Patients with heart failure who also have low blood pressure — usually taken as a good sign — may in fact have a higher risk of dying, U.S. researchers reported Tuesday.
They said doctors admitting heart failure patients to the hospital should take low or even normal blood pressure as a sign that a patient has more advanced disease.
Writing in the Journal of the American Medical Association, the researchers said they had studied the records of 48,612 heart failure patients seen at 259 U.S. hospitals between March 2003 and December 2004.
The patients with higher systolic blood pressures at the time of hospital admission had substantially lower death rates, both in the hospital and after discharge, than patients with lower blood pressure readings.
Systolic blood pressure is the "top" number in a blood pressure reading and indicates the pressure on the arteries when the heart is contracting.
A reading of 120 or lower is considered normal and anything above 140 is considered too high.
"The lower the admission systolic blood pressure level, the higher the patient mortality rate," said Dr. Mihai Gheorghiade of Northwestern University in Chicago, who led the study.
Heart failure is a chronic condition in which the heart cannot properly pump blood. It often enlarges the heart and causes blood to pool around it, leading to congestion and sometimes a cough.
It kills half of all patients within five years and is newly diagnosed in at least 500,000 people a year in the United States alone. About 1 million Americans are hospitalized with heart failure each year.
High blood pressure, viral infections and valve disease can all cause heart failure. Usually the only cure is a transplant. But blood pressure-lowering medications and other heart drugs can help control the symptoms.
"I think going back to the basics and really looking at things like blood pressure, it shows that it's still important to look at the basics of the physical exam," said Dr. William Cotts of Northwestern Memorial Hospital, who worked on the study.
Gheorghiade said temporarily higher blood pressure in heart failure patients may be a good thing.
"During stress, or at the time of admission, it appears that when you have high blood pressure for a limited amount of time, let's say hours, that may indicate that your heart is stronger," he said.
"So it's not that the high blood pressure is good, but it's a measure of the strength of the heart."