Utah researchers say heart procedure could reduce risk of Alzheimer's disease

When doctors perform a relatively simple medical procedure to keep a person's heart from beating irregularly, they often reduce the patient's risk of developing Alzheimer's disease or stroke.

That's the news doctors at Intermountain Medical Center shared with colleagues Thursday at the National Heart Rhythm Society convention in Denver.

Dr. John Day and Dr. Jared Bunch, both researchers at IMC, have used Intermountain Healthcare's large medical database to report on the outcome for thousands of patients who underwent a procedure called a catheter ablation to treat their atrial fibrillation. The disorder is a type of irregular heartbeat that can lead to medical complications.

The two researchers found last year that atrial fibrillation, when not successfully treated, is directly related to the development of Alzheimer's disease. Bunch said the most recent finding was an extension of that research.

"We saw the association and then started asking, 'Can we alter a disease state and see those rates (for Alzheimer's and stroke) go down?' " They then explored outcomes for those who had their atrial fibrillation treated with a catheter ablation — in which doctors insert a catheter into the heart and cauterize the area where irregular heart rhythm originates — and compared them to those treated only with medication, and to those who don't have the atrial fibrillation at all.

Atrial fibrillation is the most common heart-rhythm disorder in the U.S., affecting more than 2 million Americans. Medical guidelines now dictate that the first-line treatment for the condition should be medication, and the catheter procedure should only be performed if medications don't regulate the heartbeat. "The problem is, the medications don't work very well for most people," Day said.

Over a three-year period, the researchers enrolled 37,908 patients in a large, ongoing prospective atrial fibrillation study. Among patients treated with a catheter ablation, 0.2 percent developed Alzheimer's disease, and 0.4 percent developed other forms of dementia.

Among those treated only with medication, 0.9 percent developed Alzheimer's disease and 1.9 percent developed other forms of dementia.

The procedure appears to have cut the risk of stroke even more dramatically.

About 2.2 percent of atrial fibrillation ablation patients suffered a stroke, and the mortality rate was 6 percent, compared to those treated only with medication. Among them, 4.7 percent suffered a stroke, and the mortality rate was 23.5 percent.

Both researchers agree that even though the evidence is compelling, they don't expect to see standardized treatment guidelines for atrial fibrillation — which now dictate that medications should be used first — to change for several years.

Bunch said the National Institutes of Health now has a nationwide randomized trial underway, led by the Mayo Clinic, using the catheter ablation procedure as the first-line treatment for atrial fibrillation.

IMC is enrolling patients as part of that five-year study. There are also five other independent studies examining the efficacy of treating atrial fibrillation with catheterization as the first-line intervention, but "we don't yet have government-funded study on it with many people over a long period of time."

Only after such a study is complete can the standardized treatment guidelines for atrial fibrillation change, he said.

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