False positive stress tests?



D

Dahd

Guest
My internist recently sent me to a cardiologist. I'm uncertain why, though
I was complaining of excessive tiredness and stated that if this keeps up I
will be a frail old man in a few years.

A Cardiolite - adenosine stess test showed abnormal perfusion of the apex.

A resting echo appeared to show reduced ejection fraction, 45, stiffness,
enlargment of left ventricle and atrium.

Cardiac catheterization was suggested. As I had no symptoms other than just
being excessively tired much of the time and what I considered orthostatic
hypotension, I asked if it was possible that the Cardiolite stress test
result was an artifact.

To check that, a dobutamine-atropine stress echo study was done. I was told
that the wall motion was abnormal and that there was a modest drop in
ejection fraction when stressed.

Again, cardiac catheterization was recommended and I was told to anticipate
angioplasty or perhaps even a by-pass.

Cardiac catheterization studies revealed a normal heart. Normal blood flow,
proper pressures in the ventricle, proper pumping. The cardiologist stated
that he estimated the ejection fraction in the 60s just by watching how the
heart pumped the contrast dye.

Well, if this had been done in a fee for service situation I would be
thinking that I had been led down the primrose path and improperly relieved
of my money.

As it happens, this work was done by an HMO who's docs are salaried. Hence,
no motive for churning.

Also, my personal take on the docs involved is positive. I like them and
believe that they are in fact competent.

My question....Does this sort of thing happen with some regularity, or was
this a very odd or unusual set of events?
 
Dahd wrote:

> My internist recently sent me to a cardiologist. I'm uncertain why, though
> I was complaining of excessive tiredness and stated that if this keeps up I
> will be a frail old man in a few years.

Your internist is wise.

>
> A Cardiolite - adenosine stess test showed abnormal perfusion of the apex.
>
> A resting echo appeared to show reduced ejection fraction, 45, stiffness,
> enlargment of left ventricle and atrium.
>
> Cardiac catheterization was suggested. As I had no symptoms other than just
> being excessively tired much of the time and what I considered orthostatic
> hypotension, I asked if it was possible that the Cardiolite stress test
> result was an artifact.
>
> To check that, a dobutamine-atropine stress echo study was done. I was told
> that the wall motion was abnormal and that there was a modest drop in
> ejection fraction when stressed.
>
> Again, cardiac catheterization was recommended and I was told to anticipate
> angioplasty or perhaps even a by-pass.
>
> Cardiac catheterization studies revealed a normal heart. Normal blood flow,
> proper pressures in the ventricle, proper pumping. The cardiologist stated
> that he estimated the ejection fraction in the 60s just by watching how the
> heart pumped the contrast dye.
>
> Well, if this had been done in a fee for service situation I would be
> thinking that I had been led down the primrose path and improperly relieved
> of my money.
>
> As it happens, this work was done by an HMO who's docs are salaried. Hence,
> no motive for churning.
>

The quality of the testing may be subpar in the setting of cost-cutting HMOs.

>
> Also, my personal take on the docs involved is positive. I like them and
> believe that they are in fact competent.
>
> My question....Does this sort of thing happen with some regularity, or was
> this a very odd or unusual set of events?

Medical tests are not perfect especially when cost has priority over quality.

--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com/
 
A lady on this NG complained bitterly and wanted to sue when her husband was
found to be OK after an angiogram, another false positive.
I had two false positives with stress tests. I refused the suggested
angiogram the first time but they were rather insistent the second time,
suggesting that I could fall of my perch at any moment.
Derek.
"Dahd" <[email protected]> wrote in message
news:[email protected]...
> My internist recently sent me to a cardiologist. I'm uncertain why,
though
> I was complaining of excessive tiredness and stated that if this keeps up
I
> will be a frail old man in a few years.
>
> A Cardiolite - adenosine stess test showed abnormal perfusion of the apex.
>
> A resting echo appeared to show reduced ejection fraction, 45, stiffness,
> enlargment of left ventricle and atrium.
>
> Cardiac catheterization was suggested. As I had no symptoms other than
just
> being excessively tired much of the time and what I considered orthostatic
> hypotension, I asked if it was possible that the Cardiolite stress test
> result was an artifact.
>
> To check that, a dobutamine-atropine stress echo study was done. I was
told
> that the wall motion was abnormal and that there was a modest drop in
> ejection fraction when stressed.
>
> Again, cardiac catheterization was recommended and I was told to
anticipate
> angioplasty or perhaps even a by-pass.
>
> Cardiac catheterization studies revealed a normal heart. Normal blood
flow,
> proper pressures in the ventricle, proper pumping. The cardiologist stated
> that he estimated the ejection fraction in the 60s just by watching how
the
> heart pumped the contrast dye.
>
> Well, if this had been done in a fee for service situation I would be
> thinking that I had been led down the primrose path and improperly
relieved
> of my money.
>
> As it happens, this work was done by an HMO who's docs are salaried.
Hence,
> no motive for churning.
>
> Also, my personal take on the docs involved is positive. I like them and
> believe that they are in fact competent.
>
> My question....Does this sort of thing happen with some regularity, or was
> this a very odd or unusual set of events?
>
>
 
"Andrew Kerr" <[email protected]> wrote in message news:<[email protected]>...
> "Derek F" <[email protected]> wrote in message
> news:[email protected]...
> > A lady on this NG complained bitterly and wanted to sue when her husband
> was
> > found to be OK after an angiogram, another false positive.
> > I had two false positives with stress tests. I refused the suggested
> > angiogram the first time but they were rather insistent the second time,
> > suggesting that I could fall of my perch at any moment.
> > Derek.
>
> I am always amazed at how many people get angry when they think they have
> undergone unnecessary tests. The only way you find out that the screening
> tests (stress test, echo, cardiolite, etc.) were "false positive" is by
> going to the next level of testing (angiogram). If a test is reported as
> positive, it's considered positive until proven otherwise.
>
> I would be more concerned if a physician refused to follow up on a positive
> test by confirming it with another test.
>
> Andrew

Very true. Many years ago I had a sonogram test that showed a shadow
and the interpretation was possible cancer. I was sent to a surgeon
who advised surgery because I had gallstones and they then could find
out if there was cancer. I wanted a second sonogram test because I had
suspicion about the person giving me the sonogram - just a gut
feeling. I was refused a second sonogram test but I insisted that some
other test be done. They agreed to give me a CT scan. The CT scan did
not show any shadow or possibility of cancer. I again asked for a
second sonogram test to be done by a different technician and they
agreed. The second sonogram test showed no shadow and did not indicate
any possibility of cancer.

Sometimes you have to play physician yourself.

Mel
 
"Andrew Kerr" <[email protected]> wrote in message
news:[email protected]...
> "Derek F" <[email protected]> wrote in message
> news:[email protected]...
> > A lady on this NG complained bitterly and wanted to sue when her husband
> was
> > found to be OK after an angiogram, another false positive.
> > I had two false positives with stress tests. I refused the suggested
> > angiogram the first time but they were rather insistent the second time,
> > suggesting that I could fall of my perch at any moment.
> > Derek.
>
> I am always amazed at how many people get angry when they think they have
> undergone unnecessary tests. The only way you find out that the screening
> tests (stress test, echo, cardiolite, etc.) were "false positive" is by
> going to the next level of testing (angiogram). If a test is reported as
> positive, it's considered positive until proven otherwise.
>
> I would be more concerned if a physician refused to follow up on a
positive
> test by confirming it with another test.
>
> Andrew
>
>>
In this case frankly, it is very unlikely that cost cutting had anything to
do with the outcome. The HMO involved is a first rate organization with
an outstanding reputation. They have served me and my family very well for
fifteen years. Nor, do I think that anything was done wrong. On the
contrary, they were quite willing to double check initial Cardiolite results
with the dobutamine-echo.
No, this is just one of those things that happen from time to time, and I'm
not angry or upset.

My question simply was and still is, how common is such a series of events.
I'd like to know the approximate (guestimated) frequency with which two
different forms of positive stress tests both turn out to be in error.

Or perhaps more generally, what are the individual rates (probability) of
false positives per test--e.g. .15 for each would leave the chance of a
double false positive at .0225.

That 2% is quite a financial drain (on idividuals and insurance companies)
when one considers all of the costs of a cath study.

What might be done to cut this rate in half?
See where I'm going?

(I can understand how machine errors could produce a false positive for
cardiolite. I don't understand how wall motion studies can go awry. Is it
possible that the interpreters see what they are expecting to see? If so,
how can this be remedied. Could error rates be reduced if the order or
testing were reversed? )
 
"M. Schwartz" <[email protected]> wrote in message
news:[email protected]...
> "Andrew Kerr" <[email protected]> wrote in message
news:<[email protected]>...
> > "Derek F" <[email protected]> wrote in message
> > news:[email protected]...
> > > A lady on this NG complained bitterly and wanted to sue when her
husband
> > was
> > > found to be OK after an angiogram, another false positive.
> > > I had two false positives with stress tests. I refused the suggested
> > > angiogram the first time but they were rather insistent the second
time,
> > > suggesting that I could fall of my perch at any moment.
> > > Derek.
> >
> > I am always amazed at how many people get angry when they think they
have
> > undergone unnecessary tests. The only way you find out that the
screening
> > tests (stress test, echo, cardiolite, etc.) were "false positive" is by
> > going to the next level of testing (angiogram). If a test is reported as
> > positive, it's considered positive until proven otherwise.
> >
> > I would be more concerned if a physician refused to follow up on a
positive
> > test by confirming it with another test.
> >
> > Andrew
>
> Very true. Many years ago I had a sonogram test that showed a shadow
> and the interpretation was possible cancer. I was sent to a surgeon
> who advised surgery because I had gallstones and they then could find
> out if there was cancer. I wanted a second sonogram test because I had
> suspicion about the person giving me the sonogram - just a gut
> feeling. I was refused a second sonogram test but I insisted that some
> other test be done. They agreed to give me a CT scan. The CT scan did
> not show any shadow or possibility of cancer. I again asked for a
> second sonogram test to be done by a different technician and they
> agreed. The second sonogram test showed no shadow and did not indicate
> any possibility of cancer.
>
> Sometimes you have to play physician yourself.
>
> Mel
We know our bodies better than they do. I offered to bet the young doctor a
weeks wages that my arteries were ok. He would not take the bet.
Derek.
 
"Derek F" <[email protected]> wrote in message
news:[email protected]...
>
> "M. Schwartz" <[email protected]> wrote in message
> news:[email protected]...
> >
> > Sometimes you have to play physician yourself.
> >
> > Mel
>
> We know our bodies better than they do. I offered to bet the young doctor
a
> weeks wages that my arteries were ok. He would not take the bet.
> Derek.
>

Unfortunately, one of the big issues in cardiac care is denial. It's not
that uncommon for patients to insist they are fine, even in the middle of an
infarction. Also, if a positive test wasn't followed up and the patient
ended up with a heart attack, that physician would find themselves in a
lawsuit. "But the patient said they felt fine" wouldn't be much of a
defense, I'm sure.

Andrew
 
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