2011 ACC: Loose Legs in Sleep Lead to Higher Risks of Left Ventricular Hypertrophy

NEW ORLEANS — April 3 2011 – Restless legs syndrome has a cardiac connection: left ventricular hypertrophy, according to a new study reported here today in a news conference at the American College of Cardiology’s 60^th Annual Scientific Session and ACC.i2 Summit.

“From a public health point, we want to know if this is reversible, and if so, maybe it could reduce the burden of this disease,” said lead author Arshad Jahangir, MD, professor of medicine, Mayo Clinic, Arizona, who presented the study Fragmented Sleep Due to Frequent Leg Movement Is Associated with Left Ventricular Hypertrophy and Poor Cardiovascular Outcomes.

“Mounting evidence has shown that frequent sleep disturbances may predispose some people to heart conditions and left ventricular hypertrophy (LVH), and those with severe LVH have more than a two-fold risk of having any cardiac event or death.”

Researchers say the problem is widespread, with about 12 million Americans, and the problem appears to increase as a person ages. “It also is a major cause of insomnia,” Dr. Jahangir added.

The study enrolled 584 patients who underwent sleep studies and divided them into those with frequent leg movements (periodic movement index [PMI] >35 hour) and those with infrequent leg movements (periodic movement index [PMI] < or equal to 35/ hr).

Subjects with frequent leg movements were more likely to be older, male, and have a higher incidence of CAD.

Researchers reported that at a three-year follow up, patients with LVH and atrial fibrillation had higher rates of heart failure, recurrent hospitalization, and death.

“While patients with frequent leg movements were more likely to have atrial fibrillation (p < 0.01), even among participants who did not have this health rhythm disease, those with severe LVH had more cardiac events. And severe LVH was evident in 37% of people with atrial fibrillation and 20% of those without, suggesting that underlying heart condition, specifically electrical dysfunction, and RLS may somehow together lead to more cardiovascular problems,” he said.

Quality of life was assessed using validated instruments based on a point system looking at how well the patient felt after treatment.

Researchers conducted the study to identify predictors of left ventricular hypertrophy and define factors that may be reversed.

“We have known for a long time that LVH is a poor prognostic factor, and patients with LVH are at risk for more cardiac events. What is new about this study is that restless leg syndrome is another risk factor that may predispose to and lead to more complications of LVH,” he said.

Researchers pointed out that the study is a retrospective analysis, and thus “observations need to be confirmed in a larger number of patients.”

The study was funded by the NHLBI and the Angel and Paul Harvey CVD Research Endowment to CardioGerontology.