For stress tests purposes ( regular treadmill and nuclear exercise imaging) physicians typically use the formula : Maximal heart rate =220-age.
Another formula is the Tanaka formula; Maximal heart rate =209-.7age
More recently based on a Norwegian study by Nes and co workers the following formula is suggested :
Maximal heart rate= 211-.64 with an error term of +/- 10.8. See here for reference.
For the three formulas applied to a 75 year old we get maximal heart rate predictions of
145,156 and 163 . (Standard,Tanaka,Nes)
Frequently stress tests are terminated at when the patient reaches 85% of the predicted max heart rate.
For the three formula we get :
123
132
138.
The validity of a stress tests depends in part on having the patient exercise to a high enough level to induce some degree of stress into the stress tests and use of 220-age formula would seem to make false negative tests more likely.This is not breaking news, Tanaka said as much in his 2001 article in the American College of Cardiology Journal but still some stress test facilities still use the 220 formula . See here.
Monday, April 27, 2015
Thursday, April 23, 2015
Do we neeed to worry about the right ventricle in endurance exercise?
Is the right ventricle the Achilles heel of endurance exercise? I wrote briefly about this subject in 2007 .
In that regard there is more data now about which to fret. A 2011 article by researchers in Australia and Belgium gives reason to believe that endurance exercise affects the left and right ventricles differently and possibly not in a good way .Could endurance exercise induce chronic changes in the structure of the right ventricle such that it is vulnerable to ventricular arrhythmias, similar to those related to an inherited cardiomyopathy (arrhythmogenic right ventricular cardiomyopathy). See here. ARVC is very uncommon in the US but more commonly seen in Europe particularly in Italy where it is said to be the most common cause of sudden cardiac death in young athletes.
The authors studied 40 well trained endurance athletes before an event , immediately afterwards and 6-11 days later.Echocardiograms were done at all three times and cardiac MRs were done at baseline.
Immediately post race, right ventricular ejection fraction was reduced and RV volume was increased while comparable changes were not present in the left ventricle. RV function did recover by one week except for an echo derived index called "global strain".(In echo lingo strain means deformation which can be determined by tissue Doppler techniques)
Five of the 39 athletes demonstrated delayed gadolinium enhancement (DGE) in the ventricular septum. These changes believed to represent fibrosis were more common in the athletes who had been competitive endurance athletes longer and the authors suggested that the areas of fibrosis noted on the gadolinium scan were in the area of the septum which bulges into the left ventricle as a result of the tissue deformation noted in the right ventricle.
As the authors stated, the long-term clinical significance warrants further study.Will there be re-modelling of the RV in such a way as to predispose to ventricular arrhythmias?
Another publication by some of the same authors had previously examined the prevalence of gene mutations in athletes with complex ventricular arrhythmias. Specifically they looked for desmosomal gene mutations of the type typical of ARVC ( Arrhythmogenic Right Ventricular Cardiomyopathy). Desmosomes are complexes of protein that function to facilitate cell to cell adhesion. In 20 of the 47 cases no desmosome gene mutations was identified.A suggestion was made that prolonged endurance exercise could bring about remodeling of the right ventricle which would predispose to ventricular arrhythmias even in some athletes who do not have the recognized desmosomal gene mutation..I wrote in more detail about this study here.
The right ventricular issue may well be worth worrying a bit about but the small but consistently increased incidence of atrial fibrillation in long term exercisers has a more robust data base in its support.
In that regard there is more data now about which to fret. A 2011 article by researchers in Australia and Belgium gives reason to believe that endurance exercise affects the left and right ventricles differently and possibly not in a good way .Could endurance exercise induce chronic changes in the structure of the right ventricle such that it is vulnerable to ventricular arrhythmias, similar to those related to an inherited cardiomyopathy (arrhythmogenic right ventricular cardiomyopathy). See here. ARVC is very uncommon in the US but more commonly seen in Europe particularly in Italy where it is said to be the most common cause of sudden cardiac death in young athletes.
The authors studied 40 well trained endurance athletes before an event , immediately afterwards and 6-11 days later.Echocardiograms were done at all three times and cardiac MRs were done at baseline.
Immediately post race, right ventricular ejection fraction was reduced and RV volume was increased while comparable changes were not present in the left ventricle. RV function did recover by one week except for an echo derived index called "global strain".(In echo lingo strain means deformation which can be determined by tissue Doppler techniques)
Five of the 39 athletes demonstrated delayed gadolinium enhancement (DGE) in the ventricular septum. These changes believed to represent fibrosis were more common in the athletes who had been competitive endurance athletes longer and the authors suggested that the areas of fibrosis noted on the gadolinium scan were in the area of the septum which bulges into the left ventricle as a result of the tissue deformation noted in the right ventricle.
As the authors stated, the long-term clinical significance warrants further study.Will there be re-modelling of the RV in such a way as to predispose to ventricular arrhythmias?
Another publication by some of the same authors had previously examined the prevalence of gene mutations in athletes with complex ventricular arrhythmias. Specifically they looked for desmosomal gene mutations of the type typical of ARVC ( Arrhythmogenic Right Ventricular Cardiomyopathy). Desmosomes are complexes of protein that function to facilitate cell to cell adhesion. In 20 of the 47 cases no desmosome gene mutations was identified.A suggestion was made that prolonged endurance exercise could bring about remodeling of the right ventricle which would predispose to ventricular arrhythmias even in some athletes who do not have the recognized desmosomal gene mutation..I wrote in more detail about this study here.
The right ventricular issue may well be worth worrying a bit about but the small but consistently increased incidence of atrial fibrillation in long term exercisers has a more robust data base in its support.
Wednesday, April 22, 2015
Is the doc-fix bill worse than SGR?
Here is what Dr. Scott Gottlieb has to say in his Forbes column on 3/19/15:
"The current Medicare reforms being put before Congress ( he was writing before the bill was passed) are better than the existing scheme, the so-called sustainable growth rate or SGR. But the new measures sill envisions Medicare actuaries and at the center of a price setting process. Now they will also have the authority to mandate clinical practice standards. That this woeful development stands as an improvement to the status quo is a measure of how much our current approach has corroded so many aspects of medical care."
That is I believe the worse and most important part of MACRA. The folks at Medicare will mandate clinical practice standards that it turn will drive physicians compensation.Some well intentioned physicians working within various medical societies sincerely believe they can inject rationality into those yet to be written standards.Those well intentioned few are up against the lobbying powers of the various crony capitalists,the bureaucratic inertia of the administrative state, and the bully pulpit power of a subset of the leadership of professional organizations who either sincerely or cynically advocate for the purportedly calculable good of the collective over the individual patient.
Yes, of course it is good that physicians no longer have the threat of a 21% immediate reduction in fees and to receive a slight increase (less than the rate of inflation) but after you look past that the slight and temporary gains made now will seem like a Pyrrhic victory and I believe that Dr. Gottlieb may have been overly optimistic in his comments.
One of the reasons allegedly for the widespread support of MACRA was that the impending 21% cut would force many physicians to opt out of Medicare. I submit that once the Merit Based Incentive Payment System (MIPS) is implemented and understood by practicing physicians it will be likely that even more physicians will leave Medicare.
Will well meaning physicians somehow find the time,money and energy to fix the heretofore inadequate or harmful quality measures replacing them with better ones? Will the CMS quality "metrics" some how escape the inescapable reach of Goodhart's law? A measure of something looses its value as a measure when it become a target. With quality measures as will be defined by CMS and resource utilization embedded into MICRA more and more medical decisions will be made in Washington and physicians will be less and less able to act as the fiduciary agents of their patients with trust in physicians and reliance on evidence based medicine fading away.
For a detailed and frightening analysis of what MACRA contains please read this commentary by Dr. Arvind Cavale. See here.
There is so much to fret about that is explained by Dr. Cavale not the least of which is the move to have your physician share the insurance risk with the insurance company. Have a nice day.
"The current Medicare reforms being put before Congress ( he was writing before the bill was passed) are better than the existing scheme, the so-called sustainable growth rate or SGR. But the new measures sill envisions Medicare actuaries and at the center of a price setting process. Now they will also have the authority to mandate clinical practice standards. That this woeful development stands as an improvement to the status quo is a measure of how much our current approach has corroded so many aspects of medical care."
That is I believe the worse and most important part of MACRA. The folks at Medicare will mandate clinical practice standards that it turn will drive physicians compensation.Some well intentioned physicians working within various medical societies sincerely believe they can inject rationality into those yet to be written standards.Those well intentioned few are up against the lobbying powers of the various crony capitalists,the bureaucratic inertia of the administrative state, and the bully pulpit power of a subset of the leadership of professional organizations who either sincerely or cynically advocate for the purportedly calculable good of the collective over the individual patient.
Yes, of course it is good that physicians no longer have the threat of a 21% immediate reduction in fees and to receive a slight increase (less than the rate of inflation) but after you look past that the slight and temporary gains made now will seem like a Pyrrhic victory and I believe that Dr. Gottlieb may have been overly optimistic in his comments.
One of the reasons allegedly for the widespread support of MACRA was that the impending 21% cut would force many physicians to opt out of Medicare. I submit that once the Merit Based Incentive Payment System (MIPS) is implemented and understood by practicing physicians it will be likely that even more physicians will leave Medicare.
Will well meaning physicians somehow find the time,money and energy to fix the heretofore inadequate or harmful quality measures replacing them with better ones? Will the CMS quality "metrics" some how escape the inescapable reach of Goodhart's law? A measure of something looses its value as a measure when it become a target. With quality measures as will be defined by CMS and resource utilization embedded into MICRA more and more medical decisions will be made in Washington and physicians will be less and less able to act as the fiduciary agents of their patients with trust in physicians and reliance on evidence based medicine fading away.
For a detailed and frightening analysis of what MACRA contains please read this commentary by Dr. Arvind Cavale. See here.
There is so much to fret about that is explained by Dr. Cavale not the least of which is the move to have your physician share the insurance risk with the insurance company. Have a nice day.
Friday, April 17, 2015
The Doc Fix, prayers of the progressive medical elite have been answered and then some
In regards to the passage of the doc fix bill (known now by the acronym MACRA) John Goodwin said it well: " it locks in Obamacare's vision of the relationship between physicians and the state." ... Now, doctors and patients will have to get used to a new reality where the federal government and beltway lobbyists’ priorities are more deeply embedded in physicians’ offices than ever."
Further the exact details and degree of the embedding will not be made known until phase three of new payments system. Remember we have to pass the bill to see what is in it?
The changes made in physicians payments are in three phases and from the years 2015 -2020 there will be a 0.5% increase in physician CMS fees and from 2020 -2026 the increase will be zero.
Phase 1 is the "lull-docs-to-sleep" phase in which all physicians will "enjoy" increases in the payment schedule (that do not keep pace with inflation) and for a while not worry about the always impending threat of a SGR imposed fee cut. This is the deal that is too- good- to -pass-up phase which typically occurs in the early stages of a scam.This phase runs from 2015 to 2019.Docs who are part of an APM )(see below) will receive an extra 5%.
Phase 2 is what I call the the devil is in the details phase.Physicians will be reimbursed based on a formula that takes into account four buzz word filled metrics.The categories of metrics are 1)quality 2)resource utilization 3)meaningful use of electronic health record. 4) clinical practice improvements. This phase runs from 2019 through 2025 and the overarching buzz word is MIPS (Merit based incentive payment system).
CMS will play the major role is setting physician payment.Note the meaningful use requirement will likely have more teeth and there is reason to believe that the much reviled MOC has received more statutory authority,although there are conflicting claims as to whether MOC is explicitly in Doc Fix or if it was already part of ACA or not in either.The National Quality Forum (NQF) is contracted by CMS for three years to provide advice and make suggestions regarding quality issues.It should not go unnoticed that the CEO of the NQF is the same Christine Cassel who was CEO of ABIM during the time that MOC was implemented and the Choosing Wisely Campaign was launched.
Whoever the rule makers will be will be targeted by
Phase 3 is the everyone-work- for- the-man final phase in which physician pay will be dictated by their involvement in a "alternative payment model", examples of which would be an ACO or a medical home or some sort of scheme involving large vertically integrated health behemoths.This phase begins in 2026.
Medical decisions will be shifted even more than they are now to Washington and the wishes of Don Berwick and Troyen Brennan that they expressed in their book New Rules are much closer to being realized. I quote from their writing:
"Today, this isolated relationship[ he is speaking of the physician patient relationship] is no longer tenable or possible… Traditional medical ethics, based on the doctor-patient dyad must be reformulated to fit the new mold of the delivery of health care...Regulation must evolve. Regulating for improved medical care involves designing appropriate rules with authority...Health care is being rationalized through critical pathways and guidelines."
The Doc Fix also moves forward the recommendation of Dr. Robert Berenson that he and a co-author made in a 1998 Annals of Internal Medicine Article ( p 395-402):
"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."
MACRA will go a long way to achieving that proposal.
Friday, April 10, 2015
After 18 years and randomized trials with 25,000 men ,the relationship between 5 ARs and prostate cancer is still ??
This commentary from JAMA give a good summary of where we are with 5 ARs ( Five alpha reductase inhibitors) and prostate cancers.Large randomized clinical trials (PCPT trial and the REDUCE trial have been done with finasteride (Proscar) and dutasteride (Avodart).
My take is that the 5 ARs seem to reduce the risk of developing low grade prostate cancer but may increase the risk of higher grade prostate cancer. However, a reasonable argument can be made that the 5 ARs do not in fact increase the risk of high grade cancer but just make the cancers more easily detectable but we probably will never know because is is unlikely that many further studies will be done and I doubt further analysis of existing data will be convincing.
One can also argue that a 5 AR driven decrease in the occurrence of low grade prostate cancer may not translate into fewer prostate cancer deaths. Most every diagnostic or therapeutic decision involves a tradeoff, but here exactly what the tradeoff here is remains unclear.The drugs clearly decrease prostate size but in regard to prostate cancer there is much lingering doubt.
As hard as answers are to come by in preventive medicine issues ( think the changing panorama of suggestions for healthy diets and aspirin use, glucose control in diabetics, etc), it is astounding that the population medicine folks think that they can discern what preventive measures "should" be done and would be willing to recommend that some should have to forgo treatment so some in the future would be the beneficiary of some greater aggregate good. See here for Dr. Harold Sox's plan for just that policy.Hubris-city.
I used to spend considerable time giving preventive medicine advice in the context of a corporate wellness program. As I think back on what I said then ( with more certainty that the data warranted ) I have more than a few doubts now about what I said then. The only thing I am more sure about now is that for the most part regular exercise is a good thing. I am much less sure about the advice I gave about aspirin and statins for primary coronary disease prevention and for PSA screening and screening for bone density. It may well be that randomized clinical trials are the best we can do in terms of discerning medical management plans but it not uncommon to finalize RCTs and still the answer(s) remain undetermined as is the case of the reductase inhibitors.
The old plaintiff lawyer meme of "Doctor, were you wrong then or are you wrong now" continues to hit home, particularly in the enterprise of preventive medicine.
My take is that the 5 ARs seem to reduce the risk of developing low grade prostate cancer but may increase the risk of higher grade prostate cancer. However, a reasonable argument can be made that the 5 ARs do not in fact increase the risk of high grade cancer but just make the cancers more easily detectable but we probably will never know because is is unlikely that many further studies will be done and I doubt further analysis of existing data will be convincing.
One can also argue that a 5 AR driven decrease in the occurrence of low grade prostate cancer may not translate into fewer prostate cancer deaths. Most every diagnostic or therapeutic decision involves a tradeoff, but here exactly what the tradeoff here is remains unclear.The drugs clearly decrease prostate size but in regard to prostate cancer there is much lingering doubt.
As hard as answers are to come by in preventive medicine issues ( think the changing panorama of suggestions for healthy diets and aspirin use, glucose control in diabetics, etc), it is astounding that the population medicine folks think that they can discern what preventive measures "should" be done and would be willing to recommend that some should have to forgo treatment so some in the future would be the beneficiary of some greater aggregate good. See here for Dr. Harold Sox's plan for just that policy.Hubris-city.
I used to spend considerable time giving preventive medicine advice in the context of a corporate wellness program. As I think back on what I said then ( with more certainty that the data warranted ) I have more than a few doubts now about what I said then. The only thing I am more sure about now is that for the most part regular exercise is a good thing. I am much less sure about the advice I gave about aspirin and statins for primary coronary disease prevention and for PSA screening and screening for bone density. It may well be that randomized clinical trials are the best we can do in terms of discerning medical management plans but it not uncommon to finalize RCTs and still the answer(s) remain undetermined as is the case of the reductase inhibitors.
The old plaintiff lawyer meme of "Doctor, were you wrong then or are you wrong now" continues to hit home, particularly in the enterprise of preventive medicine.
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