Surgery for Blocked Arteries Is Often Unwarranted Paper Part of the data (in italics and noted within the PDF of the media report of the study) had to be a
Surgery for Blocked Arteries Is Often Unwarranted Paper Part of the data (in italics and noted within the PDF of the media report of the study) had to be added from unpublished information from the clinical trial itself because the otherwise very detailed report by the journalist writing about it in the New York Times left it out. The study is unpublished because the results were just announced on November 16th. Publication is expected in 2020. So, this is real news!Please read the instruction carefully. World Phenomenon
1. Real
__________________
Model
2. __________________
fit?
Observation/Experiment
Data
4. __________________
Reasoning/Calculation
Prediction
3. __________________
agree?
Negative Evidence?
5. __________________
Do the data agree with the
predictions of the model?
No
The data provide evidence
that the model does not fit
the real world.
No
The data provide evidence
that the model does fit the
real world.
Yes
Positive Evidence?
6. __________________
Was the data likely to agree
with the predictions of the
model even if the model
doesn’t fit the world?
Yes
The data are inconclusive regarding the
fit between the model and the real world.
Real World
Model Doesn’t Fits
Hypothesis False
What substance can
contain infectious agents
Models
Ionizing radiation Model
Protein break down Model
Model Fits
Hypothesis True
Reasoning
Experimentation
Data
Agree
Scrapie was produced in
healthy sheep as there
was protein
Prediction
Scrapie can be produced
without RNA or DNA
Do the data and
prediction agree?
Yes
Was the prediction likely
to agree with the data
even if the model does not
fit the real world?
The data are
inconclusive regarding
the fit between the
model and the real
world
Part of the data (in italics and noted within the PDF of the media report of the
study) had to be added from unpublished information from the clinical trial
itself because the otherwise very detailed report by the journalist writing about
it in the New York Times left it out. The study is unpublished because the
results were just announced on November 16th. Publication is expected in
2020. So, this is real news!
After you write your six-step evaluation, add a 7th “step” to your report to offer
a brief reflection (no more than a paragraph) indicating what you could not
have done in your evaluation had the italicized information I added to the
newspaper report not been included.
Grading Breakdown:
Your report will be graded out of 20 points: 2 points each for steps 1-6 of the
six-step evaluation. Your 7th “step” reflection is worth 2 points. And there are
2 points (1 each) for grammar/composition and argument coherence. Two
points for your diagram of the study design. Two points for your diagram of
the data. There is no need for a bibliography since we know what study you
are discussing.
Your report should be 3-5 pages long (double spaced), including diagrams.
So, that means 2-3 pages for your six-step evaluation plus a page with the
two diagrams. Some people write a bit more per step than others, so that’s
why there is a range of lengths from 3-5 pages.
Surgery for Blocked Arteries Is Often Unwarranted, Researchers Find
By Gina Kolata Nov. 16, 2019, The New York Times
The findings of a large federal study on bypass surgeries and stents call into question the medical
care provided to tens of thousands of heart disease patients with blocked coronary arteries,
scientists reported at the annual meeting of the American Heart Association on Saturday.
The new study found that patients who received drug therapy alone did not experience more
heart attacks or die more often than those who also received bypass surgery or stents, tiny wire
cages used to open narrowed arteries.
That finding held true for patients with several severely blocked coronary arteries. Stenting and
bypass procedures, however, did help some patients with intractable chest pain, called angina.
“You would think that if you fix the blockage the patient will feel better or do better,” said Dr.
Alice Jacobs, director of Cath Lab and Interventional Cardiology at Boston University. The
study, she added, “certainly will challenge our clinical thinking.”
This is far from the first study to suggest that stents and bypass are overused. But previous
results have not deterred doctors, who have called earlier research on the subject inconclusive
and the design of the trials flawed.
Previous studies did not adequately control for risk factors, like LDL cholesterol, that might have
affected outcomes, said Dr. Elliott Antman, a senior physician at Brigham and Women’s Hospital
in Boston. Nor did those trials include today’s improved stents, which secrete drugs intended to
prevent opened arteries from closing again.
With its size and rigorous design, the new study, called Ischemia, was intended to settle questions
about the benefits of stents and bypass.
“This is an extraordinarily important trial,” said Dr. Glenn Levine, director of cardiac care at
Baylor College of Medicine in Houston.
The results will be incorporated into treatment guidelines, added Dr. Levine, who sits on the
guidelines committee of the American Heart Association.
The participants in Ischemia were not experiencing a heart attack, like Senator Bernie Sanders,
nor did they have blockages of the left main coronary artery, two situations in which opening
arteries with stents can be lifesaving. Instead, the patients had narrowed arteries that were
discovered with exercise stress tests.
With 5,179 participants followed for a median of three and a half years, Ischemia is the largest
trial to address the effect of opening blocked arteries in nonemergency situations and the first to
include today’s powerful drug regimens, which doctors refer to as medical therapy.
All the patients had moderate to severe blockages in coronary arteries. Most had some history of
chest pain, although one in three had no chest pain in the month before enrollment in the study.
One in five experienced chest pain at least once a week.
All participants were regularly counseled to adhere to medical therapy. Depending on the
patient’s condition, the therapy variously included high doses of statins and other cholesterollowering drugs, blood pressure medications, aspirin and, for those with heart damage, a drug to
slow the heart rate. Those who got stents also took powerful anti-clotting drugs for six months to
a year.
Patients were randomly assigned to have medical therapy alone or an intervention and medical
therapy. Of those in the intervention group, three-quarters received stents; the others received
bypass surgery.
The number of deaths among those who had the invasive procedure (stents or bypass), n=388,
was 145, compared to 144 among the patients who received medication alone (the conservative
procedure), n=389. The number of patients who had heart attacks was 276 in the stent and
bypass group, compared with 314 in the medication group, an insignificant difference. [Italicized
information added from the unpublished clinical trials report.]
An angiogram of the arteries of a
patient who was part of the trial, prior
to receiving a stent. NYU Langone
Health
The same patient, after receiving a
stent. NYU Langone Health
Dr. Judith Hochman, senior associate dean of clinical sciences at N.Y.U. Langone Health and
chair of the study, had expected that those with the most severe chest pain and blockages would
benefit from stents or bypass.
But “there was no suggestion that any subgroup benefited,” she said.
Ischemia’s results are consistent with current understanding of heart disease. Researchers have
learned that a patient with a narrowed artery may have plaques not just in a single blocked area,
but throughout the coronary arteries.
There is no way to predict which of those plaques will break open and cause a heart attack.
Stents and bypass treat only areas that are obviously narrowed, but medical therapy treats the
entire arterial system.
Yet when a cardiologist sees a blockage, the temptation for doctor and patient alike is to get rid
of it quickly, said Dr. David Maron, director of preventive cardiology at Stanford University, the
study’s other co-chair.
When an exercise stress test indicates a narrowing, most doctors send patients to a cardiac
catheterization lab to look for blockages, Dr. Maron said. If there is a blockage, the usual practice
is to open it with a stent.
If stenting is not feasible — because of the configuration of the patient’s arteries, for example —
bypass surgery is usually the next step.
Patients with abnormal stress tests should talk to their doctors about the options, Dr. Maron said.
If a patient has chest pain despite taking recommended medications, a stent or bypass might help
improve quality of life.
Still, he said, patients have time to make considered decisions.
“You don’t have to rush to the cath lab because, OMG, you will have a heart attack soon or drop
dead,” Dr. Maron said. “If you have had no angina in the last month, there is no benefit to an
invasive strategy.”
Stenting costs an average of $25,000 per patient; bypass surgery costs an average of $45,000 in
the United States. The nation could save more than $775 million a year by not giving stents to
the 31,000 patients who get the devices even though they have no chest pain, Dr. Hochman said.
But the conventional wisdom among cardiologists is that the sort of medical therapy that patients
got in Ischemia is just not feasible in the real world, said Dr. William E. Boden, scientific
director of the clinical trials network at VA Boston Healthcare System, who was a member of the
study’s leadership committee.
Doctors often say that making sure patients adhere to the therapy is “too demanding, and we
don’t have time for it,” he said.
But getting a stent does not obviate the need for medical therapy, Dr. Boden noted. Since patients
with stents need an additional anti-clotting drug, they actually wind up taking more medication
than patients who are treated with drugs alone.
About a third of stent patients develop chest pain again within 30 days to six months and end up
with receiving another stent, Dr. Boden added.
“We have to finally get past the whining about how hard optimal medical therapy is and begin in
earnest to educate our patients as to what works and is effective and what isn’t,” Dr. Boden said.
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