Impact of a nurse-led limited risk factor modification program on arrhythmia outcomes in patients with atrial fibrillation undergoing catheter ablation

Understanding for whom, under what conditions, and how an integrated approach to atrial fibrillation service delivery works: a realist review

AIMS

To understand for whom, under what conditions, and how an integrated approach to atrial fibrillation (AF) service delivery works (or does not work).

METHODS AND RESULTS

A realist review of integrated approaches to AF service delivery for adult populations aged ≥18 years. An expert panel developed an initial programme theory, searched and screened literature from four databases until October 2022, extracted and synthesized data using realist techniques to create context-mechanism-outcome configurations for integrated approaches to AF service, and developed an integrated approach refined programme theory. A total of 5433 documents were screened and 39 included. The refined programme theory included five context-mechanism-outcome configurations for how clinical and system-wide outcomes are affected by the way integrated approaches to AF service delivery are designed and delivered. This review identifies core mechanisms underpinning the already known fundamental components of integrated care. This includes having a central coordinator responsible for service organization to provide continuity of care across primary and secondary care ensuring services are patient centred. Additionally, a fifth pillar, lifestyle and risk factor reduction, should be recognized within an AF care pathway.

CONCLUSION

It is evident from our provisional theory that numerous factors need to interlink and interact over time to generate a successfully integrated model of care in AF. Stakeholders should embrace this complexity and acknowledge that the learnings from this review are integral to shaping future service delivery in the face of an aging population and increased prevalence of AF.

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.

The effect of weight loss on recurrence of atrial fibrillation after catheter ablation: A systematic review and meta-analysis

BACKGROUND

Obesity is associated with an increased risk of developing recurrent atrial fibrillation (AF) after catheter ablation (CA). However, the current data on weight loss interventions show inconsistent results in preventing the recurrence of AF after CA.

METHODS

We conducted a systematic search in MEDLINE and EMBASE to identify studies that reported the outcome of recurrence of AF after CA in obese patients undergoing weight interventions. The subgroup analysis included: (1) Weight loss versus no weight loss, (2) >10% weight loss versus <10% weight loss, (3) <10% weight loss versus no weight loss, (4) Follow-up <12 months, and (5) Follow-up >12 months after CA. Mantel-Haenszel risk ratios with a 95% confidence interval (CI) were calculated using a random effects model and for heterogeneity, I2 statistics were reported.

RESULTS

A total of 10 studies (one randomized controlled trial and nine observational studies) comprising 1851 patients were included. The recurrence of AF was numerically reduced in the weight loss group (34.5%) versus no weight loss group (58.2%), but no statistically significant difference was observed (risk ratio [RR] = 0.76; 95% CI: 0.49-1.18, p = .22). However, there was a statistically significant reduction in recurrence of AF with weight loss versus no weight loss at follow-up >12 months after CA (RR = 0.47; 95% CI: 0.32-0.68, p < .0001). At follow-up >12 months after CA, both >10% weight loss versus <10% weight loss (RR = 0.49; 95% CI: 0.31-0.80, p = .004) and <10% weight loss versus no weight loss (RR = 0.39; 95% CI: 0.31-0.49, p < .00001) were associated with a statistically significant reduction in recurrent AF.

CONCLUSION

In patients with AF undergoing CA, weight loss is associated with reducing recurrent AF at > 12 months after ablation and these benefits are consistently seen with both >10% and <10% weight loss. The benefits of weight loss in preventing recurrent AF after CA should be examined in larger studies with extended follow-up duration.

Lifestyle changes in atrial fibrillation management and intervention

Atrial fibrillation (AF) is one of the most common arrhythmias in adults, and its continued rise in the United States is complicated by the increased incidence and prevalence of several AF risk factors, such as obesity, physical inactivity, hypertension, obstructive sleep apnea, diabetes mellitus, coronary artery disease, and alcohol, tobacco, or caffeine use. Lifestyle and risk factor modification has been proposed as an additional pillar of AF therapy, added to rhythm control, rate control, and anticoagulation, to reduce AF burden and risk. Although emerging evidence largely supports the integration of lifestyle and risk factor management in clinical practice, randomized clinical trials investigating the long-term sustainability and reproducibility of these benefits remain sparse. The purpose of this review is to discuss potentially reversible risk factors on AF, share evidence for the impact on AF by modification of these risk factors, and then provide an overview of the effects of reversing or managing these risk factors on the success of various AF management strategies, such as antithrombotic, rate control, and rhythm control therapies.

Effect of Multifactorial Risk Factor Interventions on Atrial Fibrillation: A Systematic Review and Meta-Analysis

Evidence supports the benefit of managing atrial fibrillation (AF) specific risk factors in secondary prevention of AF. However, a comprehensive summary of the effect of multifactorial risk factor interventions on outcomes of patients with AF over long-term is lacking. We searched MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases from inception to October 2021 for both randomized controlled trials (RCT) and observational studies comparing multifactorial risk factor interventions to usual care in patients with AF. Fifteen studies (10 RCT, 5 observational) with 3786 patients were included (mean age 63.8 years, 64.0% males). Follow-up ranged from 3 to 42 months. We found no significant effects of multifactorial risk factor interventions on AF recurrence [pooled relative risk (RR): 0.93, 95% CI: 0.74-1.16, P = 0.51, I² = 54%], AF-related rehospitalization at 12 months (RR: 0.69, 95% CI: 0.43-1.11, P= 0.13, I² = 0%), cardiovascular rehospitalization at 12 months (RR: 0.76, 95% CI: 0.53-1.09, P= 0.13, I² = 53%), or AF-related adverse events at 12 and 15 months. However, multifactorial interventions were associated with reduced AF-related symptoms and improved health-related quality of life (HRQoL) at all studied time points. Current evidence does not support consistent associations between multifactorial risk factor interventions and AF recurrence after rhythm control therapy or AF-related or cardiovascular hospitalization in patients with AF. However, these interventions are associated with clinically relevant improvement in AF-related symptoms and HRQoL. Additional randomized studies are required to evaluate the impact of multifactorial risk factor interventions on patient-centered health outcomes.

Obesity as a risk factor for cardiac arrhythmias

Obesity is global health problem with an estimated three billion people worldwide being classified as overweight or obese. In addition to being associated with a range of adverse health outcomes, obesity is linked to higher risks of atrial and ventricular arrhythmias, as well as sudden cardiac death. Obesity is a multifactorial disease that often co-exists with hypertension, diabetes, and sleep apnoea, which are also independent risk factors for cardiac arrhythmias. Nevertheless, compelling evidence suggests that increasing adiposity is an independent proarrhythmic risk factor and that weight loss can be a mitigating and preventative intervention to reduce arrhythmia incidence. This review briefly outlines the economic and social burden of obesity and summarises evidence for the direct and indirect effects of increasing adiposity on risk of atrial and ventricular arrhythmias. The paper also summarises the evidence for electrocardiographic changes indicative of obesity-related atrial and ventricular remodelling and how weight reduction and management of comorbidity might reduce arrhythmic burden.

Effect of weight loss on recurrence of atrial fibrillation after ablative therapy: a systematic review and meta-analysis

BACKGROUND

Landmark trials have shown superiority of ablative therapy over medical therapy in certain subpopulation with atrial fibrillation (AF). Previous studies have demonstrated an association between weight loss and reduced rates of recurrence of AF after ablation. The objective of this study is to determine if weight loss reduces the recurrence of AF after ablation.

METHODS

An extensive literature search and systematic review of studies of weight loss on recurrence of AF after ablative therapy was performed. Risk ratio (RR) and 95% confidence intervals were measured for weight loss group versus control group in each study, and comparative analysis as well as subgroup analysis was made.

RESULTS

Eight studies with a total of 1,425 patients were included. Overall, studies of patients who lost weight demonstrated lower recurrence of AF (RR 0.35; 95% CI 0.18-0.67). However, subgroup analysis of studies which included patients who lost ≥10% weight loss from baseline showed lower recurrence of AF (RR 0.18; 95% 0.03-0.89), whereas studies which included patients with <10% weight loss did not (RR 1.00; 95% 0.51-1.96). Studies of patients who had less than 12-month history of AF (RR 0.24; 95% CI 0.11-0.57) and those who lost weight prior to ablation (RR 0.40; 95% CI 0.20-0.79) also had lower recurrence of AF.

CONCLUSION

Weight loss is associated with lower long-term recurrence of AF after ablative therapy. Studies of patients with ≥10% weight loss, less than 12-month history of AF, and weight loss prior to ablation experience lower recurrence of AF.

Sleep Disordered Breathing, Obesity and Atrial Fibrillation: A Mendelian Randomisation Study

It remains unclear whether the association between obstructive sleep apnoea (OSA), a form of sleep-disordered breathing (SDB), and atrial fibrillation (AF) is causal or mediated by shared co-morbidities such as obesity. Existing observational studies are conflicting and limited by confounding and reverse causality. We performed Mendelian randomisation (MR) to investigate the causal relationships between SDB, body mass index (BMI) and AF. Single-nucleotide polymorphisms associated with SDB (n = 29) and BMI (n = 453) were selected as instrumental variables to investigate the effects of SDB and BMI on AF, using genetic association data on 55,114 AF cases and 482,295 controls. Primary analysis was conducted using inverse-variance weighted MR. Higher genetically predicted SDB and BMI were associated with increased risk of AF (OR per log OR increase in snoring liability 2.09 (95% CI 1.10-3.98), p = 0.03; OR per 1-SD increase in BMI 1.33 (95% CI 1.24-1.42), p < 0.001). The association between SDB and AF was not observed in sensitivity analyses, whilst associations between BMI and AF remained consistent. Similarly, in multivariable MR, SDB was not associated with AF after adjusting for BMI (OR 0.68 (95% CI 0.42-1.10), p = 0.12). Higher BMI remained associated with increased risk of AF after adjusting for OSA (OR 1.40 (95% CI 1.30-1.51), p < 0.001). Elevated BMI appears causal for AF, independent of SDB. Our data suggest that the association between SDB, in general, and AF is attributable to mediation or confounding from obesity, though we cannot exclude that more severe SDB phenotypes (i.e., OSA) are causal for AF.

Considerations for the Assessment of Substrates, Genetics and Risk Factors in Patients with Atrial Fibrillation

Successful translation of research focussing on atrial arrhythmogenic mechanisms has potential to provide a mechanism-tailored classification and to support personalised treatment approaches in patients with AF. The clinical uptake and clinical implementation of new diagnostic techniques and treatment strategies require translational research approaches on various levels. Diagnostic translation involves the development of clinical diagnostic tools. Additionally, multidisciplinary teams are required for collaborative translation to describe genetic mechanisms, molecular pathways, electrophysiological characteristics and concomitant risk factors. In this article, current approaches for AF substrate characterisation, analysis of genes potentially involved in AF and strategies for AF risk factor assessment are summarised. The authors discuss challenges and obstacles to clinical translation and implementation into clinical practice.

Research Priorities in the Secondary Prevention of Atrial Fibrillation: A National Heart, Lung, and Blood Institute Virtual Workshop Report

There has been sustained focus on the secondary prevention of coronary heart disease and heart failure; yet, apart from stroke prevention, the evidence base for the secondary prevention of atrial fibrillation (AF) recurrence, AF progression, and AF‐related complications is modest. Although there are multiple observational studies, there are few large, robust, randomized trials providing definitive effective approaches for the secondary prevention of AF. Given the increasing incidence and prevalence of AF nationally and internationally, the AF field needs transformative research and a commitment to evidenced‐based secondary prevention strategies. We report on a National Heart, Lung, and Blood Institute virtual workshop directed at identifying knowledge gaps and research opportunities in the secondary prevention of AF. Once AF has been detected, lifestyle changes and novel models of care delivery may contribute to the prevention of AF recurrence, AF progression, and AF‐related complications. Although benefits seen in small subgroups, cohort studies, and selected randomized trials are impressive, the widespread effectiveness of AF secondary prevention strategies remains unknown, calling for development of scalable interventions suitable for diverse populations and for identification of subpopulations who may particularly benefit from intensive management. We identified critical research questions for 6 topics relevant to the secondary prevention of AF: (1) weight loss; (2) alcohol intake, smoking cessation, and diet; (3) cardiac rehabilitation; (4) approaches to sleep disorders; (5) integrated, team‐based care; and (6) nonanticoagulant pharmacotherapy. Our goal is to stimulate innovative research that will accelerate the generation of the evidence to effectively pursue the secondary prevention of AF.