Add Boston Globe to the list of heart scan blunders

17. September 2008 William Davis (15)
Yet another piece of mass media misinformation hit the airwaves today. This time it's not from the New York Times or the LA Times, both of which have previously mangled the issues surrounding heart scans. This time it's from the Boston Globe.

In an article titled What is a calcium scan for heart disease, and who should undergo the test?, the report states:

". . . calcium scans may not be a good idea, or prove terribly useful, for most people. For one thing, the scans expose a patient to significant radiation - equivalent to roughly 50 chest X-rays" said Dr. Warren Manning, chief of noninvasive cardiac imaging at Beth Israel Deaconess Medical Center."

As many before him, Dr. Manning is confusing two tests: CT coronary angiography and CT heart scanning. Perhaps we can't blame him: This technology has had its weakest following in the northeast, for reasons not entirely clear to me. (In fact, Track Your Plaque followers have had the greatest struggle obtaining heart scans in that part of the country.) Nonetheless, you'd think he'd have his simple facts straight before talking to the press. Unfortunately, hospital public relations departments will usually just grab whoever they can willing to talk to the press--regardless of their expertise or lack of.


The story goes on to say:

. . ." it's not clear what to do with the results from a calcium scan. If you have diabetes, high cholesterol, high blood pressure, or a family history of heart disease, you already know - or should know - that you are at increased risk of heart problems and should lower these risk factors. So, a calcium scan provides little additional information," Manning said.

"Moreover, even a high score doesn't necessarily mean that the calcified plaque in your arteries is obstructing blood flow, said Dr. Adolph Hutter, a cardiologist at Massachusetts General Hospital."

"The vast majority of people with high calcium tests don't have obstructions and they do fine long-term. So you'd have to test lots and lots of people to prevent one heart attack or sudden death," said Manning.

And if you get a low calcium score, a sign of little or no calcification of plaques, that's not very useful, either, because it could be wrong, or it could be right but lull you into believing you do not have to exercise and watch your diet, cholesterol, and blood pressure levels. "You can still be at risk even if your calcium test is negative," Hutter said.


It is truly shocking how little many (not all, thank goodness) of my colleagues really know about 1) heart scans, 2) coronary disease prevention, and 3) prevention in general. These same "experts" likely advocate high-dose statin drugs and low-fat diets for people at risk. They likely refer patients to the American Heart Association for diet advice and themselves obtain a lot of information from the pharmaceutical industry. The notion of identification, tracking, and purposeful reversal of coronary plaque is entirely foreign to this bunch.

"The vast majority of people with high calcium tests don't have obstructions and they do fine long-term. So you'd have to test lots and lots of people to prevent one heart attack or sudden death." Well, take a look at a graph from a database of 25,000 people undergoing heart scans then observed for several years afterwards:




You can see quite clearly from the curves that heart scan scores very clearly predict your future (if no preventive action is taken). The higher the score, the greater the likelihood of heart attack and death. How much clearer can it get?

The most recent addition to this literature is the PREDICT study which concluded:

Hazard ratios relative to CACS [coronary artery calcium scores] in the range 0-10 Agatston units (AU) were: CACS 11-100 AU, 5.4 (P = 0.02); 101-400 AU 10.5 (P = 0.001); 401-1000 AU, 11.9 (P = 0.001), and >1000 AU, 19.8 (P < 0.001).

In other words, a heart scan score of >1000 is associated with a 20-fold increased risk of cardiovascular events (without preventive efforts). That kind of predictive power and quantitative confidence simply cannot be squeezed out of blood pressure and cholesterol values.

How about the 2008 University of California-Irvine study from the New England Journal of Medicine (do the northeast docs even pay attention to something that is published in their own neighborhood?) that reported:

There were 162 coronary events, of which 89 were major events (myocardial infarction or death from coronary heart disease). In comparison with participants with no coronary calcium, the adjusted risk of a coronary event was increased by a factor of 7.73 among participants with coronary calcium scores between 101 and 300 and by a factor of 9.67 among participants with scores above 300 (P<0.001 for both comparisons). Among the four racial and ethnic groups, a doubling of the calcium score increased the risk of a major coronary event by 15 to 35% and the risk of any coronary event by 18 to 39%.

How about the Prospective Army Coronary Calcium (PACC) project (men average age 43 years):

"In these men, coronary calcium was associated with an 11.8-fold increased risk for incident coronary heart disease (CHD) (p = 0.002) in a Cox model controlling for the Framingham risk score. Among those with coronary artery calcification, the risk of coronary events increased incrementally across tertiles of coronary calcium severity (hazard ratio 4.3 per tertile)."

Calcium score provided additional information even after factoring in the Framingham risk score.

That's just a sample of the studies. There are a number more.

Add to these conversations the fact that, unlike reducing blood pressure or LDL cholesterol, the heart scan score is a quantification of the disease itself. It can also be tracked over time to gauge the success or failure of prevention efforts. To believe that blood pressure reduction or LDL cholesterol reduction is sufficient to eliminate risk is something only a fool would believe.



Contary to the above statements, the data are clear:

--The higher the heart scan score, the greater the risk. This has been demonstrated beyond any shadow of a doubt in at least a dozen published studies. In fact, heart scan scores outshine lipid/cholesterol values several-fold.

--A person with a zero score has a nearly zero risk for cardiovascular events over a 5-year timeline.

--Heart scans are the only quantitative test available of coronary atherosclerotic plaque. This means that they can be repeated to gauge progression or regression. Cholesterol does not do that. Stress tests do not do that.

--Heart scans are not the same as CT coronary angiography.

--The lack of "need" for a procedure does not equate to the absence of disease.

The power of heart scans is that they can uncover evidence for coronary atherosclerotic plaque 10 years before a cardiac disaster strikes. Witness Tim Russert's heart scan score of 210 in 1998 at age 48. 10 years later, you know what happened.

Beware the camipaign of misinformation and ignorance that continues that is hell-bent on maintaining the procedural status quo or locking us into a "drugs for all" mentality.
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Comments (15) -

  • Anna

    9/17/2008 7:34:00 PM |

    I hate to dump on Northeasterners (I was one for the first 25 years of my life) but perhaps they have greater cognitive difficulties stemming from lack of Vit D & over-statinating?  Can't see the forest for the Framingham trees?

  • rabagley

    9/18/2008 4:46:00 AM |

    Dr. Davis, I think that you well know exactly why those statements are made the way they are Smile  The issue is that the CT heart scan does not clearly show any indication of a need for medical intervention, and therefore is considered worthless by those who think that the only justifiable reason for a diagnostic procedure is to determine if medical intervention is appropriate.

    Your argument for the utility of the heart scan is based on the ability of the scan to predict the utility of preventive behavior, reversing the accumulation of plaque by changing the composition of blood lipids.  Preventive action isn't even on these guys' radar.  You've also told us why it's not on their radar: prevention isn't profitable and doesn't pay off the student loans that cardiologists incur or the capital costs of the cardiology facilities in big medi-business.

    If I was cynical, I would say that they know the actual value of statins by the argument they use to dismiss the primary indicator of ongoing heart disease.  They know that statins have little or no effect on accumulated calcium in the heart and know that someone paying attention to heart scan scores would quickly realize the significant, painful and common side effects of statins are not worth the limited benefit.

    But anyone reading your blog or on the TYP program already knows why this is the rhetoric because you have repeatedly clearly explained what's going on any why (as usual: follow the money)

  • Anonymous

    9/18/2008 12:56:00 PM |

    50 x-rays? is that true?

  • lizzi

    9/18/2008 3:23:00 PM |

    Dr Davis.  Do you have any data that decreasing coronary calcium scores actually saves lives or decreases cardiac morbidity? As you show in this post, the association of Coronary calcium score and atherosclerotic heart disease is undeniable as well as prolific.  I would just love to believe that decreasing one's score really prevented heart attacks.

  • Anonymous

    9/18/2008 6:38:00 PM |

    It would be nice if you could address what tests us 20 and 30 somethings can have done since CT scans are not recommeneded for our age group.

  • jean

    9/18/2008 6:54:00 PM |

    "If I was cynical, I would say that they know the actual value of statins by the argument they use to dismiss the primary indicator of ongoing heart disease. They know that statins have little or no effect on accumulated calcium in the heart and know that someone paying attention to heart scan scores would quickly realize the significant, painful and common side effects of statins are not worth the limited benefit."
    -rabagley
    And knowing all of the above, why would they espouse knowledge that makes a mockery (!yes!) of their entire professional life? Having worked 10 years in a CCU as a nurse, a little thing called EGO is possibly involved (ah, the turf fights, I remember them well). Just possibly. Oh, and money. Money, money, money!
    Thank you for trying to bring these folks, kicking and screaming, into the 21st century.

  • Peter Silverman

    9/19/2008 2:58:00 PM |

    I wonder if anyone has scanned John McCain's 1000 pages of medical records to see if he's had heart scan?

  • Anonymous

    9/19/2008 10:42:00 PM |

    “The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him.”
         - Leo Tolstoy

  • Anonymous

    9/20/2008 2:56:00 AM |

    Dr Davis,

    As someone who is "in between" scores - first one 230 at 52 and 410 at 54 - with huge changes in Vit D, fish oil, etc and great results in both Berkley and MNR results.... I do wonder.

    Have there been studies that show the hard to soft ratio of calcium is constant, or in people who have declining heart scan scores, or *slowing* scores, that the soft dangerous plaque for those people is lower than those whose scores are growing.

    It seems (logically) that declining scores would indicate a change in percentages (e.g. flat scores show a significant reduction in the amount of "soft" plaque.

    Dave K

  • Anonymous

    9/20/2008 12:03:00 PM |

    Re:"50 x-rays? is that true?"

    From July 3, 2008

    On present-day CT devices, heart scans expose a patient to 0.4 mSv of radiation on an electron-beam, or EBT, device, and on up to 1.2 mSv on a 64-slice multi-detector, or MDCT, device, compared to 0.1 mSv during a standard chest x-ray. CT heart scans are therefore performed with about the same quantity of radiation as a mammogram done to screen women for breast cancer, or about the equivalent of four chest x-rays on an EBT scanner, up to 12 chest-xrays on a MDCT scanner.

  • Alan S David

    9/24/2008 2:56:00 PM |

    I have cut the wheat to less than 3% of my diet.I do eat a once a wekk lower fat pizza Smile
    My calcium scan score was a 90 last January and I am hoping ( at age 59+) to see the same or better this January. I also added 6-8 fish oil caps a day, take niacin and L-arginine, as well as increased my cardio program.
    Lost 18 pounds from an already somewhat trim weight level. My ldl though went from 170 to 220, while HDL went from 40 up to 55. Not sure why on this, other than the fish oil maybe?

  • Rick

    6/25/2009 6:55:55 AM |

    >My ldl though went from 170 to 220, while HDL went >from 40 up to 55. Not sure why on this, other than >the fish oil maybe?

    My take (based on my reading of Dr Davis's work and that of Dr Michael Eades) is that:
    1. The score is probably inaccurate because they've calculated the LDL for you rather than actually measuring it;
    2. Since your HDL has gone up (and probably triglycerides have gone down), it probably doesn't matter even if your LDL has actually gone up. ( I think Dr Davis might disagree with this second one.)

  • Rick

    6/25/2009 6:58:52 AM |

    BTW, Dr Davis, although you say that Dr Manning has confused CT coronary angiography and CT heart scanning, you don't mention what the difference is or why people would confuse them.

  • Anonymous

    9/21/2009 3:46:44 PM |

    AS A CARDIOLOGIST MYSELF: Unfortunately, this article is overly opinionated and incorrect at times. Much of the info IS correct, such as the fact that calcium DOES predict risk of coronary disease. But using this to track progression/regression is NOT appropriate and this has been shown in a very large published trial (mainly because calcium tends not to regress with treatment on statins).

    I don't mind a blog post like this with an opinion, but it is irresponsible to suggest that another physician (and one of the most respected in the field) is incorrect without confirming your facts. Dr. Manning is correct in his statments about calcium scoring, the radiation exposure, and general lack of usefulness in practice. Please post response if you would like me to further address the specifics on this issue.

  • Dr. William Davis

    12/16/2010 2:29:07 AM |

    Anonymous cardiologist--

    I'd be happy to hear more about your opinions.

    First, credible opinions do not originate from "anonymous." For all I know, you are a plumber or the guy who changes oil at the Quick Change station.

    Second, credible opinions do not start with criticizing a blog for expressing opinion. This is a BLOG, not a JACC or NEJM publication.

    As a start, I would say you've been sucker-punched into believing that serial coronary calcium scores do not work because statins don't have an effect on reducing scores. What if they were the wrong treatment to begin with?

    Are you the same guy who invites the good looking sales rep for Pfizer into your office who tells you that their "data" shows extravagant improvement in endpoints? Do you also believe that heart disease prevention ends with your prescription pad?

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Equal calories, different effects

Equal calories, different effects

9. January 2008 William Davis (15)
A great study was just published in the Journal of the American College of Cardiology:

Metabolic effects of weight loss on a very-low-carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects.

88 obese adults with metabolic syndrome were placed on either of two diets:

1) A very low-carbohydrate, high-fat diet (VLCHF): 4% calories from carbohydrates (truly low-carb); 35% protein; 61% fat, of which 20% were saturated. In the first 8 weeks, carbohydrate intake was severely limited to <20 grams per day, then <40 grams per day thereafter.

2) A high-carbohydrate, low-fat diet (HCLF): 46% calories from carbohydrates; 24% protein; 30% total fat, of which <8% were saturated.

Both diets were equal in calories (around 1400 calories per day--rather restrictive) and participants were maintained on the program for six months.

At the end of the six month period, participants on the VLCHF diet lost 26.4 lb, those on the HCLF diet 22.2 lbs (though the difference did not reach statistical significance). Thus, both approaches were spectacularly successful at weight loss.

Surprisingly, blood pressure, blood sugar, insulin and insulin sensitivity (a measure called HOMA) were all improved with both diets equally. Thus, these measures seemed to respond more to weight loss and less to the food composition.

Lipids differed between the two diets, however:


VLCHF:
Total cholesterol: initial 208.4 mg/dl final 207.7 mg/dl

LDL: initial 125 mg/dl final 123 mg/dl

HDL: initial 55 mg/dl final 64.5 mg/dl

Triglycerides: initial 144 mg/dl final 74 mg/dl

Apoprotein B: initial 98 mg/dl final 96 mg/dl


HCLF
Total cholesterol: initial 208.4 mg/dl final 187.5 mg/dl

LDL: initial 126 mg/dl final 108 mg/dl

HDL: initial 51 mg/dl final 54.5 mg/dl

Triglycerides: initial 157.6 mg/dl final 111 mg/dl

Apoprotein B: initial 100 mg/dl final 95 mg/dl


Some interesting differences became apparent:
--The VLCHF diet more effectively reduced triglycerides and raised HDL.
--The HCLF diet more effectively reduced total and LDL.
--There was no difference in Apo B (no statistical difference).

The investigators also made the observation that individual responsiveness to the diets differed substantially. They concluded that both diets appeared to exert no adverse effect on any of the parameters measured, both were approximately equally effective in weight loss with slight advantage with the carbohydrate restricted diet, and that lipid effects were indeed somewhat different.


What lessons can we learn from this study? I would propose/extrapolate several:

When calories are severely restricted, the composition of diet may be less important. However, when calories are not so severely restricted, then composition may assume a larger role. When calories are unrestricted, I would propose that the carbohydrate restriction approach may yield larger effects on weight loss and on lipids when compared to a low-fat diet.

The changes in total cholesterol are virtually meaningless. Part of the reason that it didn't drop with the VLCHF diet is that HDL cholesterol increased. In other words, total cholesterol = LDL + HDL + trig/5. A rise in HDL raises total cholesterol.

Despite no change in Apo B, if NMR lipoprotein analysis had been performed (or other assessment of LDL particle size made), then there would almost certainly have seen a dramatic shift from undesirable small LDL to less harmful large LDL particles on the VLCHF diet, less change on the HCLF diet.

The lack of restriction of saturated fat in the VLCHF that failed to yield adverse effects is interesting. It would be conssistent with the re-analysis of saturated fat as not-the-villain-we thought-it-was put forward by people like Gary Taubes (Good Calories, Bad Calories).

In the Track Your Plaque experience, small LDL is among the most important measures of all for coronary plaque reversal and control. Unfortunately, although this study was well designed and does add to the developing scientific exploration of diet, it doesn't add to our insight into small LDL effects. But if I had to make a choice, I'd choose the low-carbohydrate, high-fat approach for overall benefit.
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Comments (15) -

  • MAC

    1/9/2008 1:55:00 AM |

    Dr. Davis,
        You have to check out Dr. Eades blog on the same study. You both had different takes but came to the same conclusion. http://www.proteinpower.com/drmike/

  • Dr. Davis

    1/9/2008 3:22:00 AM |

    Hi, MAC--

    Thanks for pointing out Dr. Eades post.

    I've lately come to read his posts regularly, as I have been thoroughly impressed with his insights.

    It's good to know there's some real thinkers out there!

  • rick

    1/9/2008 4:37:00 AM |

    Had the HCLF group enjoyed the same nearly 50% drop in TG as the VLCHF group, their calculated LDL would have dropped to 117 rather than 108.  So part of their comparative advantage is not a benefit at all.

  • Anonymous

    1/9/2008 5:33:00 AM |

    Hello,

    Dr. Davis, what is your viewpoint on saturated fat intake and arterial damage? Although perhaps saturated fat doesn't affect lipid values too negatively (in fact, it seems to raise HDL), maybe it can eventually lead to heart disease by other means -- inflammation/damage to arteries, leading to plaque build-up?

    There is a reference to a study here, which you've probably seen:

    http://www.sciencedaily.com/releases/2006/08/060808091635.htm

    I'm curious on your viewpoints, as we know not all fats are bad, but it seems a little muddy as to if certain saturated fats are bad or not.

  • chcikadeenorth

    1/9/2008 5:37:00 AM |

    Hi, you commented once on my high hdl..68...it happened after I low carbed, high calories( plus 1800 a day) and hi fat but under 20 gr of sat fat a day.My Ldl went up but lipoprotein(a) was still within the norm not for TYP but for lab values,
    I hear nothing but good results  with LC going back to Atkins,Bernsteins, Eades, Westman and you Dr D so keep plodding along. Soon everyone will know what a wheat belly is and rather than plod you'll be galloping writing another book SmileThnx for all.

  • Dr. Davis

    1/9/2008 1:33:00 PM |

    Most of the feeding studies like the one you cited are flawed in that they claim to have isolated the effect of saturated fat on some measure, brachial forearm dilatation, in this instance. Unfortunately, they did no such thing. They did not control well for carbohydrate effects. Gary Taubes would point out that they presumed that carbohydrates are good and therefore all adverse effects must be from the saturated fat component.

    We are planning a thorough review of the issue in future.

  • g

    1/9/2008 4:50:00 PM |

    You know... I'd love to see the CAC scores (or even IMT if possible?) for people on Protein Power?  Has that ever been studied?  Mac, have you ever had an EBT/CT scan? (are you > 40 yr?)

    I think that would be very very COOL data Smile   Thanks for sharing -- I've checked DR. Eades out since you started posting...  His wife does a nice 'tablescape' like Sandra Lee!  
    I loved his post on foie gras!  That's what I tell my elevated liver test patients -- they are making their fatty livers into FOIE GRAS (and good think I'm not Hannibal... but I like chianti *ha ahaaa*).

    g

  • andyj

    1/9/2008 5:53:00 PM |

    While I would dearly love to try this myself, I am still (as always) having a mental problem with the high-fat part.  I am currently trying to fine tune a plan to do a calorie-restricted diet (about 1600 calories) but I'm not sure how low I can get the carbohydrate segment to go  -- certainly not under 10%.   Most of the fat will be from nuts and chocolate (and salmon and sardines) and I will certainly do a NMR after the fact.  The biggest problem is crafting something you can actually live with for an extended period of time, not just a couple of months.  Therein lies the real problem.  Maybe we should just stop eating altogether!  I have plans for a blog entry on just this subject --  what if we ate only when we truly had to?  Some days I'd have no problem dropping down to about 1000 calories a day, but of course then exercise would be out of the question.  Yeah, this plan still needs some tinkering before I attempt it.  
              andysheart.blogspot.com

  • MAC

    1/9/2008 8:01:00 PM |

    Dr. Davis,
       New paper on Vitamin D and heart diseases. Paper says they cannot recommend testing for Vit D nor recommend supplementaion for those with a known deficiency.
    http://www.sciencedaily.com/releases
    /2008/01/080107181600.htm

    To g: I am over 40 and only low carbing recently. Previous to that used vegan diet to lose weight successfully. Have not had a heart scan yet but seriously thinking of it as my father was diagnosed with Type 2 at 65 and had quadruple bypass.

    P.S. Went to doc the other day and we decided to do some blood work since it had been while and unbeknownst to me until I looked at the paper work he had ordered a Vit D 25OH test and I got him to order a lipoprotein analysis for the lipid part. No discussion, he agreed. I think he keeps up on  latest research.

  • Dr. Davis

    1/9/2008 8:25:00 PM |

    Hi, MAC--

    Progress!

  • MAC

    1/9/2008 11:18:00 PM |

    FYI.

    Posted by me on Dr. Eades site:

    "You and Dr. Davis both reviewed the same study in your respective blogs on the same day. Bit of different takes but same conclusion. http://heartscanblog.blogspot.com/

    Hi MAC–

    I’m a reader of Dr. Davis’ blog from time to time. I guess today that great minds thought alike.

  • g

    1/10/2008 4:20:00 AM |

    MAC -- it sounds like you have a biochem background too?  Yes, I agree many great thinkers are coming up with vastly similar conclusions!  I think that the best balance betw being fed and 'fasting' maybe key (didn't u discuss earlier?). Where is that? maybe being mildly ketotic? at 5-10? or 0-20?  for CAD who knows yet?

    Here's an example of industry looking for a single drug ligand/target (a $325 million one)...  The answer has already been discovered.  you've found it, dude!  I'm not sure about the relationship betw protein and plaque and CAD yet...  do you have some insights?

    http://blogs.wsj.com/health/2008/01/08/rna-mania-genzyme-drops-325-million-on-cholesterol-shot/#comment-60086

    THANKS!! g

  • MAC

    1/10/2008 3:24:00 PM |

    To g: I think you have me confused with another poster. Sorry don't think that was me. Maybe Peter? Minor in chemistry and lots of science courses but no biochem.

    BTW, the great mind in this case was Dr. Davis, and that was Dr. Eades paying him the compliment.

  • g

    1/10/2008 8:49:00 PM |

    Sorry for the confusion -- so many quality post-ers here!  It's great that you're considering starting on vit D -- it improved insulin sensivity in a small trial 60% (that's more than any drug out there like metformin or Actos).

  • chickadeenorth

    1/11/2008 7:45:00 PM |

    g et al  do you have some reading material about Vit D improving insulin resistance I could take to my doc. I am on 4000 units a day, haven't noticed any difference but it is only about 2 weeks now.

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