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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