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Is the new professionalism and ACP's new ethics really just about following guidelines?

The Charter ( Medical Professionalism in the New Millennium.A Physician's Charter) did not deal with just the important relationship of ...

Tuesday, September 30, 2014

Can long standing endurance exercise training mitigate the of age related loss of compliance of left ventricle?

With more evidence available to generate legitimate concern about an increased risk of atrial fibrillation with  many years of endurance exercise and papers about long time endurance athletes and the  much less likely risk of developing arrhymogenic right ventricular dysplasia (ARVD), some good news for the crazy, old long distance runners was very welcome.

Here is a link to summary of the paper by Dr. Paul Bhella et al. entitled "Impact of Lifelong Exercise "dose" on Left Ventricular Compliance and Distensibility"

Here is the authors'conclusion :

" Low doses of casual, lifelong exercise do not prevent the decreased compliance and distensibility observed with healthy, sedentary aging. In contrast, 4 to 5 exercise sessions/week throughout adulthood prevent most of these age-related changes. As LV stiffening has been implicated in the pathophysiology of many cardiovascular conditions affecting the elderly, this "dose" of exercise training may have important implications for prevention of cardiovascular disease."

Is there an age related decrease in left ventricular compliance.  According to a 1984 article by Rodeheffet et al the aging heart may be able to maintain cardiac output in the face of an age associated decrease in maximal heart rate by increasing stroke volume. See here for link. The older person relies more on an increase in end diastolic volume and riding the beneficial part of the Starling curve, but if the left ventricle become less compliant, which it is claimed it does as a function of age that adaptation would only work for a while.

Is the decrease in LV compliance due to just getting old or might it be due to lack of vigorous physical exercise. Dr. Armin-Zaeh and coworkers at the Dallas Based Institute for exercise and environment medicine  believe  it is the latter. See here.  My personal bias is obviously to agree with them. Here are the conclusions from the above linked article.

"In conclusion, a sedentary lifestyle is associated with a decline of ventricular compliance, leading to higher cardiac filling pressures and lower stroke volumes for a given filling volume compared with age-matched athletes or young individuals. Prolonged, sustained endurance training preserves ventricular compliance with aging and may be an important approach to reduce the probability of heart failure with aging."

A partial,apparent  counterpoint to the  above studies can be found here in this 2003 article by  P E Gates and co-authors whose analysis and summary minimized the importance of one of their own findings  ( namely that a standard measure of diastolic function (the e/a ratio) was higher in endurance trained subjects) and instead emphasized the value of the decreased arterial stiffness noted in long term exercisers.Either way, a less stiff ventricle and/or a less stiff aorta, it is  good news to long term endurance exercisers.

addendum: 10/1/14 Correction made on title, "Stiffness" changed to "Compliance"
addendum-1/22/14 Title reworded to a less awkward version 

addendum; 10/4/15 An article by Daniel Forman  entiltted "Enhanced left ventricular filling associated with long term endurance exercise." The title tells their conclusion . The link below is just for an abstract so I cannot comment on the data or how well their summary captures the data. or how old the masters were. The authors state "Early ventricular filling indices in master athletes more closely resemble transmitral flow patterns of health young adults." (Journal of Gerontology 1992, 47 2)

Friday, September 26, 2014

Another chapter in "were you wrong then doctor, or are you wrong now?" this time regarding stenting of non culprit lesions.

The American College of Cardiology recently retracted one of its magic five "Choosing Wisely" recommendations.In 2012 ACC had advised that in the setting of an acute coronary event one should only revascularize the "culprit artery".This is the artery thought to be responsible for the event and if other obstructions are detected the ACC said that there was evidence that the fix everything approach might be harmful.This advice was based on non randomized trials. Here is ACC's official statement.

Now apparently two randomized trials  suggest one should fix (place a stent in ) the other obstructions. Here is quote from ACC:

 “over the last two years, new science has emerged showing potential improvements for some patients in their overall outcomes as a result of complete revascularization.”

Larry Husten,prolific medical journalist whose Forbes article on this subject is linked above, really nailed it , quote:

" It seems to me that the medical organizations that produce guidelines should freely admit this lack of evidence for most recommendations. Then, instead of getting their panties all in a bunch trying to defend the indefensible– as we saw recently with the salt guideline– they could advocate for better evidence...So if they want to make the case for more data they will have to first acknowledge their ignorance.

Acknowledging ignorance seems the last thing  likely to emerge from the guidelines generating organizations.

In 1728, the three verdict system arose in Scottish Criminal cases.The accused could be found guilty,not guilty or not proven. So guilty, not guilty or admitting their ignorance and admitting we just can't say.

Being  a guideline author seems to confer immunity for having to say you are sorry.  The individual physician strives to do what is the right thing for his patient and hopes that what he does is right, the quality rule makers are able to summon up sufficient hubris to  presume to know what is good for everyone. Of course they frequently do not. Remember the beta blocker fiasco.


Friday, September 19, 2014

Are pediatric football concussions different from high school and college head trauma?

It would be nice to think so and a 2012 study by Maugans et al provides some data ( see here for full text) which suggests it may be the case. Eight young football players  (in a study of 12 athletes ) were studied early post concussion and at two subsequent times.The football players ages were : two 12 year olds,one thirteen year old,three 14 years olds and 2 aged 15.

Multiple Imaging techniques were used . The diffusion tensor imaging (TDI) tests were normal  as were conventional MRIs,and proton magnetic resonance spectroscopy.

 This is in contrast to two studies in college and two studies in high school football players, none of whom experienced a concussion ,which showed decreased fractional anisotropy (FA) in certain white matter tracts and/or functional MR  abnormality in the dorso-lateral frontal cortex.See here for Talavage's article regarding functional MR changes in high school players.

Further ,one study (Bazarian,  (see here for full text)) showed persistence of the TDI changes six months after the college football  season ended. Here is the authors' summary:

" we have demonstrated that a single football season of RHIs  [ repeated head impacts]without clinically evident concussion resulted in WM changes on DTI. These DTI changes correlated with multiple helmet impact measures and persisted despite 6 months of no-contact rest. This lack of WM recovery could potentially contribute to progressive, cumulative WM damage with subsequent RHI exposures. If this relationship is confirmed in longitudinal studies, efforts to limit the development of RHI-related WM changes by monitoring helmet impact measures, and further elucidation of modifiable factors that may influence WM recovery, could mitigate the long-term risk of CTE [chronic traumatic encephalopathy]."

Maugan's group did demonstrate decrease in  cerebral blood flow ( CBF) in the concussed subjects which tended to return to normal over a few weeks.The authors' conclusion;

"Pediatric SRC [sports related concussion] is primarily a physiologic injury, affecting CBF significantly without evidence of measurable structural, metabolic neuronal or axonal injury.(I am still trying to figure out what a "physiologic injury" means.)
What might account for the apparent differences in brain scan results in the college and high school players and the younger athletes studied by Maugan?

Possibly the younger players have a  threshold for CNS symptoms given a head blow  that is lower that the  threshold for whatever tissue changes take place that are reflected in DTI findings.There are contradictory data regarding the question of whether younger brain are more or less susceptible to damage for head trauma.

While it has been shown that  some head  impact levels ( as measured by accelerometers in helmets) in  youth football may approach those demonstrated in high school and college they are on average lower.(see here for full text of article by Cobb, 2013 for detailed data of head impact forces ) Further, the total number of impacts in a season of high school or college practice and game time may be considerably more than in a season of youth football and it may be the cumulative effects is what drives the DTI changes and whatever underlying tissue changes that may occur.Also as the years pile up, youth football and then high school and then college and then for a few professional football the total  number of head impacts grows and it may be the long term cumulative effect of multiple sub-concussive plus the occasional concussive blow that  leads to CTE in a minority of football participants.A definitive link between the imaging findings on active players and the pathological changes seen in chronic traumatic encephalopathy has yet to be established.

Although parents may feel some reassurance from Maugan's research, there is little to be reassured about in  the brain imaging studies of high school and college football players following a concussion free season as well as those studies on players with concussions.There is certainly little reassurance offered in this lengthy and detailed  article from Rolling Stone.There is an increasing about of research on the effects of football related head trauma ( as well as ice hockey) .One pundit, a retired football  player,commented  that it is the parents who really need their heads examined.

Addendum : Minor alterations in syntax and spelling and grammar done on 9.24.14.The original, unfinished version was published on 9/19/14 by mistake .

Thursday, September 18, 2014

Is the "triple aim of health care" analogous to the dual mandate of the Federal Reserve

Well, it can be argued that they are both unachievable and the execution of their aims and goals will require wise men such as the "Men of system" discussed by Adam Smith.

In 1977,  Congress, having accepted at least part of the theory of Keynesian economics, amended The Federal Reserve Act, with the passage of the Humphrey-Hawkins Act, stating the monetary policy objectives of the Federal Reserve as:

"The Board of Governors of the Federal Reserve System and the Federal Open Market Committee shall maintain long run growth of the monetary and credit aggregates commensurate with the economy's long run potential to increase production, so as to promote effectively the goals of maximum employment, stable prices and moderate long-term interest rates."

In other words, the Federal Reserve System is tasked by law to control inflation and maximize employment in spite of the fact, given the tools to which the system has access, that the two mandates might be incompatible.

Dr Don Berwick speaks of medicine's "triple aim"  ( as envisioned by the Institute for Health Care Improvement)  : Population health,the patient's experience and the per capita cost.The collective medicinal "we" should strive  to improve population health,the individual patient's experience and reduce the per capita cost.

I am reminded of a series of  articles in JAMA in 1994 by Dr. David Eddy ( "Rationing resources while improving quality" ) in which he promised to provide a means to improve quality of medical care and reduce costs. This was to be done by utilizing a utilitarian cost calculus.The idea was to do what was best for the group,the health care collective statistically, even though he admitted that in such a system there would be winners and losers but the utility to the former would out way the dis utility to the minority. Of course in this scheme quality had to be defined or redefined as  what is better for the aggregate. At least Eddy was candid about there being losers,in Berwick's utopian visions in the picture he paints there seem only to be winners.The population will do better, the individual patient's experience will improve and "we" will spend less money per patient. Everyone will do better and it will even cost less.What could possibly be wrong with that?

I believe that IHI's policy recommendations are basically Eddy's prescription adorned with a layer or two of management-speak verbiage dumped on the top to obfuscate what is really happening. When you claim to improve population health care or outcome and simultaneously  decrease per capital costs, you essentially are doing a cost effectiveness analysis based on a statistical benefit to some group ( e.g. those covered lives in an ACO or HMO) regardless of what determent might befall some other  individuals in the group making the third aim of improving the  patient's experience little more than a fraudulent claim. This is population medicine dressed up in polite euphemisms designed to flimflam the members of the health care collective.

Both Dr. Robert Berenson and Dr. Harold Sox,former president of the American College of Physicians, are  perhaps more candid about about their visions for medical care in the country.

Berenson writing in 1998 in the Annals of Internal Medicine said.

"We propose that devotion to the best interests of each individual be replaced with an ethic of devotion to the best interests of the group for which the physician is personally responsible.

Berenson makes it clear that the individual's interest should be trumped by the group's interest.

Dr Harold Sox, former president of the American College of Physicians, in his commentary regarding "population medicine"  made it clear that in shifting funds from managing one disease to another would involve for at least a few generations a situation in which some patients might not receive  treatment so that others might enjoy some type of preventive measures.

Quoting Sox's  November 12, 2013 JAMA commentary:

 "Planning to optimize population health will mean determining the frequency,causes and consequences of he common medical conditions in a population and devising strategies for dealing with them over a lifetime. "...
resources must be allocated across program to prevent,detect and treat disease and its risk factors. "...One reasonable principle to move resources from groups of patients less likely to benefit to groups more likely to benefit...

With the application of this utilitarian calculus there will be winners and losers which Sox seems to admit implicitly the following paragraph.

"It will take several generations to realize the benefit of investments in disease prevention.In the short run, these investments may draw resources away from the tests and treatment of some sick people.In the long run, diseased prevention and better low-cost technology could reduce the outlay for treatment."

If Berwick's, triple aim is something other than  the utilitarian approach of Eddy,Berenson and Sox I wish someone would explain. It is the old wine in newly labeled bottles, this time labeled "enhanced patient experience" and the platitudinous "patient centered care" when really it is the greatest good for the greatest number as judged by cost effectiveness calculation and the real winners are the third party payers and their fellow travelers.

addendum: 12.8/2014.Some editorial changes made to clarify some points and correct spelling.

Friday, September 05, 2014

Is there convincing evidence that some high school football players develop traumatic brain injury without sustaining a concussion?

Traumatic brain injury (TBI) is classified as mild,moderate and severe based on mental status change and duration of loss of consciousness (LOC). Mild TBI  involves LOC less than 30 minutes and corresponds to  a Glascow Coma Scale rating of 13-15. For example, a football player who appears stunned and confused with only brief of no loss of consciousness would have a Glascow score of 14.

A major element of TBI is diffuse axonal injury thought to be caused by rotational and linear acceleration of the brain. Conventional MR imaging and CT images do not detect that type of changes. However, diffusion tensor imaging (DTI) can detect changes in fiber tracts reflecting changes in diffusion of water into nerve tissues.A DTI based measurement ,fractional anisotropy (FA) ,reflects water movement along the axons.In normal tissue FA is high ( approaches 1)

DTI abnormalities have been demonstrated in concussive cases of  mild TBI and the degree of abnormality correlates with the severity of post trauma symptoms.(see here). Typically FA increases acutely in TBI and later on values are decreased (see here ), although there is some inconsistency about the direction of change in this measurement  in the literature and there are case reports in which acutely FA decreases.

Football players  college,high school and professional, who have sustained concussions,have been shown to have abnormal DTIs.

There are  several publications  (1. Davenport et al,2.Talavage,3.Barzarian  4.McAllister )describing research involving college and high school football players that have shown similar DTI changes in athletes who did not have clinical concussions,These imaging changes seem related to multiple sub-concussive head blows.Some studies-but not all- have also shown that these DTI findings correlate with decrements in memory test results over the course of one season.Generally these DTI abnormalities correlate with measurements of acceleration forces of the skull detected by in- helmet accelerometers.

 1)EM Davenport and her colleagues from Wake Forest studied the cumulative effects of head impacts in a single high school football season in players without a recognized concussion.(Abnormal white matter integrity related to head impact exposure in a season of high school varsity football" J of Neurotrauma 2014 Jul 14, published ahead of print).

The authors' summary:

"We show that a single season of football can produce MRI measurable brain changes that have been previously associated with mTBI (mild TBI) .Finally, we demonstrate that these impact related changes in the brain have a strong association with postseason change in cognitive function." The cognitive function was noted in a verbal memory composite score which correlated with the magnitude of the MR findings.

 2) TM Talavage and coworkers studied 11 high school players with functional MRs (fMR),measures of head impact events and neurocognitive function testing. "Functionally detected cognitive impairments in high school football players without clinically diagnosed concussion." J of Neurotrauma. 31:327-338,Feb 2014)

 Unlike most of imaging studies of TBI this group found abnormalities in the frontal lobe with functional MR.DTI was not done.

 Quoting from the authors summary:

"Additionally, we observed players in a previously undiscovered third category, who exhibited no clinically-observed symptoms associated with concussion, but who demonstrated measurable neurocognitive (primarily visual working memory) and neurophysiological (altered activation in the dorsolateral prefrontal cortex [DLPFC])."

3 JJ Bazarian  studied 10 college football players over the course of one season. ( "Persistent Long Term cerebral White Matter Changes after Sports related Repetitive Head Impacts. Plos one 9(4),e94737)

 Head impacts were recorded and measured by helmet accelerometers and DTI was done preseason, immediately post season and six months after the end of the season.

 DTI abnormalities in white matter were noted in these players none of whom sustained a clinically evident concussion. The changes in most players,but not all, were also seen in the six month followup images. .. There was a positive  correlation between number of head impacts and DTI findings. The DTI changes were not correlated with changes in cognitive testing or tests of balance.

4)  TW McAllister's study involved 80 college football and hockey players ( "Effect of head impact of diffusivity measures in a cohort of collegiate contact sports athletes", Neurol. 10:1212/01Dec 11 2013.)
Quoting the authors:
"The magnitude of  [TDI] change in corpus callosum MD (mean diffusivity) was associated with poorer performance on a measure of verbal learning and memory."  Again these findings occurred in players with no recognized concussions.

The risk of concussion is greater in certain positions such as quarterback and wide receivers. Lineman , on the other hand have fewer concussions but most experience multiple head impacts during each game and each full contact practice session.See here for a detailed study on impact forces on various player positions.

Maugans and coworkers studied athletes younger than typical varsity high school players.These players were 12 to 15 years of age and DTI scans done fairly soon after the concussion did not show abnormalities in diffusion indicators including fractional anisotropy.

Dementia Pugilistica as a clinical condition in professional boxers was described as a clinical entity in a JAMA article in 1928.In 1973 the pathological findings were published. In 2005,Omalu et al published the results of an autopsy on an National Football League  player, Pittsburgh Steeler center,Mike Webster, on whom Dr. Omalu had performed an autopsy 3 yearns earlier.This was the first report of Chronic Traumatic Encephalopathy in a football player.

Zhang et al provided some data regarding brain changes in boxers who were symptoms free and who had a normal neurological exam. 47 professional boxers ( age 30 +/-4.5 years ) underwent conventional MRIs and DTIs.In 42 the conventional MRI was normal while 7 demonstrated some focal non specific white matter changes. The 42 demonstrated abnormal DTIs, with decreased fractional anisotropy in regions of the corpus callosum and internal capsule.Boxers have been the canaries in a coal mine.Their experience has made it clear that repeated blows to head can cause permanent progressive brain damage that is not immediately apparent but develops over a  variably long period of time.The question is to what extent does this apply to football in which the players wear helmets.For years it was believed that helmets were adequately protective but now that view is increasingly less plausible.

By 2013 the NFL agreed to settle a class action law suit brought about by former NFL players and their families  but the judge did not agree to the amount offered..Now the NFL has seemingly admitted that as many as one third of players will develop some sort of cognitive impairment and that they will have funds available to cover the agreement.

The distinction between a concussive and a sub-concussive head blow is on the margin indeterminate.  A player may experience a blow to the head and feel slightly dizzy or dazed and not report those symptoms to the coach or trainer. There may be social or peer pressures on players to not report symptoms as they would be benched and not allowed to play until they complete whatever concussion protocol is in place.So the distinction between a group of players with a concussion and a group with no history of reported concussion is  not one based on clear cut objective criteria,often relying on the voluntary reporting of subjective symptoms.So it should not be surprising that cognitive tests and brain imaging studies show similar findings in football players with and without a concussion history.

So in reply to the title question, yes I believe there is convincing evidence, But there has not yet been established a clear linage between the changes in cognitive tests and brain imaging studies  seen after a season of high school or college football  and the development of  chronic traumatic encephalopathy .