The HCPLive Peer Exchange: Advances in Heart Failure Management features expert opinion and analysis from leading physician specialists on the latest developments in heart failure research, diagnosis, and management.
This Peer Exchange is moderated by Peter Salgo, MD, professor of medicine and anesthesiology at Columbia University and an associate director of surgical intensive care at the New York-Presbyterian Hospital in New York City.
The panelists are:
In this segment of the Peer Exchange, the panelists discuss modifiable risk factors for heart failure, including smoking, weight loss, and exercise. They also discuss the “obesity paradox” and how edema can mask weight loss and complicate the diagnosis of heart failure.
Although obesity is a risk factor for many cardiovascular complications, including heart failure, Christian Schulze, MD, PhD, notes that relationship between obesity and hear failure is complicated. “Obesity is associated with a higher rate of diabetes. High blood pressure is part of the metabolic syndrome definition. Obesity is part of the body mass index definition, and obesity leads to more cardiovascular disease which leads to heart failure. I think this is a clear epidemiologic relation that has been described in multiple studies,” he says.
However, “we have also learned over the last years -- and this was striking and in a way shocking to many of us -- that patients with advanced heart failure, once they have established disease do better when they have a high body mass index,”
Dr. Schulze says the finding that obesity is associated with better outcomes in patients with established heart failure is known as “the obesity paradox.”
He says that one way to explain this is that patients with obesity have a more favorable metabolism. This phenomenon is not confined to heart failure; Dr. Schulze notes that studies have shown that “patients with advanced renal disease, patients with HIV and AIDS, cancer patients -- all of these patients seem to benefit from a higher body mass index.”
Michael Felker, MD, notes that “it’s important to point out that these are epidemiologic associations, and that’s not the same as an association that can clearly drive a recommendation to a patient.” He says no one should recommend that heart failure patients gain as much weight as possible to improve their chances of a good outcome. In fact, he points out that many of the diseases mentioned here are “wasting diseases in their late stages,” and that some of this is “driven by the fact that low BMI or involuntary weight loss in diseases like cancer, chronic kidney disease, HIV, and heart failure is associated with a bad prognosis.”
Jim Januzzi, MD, concurs, noting that weight loss in heart failure patients is a risk marker and being obese is not necessarily protective. “It’s the absence of risk, and how that process develops is very poorly understood,” he says.
The panelists also talk about how the edema associated with decompensated heart failure can mask weight loss and complicate the diagnosis. “This illustrates why it’s so hard to recognize heart failure sometimes because the patients may exchange well body mass for fluid. So they go from visit to visit with their doctor, not really changing too much other than the sort of incipient symptoms of fatigue and dyspnea. Then when they’re finally diagnosed, and this is quite characteristic in preserved ejection fraction heart failure, and you mobilize 10 or 20 pounds of fluid, then the true manifestation of wasting is seen,” says Januzzi.