The LEGACY of Sustained Weight Loss
Interview | Obesity is a clear problem in the United States, and, for a variety of patients, it can be a particularly complicated problem. CardioSource WorldNews spoke with Parash Sanders, MBBS, PhD, professor Center for Heart Rhythm Disorders in the University of Adelaide in Australia, and Rajeev Pathak, MD, a cardiologist and electrophysiology fellow at the Center, about their JACC publication “Long-term Effect of Goal-directed, Weight Management in AF Cohort.” LEGACY—a long-term, follow up study—grew from the notion that weight loss lessens the burden of AF. What investigators did know is whether benefit of weight loss on rhythm control was sustained, had dose effect, or was impacted by weight fluctuation.
CardioSource WorldNews: Tell us about LEGACY. Let’s start there.
Rajeev Pathak, MD: So this is a study looking at the long-term effect of weight loss and impact on atrial fibrillation burden. This is a registry-based report in which we had 1,450 inpatients—out of which we found 825 had BMI more than 27. All these patients were counseled on the importance of weight and risk-factor management. After excluding patients with severe medical condition and permanent atrial fibrillation, we had 355 patients. These patients were then divided to look at the response effect of weight loss. So less than 3% weight loss, 3% to 9% weight loss, and more than 10% weight loss. And we found significant improvement in their metabolic profile and the structural parameters, as well, as there was a dose-dependent effect on atrial fibrillation burden.
Now in the case of directed management, how is that defined in terms of this study.
Parash Sanders, MBBS, PhD: In the directed management, we have a separate clinic that runs a weight and risk-factor management site. They don’t manage the fibrillation that these patients had. That’s managed by the electrophysiology team. So in this clinic, we get to know our patients, we get to know their diet, we get to know their exercise regime. And we really aim at setting goals, together with them—so it’s a bit of a partnership so that they can then go and achieve their goals. We can then review what happens with their diet and exercise over that time and make suggestions on how they’re able to change. And what we found is this is an effective way of gaining compliance with patients, motivating them to take control of their disease. Not only do they lose weight but, in this study and in LEGACY, we were able to show that, at 5 years, most of these patients were able to keep that weight off and keep their AF away. So this was kind of an important finding for us in the LEGACY study.
What is it that helps drive this weight loss? What’s your secret?
Pathak: As Professor Sanders said, this is a very simple clinic. We have one patient and one physician. We do not have any props. Basically, they work with the patient; we discuss the strategies, areas wherein we can improve and, with the patient and consultation, come up with a meal plan which is a low-carb or low-fat, high protein diet. More importantly along with that, they also maintain a lifestyle journal wherein they’re going to log everything they put in their mouth. So that helps us to look at their diet and give them necessary advice. More importantly for themselves, they can self-reflect and look at [their diet] and make changes. So it’s the patient making himself make those changes, and we have found this is a very effective behavioral tool to make changes—really effective not only in making them lose weight but, because they are in charge of their own weight loss and with this much encouragement and involvement, they do not fluctuate, and they keep the weight off.
What’s the intersection in which obesity starts to affect AF and vice versa?
Sanders: So I think the data is there now from large population studies, which links obesity with atrial fibrillation. We actually found that, in our data, in terms of losing weight, we haven’t found much of a benefit coming from below a BMI of 27, and that may be because our numbers are lower in the BMI less than 27. So our aim really is first to lose 3% of weight. We then aim to lose 10% where we’ve seen the maximum impact and then we really get their weight below a BMI of 27—because once we get down below that, the benefit in terms of the atrial fibrillation seems to be much lower. Now, we may have new data in the future as we get more numbers to refine that a bit more, but that’s the state at this current point.
It’s rather interesting because a lot of studies have been trying to get apps to do the job of doctors—maybe a phone call or a text or something else to help with the process. It is rather ironic that we’re going back to “that a one-on-one situation may be the best.”
Pathak: I think that helps to build up that rapport, especially coming from a physician, if we can talk in their language, as well as a physician. Once you can convince them, the compliance definitely improves and increases. So that’s where it started. It’s a proof of concept. It doesn’t mean that it cannot be done out in public and done by others, but that has to be proven before we can really extend that to other allied professionals to be able to do this.
Now, is this something that’s going to continue so that we’ll be able to see more LEGACY data further down the line?
Sanders: We started with the ARREST-AF cohort study, which was published in JACC at the end of last year; we now have LEGACY, and we have a series of these studies that will come out over the next 2 years or so. We do want to be able to take this away from the one-on-one physician consultation in order to be able to make it available to the masses, and so I think the an important step for us is to see how we can translate this into nurse practitioners delivering this or concurrently using apps that might be able to help. Now, apps can make it difficult to motivate someone to do something, and so that’s where it’s going to need a personal touch—but that’s not to say it’s going to work; it’s something that we have to prove that it can work.
But it is the possibility that the personal touch certainly is a good place to start.
Sanders: In our opinion, it’s a crucial start.
Pathak RK, Middeldorp ME, Meredith M, et al. J Am Coll Cardiol. 2015;65(20):2159-2169.
Keywords: CardioSource WorldNews, Obesity, Weight Loss, Atrial Fibrillation
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