Extreme Obesity is Associated with Low Success Rate of Atrial Fibrillation Catheter Ablation

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.

Impact of Obesity on Atrial Electrophysiological Substrate

(1) Background. Obesity is a well-established worldwide recognised risk factor for atrial fibrillation (AF). Prior review papers reported on the associations between obesity and AF development, but not on the relation between obesity and atrial electrophysiology. We therefore conducted a systematic review to describe the current knowledge of the characteristics of the atrial electrophysiological substrate in obese individuals and how they relate to the development of AF. (2) Methods. A search was conducted in Pubmed, Embase, and the Cochrane Library for publications evaluating the impact of obesity on atrial electrophysiology, electrical substrates, and their relation to the development of AF. (3) Results. A systematic literature search retrieved 477 potential publications based on the inclusion criteria; 76 full-text articles were selected for the present systematic review. The literature demonstrated that obesity predisposes to not only a higher AF incidence but also to more extensive atrial electrophysiological abnormalities increasing susceptibility to AF development. (4) Conclusion. Obesity may predispose to an overall increase in atrial electropathology, consisting of an increase in the slowing of the conduction, conduction block, low-voltage areas, and complex fractionated electrograms. To determine the impact of obesity-induced atrial electrical abnormalities on the long-term clinical outcome, further prospective studies are mandatory.

[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.