March
13,
2006
Plavix and Aspirin -- Stent Patients, Don't
Stop Taking Your Meds
So you've just had a stent put in and your
cardiologist has prescribed aspirin and Plavix (clopidogrel) for
a year. And you're watching KARE11-TV in Minneapolis and see a news
story,
titled "Plavix
and Aspirin a Dangerous Combination". This combination doubles
the risk of death, says the reporter.
You might try calling your cardiologist to find
out why you were given such a dangerous drug combination, but most
likely the line is busy
because all his/her other patients are calling about the same thing.
(We're
getting questions as well
in our Forum
topic on the subject.)
No doubt today doctors across the country are fielding
questions from patients -- and the genesis for these reports is the CHARISMA
study, presented yesterday at the annual meeting of the American College
of Cardiology -- or rather the relatively misleading headlines about
that study (some of the articles themselves are a bit clearer, but editors
tend to go for attention-grabbing headlines; I call them dreadlines.)
So, first off and most important: if you have
a stent, a recent angioplasty, heart attack, been diagnosed with
acute coronary
syndrome,
etc.
don't stop taking your Plavix/aspirin combo without discussing
it with your doctor!
What has been left out of the scores of news
articles I've read this morning is that nothing in this study changes
the current indications for patients with Acute Coronary Syndrome,
recent heart attack or coronary intervention with balloon or stent.
And more importantly, if you have had a stent placed, stopping
Plavix and aspirin could be very dangerous!
The combination of Plavix and aspirin has been shown
in many studies to be a definite benefit to patients with confirmed
vascular disease and premature withdrawal of Plavix, especially for
patients with drug-eluting stents, can increase the incidence
of stent thrombosis (blood clotting inside the stent). This has
been the subject of other studies and a topic I have discussed before.
So the bottom line: the misleading media reports about
this study are confusing and could be dangerous to heart patients.
For
more on what the study really showed, read on.
CHARISMA (Clopidogrel for High Atherothrombotic
Risk and Ischemic Stabilization Management and Avoidance) was a
study funded
by sanofi-aventis and Bristol-Myers Squibb Company, the people who
make Plavix. The study was designed to determine if clopidogrel
(Plavix) and
aspirin together were of benefit as a preventative therapy. The
company obviously hoped that the results would be positive --
there's a lot of money to be made if the drug was shown to prevent
coronary events. They were disappointed, to say the least.
The patient population was made up of two groups:
symptomatic patients with established atherothrombotic disease
(80%) and asymptomatic
patients -- those
with multiple risk factors (high blood pressure, etc.) for
atherothrombotic events (20%) but who had not yet experienced the
symptoms of vascular disease. The results did show a little benefit
(about 1%) in the symptomatic patients, but not enough to warrant
prescribing the combination therapy.
The surprise to researchers was that the asymptomatic
group (those without actual disease) showed a higher rate
of death from cardiovascular causes, from 2.2% in the aspirin
only to 3.9% in the combination of aspirin plus Plavix. It is this
subset of patients that has generated the headlines. One
of the primary investigators for the CHARISMA
study, Dr. Deepak Bhatt of the
Cleveland Clinic, stated that the results mean that "dual antiplatelet
therapy should not be used in patients without a history of established
vascular disease. "
So the CHARISMA study is very important. It cautions against prescribing
Plavix (clopidogrel) as a preventative therapy, especially when simple
aspirin works as well or better. But for patients who already have
more advanced disease, to the point where angioplasty has been performed,
the dual antiplatelet combination of aspirin and Plavix is a life-saver.
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