Blood Sodium Levels Affect Heart Failure Survival
Doctors should pay closer attention to this key factor, study finds
MONDAY, March 7, 2005 (HealthDay News) -- A lower-than-normal level of sodium in the blood (a condition known as hyponatremia) is a major predictor of poor outcomes for heart failure patients, researchers report.
"Even a minor decrease in a person's serum sodium level -- levels that are now dismissed by physicians -- had a major impact on mortality of heart failure patients," lead presenter Dr. Mihai Gheorghiade, associate chief, division of cardiology, Northwestern Memorial Hospital and Northwestern University Feinberg School of Medicine, said in a prepared statement.
A second study by the same team found that by increasing blood sodium levels, doctors could significantly boost heart patients' survival.
Reporting Monday at the scientific sessions of the American College of Cardiology in Orlando, Fla., Gheorghiade's group found that hyponatremia doubled the death rate of severe heart failure patients within 60 days after hospital discharge.
Hyponatremia affects about 25 percent of patients with severe heart failure and can be easily measured through blood tests. Each year in the United States, heart failure accounts for about 1 million hospital admissions.
"These findings illustrate that not all heart failure is created equally -- heart failure accompanied with hyponatremia is especially dangerous," Gheorghiade said. "Levels of serum sodium may prove a useful and easily accessible risk assessment tool in the clinical management of patients hospitalized for heart failure."
Sodium is an electrolyte that helps maintain blood pressure and also assists with muscle and nerve function.
The team's second study found that boosting blood sodium helped extend lives. Gheorghiade and colleagues report that patients with a serum sodium improvement at time of hospital discharge had a 15.6 percent death rate over the next 60 days, compared with a 30.4 percent death rate for patients who showed no improvement in blood sodium levels.
"Currently, the medical community is not paying much attention to sodium serum levels in heart failure patients. However, serum sodium appears to be a modifiable target that can be treated," Gheorghiade said.
The National Library of Medicine has more about heart failure.