Brigham. US: High blood pressure is the most common risk factor for heart disease
and death worldwide, and yet the answers to some of the most basic
questions about how
to manage it – when to introduce new medications, intensify treatment or
re-evaluate a patient – remain unclear. In a new study published this
week in the British Medical Journal, researchers
from Brigham and Women’s Hospital (BWH) examined the outcomes of 88,000
adults with hypertension to pinpoint
the precise high-blood-pressure level and critical time points at
which intervening was tied to a decrease in the risk of death.
“Ours is the first study to look at these key metrics in a large
database of primary care patients with hypertension,” said senior author
Alexander
Turchin, MD, MS, a physician and researcher in the Division of
Endocrinology at BWH. “Our findings could help guide clinicians as they
think about how
their patients should be treated in the clinic.”
Current guidelines and recommendations for managing the care of
patients in the earliest stage of hypertension differ substantially.
Patients with systolic
blood pressure levels between 140 and 159 mm Hg are considered
“stage 1.” Recommendations regarding the best treatment path for these
individuals differ
among national guidelines such as the JNC8 guidelines, mainly used
in the United States, and NICE guidelines, mainly used in European
countries. Such
guidelines are based on a mix of expert opinion and clinical trial
data (when data are available). Although some studies have examined how
treating
patients with a baseline systolic blood pressure between 150 and 159
influences outcomes, no previous studies have examined the impact of
treatment on
outcomes for patients with blood pressure between 140 and 149.
Researchers identified three factors that were tied to greater risk
of death or cardiovascular event (heart attack, stroke and others): a
systolic blood
level above 150, delays in intensification of treatment and delays
in reassessment of patients.
“The outcomes that we measured are ones that matter: death and
cardiovascular events,” said Turchin who is also director of clinical
informatics at the
Harvard Clinical Research Institute. “We wanted to gather more
evidence to better understand how delays in treatment of elevated blood
pressure influenced
these outcomes.”
In patients with systolic blood pressures between 130 and 150, the
research team did not detect an increase in risk, but above the 150
threshold, the team
observed progressively greater risk of an acute cardiovascular event
or death.
They also found that delaying the intensification of treatment
(increasing dosage or adding in new medications when blood pressure
levels rise) by more
than 1.4 months was tied to increased risk of death or
cardiovascular event. Current guidelines differ slightly, with some
recommending intensifying
treatment within two to four weeks and others recommending within
one month. However, the majority of patients in the retrospective study
did not receive
medication intensification within 1.4 months.
In addition, the team found that when patients received a
reassessment of blood pressure levels more than 2.7 months after
medication intensification, risk
of death increased. The majority of patients in the study did
receive follow-up assessments within this window of time.
“Hypertension is treatable – the right medical treatment can
mitigate a person’s risk. But we need to know the optimal blood
pressure, the optimal time to
intensify treatment and the optimal time to reassess,” said Turchin.
“Our research supports the importance of avoiding delays in treatment
and having
follow-up appointments for patients with hypertension.”
This study was funded by the Harvard Center for Primary Care.