Tag Archives: calcium scan

Coronary Artery Calcium Scan Embraced By New AHA/ACC Cholesterol Guidelines: Will Insurance Coverage Follow?

The skeptical cardiologist has been utilizing coronary artery calcium (CAC) scans to help decide which patients are at high risk for heart attacks, and sudden cardiac death for the last decade. As I first described in 2014, (see here) those with higher than expected calcium scores warrant more aggressive treatment and those with lower scores less aggrressive treatment.

Although , as I have discussed previously, CAC is not the “mammography of the heart” it is incredibly helpful in sorting out personalized cardiovascular risk. We use standard risk factors like lipids, smoking, age, gender and diabetes to stratify individuals according to their 10 year risk of atherosclerotic cardiovascular disease (ASCVD) but many apparent low risk individuals (often due to inherited familial risk) drop dead from ASCVD and many apparent high risk individuals don’t need statin therapy.

Previously, major guidelines from organizations like the AHA and the ACC did not recommend CAC testing to guide decision-making in this area. Consequently, CMS and major insurers have not covered CAC testing. When my patients get a CAC scan they pay 125$ out of their pocket.. For the affluent and pro-active this is not an obstacle, however those struggling financially often balk at the cost.

I was, therefore, very pleased to read that the newly updated AHA/ACC lipid guidelines (full PDF available here) emphasize the use of CAC for decision-making in intermediate risk patients.

 

 

 

 

 

 

 

 

For those patients aged 40-75 without known ASCVD whose 10 year risk of stroke and heart attack is between 7.5% and 20% (intermediate, see here on using risk estimator) the guidelines recommend “consider measuring CAC”.

If the score is zero, for most consider no statin. If score >100 and/or >75th percentile, statin therapy should be started.

I don’t agree totally with this use of CAC but it is a step forward. For example, how I approach a patient with CAC of 1-99 depends very much on what percentile the patient is at. A score of 10 in a 40 year old indicates marked premature build up of atherosclerotic plaque but in a 70 year old man it indicates they are at much lower risk than predicted by standard risk factors. The first individual we would likely recommend statin therapy and very aggressive lifestyle changes whereas the second man we could discuss  taking off statins.

Neil Stone, MD, one of the authors of the guidelines was quoted  as saying that the imaging technique is “the best tiebreaker we have now” when the risk-benefit balance is uncertain.

“Most should get a statin, but there are people who say, ‘I’ve got to know more, I want to personalize this decision to the point of knowing whether I really, really need it.’ … There are a number of people who want to be certain about where they stand on the risk continuum and that’s how we want to use it,”

Indeed, I’ve written quite a bit about my approach to helping patients “get off the fence” on whether or not to take a statin drug.

I recommend reading “Are you on the fence about taking a statin drug” to understand the details of using CAC in decision-making and the follow up post on a compromise approach to reducing ASCVD risk.

Deriskingly Yours,

-ACP

Full title of these new guidelines includes an alphabet soup of organization acronyms

2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol

N.B. For your reading pleasure I’ve copied the section in the new guidelines that discusses in detail coronary artery calcium.

Two interesting sentences which I’ll need to discuss some other time

-When the CAC score is zero, some investigators favor remeasurement of CAC after 5 to 10 years

CAC scans should be ordered by a clinician who is fully versed in the pros and cons of diagnostic radiology.

In MESA (Multi-Ethnic Study of Atherosclerosis), CAC scanning delivered 0.74 to l.27 mSv of radiation, which is similar to the dose of a clinical mammogram 

-4.4.1.4. Coronary Artery Calcium

Substantial advances in estimation of risk with CAC scoring have been made in the past 5 years. One purpose of CAC scoring is to reclassify risk identification of patients who will potentially benefit from statin therapy. This is especially useful when the clinician and patient are uncertain whether to start a statin. Indeed, the most important recent observation has been the finding that a CAC score of zero indicates a low ASCVD risk for the subsequent 10 years (S4.4.1.4-1–S4.4.1.4-8). Thus, measurement of CAC potentially allows a clinician to withhold statin therapy in patients showing zero CAC. There are exceptions. For example, CAC scores of zero in persistent cigarette smokers, patients with diabetes mellitus, those with a strong family history of ASCVD, and possibly chronic inflammatory conditions such as HIV, may still be associated with substantial 10-year risk (S4.4.1.4-9–S4.4.1.4-12). Nevertheless, a sizable portion of middle-aged and older patients have zero CAC, which may allow withholding of statin therapy in those intermediate risk patients who would otherwise have a high enough risk according to the PCE to receive statin therapy (Figure 2). Most patients with CAC scores ≥100 Agatston units have a 10-year risk of ASCVD≥7.5%, a widely accepted threshold for initiation of statin therapy (S4.4.1.4-13). With increasing age, 10- year risk accompanying CAC scores of 1 to 99 rises, usually crossing the 7.5% threshold in later middle age (S4.4.1.4-13). When the CAC score is zero, some investigators favor remeasurement of CAC after 5 to 10 years (S4.4.1.4-14–S4.4.1.4-16). CAC measurement has no utility in patients already treated with statins. Statins are associated with slower progression of overall coronary atherosclerosis volume and reduction of high-risk plaque features, yet statins increase the CAC score (S4.4.1.4-17). A prospective randomized study of CAC scoring showed improved risk factor modification without an increase in downstream medical testing or cost (S4.4.1.4-18). In MESA (Multi-Ethnic Study of Atherosclerosis), CAC scanning delivered 0.74 to l.27 mSv of radiation, which is similar to the dose of a clinical mammogram (S4.4.1.4- 19). CAC scans should be ordered by a clinician who is fully versed in the pros and cons of diagnostic radiology.

Downloaded from http://ahajournals.org by on November 11, 2018

from Grundy SM, et al.
2018 Cholesterol Clinical Practice Guidelines

The Widowmaker Documentary: A Need For Heroes and Villains Detracts From The Truth

The documentary, The Widowmaker (available on Netflix streaming)  should definitely be watched by everyone.

It presents some great information on dying suddenly from heart attacks in an entertaining way.

It makes two important points: coronary stents don’t prevent heart attacks and coronary scans can identify advanced coronary artery disease before heart attacks happen.

I am in total agreement with these two points and have made them several times in previous posts (here and here).

The film is a work of advocacy, however, and twists the truth to prove its underlying theory: that greedy doctors and hospitals are choosing to “push” expensive coronary stents that do no good until you are having a heart attack. Also, that doctors and hospitals are also somehow suppressing the use of coronary calcium scans, which could prevent millions of heart attacks and deaths.

Creating black and white heroes and villains in documentaries makes for riveting entertainment, but often at the cost of sacrificing the truth.

Let’s look at the  villains that The Widowmaker presents.

First up is Julio Palmatz. Dr. Palmatz is a vascular radiologist who invented, along with Dr. Shatz, one of the three primary stents that ultimately gained widespread clinical usage. The Widowmaker implies that Palmatz was THE stent developer, and follows Julio as he revisits the garage in Texas where he developed prototypes for the slotted tube stent.

At this point in the movie, it would be understandable if you thought Julio was going to be one of the heroes. He seems very personable as he describes the inspiration for his stent design and points out the area in the garage where his work bench stood.

However, the documentary wants, ultimately, to portray Palmatz as greedy, unconcerned about patient welfare, and in the pocket of wealthy investors.

He has done well financially because the patent on his coronary stent was eventually sold to Johnson and Johnson for millions (and he is interviewed on the grounds of his Napa Valley vineyard).

A recent scholarly analysis of the process of the development of stents differs with this portrayal of Palmatz:

“We found that the first coronary artery stents emerged from three teams: Julio Palmaz and Richard Schatz, Cesare Gianturco and Gary Roubin, and Ulrich Sigwart. First, these individual physician-inventors saw the need for coronary artery stents in their clinical practice. In response, they developed prototypes with the support of academic medical centers leading to early validation studies. Larger companies entered afterwards with engineering support. Patents became paramount once the technology diffused. The case of coronary stents suggests that innovation policy should focus on supporting early physician-inventors at academic centers.”

Although stents ultimately have become over-utilized, they represent a tremendous invention and contribution to cardiac care.

In the setting of acute heart attacks, stents are clearly life saving and thousands of patients have had their clinical angina or claudication greatly relieved when stents are utilized appropriately for blocked coronary and peripheral arteries.

Consequently, Palmatz and many of the other interventional cardiologists who developed and performed early studies on coronary stents are widely considered heroes by the vast majority of knowledgeable cardiologists.

There is no evidence that they have colluded with industry to inappropriately promote stents or to suppress utilization of methods for early diagnosis and prevention of coronary artery disease.

The documentary then switches to characterizing the world of cardiology after stents were approved by the FDA in the early 90s.

There clearly was (and is) an irrational exuberance about stents and some of this sprang from excellent reimbursement for doing the procedures.

The focus moves to Mt. Sinai Hospital in Manhattan, and arguably the busiest interventional cardiologist in the world, Samir Sharmin.

The movie implies that Mt. Sinai was going broke until it began performing lots of catheterization and stent procedures. Sharmin who does over 1500 interventions per year and apparently earns over 3 million dollars per year is interviewed and filmed performing a stent procedure.

The average viewer likely gathers from the context of the interview with Sharmin, that he is only doing these procedures to make money.

At various points during the movie, Dr. Steven Nissen, past president of the American College of Cardiology, is interviewed and referred to as “America’s top cardiologist.”

In my opinion, Nissen has been an outstanding, independent voice of reason in the world of cardiology. During the interview, he makes the very valid points that coronary calcium scans have not been embraced for routine usage because there are no outcomes data.

At one point he says, “I don’t like medical cults” in reference to those who support more widespread coronary calcium scans.

The movie leaves the uninformed viewer thinking that Nissen is part of a cabal blocking coronary calcium scans, perhaps due to his connections with industry or an inappropriate resentment of the “calcium club” pushing the scans.

Nothing could be further from the truth. I think Nissen is one of the few prominent cardiologists who are not subject to major bias of one type or another and I strongly respect his opinions.

The movie also attempts to portray the editor of Circulation, a major cardiology journal supported by the American Heart Association as inappropriately withdrawing a paper that would have endorsed coronary calcium scanning. It’s not possible to really tell what the truth is about this withdrawal, but this is a very minor episode in the history of coronary calcium scanning.

Ultimately, The Widowmaker fails its audience in presenting the truth because it desperately wants to convince us that there is a connection between the promotion of coronary stents and the failure of coronary calcium scans to be accepted by guidelines and covered by insurance.

There is no such connection. Many interventional cardiologists are enthusiastic promoters of prevention and aggressive use of coronary calcium scans. I have seen no evidence of greedy interventionists trying to  suppress coronary scans.

In Part II of this analysis, I will take a look at the “heroes” of The Widowmaker, the inventors and promoters of coronary calcium scans, and we will see if they are truly heroic.