Sunday, June 29, 2008

Revisiting Cardiac CT Angiograms

The New York Times published an extensive article on the CT angiogram (CTA) for the diagnosis of coronary disease and is a very worthwhile read. In the report, they describe the controversy between cardiologists surrounding these tests. But in their push to provide eye-catching content, they permitted a CT angiogram proponent, Dr. Harvey Hecht of The Lenox Hill Heart and Vascular Institute of New York, to show perfect 3D images of a normal CTA obtained in nice, slow, regular heart rhythm that peels away the rib structures and shows some of the coronary arteries, the inside surface of the heart, and heart valves as he narrates the video. It's like watching something from the "Undersea World of Jacque Cousteau." Yes, they are beautiful pictures and demonstrate the incredible capabilities of this technology. Gosh, who wouldn't want those beautiful pictures of their heart?

Thank you, NYT, for giving Dr. Hecht, and the entire CT proponents all they need to peddle their scans, after all, a picture is worth a thousand words, right?

But if you read the article carefully, those beautiful pictures come at a price: both for the patient and our economically-burdened healthcare system. Not only are they fairly expensive, but the risks of radiation to the patient are real. To the authors' credit, they made this point. But they also failed to explain that for women with generally smaller frames and greater levels of breast tissue, those risks of radiation are amplified. They also didn't show a flawed CTA in their online article sidebar: like one taken in atrial fibrillation (an irregular heart rhythm) or with lots of skipped heart beats - you see, those images aren't quite so clear. Because the heart is a moving organ, collection of the images must be precisely gated to the heart beat. In people with irregular heart rhythms, motion artifact is introduced, degrading the quality of the images obtained.

The authors also failed to show the images of a patient with a heavy coronary calcium score. Those CTA images sometimes don't turn out so well, either. All CT angiograms use iodinated contrast material injected rapidly through an intravenous line placed in the arm. Scanning begins a few seconds later, after the operators think the dye has reached the patient's coronary arteries (the circulation time is estimated). Once the contrast agent reaches the arteries, it causes the blood vessels and chambers of the heart to "stand out" from the surrounding walls of the heart and blood vessels. In the case of someone with too much calcium in the arteries, the native calcium also "stands out" and might shadow the actual ability of the contrast to define the lumen of the blood vessel. Also, things like stents, which are metallic, interfere the same way. Additionally, the contrast agents used might be harmful to a patient if they have compromised kidney function, so most people have a blood test to evaluate their kidney function before the test (yes, more money).

Certainly in complex congenital heart disease, here are few tests better than CTA to define to course of anomalous blood vessels. CTA has also been invaluable to electrophysiologists to image the left atrium and the pulmonary arteries to define the size, number, and orientation of vessels before left atrial catheter ablation procedures. Likewise, there might be a role to perform CTA to exclude coronary artery disease in the chest pain patient who presents to the Emergency Room. But as a screening test for the general population or even our "walking well" in the cardiology clinic, these scans have no role today, despite what others may suggest.

Despite this, the patient testimonial was telling:
Nonetheless, in February, Mr. Franks took a test called a calcium score, which measures the amount of calcified plaque in the arteries. The test, a less extensive form of scanning, revealed a moderate buildup of calcium in his arteries, a potential sign of heart disease.

So he decided to have a nuclear stress test. When that test showed no problem, the cardiologist who conducted it said he did not need more testing.

But Mr. Franks was still not satisfied. “I’m someone who wants to know,” he said.

After doing research on the Internet, he found Dr. Hecht, who recommended a CT angiogram. Dr. Hecht acknowledged that Mr. Franks probably did not have severe heart disease. But he said the scan would be valuable anyway because it might reassure him. And his insurance would cover the cost.
"If it's free, it's for me," right?

Boo rah.

But adding up this patient's cumulative radiation dose (10 mSV for the "Calcium Score" + 27.3 mSv for the thallium study + another 21.4 mSv for the CTA) gives him the equivalent of almost 3000 chest x-rays worth of radiation.

And then his cardiologist (Dr. Hecht) wanted to repeat the test every year "so he could see how quickly the plaque in Mr. Franks’s arteries was thickening" claiming "how do we know that our therapy is effective?"

Boo rah.

For the record, I know of no study demonstrating the safety, cost effectiveness, or the ability of CTA to document CAD progression year to year. Further, Hecht's own paper demonstrated that even with extensive cholesterol lowering, no change to plaque burden was documented. I also have never seen such documentation be able to predict a cardiac event of any type. But Dr. Hecht seems to feel insults to those questioning the utility of CTA are appropriate:
Cardiologists like Dr. Brindis (and Dr. Wes, it seems) hurt their patients by being overly conservative and setting unrealistic standards for the use of new technology, Dr. Hecht said.

“It’s incumbent on the community to dispense with the need for evidence-based medicine,” he said. “Thousands of people are dying unnecessarily.”
Hmmm. Dispense with need for evidenced-based medicine? I wonder what Dr. Hecht will say to his patient when the CTA scan shows a tumor mass one year.

-Wes

References: Nico R. Mollet, Filippo Cademartiri, Carlos A.G. van Mieghem, Giuseppe Runza, Eugène P. McFadden, Timo Baks, Patrick W. Serruys, Gabriel P. Krestin and Pim J. de Feyter. "High-Resolution Spiral Computed Tomography Coronary Arteriography in Patients Referred for Diagnostic Conventional Coronary Angiography." Circulation 2005; 112: 2318-2323.

Abelson R, "Heart Scans Still Covered my Medicare." New York Times 13 March 2008.

Addendum 29Jun2008 @ 1523: - the opposing view over at "The Voice in the Ear".

11 comments:

Michael said...

The most chilling part of the article was when Hecht said, “It’s incumbent on the community to dispense with the need for evidence-based medicine.” This guy has totally lost it. He took an oath to provide ethical care in the best interest of the patient. How much money do you need? How much food can you eat? How many houses can you live in? I simply could not treat my patients this way.

htwe said...

To Dr Wes and michael,
I read that NYT article today and I am quite surprised by what Dr Hecht said. Since I am non native speaker of English (I am a Burmese),I have to check the word "dispense with" in Webster online dictionary to make sure that I understand correctly.

Anonymous said...

Wow. Wowie wow wow.

Being quoted saying that in the new york times may be a literal career ender. It's already spreading over the internet. Unbelievable.

Anonymous said...

Nice job Dr Wes.

As our nation continues down the "road of reality" in the delivery of healthcare, it's nice to see your position on unnecessary wasteful dollars being spent on unnecessary procedures. Do your think it's time to risk stratify for the 1/3 unecessary ICDs going in patients today?
What do you think about the vicor technology?

Their claim " recent registry studies have noted that 70% of ICDs never have an appropriate firing. This over-implantation has led to a substantial and unnecessary medical cost burden, and puts patients at risk because of complications that can accompany implantation surgery."

Dr. Brad said...

This analysis highlights one of hundreds of examples where market penetration has been permitted by the FDA and Medicare/Congress prior to evidence showing effectiveness (let alone cost-effectiveness). And we wonder shy healthcare is spiraling out of control....

For specific reference to the AHA Scientific STatement on Assessing CAD using Cardiac CT, go to http://circ.ahajournals.org/cgi/content/full/114/16/1761. Bottom line - they are even more conservative and state that the cardiac CT is indicated only for intermediate-risk (10-20% Framingham Risk Score) patients in which "the goal if refining clinical risk prediction to select patients for more aggressive target values for lipid-lowering therapy (Class IIb, Level of Evidence: B)" --- i would argue that we should strive for aggressive lipid-reduction in anycase. Best achieved with aggressive lifestyle modification and moderate medication dosing.

Anonymous said...

I never understood why cardiologists doing expensive tests in the office isn't a violation of conflict-of-interest laws a la pete stark. Tests like nuclear stress & echo don't even require the presence of a cardiologist.

Of note, Stark's top campaign contributors include the Amer Coll of Radiology!
http://www.opensecrets.org/politicians/summary.php?cid=N00007397

Anonymous said...

Just want to note some other bloggers who blogged on this:

http://hcrenewal.blogspot.com/2008/07/blogscan-evidence-we-dont-need-no.html#links

http://www.gooznews.com/archives/001098.html

http://www.thehealthcareblog.com/the_health_care_blog/2008/06/a-classic-from.html

My friend Merrill Goozner, when I sent him your post today, wondered why you don't have Gooznews on your blogroll. (Maybe he should put Dr. Wes on his blogroll!)

Andrew Whitman said...

What struck me in The New York Times article “Weighing the Costs of a CT Scan Inside the Heart” was what the story omitted: peer-reviewed and emerging clinical trial data showing that CTA scans produce cost savings and improve patient outcomes. Also, for a story of this length to leave out any discussion of appropriateness criteria – even though cardiology and radiology medical societies already have programs in place, and both criteria are part of the current policy discussion – is curious. In my estimation, it fails to offer readers balanced information to help inform their decisions.

There are numerous peer-reviewed studies demonstrating that CT scans detect heart disease and help patients avoid cardiac catheterization. For example, the article could have cited a 2007 study in the Journal of the American College of Cardiology, which found that multi-slice heart scans significantly reduced diagnostic time and produced cost savings. It could have also cited a recent study demonstrating how CT heart scans are an effective and cost-saving tool in selecting patients for cardiac catheterization. The selective catheterization resulted in average cost savings of $1,454 per patient.

Proper utilization of any medical technology is important, and the majority of doctors do use medical imaging appropriately, without standing to realize any financial gain from doing so. In fact, according to 2005 Medicare claims data, an average of 94% of CT, MRI, PET and SPECT referrals are made to physicians who do not order the tests, and that percentage is even higher for cardiac imaging. To address the small minority of instances when imaging is improperly used, policymakers and medical societies are embracing appropriateness criteria and accreditation requirements as effective solutions that allow health decisions to remain in the domain of physicians and patients rather than insurance companies. Unfortunately, The Times story made no mention of this either.

CT heart scans eliminate the need for an invasive and expensive procedure to diagnose coronary artery disease by providing precise and comprehensive information on heart ailments without surgery and within seconds. Yes, a CT heart scan may seem expensive when viewed in isolation, but compare the price tag of a one time scan to the cumulative, long-term costs that will come with its regrettable alternatives: repetitive consultation and progression of disease and inappropriate treatment. Talk about penny wise and pound foolish—especially considering that coronary artery disease is the most common type of heart disease, and the number one killer for both men and women.

Thankfully, Medicare’s recent heart CT scan coverage decision allowed continued patient access to these tremendously valuable scans, which have revolutionized the way doctors diagnose heart disease, and become the standard of care for cardiac disease throughout the country and the world. I am certain that patients across America are benefiting as a result, and in this vein, it is incumbent upon us and our healthcare system to ensure that physicians are continually armed with improved resources for diagnosing and treating disease more precisely, effectively and efficiently – not restricted in their ability to save lives.

Andrew Whitman
Vice President, Medical Imaging & Technology Alliance

MedInformaticsMD said...

Radiation? Who cares about damn radiation?

In the scam known as Worker's Comp here in Philadelphia, I used to regularly see young patients of both genders involved in minor car accidents go through months and months of chiropractic, and undergo repeated lumbar spine series, CT scans, etc. to evaluate their "subluxations."

Of course, this ran up the medical bills, paid for by taxpayers, and also ran up the settlement which was shared by patient and attorney.

The most absurd examples were bus drivers whose 30,000 lb. bus was rear ended at 5 MPH by a car. Somehow the forces were mysteriously transmitted up the frame of the bus, up the air-spring-cushioned drivers seat, and into their backs. "Lumbar strain and sprain and myofasciitis" was the invariable diagnosis from the local neighborhood injury scam doc.

As an occupational medicine physician, I would challenge this, but the challenge was usually lost at arbitration unless we had a surveillance tape of the "patient" enthusiastically playing basketball or other sport!

I warned these folks that every lumbar series exposed them to a lot of radiation (5 rads?), and had a little book showing the increased risk of cancer by exposure and site.

They did not care. I saw some people go through 4 or 5 lumbar spine film series in a year.

Oh, and by the way, in my current role as Medical Informaticist with expertise in building registries and research databases for very complex areas in biomedicine (invasive cardiology as a pertinent example), the statement that

We didn’t need to be talking about registries and the research

is the utmost in pseudo-medical nonsense and hubris. These guys give medical science a bad name.

Anonymous said...

Hmm. What do you think about a CTA for my dad. He's 71, symptom free but has had cholesterol's in the high 200's (untreated) for probably 10 years, and might have OSA (certainly he's got a big waistline). Wears size extra large. He's active. mom died alzheimer's dad died of some catastrophic medical event in his 30's (not clear). EKG has some q's inferiorly x 10 years. Thanks in advance (doc with limited expereience in the field).

Anonymous said...

There is a deeper story here:

1. The patient Hecht scanned had chest pain (making them symtomatic), but the author chose to omit that.

2. Was this article base dupon any new evidence? Or was it mostly anecdotal?

3. In the wake of Tim Russert's death, many patients with chest pain ran to get CTAs. Who would lose money in that scenario?

4. Go search Google for the word CMTP, Tunis and Redberg. You will find out the full story... this is a supposed non-profit that is backed by private payers (i.e. BCBS) who is looking to force clinical trials on new emerging technologies, and then profit on those clinical trials. Would it surprise you that both Tunis and Redberg are/were on Medicare panels that decide whether clinical trials are required?

Why would private payers want new technologies delayed 5-10 years by outcome studies?

Why would NYT quote Redberg and Tunis without disclosing their possible conflicts of interest?

Dip deeper...