, p = 0.048, I2% = 25%). Regarding radiation exposure, fluoroscopy time was increased in patients with class I obesity compared to normal-weight or overweight patients and dose area product was also increased in obese patients compared to non-obese patients. Lastly, the risk of complications did not differ between obese and non-obese patients. Statistical heterogeneity and the small number of patients included are the main limitations of this study. Conclusion: CBA seems to be effective for obese patients suffering from AF, featuring also similar safety outcomes with non-obese individuals. Radiation exposure was increased in obese patients.

A negative relationship between first-pass pulmonary vein isolation and body mass index in ablation index-guided pulmonary vein isolation

Background

We previously reported the relationship between first-pass pulmonary vein isolation (FPI) and pulmonary vein isolation (PVI) durability in ablation index-guided atrial fibrillation ablation. Obesity is a worsening factor for atrial tachyarrhythmia (AT) recurrence. However, the impact of obesity on FPI has been scarcely reported. General anesthesia (GA) facilitates completing PVI by preventing airway obstruction caused by sedative drug use. However, the impact of GA on the relationship also has not been elucidated.

Objective

The study sought to evaluate the impact of obesity and its relationship with GA on FPI.

Methods

We retrospectively studied 2187 consecutive patients undergoing ablation index-guided first atrial fibrillation ablation (conscious sedation in 1969 and GA in 218). We divided them into 4 groups according to body mass index (BMI): underweight (BMI < 18.5 kg/m2) (n = 80), normal (18.5 kg/m2 ≤ BMI < 25 kg/m2) (n = 1,160), overweight (25 kg/m2 ≤ BMI < 30 kg/m2) (n = 763), and obesity (BMI ≥30 kg/m2) (n = 184).

Results

FPI rate decreased as BMI increased in both conscious sedation (68.1% in underweight, 61.5% in normal, 48.7% in overweight, and 39.0% in obesity; P < .001) and GA (87.5%, 67.1%, 61.3%, and 44.7%, respectively; P = .01). Multivariate analysis revealed overweight (odds ratio 0.65, 95% confidence interval [CI] 0.53-0.79, P < .001, vs normal) and obesity (OR 0.44, 95% CI 0.31-0.62 P < .001, vs normal) as independent predictors for FPI and obesity as an AT recurrence predictor (hazard ratio 1.35, 95% CI 1.01-1.81, P = .04).

Conclusion

BMI increase was negatively related to the FPI rate. Notably, the FPI rate in obese patients, even under GA, was low, which might be related to their high AT recurrence.

Impact of Body Mass Index on the Outcomes of Cryoballoon Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is prevalent among obese patients, and cryoballoon ablation (CBA) is an effective strategy for the rhythm control of AF. The impact of body mass index (BMI) on the clinical outcomes of CBA for AF is not fully explored.

METHODS

85 consecutive patients with paroxysmal AF were enrolled and were categorized into three groups as per their BMI: normal weight (BMI 18.5-25 kg/m2), overweight (BMI 25-30 kg/m2), and obese patients (BMI > 30 kg/m2). The primary study endpoint was a late (12 month) recurrence of AF. Early recurrence of AF, symptom improvement, and procedural outcomes were some key secondary outcomes.

RESULTS

20 patients had normal weight, 35 were overweight, and 30 were obese. Obese patients featured a higher prevalence of diabetes mellitus, heavier exposure to smoking, and worse baseline symptoms (as assessed through EHRA class at admission and 12 months before CBA) compared to overweight and normal weight patients. Both late and early (<3 months) AF recurrence rates were comparable across the three groups. Of note, obese patients showed greater improvement in their symptoms post-CBA, defined as improvement by at least one EHRA class, compared to normal weight patients; this might be explained by improved diastolic function. Total procedure time and dose area product were significantly increased in obese patients. The multivariate logistic regression analysis indicated that early AF recurrence and the duration of hypertension are independent predictors of late AF recurrence.

CONCLUSION

CBA is effective in overweight and obese patients with paroxysmal AF. Procedure time and radiation exposure are increased in obese patients undergoing CBA.

Cryoablation of atrial fibrillation in "very severe" obese patients (BMI ≥ 40): Indications, feasibility, procedural safety and efficacy, and clinical outcome (the ICE-Obese Extreme)

BACKGROUND

Management of atrial fibrillation (AF) in very severe obese patients is challenging. Cryoballoon ablation (CBA) represents an effective rhythm control strategy. However, data in this patient group were limited.

METHODS

Highly symptomatic AF patients with body mass index (BMI) ≥ 40 kg/m2 who had failed antiarrhythmic drug therapy and electrocardioversion and failure to achieve targeted body-weight-reduction underwent CBA.

RESULTS

Data of 72 very severe obese AF patients (Group A) and 129 AF patients with normal BMI (Group B, BMI < 25 kg/m2) were consecutively collected. Group A had significantly younger age (60.6 ± 10.4 vs. 69.2 ± 11.2 years), higher BMI (44.3 ± 4.3 vs. 22.5 ± 1.6 kg/m2). Procedural pulmonary vein isolation (PVI) was successful in all patients (2 touch-up ablation in Group A). Compared to Group B, Group A had similar procedural (61.3 ± 22.6 vs. 57.5 ± 19 min), similar fluoroscopy time (10.1 ± 5.5 vs. 9.2 ± 4.8 min) but significantly higher radiation dose (2852 ± 2095 vs. 884 ± 732 µGym2). We observed similar rates of real-time-isolation (78.6% vs. 78.5%), single-shot-isolation (86.5% vs. 88.8%), but significantly longer time-to-sustained-isolation (53.5 ± 33 vs. 43.2 ± 25 s). There was significantly higher rate of puncture-site-complication (6.9% vs. 1.6%) in Group A. One-year clinical success in paroxysmal AF was (Group A: 69.4% vs. Group B: 80.2%; p < .001), in persistent AF was (Group A: 58.1% vs. Group B: 62.8%; p = .889). In Re-Do procedures Group A had a numerically lower PVI durability (75.0% vs. 83.6%, p = .089).

CONCLUSION

For very severe obese AF patients, CBA appears feasible, leads to relatively good clinical outcome.

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.

Impact of obesity on catheter ablation of atrial fibrillation: Patient characteristics, procedural complications, outcomes, and quality of life

INTRODUCTION

Obesity is a well-known risk factor for atrial fibrillation (AF). We aim to evaluate the effect of baseline obesity on procedural complications, AF recurrence, and symptoms following catheter ablation (CA).

METHODS

All consecutive patients undergoing AF ablation (2013-2021) at our center were enrolled in a prospective registry. The study included all consecutive patients with available data on body mass index (BMI). Primary endpoint was AF recurrence based on electrocardiographic documentation. Patients were categorized into five groups according to their baseline BMI. Patients survey at baseline and at follow-up were used to calculate AF symptom severity score (AFSS) as well as AF burden (mean of AF duration score and AF frequency score; scale 0: no AF to 10: continuous and 9 frequencies/durations in between). Patients were scheduled for follow-up visits with 12-lead electrocardiogram at 3, 6, and 12 months after ablation, and every 6 months thereafter.

RESULTS

A total of 5841 patients were included (17% normal weight, 34% overweight, 27% Class I, 13% Class II, and 9% Class III obesity). Major procedural complications were low (1.5%) among all BMI subgroups. At 3 years AF recurrence was the highest in Class III obesity patients (48%) followed by Class II (43%), whereas Class I, normal, and overweight had similar results with lower recurrence (35%). In multivariable analyses, Class III obesity (BMI ≥ 40) was independently associated with increased risk for AF recurrence (hazard ratio, 1.30; confidence interval, 1.06-1.60; p = .01), whereas other groups had similar risk in comparison to normal weight. Baseline AFSS was lowest in normal weight, and highest in Obesity-III, median (interquartile range) 10 (5-16) versus 15 (10-21). In all groups, CA resulted in a significant improvement in their AFSS with a similar magnitude among the groups. At follow-up, AF burden was minimal and did not differ significantly between the groups.

CONCLUSION

AF ablation is safe with a low complication rate across all BMI groups. Morbid obesity (BMI ≥ 40) was significantly associated with reduced AF ablation success. However, ablation resulted in improvement in QoL including reduction of the AFSS, and AF burden regardless of BMI.

[Metabolic syndrome and atrial fibrillation]

Metabolic syndrome is defined by the simultaneous occurrence of the cardiovascular risk factors obesity, hypertension, diabetes and dyslipidemia. Overweight, in particular, is continuously increasing in many countries. In this respect, metabolic syndrome is a strong risk factor for atrial fibrillation. Only few data are available on the influence of obesity on antiarrhythmic drugs. Sodium channel blockers, in particular, appear to show a reduced effectiveness. Direct oral anticoagulants can be used for anticoagulation in obese patients. With a body weight > 140 kg, a plasma level measurement is recommended. Severe overweight reduces the chances of successful ablation treatment and leads to more complications. Consistent treatment of the metabolic syndrome, and in particular weight reduction, can significantly improve the risk and the frequency of atrial fibrillation, the associated symptoms and the success of treatment for maintaining cardiac rhythm.

Diabesity in Elderly Cardiovascular Disease Patients: Mechanisms and Regulators

Cardiovascular disease (CVD) is the leading cause of death in the world. In 2019, 550 million people were suffering from CVD and 18 million of them died as a result. Most of them had associated risk factors such as high fasting glucose, which caused 134 million deaths, and obesity, which accounted for 5.02 million deaths. Diabesity, a combination of type 2 diabetes and obesity, contributes to cardiac, metabolic, inflammation and neurohumoral changes that determine cardiac dysfunction (diabesity-related cardiomyopathy). Epicardial adipose tissue (EAT) is distributed around the myocardium, promoting myocardial inflammation and fibrosis, and is associated with an increased risk of heart failure, particularly with preserved systolic function, atrial fibrillation and coronary atherosclerosis. In fact, several hypoglycaemic drugs have demonstrated a volume reduction of EAT and effects on its metabolic and inflammation profile. However, it is necessary to improve knowledge of the diabesity pathophysiologic mechanisms involved in the development and progression of cardiovascular diseases for comprehensive patient management including drugs to optimize glucometabolic control. This review presents the mechanisms of diabesity associated with cardiovascular disease and their therapeutic implications.