Is it really just ablation and drugs? - The case for lifestyle intervention in atrial fibrillation
Szabolcs Nagy, ST4 in Cardiology, South London Deanery
Guidelines from the European Society of Cardiology for atrial fibrillation (AF) suggest that it is reasonable to offer catheter ablation as a first-line intervention for patients, with a low risk profile for procedure-associated complications, who would like to have interventional treatment rather than medication.(1)
The number of AF ablation procedures has increased steadily over recent years,(2) a tendency that will very likely continue in the future. We must not, however, forget that, catheter ablation may have severe complications. Risk factor modification (RFM) is a frequently neglected intervention that may result in a significant change in AF burden, and alleviation of symptoms.
The Atrial Fibrillation Ablation Pilot Study, surveyed 72 hospitals in ten European countries in the form of a prospective registry consisting of 20 consecutive patients from each centre undergoing their first AF ablation. Ablation was successful in 73.7% defined by no arrhythmia detection after the 3-month blanking period. However, 18.3% of patients needed a second ablation to achieve this success rate. Complication rates were also reported, with 4.7% adverse cardiovascular events, most commonly bradycardia, cardiac perforation, and pericarditis. The most common complication during follow-up was the occurrence of atrial tachycardia or atrial flutter, appearing in 19.4% of patients (3).
Compared to short-term ablation success less data exists for longer-term success rates of AF ablation. However, it has been shown that the beneficial effects of the procedure do not persist in all patients, and the proportion of individuals who are free from AF reduces with time (4–6).
In recent years evidence has emerged that obesity is a significant risk factor in the development of new AF and the deterioration of paroxysmal into permanent AF (7, 8). However, the 2012 focused update of the ESC Guidelines for the management of AF does not mention the role of risk factor modification in treatment or secondary prevention of AF (1).
In this short overview, I would like to summarise the main take home points from two pivotal studies that should introduce new areas of discussion with our patients in the arrhythmia clinic.
The ARREST-AF trial, published in 2014, evaluated the effect of aggressive risk factor management (RFM) on the success of AF ablation. The researchers recruited 281 consecutive patients and offered RFM to 165. One hundred and forty-nine patients with a body mass index (BMI) ≥27 kg/m2and ≥1 risk factor (hypertension, glucose intolerance/ DM, hyperlipidemia, OSA, smoking, or alcohol excess) were included in the analysis. Sixty-six patients accepted RFM, and the remaining 88 individuals served as the control group.(9)
Aggressive risk factor management took place in a dedicated RFM clinic. It included; blood pressure reduction with a goal of 130/80 mmHg, weight management with a motivational face-to-face and goal-directed program including low-intensity exercise and a low-calorie diet, lipid management and glycaemic control, the management of sleep-disordered breathing, smoking cessation advice and alcohol reduction.
The control group received information on RFM and received further advice from their treating physician.
Only patients with ongoing symptoms despite RFM and antiarrhythmic drug therapy were offered AF ablation. Mean time to ablation was 9.8 ± 7.1 months in the RFM group and 10.2 ± 9.2 months in the control group.
Patients were seen every 3 months for the first year and every 6 months thereafter. At every clinic appointment, symptoms were assessed, electrocardiograms and ambulatory 7-day monitoring were performed. AF symptom burden was evaluated by the atrial fibrillation severity score (AFSS).
Results for all risk factors were more favourable in the RFM group for systolic BP, weight and BMI decline, dyslipidaemia, glycaemic control, the adoption of treatment for obstructive sleep apnoea, smoking cessation and alcohol reduction. Left atrial size indexed to body surface area showed a significantly greater reduction and interventricular septal thickness reduced to a greater extent in patients in the RFM group.
The rate of AF ablation was similar in both groups but AF symptom burden showed a significantly greater reduction in the RFM group. Almost a third of RFM patients (32.9%) remained arrhythmia-free after a single procedure compared to 9.7% in the control group. At the final follow-up of 2 years, 87% of the RFM group were free of arrhythmia, compared to 17.8% in the control group (10).
Pathak and colleagues followed up ARREST-AF with the LEGACY trial a year later, taking a closer look at the effect of weight loss and weight fluctuation in AF. The group analysed data from 355 patients with a BMI ≥27 kg/m2.Weight loss was categorised as ≥10% (group 1), 3% to 9% (group 2) and <3% (group 3) (11).
Patients took part in a structured, motivational, goal-directed programme with follow up initially with 3-monthly visits. Weight loss, weight trend and weight fluctuation were assessed and the primary outcome was AF burden as demonstrated by symptoms using the AFSS and freedom from AF. Ablation was used in patients who remained symptomatic despite antiarrhythmic medications. Follow-up duration was similar at approximately 48 months for all weight loss groups.
Group 1 performed better than group 2 and 3 with regards to blood pressure, lipid profile, glycaemic control, inflammation measured by high-sensitivity C-reactive protein (hsCRP), LA volume indexed for body surface area and interventricular septal thickness reduction. Use of AF ablation was similar in all 3 groups.
All aspects of AF (frequency, duration, symptoms, symptom severity) were improved in groups 1 and 2 compared to group 3. At the end of the follow-up period, 45.5% of group 1, 22.2% of group 2, and 13.4% of group 3 were arrhythmia-free without antiarrhythmic drugs or ablation. Total arrhythmia-free survival taking into account all management options was significantly better in group 1 (86.2%) than in group 2 (65.5%) and group 3 (39.6%) with considerable attrition in group 3. Weight fluctuation had a negative effect on freedom from AF (76% vs 59%). Compared with group 3, group 1 had a 6-fold greater freedom from AF (HR:5.9; 95% CI: 3.4 to 10.3; p < 0.001) (11).
These data show that sustained and progressive weight loss can lead to significant reduction in AF recurrence and freedom from AF related symptoms.
Great emphasis is placed on drugs and intervention in the management of patients with AF. Outpatient clinics are busy and a twenty minute appointment is rarely enough for in-depth discussions. Patients come to us for help and expect to walk away with something tangible such as a drug prescription or a referral for an intervention that will cure them of their disease.
We quote numbers for complication rates, success rates and side effects that are difficult to interpret and translate into real-life experience. We tend to forget, however, how much simple interventions, that require far more participation and time from medical professionals and patients alike compared to prescriptions and intervention, can help to improve our patients’ outcomes.
Discussions about patient-modifiable risk factors are difficult with patients we have just met, and we need time to establish rapport to broach this often very sensitive subject.
These two studies highlight the importance of lifestyle advice and weight loss. The programme that led to success in both of these trials was very intensive and time-consuming with close follow-up, but clearly showed that simple, low-risk interventions such as weight loss can change outcomes significantly.
Setting up risk factor management services for AF is complex and, in order to be viable in the long term, requires collaboration from cardiac electrophysiologists, community services and general practitioners.
However, while we try to find solutions to set up these services, we have a duty to our overweight patients suffering from AF to explain to them that they are in control and they have the potential to avoid complex electrophysiological intervention or the potential side effects of antiarrhythmic drug therapy by achieving sustained weight loss.
Click here to download the editorial as a PDF file