Risk Factor Modification in Atrial Fibrillation: Approach From the UW Medicine AF Program

In this article, the author discusses risk factor modification (RFM) as the focus of care at the UW Medicine AF Program in Seattle, Washington.

Background

Atrial fibrillation (AF) is the most common arrhythmia encountered in the clinical setting, affecting an estimated 6 million people in the U.S. and 33 million people worldwide. It is well known that the risk of developing AF increases with age, and with an increase in the aging population, the overall prevalence of AF is projected to exceed 12 million people in the U.S. by 2030.^1,2 As AF is often asymptomatic, these projections may be underestimating the true prevalence of this arrhythmia. Additionally, as wearable technologies become more available, the diagnosis of AF may increase substantially, further stressing the healthcare system. 

It is important to recognize that age is not the only risk factor associated with AF. Studies show the increase in prevalence of AF to be higher than the growth rate of the aging population, suggesting other contributing factors.² Furthermore, AF is associated with significant morbidity and mortality with a long-term risk of stroke and heart failure, leading to recurrent hospitalizations with cost estimates of $16-26 billion annually in the U.S.^3,4  

Traditionally, the routine management of AF focused on three pillars: anticoagulation, rate control, and rhythm control. We have seen advances in anticoagulation with the development of the direct oral anticoagulants, which have been found to be a safe alternative to warfarin.⁵ Unfortunately, we have not seen major advances in rhythm control drugs. Despite our increased understanding of cardiac action potentials and ion channels, there have been no new antiarrhythmic drugs since dronedarone was approved by the U.S. Food and Drug Administration (FDA) in 2009. Additionally, many of these drugs are contraindicated in commonly seen comorbidities with AF (eg, structural heart disease or renal insufficiency) or are poorly tolerated. Catheter ablation has been shown to be effective in reducing mortality and hospital admissions for AF patients with heart failure in the CASTLE-AF study,⁶ and was recently shown to improve quality of life compared to medical therapy in the CABANA trial,⁷ which has led many clinicians to offer ablation as first-line therapy. The current focus of AF ablation is substrate modification and elimination of pulmonary vein and non-pulmonary vein triggers; however, success rates vary between 40-80% in various patient populations after one ablation and are not without risk.⁸ As we continue to make advances in catheter ablation therapy to increase efficacy and safety, we should remain focused on what we learned from the registry data from the ARREST-AF study, which established aggressive management of key risk factors that led to significantly better long-term outcomes after catheter ablation.⁹

This focus on risk factor modification, including hypertension, obesity, and obstructive sleep apnea (OSA), is now recognized as the fourth pillar of AF management and the focus of care at the UW Medicine AF Program. 

Addressing Overweight and Obese Patients

Addressing obesity is of particular interest because of its role in the progression of AF and subsequent long-term management. The Centers for Disease Control and Prevention (CDC) estimates that nearly 50% of the U.S. population will be obese by the year 2030, hitting epidemic proportions. In addition, there is a well-established connection between overweight and obesity with hypertension, obstructive sleep apnea, and cardiovascular disease. For each patient seen during an initial consultation that is either overweight or obese, we start by using the 5 A’s framework (Ask, Assess, Advise, Agree, and Assist), which originated from the U.S. Department of Health and Human Services for tobacco cessation and has since been adopted by the Obesity Medicine Association. This tool is based on the understanding that obesity must be managed as a chronic condition. This is a model of care that can be used by all practitioners to promote behavioral change and lead to long-term success. The initial step is the most crucial — you must Ask if the patient is ready to discuss weight loss. If not, the topic will need to be revisited at every visit. If the patient is agreeable, you can move on to Assess and Advise. This is where the drivers and complications of excess weight can be explored, as well as counsel can be given on the health risks of obesity and benefits of modest weight loss. The LEGACY study demonstrated that weight loss was associated with a dose-dependent reduction in AF burden, so even a 5-10% weight loss is significant.¹⁰ This is also an ideal time for a discussion on the need for long-term strategies and different treatment options. Dietary counseling focuses on increasing the daily amount of fruits and vegetables, decreasing animal products, eating whole grains, and limiting highly processed foods. These recommendations mirror the Mediterranean dietary pattern, which is supported by cardiovascular societies worldwide. Also beneficial is ChooseMyPlate.gov, the dietary approach promoted by the USDA that highlights healthy eating by reaching goals one at a time; their app makes it easier for some patients to track their food choices and successfully reach their goals. By the end of the first clinic visit, realistic weight-loss expectations, goal target weight, behavioral changes, and specific details of the treatment plan have been Agreed upon. Finally, we Assist the patient in identifying and addressing barriers, provide individualized resources, assist in finding and consulting with appropriate providers, and arrange regular follow-up. 

Although we have not required every patient that is overweight or obese to lose weight prior to ablation, we have offered ablation only after weight loss to select patients. Patients were counseled on the beneficial effects of weight loss and set a goal of losing 10% of their initial weight over a 6-month period. Catheter ablations were then performed, and patients were followed up for weight change and arrhythmia recurrence. What we found was in line with what we see in the general population: sustainable weight loss is difficult to achieve, and significant fluctuation is common, which is strongly associated with arrhythmia recurrence in obese patients (Figure 1).¹¹ Weight loss intervention is crucial to successful outcomes, and is a growing area of concern that will take a collaborative approach across many disciplines. Early referrals to dieticians and medical weight management specialists should be top priority.  

Addressing Hypertension

The approach to hypertension management starts with patient history to better understand their level of knowledge surrounding the effects of high blood pressure and blood pressure management goals. If they are not already being managed by another provider or if they need tighter control, we start with lifestyle modification focusing on weight loss, sodium reduction, and increased physical activity. I recommend following the Dietary Approaches to Stop Hypertension (DASH) diet with discussion and handouts on how to make small changes to reduce overall sodium intake. Patients are asked to keep a home blood pressure log to be reviewed at their next visit. If agreed upon goals are not reached by lifestyle changes, we initiate or intensify blood pressure medications, working closely and collaboratively with other providers.

Addressing OSA

The management of OSA is a collaborative approach with our sleep medicine colleagues. Population-based studies show the prevalence of OSA ranges from 21-74% in patients with AF, with data from randomized controlled trials suggesting treatment of OSA may improve success rates of catheter ablation.¹² During initial consultation with patients, we discuss the link between OSA and AF. There are a variety of screening tools used to identify which patients are at a low, moderate, or high risk of OSA. We use the STOP-BANG screening tool (Table 1), which utilizes a yes/no questionnaire, as it has been shown to be the most sensitive and easiest to administer compared to three other common screening tools.¹³ Recently, it was shown that the association of sleepiness seen in the general population with OSA is not seen in patients with AF; therefore, the current screening method may underestimate which patients should be referred for further evaluation. It is important to ask about CPAP compliance at every follow-up visit. If patients are not tolerating their current CPAP or if they have not had a follow-up appointment with sleep medicine within the year, they are referred back for further management. 

Importance of NP-Led Programs

The biggest limitations of RFM are time commitment and limited resources. We know that early intervention and individualized treatment are the cornerstones of AF management; therefore, the future will need a culture shift on how modifiable risk factors are addressed in each patient’s overall care plan from initial diagnosis. As physician time is limited, clinic visits are often focused on treatment with medication and procedures, which does not leave enough time to discuss the importance of RFM. An important consideration for the electrophysiology specialty is for NP-led AF programs. Nurse practitioners are excellent educators and have the time to provide much-needed information on the pathophysiology of AF, treatment options, importance of RFM, and psychosocial challenges. This could be done in a variety of ways, including telehealth, group appointments, and community classes. Nurse practitioners are often more accessible to answer patient questions in a timely manner and can provide frequent follow-up visits, which can improve quality of life. This is extremely important, as AF is viewed as the third most demanding and the second most difficult condition to manage.¹⁴ Additionally, education by nurse practitioners has been shown to improve both patient outcomes and patient satisfaction, subsequently leading to increased adherence to treatment plans.¹⁵ It is not only viable, but essential for all institutions that have or are growing an AF program to ensure nurse practitioners are in lead roles to address this fourth pillar of AF management. 

Contact the author on Twitter: @Deanna_EPNP

Disclosure: Mrs. Tregoning has no conflicts of interest to report regarding the content herein.

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