Doctors change how they evaluate blood pressure
numbers
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By Geraldine A. Collier
Correspondent
Correspondent
Posted Jan. 27, 2016 at 8:55 AM
If you were diagnosed some years ago with hypertension – high
blood pressure – you might just want to have another conversation with your
doctor.
If you have been told you are “pre-hypertensive,” you might also
want to talk to your doctor.
Not all that long ago, you were considered to be healthy or
“normal” if your blood pressure measured 120/80 to 139/89 – nothing to worry
about unless that last reading went higher.
We may not have changed, but the standard way the medical world
uses to evaluate us has. High is still high, but what once was normal is now
labeled “pre-hypertensive” and only abut half of us over the age of 18 are
considered to be normal with blood pressure lower than 120/80. The rest of us –
millions and millions of us – have to worry about our chances of having a
stroke, cardiovascular problems and/or kidney disease.
Not only has the definition of blood pressure readings changed,
but so has the best method for detecting the problem and the treatments
prescribed. The goal we need to reach in order to improve our chances of
staying healthy? Well that’s a moving target.
Let’s look at blood pressure numbers.
The systolic (top number) measures “the pressure in the arteries
when the heart muscle contracts,” according to the American Heart Association,
while the diastolic (bottom number) measures “the pressure in the arteries when
the heart muscle is resting between beats and refilling with blood.”
“I tell people to think about garden hoses,” explained Dr.
Kenneth Kronlund, an internist and quality chief for adult primary care at
Reliant Medical Group.
“Say that you have a sprinkler out in the garden and you turn
the spigot on and the hose fills up and then you turn the spigot off and the
sprinkler still sprinkles until the pressure goes away.
“The pressure at the top (systolic) is the maximum pressure when
the garden hose is as distended as it will get and the bottom number
(diastolic) is as low as it will get before you turn the spigot on again,”
added Dr. Kronlund.
If you pre-hypertensive – 120/80 to 139/89 – your doctor will
probably recommend lifestyle changes, including weight loss, although some
physicians will also ask you to take medication while you are making those
changes.
If you are diagnosed with high blood pressure, you’re going to
have to take a pill for the rest of your life. However, that pill isn’t the
same as the pill you would have been prescribed some years ago. (You might want
to talk to your doctor about that.)
“The drugs that we used 10 years ago commonly were beta blockers
drugs (Metoprolol, for instance), but beta blockers have fallen way down in
preference,” said Dr. Kronlund. Instead, diuretics, ACE inhibitors or calcium
channel blockers are likely to be the medications prescribed today.
By the way, that blood pressure reading taken in your doctor’s
office shouldn’t be the final word.
In October, the U.S. Preventative Services Task Force
recommended that before starting any treatment, elevated blood pressure
readings taken in a doctor’s office should be confirmed by a number of outside
readings.
The preferred method for doing this involves a device called an
ambulatory blood pressure monitor, which involves wearing a cuff attached to a
small, portable machine that records blood pressure over a period of 12 to 48
hours.
However, USPSTF says home blood pressure cuffs, which measure
blood pressure in the upper arm, are OK for diagnosis when used twice in the
morning and twice in the evening for a minimum of three, but preferably seven
consecutive days. Many, but not necessarily all, primary care physicians do
loan out these blood pressure cuffs for home testing.
Like many doctors, Dr. Stephen Martin, who specializes in family
medicine at UMass Memorial Medical Center’s Barre Family Health Center, also
recommends that people who have high blood pressure or are pre-hypertensive
purchase a cuff monitor – not a wrist monitor – to keep track of their readings
in between visits to the doctor.
They are available at most drugstores, but you first might want
to ask your doctor for a recommendation or check out this month’s issue of
Consumer Reports, according to Dr. Martin. It’s also a good idea to have your
doctor calibrate the cuff monitor to make sure it’s accurate.
Two major studies have looked at different patient populations
who are at high risk for serious or even deadly consequences from high blood
pressure: non-diabetics in the very recent Systolic Blood Pressure Intervention
Trial - SPRINT - and diabetics in the Action to Control Cardiovascular Risk in
Diabetes (ACCORD) clinical trial.
The SPRINT study enrolled 9,361 patients – 56 came from UMass
Memorial Medical Center. They were at least 50 years old, with a systolic blood
pressure measurement of at least 130 to 180; any type of cardiovascular disease
other than stroke; or chronic kidney disease, or a 10-year-risk of
cardiovascular disease of 15 percent or greater based on the famous Framingham
study or an age of 75 years or older. (Yup, living longer is definitely a risk
factor.)
“This is not some arcane group of people with an obscure
disease,” said. Dr. Gerard P. Aurigemma, a cardiologist at UMass Memorial who
was the principal investigator for the SPRINT trial at that site.
“This is bread and butter adult internal medicine,” said Dr.
Aurigemma. “These are the patients that we see day in and day out in the
office. This is one reason why this study is so important, because it helps us
to understand how best to treat patients that we see on a regular basis.
“Clinical data has always told us that small blood pressure
reductions have a big payoff in terms of reduction in events, particularly
stroke,” added Dr. Aurigemma. “So, the results of SPRINT were not very
surprising to me. It was the magnitude of the benefit that was the surprise.”
While patients in the SPRINT study who were prescribed two blood
pressure medications to bring their blood pressure below 140 had some benefit
occur, patients who were prescribed three blood pressure medications to bring
their blood pressure below 120 had significantly reduced cardiovascular events
by 30 percent and all-cause mortality by nearly 25 percent.
Hopefully, the SPRINT study will bring a uniform voice on
targets for blood pressure,” said Dr. Glenn R. Kershaw, a nephrologist (kidney
disease specialist) who directs the Hypertension Clinic at UMass Memorial
Medical Center.
“When we can look at the different complications and the
different subsets of patients – that is when the experts will come out with
some guidelines and some recommendations for each of the subsets of patients,
and the medical community will have a more uniform voice on what these blood
pressure targets should be.”
However, one puzzlement remains for those who manage high blood
pressure in their patients. In studying diabetics’ responses to blood pressure
lowering, the ACCORD study, which was done several years ago, showed that
patients whose blood pressure was brought below 140 derived benefit, but no
significant further benefits were found for those diabetics taking three blood
pressure medications to drop blood pressure readings to below 120.
Some experts believe that the ACCORD study, which was smaller
than the SPRINT study, would have shown similar benefits for those whose blood
pressure was pushed to below 120 if the study had been larger. However, no one
knows for sure.
“I think we need to be aware of the fact that one size doesn’t
necessarily fit all,” said Dr. Kershaw. “The most important thing is that a
doctor knows his patient and works with his patient and they have a partnership
in deciding what target blood pressure they want to achieve.”
