Even a minor decrease in a person's (blood) sodium level � levels that are now dismissed by physicians � had a major impact on mortality of heart failure patients," says one of the study's leaders.
About a quarter of all patients with severe heart disease have low blood sodium levels, a condition known as hyponatremia, and the new study found that those with the condition died nearly twice as often as others.
The new finding may change the way doctors determine prognosis for heart disease patients. Blood sodium levels can be measured through simple blood tests.
Research presented today at the American College of Cardiology's Scientific Sessions in Orlando pinpoints a major marker of a poor prognosis for heart failure, hyponatremia, or a lower than normal concentration of serum or blood sodium.
Researchers found that hyponatremia, which is found in almost a quarter of patients with severe heart failure, doubled death rates within 60 days of hospital discharge.
"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," says Mihai Gheorghiade, MD, associate chief, Division of Cardiology, Northwestern Memorial Hospital and Northwestern University Feinberg School of Medicine, and lead presenter of the findings from the ESCAPE trial during a poster session on Monday.
"These findings illustrate that not all heart failure is created equally -- heart failure accompanied with hyponatremia is especially dangerous.
Levels of serum sodium may prove a useful and easily accessible risk assessment tool in the clinical management of patients hospitalized for heart failure," says Dr. Gheorghiade.
The good news is that a separate study presented Monday by Dr. Gheorghiade showed that improvement in sodium serum levels during hospitalization was associated with improved outcomes.
In the ACTIV trial, patients with a serum sodiuim improvement at hospital discharge had a 15.6 percent mortality rate at 60 days post discharge, compared with a 30.4 percent mortality rate in those showing no improvement.
"Currently, the medical community is not paying much attention to serum sodium levels in heart failure patients.
A paper authored by Dr. Gheorghiade and published in JAMA in April of 2004 found that the medication tolvaptan was a promising addition to standard therapy for patients hospitalized with heart failure.
Now, we think it can be treated, and we have an understanding that treating it can make a huge difference for the patient," says Dr. Gheorghiade.
Sodium must be maintained at a specific concentration in the blood and the fluid surrounding the body's cells for the body to function properly.