Barbara Walters and Aortic Stenosis

Celebrities deserve the same rights to privacy, with respect to their medical conditions, as everyone else. However, when they chose to go public with details about their health, it can raise the public awareness of medical conditions and aid in education. Such was the case this week with Barbara Walters revelation that she has aortic stenosis and was scheduled to undergo valve replacement surgery.
Aortic stenosis affects approximately 6% of the US population or about 3.5 million people. The incidence increases with age. About 2% of 60 year olds, 3% of 70's and 4% of 80 year olds are affected.
The aortic valve is between the left ventricle (main pumping chamber of the heart) and the aorta (the main artery leaving the heart to the rest of the body). Normally it is comprised of 3 very thin leaflets. When the ventricle squeezes, the force of the blood ejecting opens the valve completely allowing the blood to pass into the aorta. The valve then closes so the blood does not leak back into the heart but continues its forward movement. The gradient, or pressure difference across the valve is normally essentially zero.
Aortic stenosis is a condition in which the leaflets of the valve thicken and stiffen. This then reduces their mobility and the heart is now pumping against a partially closed door. As this process continues the stiffness of the valve progresses and the opening shrinks leading to a significant gradient across the valve. About 15% of the population is born with an aortic valve that has 2 leaflets instead of 3. These valves are more prone to developing aortic stenosis, though usually not until later in life. Some however are tight from birth and require surgery in childhood.
A mean gradient of 40 mm of mercury is generally considered significant. With a gradient of 40 across the valve if the blood pressure measured in your arm is 120/ the pressure within the ventricle would then be 160/. If the gradient was 80 a BP of 120/ would mean the intra-cardiac pressure is 200, and so on. This is not a good situation for the heart.
Another measurement of the valve involves estimating the cross sectional area of the opening. Echocardiography is a good way to view this and an area of less than one centimeter is considered severe aortic stenosis.
As you would expect, the heart has to pump harder to push the blood thru this smaller opening. It causes the muscle to strain and thicken. The jet going thru the narrow opening is like putting your finger over the end of an open water hose. The resulting increased blood velocity can cause the aorta to enlarge. Also the straining of the heart to pump against this resistance can lead to chest pain, rhythm problems, fainting spells and heart failure. When fainting spells or heart failure develop from aortic stenosis there is a 50% risk of dying within 3 years.
For patients with symptomatic or severe aortic stenosis surgery to replace the valve is recommended. This is a mechanical problem and there are no medications to reverse it. There is also no good evidence that diet is implicated in its development or treatment.
Surgery to replace the aortic valve is typically performed thru a sternotomy (splitting the breastbone), however in many cases minimally invasive options are available (see previous post). A procedure to implant aortic valves via a needle stick in the groin is currently under investigation in the US.
There are a number of choices of valve type for replacing the aortic valve. Bioprosthetic or tissue valves are the most common choice in the US. These valves are either the aortic valves from pig hearts or are constructed from the pericardium (sac the heart lives in) of cows or horses. These are mounted on a covered stent and are available in a range of sizes. The advantage of tissue valves is that no medication is required following their implantation. The disadvantage is that they wear out. Current generations of valves have improved durability and their longevity is said to be over 90% at 12 years following implant.
The second most common type of valve is a mechanical valve. These are manufactured from pyrolytic carbon and have a bi-leaflet design. They look like a disc split in half that pivots open and closed with the blood flow. The advantage of this type of valve is that it can last virtually indefinitely. The disadvantage is that a blood thinner (warfarin or Coumadin) is required indefinitely.
These two valve types account for the vast majority of valve replacements.
Other options include homograft (cadaver human) valves and autografts. Autografts involve a procedure known as the Ross procedure in which a patients own pulmonary valve is removed and placed in the aortic position, then a homograft in used to replace the pulmonary valve.
How is a decision made as to which type of valve to implant? In the absence of any mitigating factors, age is a reasonable guideline for deciding. It is generally recommended that individuals less than 65 receive mechanical valves and over 65 lean toward tissue valves. This is NOT a hard and fast rule but a guide, and either valve type can be reasonably placed in either population. Obviously if a patient is unwilling or unable to take a blood thinner and have his blood routinely checked, then a mechanical valve is not for him.
Bottom line is that there are many good options. A thorough discussion of options, pros and cons with your surgeon is imperative prior to proceeding with your surgery

Dietary/Nutritional education

Jamie Oliver gets it. Juvenile obesity and diabetes are on the rise. Most of the "diseases of affluence" start during youth. To make a real lifelong impact, nutritional education must start in school or before. Check out his talk at TED http://www.ted.com/talks/jamie_oliver.html

Forks over Knives

New film being made about Drs. Campbell and Esselstyn and their research. Trailer looks great, check out the website and view the trailer: http://forksoverknives.com/

Richmond Times Dispatch

Amazed at number of positive responses to newspaper article today. http://bit.ly/913XmP

Working on setting up seminars, support groups. Many have questions about the study, we have a grant proposal pending on; it will be for those with documented coronary artery disease to measure the impact of diet on the disease. For others, stay tuned working on more options.

The China Study

     Dr. T. Colin Campbell, Professor of Nutritional Biochemistry at Cornell University lead a study of 65 counties across 24 provinces in rural China.  It involved 6500 adults aged 35-64.  Dietary questionnaires, blood and urine samples were analyzed yielding over 347 data points for interpretation.

     Some key findings:

Fat intake:rural China 14% of total caloric intake vs US >35%

Protein intake: rural China 10% of calories from animal protein, US 70%

Total caloric intake of rural Chinese diet was 20-30% more that in US

     The diet consumed in rural China is plant based nutrition compared with the typical American diet based upon animal protein.

     The study analysis showed a tremendous difference in the incidence of "Diseases of Affluence", specifically cancer, heart disease and diabetes.  These diseases exist in very low rates in rural China compared to the US.  What's more, rural Chinese who emigrated to the US, adopting the local diet then developed these diseases at the same rate as native born Americans.  One finding I found to be particularly amazing involved a 3 county area in China with a population of over 400,000 in which, during the 3 years of the study, not a single person died from a heart attack.  In a comparable sized US region the rate of death from heart attacks is about 80 per year, so 240 over a 3 year period compared to zero.  I find that astounding.

     The effects of these dietary differences were also noted to impact other disease states i.e. kidney stones, osteoporosis, and autoimmune diseases.  The implications are broad.  Adopting a plant based diet can significantly impact the incidence and prevalence of the leading causes of death and disability in the U.S.  It will, however, take a tremendous change in our dietary habits.  

     Reading the China Study, as well as Dr. Esselstyn's Prevent and Reverse Heart Disease, has totally changed my perspective on diet and health.  I am now 2 months into my adoption of these dietary changes and feel great.  Join me, it's not as daunting a task as it first appears.   In fact it is quite simple.  Read the China Study, it is eye opening.

Cholesterol - It's not just bad for your heart

     It is widely publicized that high cholesterol levels are linked to coronary artery disease.  But.... did you know that the single biological factor associated with 'diseases of affluence' (diabetes, coronary artery disease and cancers of the brain, breast, colon, liver, stomach and leukemia) is..... you guessed it......Cholesterol.

     In the China Study,  Dr. T. Colin Campbell found that in rural China, where a plant based diet is followed the incidence of these diseases of affluence was extremely low.  In this region the average total cholesterol was 127! (The average in the US is ~200)

    More on this comprehensive study to come.

Prevent and Reverse Heart Disease

    I have recently finished reading 'Prevent and Reverse Heart Disease' by Dr. Caldwell Esselstyn.  It is more than interesting.  His general message is very powerful.  Western diets based on animal protein lead to significant vascular inflammation and development of plaque (blockages).  Additionally the inflamed lining of these vessels also makes "vulnerable" plaques at higher risk of rupture.  People with a total cholesterol of less than 150 and LDL of less than 80 are at extremely low risk for coronary events.  His study spanning more than 15 years showed solid evidence of stabilization and even reversal of coronary artery disease.  This is remarkable.

    To achieve these results the study patients followed a strict change in diet.  A no fat vegan dietary plan.  "Nothing with a face or a mother" is allowed to be eaten.  This includes no fish, dairy, nuts (except a few walnuts in low risk people), no avocados, no oils, and no soy milk (except non fat).  This may sound spartan at first blush but he goes on to describe many food ideas and the last half of the book contains many recipes and meal plans.  I have been following this diet for the last 2 weeks and have been very pleasantly surprised.  No hunger, no cravings and many options.  It does take more work, both mental and physical, as most prepared foods are off limits.

     Now, as a cardiac surgeon, how is this new information to be integrated into my practice? First, I still believe that patients with tight lesions and unstable symptoms need urgent revascularization to relieve symptoms and ideally avoid muscle damage.  Next, I will be informing my patients about these findings, the potential impact on their long term health and encourage them to read this book and adopt the dietary changes. I am continuing my research in the exciting area.  

    Congratulations to Dr. Esselstyn for an amazing study over a long period, breaking with standard conventions and achieving stunning results.

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