Smoking Is The Single Most Dangerous Adverse Health Behavior

No other cause of illness or death is more important than smoking. This is the clear message of two new studies of large numbers of Americans conducted by Jha etal and by Thun etal and published by the New England Journal of Medicine on January 24, 2013.

About 19% of Americans smoke regularly today, down from about 40% a few decades ago. Good progress. But for those who do smoke, diseases leading to death are common. Smokers mortality is about 3 times that of nonsmokers and essentially equal between men and women. Certain diseases have been clearly linked to smoking and these caused about 60% of the smokers’ deaths – ischemic heart disease (heart attacks and related), stroke, chronic lung disease and lung cancer being the most common.

The Thun study compared data from three time periods reaching back 50 years. Overall mortality declined by 50% over those 50 years in large part as a result of progress against heart disease. But this was a benefit largely enjoyed only by the nonsmokers since smoking exacerbates coronary artery disease.

Thun made some key observations. First, smoking deaths continue to increase among women because women who smoke smoke as much as do men. Second, death from all causes is at least 3X higher for smokers than for nonsmokers with at least two thirds of all deaths in smokers directly related to smoking. Third, the rate of death from chronic lung disease (COPD) is rising among both men and women.  They hypothesize that this rise in incidence is related to the changes in cigarettes over the years that encourage deeper inhalation with more toxins reaching the periphery of the air sacs. Using the same reasoning, they suggest that deeper inhalation than in the past may be causing the increased incidence of peripheral lung cancers especially adenocarcinomas rather the more centrally located mostly squamous cell cancers that were more common in the past. Fourth quitting smoking lowers death rates very substantially and quitting before the age of 40 can eliminate the relative risk of early death.

 

In the Jha study, the increased risk for ischemic heart disease among smokers compared to nonsmokers was about 3.5 i.e., smokers had 3.5 times as many deaths from heart disease as did the nonsmokers. Since heart disease is more frequent than lung cancer or chronic lung disease, this represented a large and common cause of death for smokers. Considering just women for example, among the 23,839 women who smoked in the study, 251 died of heart disease compared to 382 of the 67,574 women who never smoked. Lung cancer caused fewer total deaths but the relative risk for smokers was very high – 18 – based upon 289 women who smoked and died of lung cancer compared to 83 lung cancer deaths for the larger number of women who never smoked.

These two studies are a stark reminder that smoking is not simply a health hazard. It directly leads to very substantially increased risks of death from heart disease, stroke, chronic lung disease and lung cancer, among others. In the Jha study, 62% of the smokers’ deaths were attributable to smoking.

Attempts to curtail the initiation of smoking and to assist with smoking cessation are important – perhaps the single most important - health promotion and disease prevention goals for America.

Mitral Valve Repair Without Open Surgery – Exciting Development in Medical Devices

The mitral valve separates the heart’s left atrium from the left ventricle. When the ventricle contracts to send blood to the aorta and out to the body, the mitral valve closes to prevent blood rushing backward into the atrium and back to the lungs. The mitral valve can become stiff and tight, called stenosis or it can become unable to close tightly, called regurgitation. Once the regurgitation becomes sufficiently severe to cause heart failure, the death rate reaches about 5% per year. Most such individuals are referred for cardiac surgery to either try to repair the valve, replace the valve or do a procedure that in effect lessens the amount of regurgitation without actually replacing the valve. The latter procedure, although not curative, can be quite successful and alleviate the heart failure and the symptoms leading to a longer and better quality life.

A new procedure has now been reported in the New England Journal of Medicine, April 14, 2011 that does not use open surgery to repair the mitral valve leak. The process is to insert a catheter via the large femoral vein in the groin and pass it up to the heart. From the right atrium it crosses over to the left atrium and then is positioned at the opening of the mitral valve. This mechanical device, manufactured by Abbott Vascular, is able to grasp the two sides of the mitral valve and clip the two leaflets together. It does not create a tight seal but in most cases can markedly reduce the amount of regurgitant flow back into the atrium.

The study randomly allocated patients with grade 3+ or 4+ (i.e., serious) mitral valve dysfunction to either the customary open repair or replacement (the specific procedure at the surgeon’s discretion based on the valve status) or to have a percutaneous repair done with the new device. The study endpoints were freedom from death, freedom from surgery for mitral valve dysfunction and freedom from grade 3+ or 4+ regurgitation at the end of 12 months. The primary safety end point was freedom from major complications during the 30 days post procedure.

The study ws performed at 37 institutions in the United States and Canada. 279 patients were randomized with a 2:1 ratio of percutaneous vs. open procedures. 21 patients withdrew consent before the procedure was done, leaving 258 treated patients.

After the procedure, 41 of 178 (23%) patients who had the percutaneous procedure still had grade 3+ or 4+ regurgitation and were therefore referred for open surgery. Among those 80 patients who initially had open surgery, all had less that 3+ regurgitation after the procedure. By the 12 month end of study time, the composite of freedom from death, from surgery or from grade 3+ or 4+ valve dysfunction for all randomized patients were 55% vs. 73%. If one looks only at those who actually were treated per the protocol (i.e., did not exclude themselves, etc) then the rates were 72% vs. 88%. As to safety, the rates of major adverse events (most often the need for transfusion) as of 30 days were 15% vs. 48%. Quality of life improved in both groups of patients over the 12 months although there was a decrease at 30 days for the open surgery patients.

What these results suggest is that open surgery is more likely to greatly relieve the mitral regurgitation than will the percutaneous catheter procedure. However, the percutaneous procedure is safer, requires less time in the hospital, and is associated with improved quality of life and improved ventricular function from baseline. Many patients might therefore decide to choose the percutaneous catheter-based procedure on the grounds that it greatly relieves the problem in almost three quarters of the patients, is less invasive and is safer than surgery. Then if that individual patient was not among the success stories, he or she can choose to have the follow-up open surgery.

Further, although not mentioned in this article, there are patients who simply cannot tolerate open surgery for any number of reasons who might still be able to undergo the catheter-based procedure. This might then open up an option for repair not otherwise available today with open surgery. Not discussed in the article was cost. This might become a deciding factor as well once the procedure is on the market.

In an accompanying editorial, Otto and Verrier suggest that the decision on surgery (and which surgical procedure) or one of a number of catheter-based procedures (assuming logically that others will undoubtedly arrive soon) should rest on the advice of not one physician but the joint opinion of a multi-disciplinary team of, at least, a nonprocedural valve-disease specialist, and interventionalist cardiologist and a cardiac surgeon, each with substantial expertise in mitral valve disease. To this team I would add the patient’s primary care physician and principal cardiologist – both of whom will have known the patient and his or her overall health and family situation over the years. The other addition to the team is the patient --whose opinions should be incorporated from the beginning of the evaluation and advice process.

Surprise – Adolescent Obesity Leads To Later Heart Disease and Diabetes

Well, probably not a surprise at all. The seeds of coronary artery disease (CAD) are laid down early and over long periods. But given our current pandemic of obesity beginning in childhood, should we worry about an epidemic of chronic disease like diabetes and CAD in the years to come? The clear answer is a resounding “Yes.”

There has been a long term study of military men in the Israeli Defense Force. An article in the New England Journal of Medicine, April 7, 2011 reports on what happened over an average follow-up of 17 years after army induction at age 17 for those who chose to remain in the military after the required three years. This amounted to 37,674 healthy men followed for about 650,000 person years. Among them, 1173 developed diabetes type 2 over time and 327 developed angiography-proven CAD. All by the age of 45.

Here is the baseline data:

Blood pressure, resting heart rate, fasting blood sugar, and low density lipoprotein (LDL – the “bad stuff”) and smoking incidence progressively increased with increasing BMI (BMI, a calculated ratio of weight and height) among the 17 year old inductees. High density lipoproteins (HDL – or the “good stuff”) declined as did the amount of weekly exercise with increasing BMI.



Here is the follow-up data:

Since this was a study of men beginning at age 17 and lasting an average of 17 years, it follows that the 327 cases of CAD and 1173 of diabetes were among relatively young men – aged 25-45 years old. When the investigators adjusted for age, family history of CAD, blood pressure, smoking status, LDL, HDL and triglycerides they found that an elevated BMI at age 17 was a significant independent risk factor for CAD. Indeed the risk increased by 12% for each increment of 1 unit of BMI. They also noted that CAD occurred even in those with BMIs that are generally considered within the acceptable range today.

BMI at age 17 also predicted for the later development of diabetes mellitus type 2 (DM) with risk increasing about 10% for each additional 1 unit of BMI. But with diabetes, it was the adult level (age 25 and beyond) that was associated with a greater increase in diabetes relative risk. Said differently, higher levels of BMI at age 17 correlate with higher risk of CAD and diabetes in early adulthood. Persistent elevations of BMI increase that risk. Elevation in early adulthood increases the risk of DM during early adulthood whether or not the person had a higher BMI at age 17.

My takeaway:

It is imperative to intervene now in the growing pandemic of childhood and adolescent obesity. Even modest increases BMI can predispose to later CAD and DM. Once developed, these are chronic illnesses that persist for life, are challenging to manage, are expensive to treat and have a high impact on both quality of life and longevity. Our children are our future; it is our obligation to protect them. And if that is not reason enough, then think of your wallet. The high costs of their care will have a very significant impact on each of us in our taxes and our insurance premiums.