Systolic blood pressure, a readily available vital sign taken at hospital
admission, has been found to be a key factor in predicting mortality risk and
revealing important disease characteristics for heart failure patients,
according to a team of academic researchers.
These new findings indicate
that heart failure patients with higher systolic blood pressures had
substantially lower death rates compared to patients with lower systolic
pressures, and that lower systolic pressures may indicate more advanced disease
and a poorer prognosis.
Published in the Nov. 8 issue of the Journal of
the American Medical Association, the new study found that the level of systolic
blood pressure taken at hospital admission offers insight into different stages
of heart failure, prognosis, and disease development. This study also revealed
that systolic hypertension is very common in patients admitted to the hospital
for heart failure -- present in over 50 percent of patients.
"Systolic
blood pressure taken at hospital admission was a strong independent predictor of
mortality and morbidity in this large, representative heart failure patient
population. We hope the findings may help clinicians more effectively stratify
risk and offer more targeted treatments based on a patient's systolic blood
pressure level," said Dr. Gregg C. Fonarow, The Eliot Corday Chair in
Cardiovascular Medicine and Science, principal investigator and director,
Ahmanson-UCLA Cardiomyopathy Center.
Systolic blood pressure demonstrates
the maximum arterial pressure during contraction of the left ventricle of the
heart -- typically the first number in a blood pressure reading (for example,
120 mm Hg when the blood pressure is reported as 120/80 mm Hg -- measured in
millimeters of mercury). Heart failure occurs when the heart is not working
effectively, including when the heart's left ventricle can't pump enough blood
to the body's other organs.
The study is the first to utilize patient
data from a large heart failure patient registry called the Organized Program to
Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure
(OPTIMIZE-HF). Researchers included information on 48,612 heart failure patients
seen at 259 U.S. hospitals between March 2003 and December
2004.
Researchers found that patients with higher systolic blood
pressures at hospital admission had substantially lower in-hospital and
post-discharge mortality rates compared to patients with lower systolic
pressures. This finding applied to patients irrespective of their left
ventricular ejection fraction, a common measure of ventricular
function.
"Elevated systolic blood pressure appears to signal specific
pathophysiological processes that differ from the underlying processes in
patients with low systolic blood pressure. Because the characteristics and
outcomes are different among patients with heart failure with varying systolic
blood pressure levels, management may need to vary according to this readily
available vital sign." said Dr. Mihai Gheorghiade, professor of medicine,
division of cardiology, Feinberg School of Medicine, Northwestern University and
first author of the study.
The study revealed the following in-hospital
mortality rates by systolic blood pressure levels: 7.2 percent mortality rate
for patients with low systolic pressures of less than 120 mm Hg.; 3.6 percent
mortality rate for patients with pressures between 120 and 139 mm Hg (generally
considered in the normal range); 2.5 percent for patients with higher systolic
pressures between 140-161 mm Hg; and 1.7 percent mortality rate for patients
with very high systolic pressures over 161 mm Hg.
"We found that despite
current pharmacologic therapies, the lower the admission systolic blood pressure
level, the higher the patient mortality rate," said
Gheorghiade.
According to researchers, it had traditionally been thought
that most patients with heart failure had lower systolic blood pressures when
they presented to the hospital with worsened heart failure, but the study
revealed that over fifty percent of patients had a high systolic blood pressure
-- over 140 mm Hg.
"To optimize treatment, we may need to medically
approach heart failure patients differently depending if their systolic blood
pressures are normal, low or high," said Fonarow.
Researchers note that
systolic blood pressure may be an indicator of the stage of heart failure with
lower systolic blood pressures indicating more advanced disease and prognosis.
Clinical trials designed for each patient group may lead to more insight into
heart failure disease development.
The study was funded by
GlaxoSmithKline that sponsors the OPTIMIZE-HF registry. Drs. Gheorghiade and
Fonarow have received research grants, honoraria and served as consultants for
GlaxoSmithKline. Additional author financial disclosure is available in the full
JAMA paper on page 2226.