The most
important recent development affecting older patients, without a doubt, is the issuance
of new guidelines for the diagnosis and treatment of high blood pressure. The Wall Street Journal proclaimed “Nearly Half of US Adults Have High Blood Pressure
Under New Guidelines,” and venerable health columnist Gina Kolata of the NY Times wrote: “The
nation’s leading heart experts on Monday issued new guidelines for high blood
pressure that mean tens of millions more Americans will meet the criteria for
the condition, and will need to change their lifestyles or take medicines to
treat it.” The report, which took me a while to track down and read
since most of the references are to summaries of the report or commentaries on
the report but not to the actual document, is 175 pages. It was issued or
endorsed by eleven organizations, whose initials actually form part of the name
of the report: its full name is the “2017
ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPCNMA/PCNA Guidelines for the Prevention,
Detection, Evaluation, and Management of High Blood Pressure in Adults.” The subtitle
is: “A Report of the American College of Cardiology/American Heart Association
Task Force on Clinical Practice Guidelines.” Now that I’ve had a chance to
digest this—what should we make of it?
I remember the
day in 1991 when JAMA published the results of the “SHEP” trial, a study of
the treatment of isolated systolic hypertension in the elderly that upended
what I’d been taught in medical school. Gone was the belief that high blood
pressure was good for older people because they needed greater force to push
blood through their stiff arteries; suddenly, there was compelling evidence
that high blood pressure was dangerous—it caused strokes and heart attacks.
Keeping the systolic blood pressure below 160 reduced the risk of stroke by 36
percent and the risk of a cardiac event by 27 percent. Overnight, the practice
of medicine changed.
To be sure,
there were skeptics. Wouldn’t lowering the blood pressure cause older people to
become dizzy and to faint? Just how far were we supposed to lower blood
pressure anyway? But to me and many others, the choice was clear. Stroke was
one of the worst fates that could befall older patients: sometimes it killed
them, but more often, it left them impaired, often profoundly, significantly diminishing
the quality of life.
But I also
remember a book by physician and historian of science, Jeremy Greene, published
in 2008 and called Prescribing by Numbers: Drugs and the Definition of Disease. Greene argued persuasively that the pharmaceutical industry has a vested
interest in lowering the cut-off for treatment of a variety of chronic
conditions, such as hypertension, high cholesterol, and diabetes. Defining “pre-diabetes”
as a real condition warranting treatment or repeatedly dropping the threshold for
treating cholesterol with statins had clear implications for the drug companies:
they would sell more pills. More volume, more revenue, more profits. So are the
new guidelines just another instance of “diagnosis creep,” a way for Pharma to
make more money?
It’s important
to realize that what tipped the scales for the guideline writers, what’s
different now from the last time they wrote a guideline, three years ago, is
the 2015 “SPRINT” study (Systolic Blood Pressure Intervention Trial), a
randomized trial of high risk patients over 50 to either a systolic blood
pressure target of 140 or 120. The study, which was reported in the New England Journal of Medicine, found a 25 percent reduction in cardiovascular events (such
as stroke or heart attacks) when physicians tried to reduce the blood pressure
to the lower value.
As Gilbert Welch of the Dartmouth Institute, co-author of Overdiagnosed: Making People
Sick in the Pursuit of Health (2012) and Less Medicine, More Health (2016),
commented, that 25 percent sounds pretty good, but it’s the relative risk
reduction. In fact, the rate of cardiac events fell from 8 percent in one group
to 6 percent in the other—an absolute difference of only 2 percent. Or, looked
at differently, 92 percent of people in one group and 94 percent of people in
the other group did just fine. Suddenly, the impressive results don’t look
quite so impressive. Moreover, all these patients were already at increased
risk of cardiovascular disease because of other factors such as
cigarette smoking or diabetes. Presumably, had the same study been carried out
in people of average or lower risk, the benefits would have been
correspondingly smaller.
So if the new
guidelines are based predominantly on the findings from one study, and the one
study isn’t quite as compelling as it seemed at first glance, what should we
make of the new recommendations? Should we really treat everyone with a
systolic blood pressure over 120 who has at least a 10 percent risk of cardiac
disease in the next decade?
The answer, I
think, is yes, but with caveats. First, the guideline writers are at great pains to
insist that blood pressure be measured the way it was measured in the SPRINT
trial—in a way that it’s almost never measured in the doctor’s office, namely
after sitting quietly for five minutes and averaged over three readings. They
also advocate use of home monitoring to confirm (or refute) the diagnosis of
high blood pressure, as well as to guide medication adjustment once treatment
is started. Next, physicians need to be prudent about what medications to use
if they’re going to embark on pharmacologic treatment. We have ample numbers of
cheap, effective medicines that have been around for years, such as diuretics
and beta blockers, and these should be tried before pricier medicines. Finally,
both physicians and patients need to be vigilant about medication side effects,
which means doctors need to tell their patients what to look for, patients need
to report their symptoms, and doctors need to change course if symptoms
develop. In addition, non-pharmacologic treatment should be attempted,
including exercise, weight loss, and a low salt diet. If we follow all these
steps, we can be confident we will be changing how we deal with blood pressure
because it’s what’s best for patients, not because it’s what’s best for the
pharmaceutical industry.