How Quickly Electrical Currents Move Through The Legs May Help Predict Heart Failure
Source: American Heart Association
Summary: Researchers at Stanford University School of Medicine found that people who had lower leg bioimpedance were at higher risk for heart failure.
Imagine stepping onto a scale – not to measure your weight, but the chance of your heart failing. That’s the potential scenario envisioned by researchers who may have discovered a new risk factor for heart failure: leg bioimpedance. More frequently used to calculate body fat, bioimpedance uses low electrical currents to measure resistance within a tissue. Water, blood and other fluids easily conduct electricity and have lower bioimpedance than something more solid such as muscle tissue, which has higher resistance. Researchers at Stanford University School of Medicine found that people who had lower leg bioimpedance were at higher risk for heart failure. The discovery could potentially lead to earlier diagnosis and preemptive treatment of the condition. The study findings were published in the Journal of the American Heart Association.
The study’s authors examined data on more than 500,000 U.K. patients between the ages of 49 and 69 in a search to find new risk factors for heart failure, a condition in which the heart fails to pump blood efficiently enough to meet the body’s needs. They used computer-assisted techniques to weed through 3,646 variables reflecting lifestyle, health and disease-related factors for each patient. The results did not surprise – among the top predictors of heart failure were having a previous heart attack, chronic heart disease and a history of diabetes. Bioimpedance was measured using a body composition analyzer, which looks like a standard scale but with handlebars. Electrodes beneath each foot send small electric currents and measure impedance, or resistance, met in the tissue.
The study’s authors suggest that a simple algorithm they developed based on their findings could provide an accurate prediction of developing heart failure within eight years. The formula combines leg bioimpedance with a patient’s age, sex and whether the person has had a heart attack or not.
More Information: Daniel Lindholm et al, “Bioimpedance and New‐Onset Heart Failure: A Longitudinal Study of >500,000 Individuals From the General Population”, Journal of the American Heart Association (2018). DOI: 10.1161/JAHA.118.008970