February 26, 2010 | 4:53 pm

Carotid Stenting Still Controversial

Posted by Albert Fuchs, M.D.

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Almost 800,000 Americans suffer a stroke every year.  Strokes are the third most common cause of death in the US, and are frequently disabling to those who survive.  These sobering numbers are despite the substantial improvement in recent decades in stroke prevention through the use of medications that lower blood pressure and cholesterol.

This week’s hubbub relates to carotid arteries, the large arteries in the neck that carry blood to the brain.  But before we dig into the details we have to understand that most strokes have nothing to do with any problem with the carotid arteries.  Strokes have many different causes, including high blood pressure, aneurisms, and abnormal heart rhythms.  One of these many causes of strokes is a buildup of cholesterol inside the walls of the carotid arteries.  This fatty plaque buildup can break off the artery wall and float to the brain, where it occludes a small artery and causes a stroke.

When a stroke is caused by this severe narrowing of the carotid artery by cholesterol plaque, studies have shown that surgery (called carotid endarterectomy) to remove this plaque helps decrease the risk of a second stroke.  The surgery is not a minor procedure and carries substantial risks.

For several years, researchers have speculated that a safer way to prevent strokes in patients with carotid artery plaque is to put stents (metallic mesh tubes) inside the arteries, much like the stents used in heart arteries to keep them open.  The rationale was that placing a stent in an artery is a much less invasive and less risky procedure than actually operating on it, so the hope was that stenting would be safer and just as effective.

That hope hasn’t yet materialized.

Several earlier trials showed that surgery prevents subsequent stroke better than stenting.  Two large randomized trials which reported their results this week add confusion, not clarity to the issue.  A large study, the Carotid Revascularization Endarterectomy versus Stenting Trial, just released results suggesting that stenting is as safe as surgery for carotid narrowing.  A second trial, the preliminary results of which were just published in the British medical journal Lancet, reaches the opposite conclusion – significantly more strokes in the stenting group than in the surgery group.

So for the time being, surgery is still the proven standard for fixing narrowed carotid arteries that have caused a stroke.  But we shouldn’t forget the bigger picture – keeping blood pressure and cholesterol low prevents many more strokes than fixing carotid arteries after they’ve already narrowed.

Learn more:

Mayo Clinic patient review of stroke

Wall Street Journal article:  Big Studies On Neck-Artery Stents Show Different Findings

New York Times article:  Study Finds Stents Effective in Preventing Strokes

Study in The Lancet:  Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

February 19, 2010 | 2:56 pm

Alarms about Asthma Agents

Posted by Albert Fuchs, M.D.

(or, LABAs Relabeled)

Long acting beta agonists (LABAs) are a family of inhaled medicines used to control asthma symptoms.  LABAs include the medicines in Serevent and Foradil.  LABAs are also available in combination inhalers, Advair and Symbicort, which combine a LABA with an inhaled steroid.

Though LABAs dilate airways and improve airflow, they have long been associated with an increased risk of worsening asthma symptoms.  It has previously been thought that using an inhaled steroid with a LABA eliminated that risk, but until this is proven definitively the FDA took action to strengthen its warnings about LABAs.

In an announcement published yesterday (see link below), the FDA stressed that LABAs should never be used alone, and should only be used with an inhaled steroid.  This much is not new and had been recommended in the past.  (See my post about LABAs a year ago, link below.)  The FDA also recommended that even when used in combination with inhaled steroids, LABAs should only be used for the minimum duration necessary to control symptoms, and then if possible should be discontinued.  Only patients whose symptoms cannot be controlled on an inhaled steroid or other asthma controlling medication should be treated with a LABA for extended periods.

So if you’re using one of the above inhalers, a conversation with your doctor is in order.  Obviously, don’t stop any of your asthma medicines without your doctor’s advice.

Finally, my regular readers know that I’m a big fan of electronic medical records.  This is a perfect example of an instance in which electronic records extend patient care in a way that is impossible with paper charts.  My partners and I will generate a report listing all our patients on LABAs so we can contact them to discuss whether a change is appropriate.  With paper charts we would have just hoped that our patients heard the FDA warning and called us.

Learn more:

Reuters article:  U.S. requires new warnings for asthma drugs

FDA announcement:  FDA Announces New Safety Controls for Long-Acting Beta Agonists, Medications Used to Treat Asthma

My previous post about the dangers of LABAs:  Lugubrious About LABAs

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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February 12, 2010 | 5:52 pm

Gastric Banding is an Effective Option for Obese Teens

Posted by Albert Fuchs, M.D.

What’s my advice to my overweight patients?  Eat less and exercise more.  I give this advice every day, but following this advice is much harder than giving it.  Overweight people frequently struggle with diet and exercise for years, sometimes successfully, sometimes regaining their previously lost weight.

And as we become more overweight as a nation, obesity is no longer just a problem for adults.  Over 5 million adolescents are estimated to be obese in the US, which predicts bad things for their likelihood of developing diabetes, high blood pressure and other health problems.  Being an obese teen can also be a serious social and psychological burden.  Anyone who remembers adolescence knows that teens aren’t always accepting, nurturing and ethical peers.

I’ve written in the past about the slowly amassing scientific evidence that surgery for obesity has definite health advantages over continued attempts at diet and exercise.  This week, that evidence is extended to adolescents.

A study published in this issue of The Journal of the American Medical Association enrolled 50 teenagers between 14 and 18 years of age with a body mass index (BMI) higher than 35.  (For a person who is 5 feet 8 inches tall, a BMI of 35 means a weight of 235 lb.)  The enrolled teens also had to have been attempting to lose weight through diet and exercise for more than 3 years.

The teens were randomized to two groups.  One group underwent laparoscopic gastric banding.  In this surgery, an inflatable plastic belt is wrapped around the upper part of the stomach, decreasing how much food can be ingested.  In post-operative follow up the band can be adjusted by inflating or deflating it, thereby calibrating how much it constricts the stomach.  The second group was randomized to a supervised lifestyle intervention involving an individualized diet plan and a structured exercise program.  The groups were followed for two years.

The results were dramatic.  The group that underwent gastric banding lost an average of 76 lb over two years, compared to an average 7 lb in the lifestyle modification group.  The group that underwent gastric banding also had a higher quality of life and improvement in other health-related measurements.

The authors were quick to caution that gastric banding is no “quick fix”.  Patients still have to eat differently and be willing to have periodic follow up, potentially forever.  The authors still recommend diet and exercise as the first choice for weight loss.  But now for the many teens who do not lose weight after many attempts, there is a proven alternative.

Learn more:

Wall Street Journal article:  Weight-Loss Surgery for Obese Teens Backed by Study

Journal of the American Medical Association study:  Laparoscopic Adjustable Gastric Banding in Severely Obese Adolescents

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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February 5, 2010 | 2:56 pm

Twelve Years Later, the Truth about Vaccines and Autism

Posted by Albert Fuchs, M.D.

Ideas have consequences.  False ideas, especially popular false ideas, can cause harm.  For example, the very popular false idea “corduroy pants and wide lapels are far out, man” made an entire nation ugly for about a decade.  And some false ideas do even more harm than that.

In 1998 the British medical journal The Lancet published a paper authored by Dr. Andrew Wakefield that claimed to link autism to the vaccine against measles, mumps and rubella (MMR).  The study looked at 12 children (that’s right, twelve, not twelve thousand) with developmental abnormalities and intestinal conditions that may have presented after the administration of MMR.

This supposed association spawned a large popular movement that urged suspicion of vaccines and recommended that parents refuse vaccines or delay their children’s immunizations.  Multiple subsequent larger studies have refuted the conclusions of the 1998 article, repeatedly finding no link between vaccinations and autism.  But undeterred by the actual evidence, the anti-vaccine movement continued to spread unfounded allegations, frightening parents about vaccines.

The consequences of this false idea were predictable, and devastating.  In the UK and US, vaccination rates dropped and in the last few years epidemics of measles have occurred.  Despite the decreased vaccination rate, the incidence of autism has not decreased, and the true cause of autism remains elusive.  Meanwhile Dr. Wakefield, the author of the 1998 study, has become a celebrity in the anti-vaccine movement, as its disciples have only his small study to lean on.

Recently, The Lancet learned that the study itself was deeply flawed.  First, the 12 patients were chosen in a way that could have introduced a great element of bias.  Second, many invasive and medically unnecessary procedures were done on the children without oversight of a research ethics board and without parental consent (an important protection that is mandatory in all research on human subjects).  Finally, Dr. Wakefield did not disclose that he received funding from attorneys with litigation against vaccine manufacturers.

So this week the editors of The Lancet publicly retracted the 1998 study.  Dr. Wakefield has been discredited and the anti-vaccination movement lost their last thread of scientific credibility.

I hope that public figures like Jenny McCarthy and Robert F. Kennedy Jr. who have promoted the false and lethal idea that vaccines cause autism will take this opportunity to publically recant and find less pernicious crusades to pursue.  I’m waiting for their announcement, but I may be waiting until corduroy pants make a comeback.

Tangential miscellany:

My post last week about normal weight obesity generated many interesting comments.  One attentive reader corrected me that fat is never converted to muscle.  That’s true.  I should not have used that phrase.  Fat cells remain fat cells forever, and muscle cells remain muscle cells.  Exercise burns fat, shrinking fat cells and enlarging muscle cells.  I appreciate the correction and changed the wording of the original post.

Learn more:

NY Times article:  Journal Retracts 1998 Paper Linking Autism to Vaccines

Retraction in The Lancet:  Retraction—Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children

BBC News article from a year ago:  Rise in measles ‘very worrying’

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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January 29, 2010 | 10:03 pm

Normal Weight Obesity:  Why Losing Weight Is Not Always the Answer

Posted by Albert Fuchs, M.D.

Weight loss is one of the most common recommendations that doctors make.  How do we know if a patient should lose weight?  We usually use the Body Mass Index (BMI) which is a way to compare a patient’s weight to her height.  (For all you math geeks, it’s the weight in kilograms divided by the height in meters squared.  For all you physicists, I know the units make no sense.)  A BMI of 18.5 to 25 is considered normal.  A BMI of 25 to 30 is considered overweight, and over 30 is considered obese.  (See the link below to calculate your BMI.)

An article in the health section of Tuesday’s Wall Street Journal reminds us that BMI may not be telling us the whole story.  The article cites a study published in the European Heart Journal last year which followed over 6,000 adults with a normal BMI.  They all had their body fat percentage measured and were followed for about 9 years.

Surprisingly, even in these adults with a “normal” weight, those with a high body fat content had a higher likelihood of high blood pressure, high cholesterol and cardiovascular disease.

This study is too small to be definitive, and it’s observational, not randomized.  So we don’t know whether lowering body fat reverses any of these risk factors.  I’m not suggesting we all run out to measure our body fat content.  Still the article suggests a few tantalizing possibilities.

First, dieting may not be enough in improving cardiovascular health.  It may decrease overall weight without decreasing percent body fat.  Exercise is critical to burn fat and build muscle, thereby decreasing percent body fat.

Second, thin people who are inactive may have a high body fat percentage and may be falsely reassured by their “normal” weight.  This is what the authors call “normal weight obesity”.

Finally, for those of you who are exercising and not losing weight, don’t despair.  You may be losing inches from your waist, burning fat and building muscle, muscle while your weight stays the same.  Going by the weight alone is a recipe for frustration when in reality your health is improving.

Learn more:

The Centers for Disease Control BMI calculator

Wall Street Journal article:  The Scales Can Lie: Hidden Fat (only by subscription)

European Heart Journal article:  Normal weight obesity: a risk factor for cardiometabolic dysregulation and cardiovascular mortality

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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January 22, 2010 | 6:12 pm

A New Treatment for Clostridium difficile

Posted by Albert Fuchs, M.D.

You may not yet have heard of the bacterium Clostridium difficile (C. dif.), but in the next few years it will likely become a household name, as well known as Staph and Strep.  C. dif. causes a severe infection of the colon leading to severe diarrhea.  It frequently results as a consequence of antibiotic use.  Antibiotics can kill the normal intestinal bacteria and allow harmful bacteria like C. dif. to proliferate.

Decades ago, C. dif. infection was a minor nuisance, but in the last decade, due perhaps to increasing use of broad-spectrum antibiotics, C. dif. has become more common and more severe.  Many patients, especially older patients, require hospitalization for C. dif. diarrhea.  Besides causing severe dehydration, C. dif. can cause systemic infection and sometimes death.

Ironically, the typical treatment for C. dif. colitis is antibiotics.  But since antibiotics don’t allow the normal gut bacteria to return, recurrence of C. dif. diarrhea after treatment is completed is a frequent problem.  In hospitals and nursing homes spread of C. dif. has become a menace.

A study published in this issue of the New England Journal of Medicine offers hope against this worsening problem.  The study randomized 200 patients with C. dif. diarrhea.  All patients received conventional antibiotic treatment.  Half the patients also received a new intravenous antibody directed at C. dif. toxin; the other half received intravenous placebo.  The results were encouraging.  Only 7% of the patients that received the intravenous antibody developed another episode of C. dif. infection, compared to 25% receiving placebo.  That means that for every about six patients that receive the antibody, one recurrent infection is prevented.

This new treatment will have to undergo larger trials before it is approved.  In the meantime the cornerstones of C. dif. prevention remain judicious antibiotic use and preventing spread between patients in hospitals and nursing homes.

Learn more:

New England Journal of Medicine article:  Treatment with Monoclonal Antibodies against Clostridium difficile Toxins

New England Journal of Medicine editorial:  Clostridium difficile — Beyond Antibiotics

Forbes post on The Science Business:  Why You Should Care About Treatment with Monoclonal Antibodies against Clostridium difficile Toxins

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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January 15, 2010 | 7:56 pm

To Clot or to Bleed?

Posted by Albert Fuchs, M.D.

Aspirin has long been known to prevent strokes and heart attacks in patients with a previous stroke or heart attack.  But aspirin has potentially serious side-effects.  Aspirin can cause stomach ulcers, and it inhibits blood clotting raising the risk of life-threatening bleeding.

If we knew in advance that a patient was going to be in a car accident or have a bleeding stomach ulcer, we would discontinue the aspirin a week before the event and minimize the bleeding risk.  (This is exactly what we do in anticipation of routine surgery.)  But of course such events don’t herald themselves, so doctors are left reacting to adverse events after they occur.  If a patient has life-threatening bleeding we stop the aspirin and consider that the risk may outweigh the benefits.  If the patient months or years later has a stroke we reconsider restarting the aspirin.  But this strategy is irrational.  What is needed is a way to balance risks and benefits of aspirin based on the likelihood of future events, regardless of which event happened most recently.

A study published in this issue of Annals of Internal Medicine examines the wisdom of the current practice of discontinuing aspirin after bleeding from stomach ulcers.  The study followed 156 patients who had been taking aspirin for stroke or heart attack prevention and developed bleeding stomach ulcers.  All patients had endoscopy to determine the site of bleeding and to stop the bleeding.  They were all then started on acid suppressing medication to decrease the risk of future bleeding.  Half the patients were randomized to continue 80 mg of aspirin daily and the other half to placebo.

The patients were followed for 8 weeks to test whether the patients on aspirin had more recurrent bleeding than those on placebo.  The hope was that the acid blocking medication would make the aspirin safe.  It didn’t.  Significantly more patients had bleeding on aspirin than on placebo.  But surprisingly, more patients died on placebo than on aspirin.  The reason was that more patients had strokes and heart attacks on placebo.

This study is too small to reach definitive conclusions, but its results should rattle our current thinking.  Rather than stop aspirin because an adverse effect occurs, the right course may be to remember why we recommended aspirin in the first place.  After all, strokes and heart attacks are much harder to fix than bleeding ulcers.

Learn more:

Annals of Internal Medicine article:  Continuation of Low-Dose Aspirin Therapy in Peptic Ulcer Bleeding

Annals of Internal Medicine editorial:  Aspirin Withdrawal in Acute Peptic Ulcer Bleeding: Are We Harming Patients?

Tangential miscellany:

My post last week, Antidepressants for Mild Depression May Not Help Much, generated many interesting comments, some from the handful of psychiatrists and psychologists who are my patients.  Many comments pointed out important limitations of the study I wrote about.  Two psychiatrists pointed me to the following New York Times articles which make the case that antidepressants are more beneficial than the study I cited suggests.  I’m grateful to all who wrote to me.

New York Times article:  Before You Quit Antidepressants ...

New York Times Op-Ed:  The Wrong Story About Depression

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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January 8, 2010 | 8:10 pm

Antidepressants for Mild Depression May Not Help Much

Posted by Albert Fuchs, M.D.

Treatments for depression are difficult to study.  First, depression is a condition that can improve without treatment.  So any treatment must be compared to placebo to see if the treatment is responsible for the improvement or if the depression improved on its own.  Also, depression can not be measured objectively.  There is no objective test like an X ray or a blood test that can diagnose depression.  (At least not yet.  As our understanding of brain function improves, such a test is certainly conceivable.)  For now, the most reliable measures of depression used in research are standardized questionnaires.  Another difficulty is that depression has a high response rate to placebo, so demonstrating that a treatment is better than placebo isn’t easy.

Because of these difficulties, most randomized trials testing antidepressants tend to study severely depressed patients, and they clearly show that antidepressants are beneficial.  But is the benefit the same in patients with milder depression?  A study in this issue of the Journal of the American Medical Association answers that question.

The study collected the data from six trials which randomized a total of 718 patients with depression to an antidepressant or to placebo.  It then compared how much more improvement antidepressants offered over placebo in patients with different levels of depression severity.  Surprisingly, for patients with mild or moderate initial symptoms, the difference between antidepressant and placebo was not significant.  The benefit of antidepressants over placebo grew in those with more severe symptoms.

The authors conclude:

The magnitude of benefit of antidepressant medication compared with placebo increases with severity of depression symptoms and may be minimal or nonexistent, on average, in patients with mild or moderate symptoms. For patients with very severe depression, the benefit of medications over placebo is substantial.

What does that mean in practical terms?  First, it’s another reminder that antidepressants help patients with severe depression.  But for patients with mild symptoms it suggests that the visit with an attentive doctor, the anticipation that the medication may work, and the simple passage of time help more than the medicine itself.

Learn more:

Wall Street Journal article:  Effectiveness of Antidepressants Varies Widely

LA Times article:  Study finds medication of little help to patients with mild, moderate depression

Journal of the American Medical Association article:  Antidepressant Drug Effects and Depression Severity

Important legal mumbo jumbo:
Anything you read on the web should be used to supplement, not replace, your doctor’s advice.  Anything that I write is no exception.  I’m a doctor, but I’m not your doctor despite the fact that you read or comment on my posts.  Leaving a comment on a post is a wonderful way to enter into a discussion with other readers, but I will not respond to comments (just because of time constraints).

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