Should I get a CT scan for coronary artery disease?

August 13, 2008 12:54 PM

Should I get a CT scan for coronary artery disease or atherosclerosis? My cardiologist wants me to have a CT scan , but after reading this, this, and an article in Consumer Reports on Health March 2007 entitled "Angioplasty: Resist the rush", I am skeptical.

BACKGROUND
Note: I live in Toronto (Canada) so neither cost nor a private health plan is an issue here. [Doctor or clinic profit may be.]

I am a 63-year-old male in good health, 5' 7" and 190 lbs, with a 36" waist.
January 2007: routine ECG showed a 3 mm depression in the ST segment. I had no symptoms.
March 2007: blood tests, an echocardiogram, and a perfusion MRI stress test showed that I had "a 70% chance of a 70% blockage" in the left anterior descending artery (LAD). During the stress test I felt a tightness in my chest, as if my rib cage was not big enough for my lungs.
The cardiologist recommended an angiogram and probably a stent. I refused and opted for treatment by exercise and diet.
May 2008: the above tests repeated. Now only a 1.5 mm depression in the ST segment. No symptoms except the tightness during the stress test.

The CT scan seems to me inadvisable for two reasons: 1) it can't tell whether my plaque is going to dislodge or not; and 2) it's the equivalent of about 400 chest x-rays.

Preliminary question: do I have angina (variously described on the internet as ranging from "severe chest pain" to "discomfort")? No one will give me an unequivocal face-to-face answer.

Big question: Should I have the CT scan?

The big a-ha! : I'm afraid to tell the cardiologist I don't want the scan. After all, he's the expert and I read only the NY Times, Life and Consumer Reports; it doesn't seem to be a fair match. Also, I have a feeling that no other cardiologist out there would disagree with him.

(Can anyone recommend a non-invasive, non-interventionist, evidence-based-medicine cardiologist in the GTA?)

posted by feelinggood to health & fitness (8 comments total)

My opinion: The CT is worth it. Don't play games with your heart. The radiation shouldn't be a factor, as long as you don't make a frequent habit of getting CT scans.

(I'm basing this strictly on the stress test results, BTW.)

As for an angioplasty, that's worth a second and third opinion, as it's seriously invasive. You don't want it unless you have to have it. The problem, of course, is that even if there's a small chance of a heart episode, you want to get out in front of it. Second and third opinions are good for quandaries like this.

Unfortunately, there is no test that can tell whether a blockage will dislodge in whole or in part. But, a very experienced cardiologist (or three) can tell you whether you're chances are good or bad based on the imaging.

Good luck!
posted by Citrus at 1:11 PM on August 13, 2008

I vote for getting the CT scan. My cardiologist tells me that an angiogram will detect blockages greater than 40% but to visualize anything below 40% you'll need the cardiac CT

Since you're talking about a (potential) 70% blockage, the angiogram may detect it.
Pros: you can put in a stent immediately if it's necessary
Cons: it's not comfortable and if they use the Angio-Seal to close up the hole in your leg, you'll have to keep that leg still for 6 hours.

But it does remain a 70% chance of a 70% blockage so it might not detect it. In which case a CT scan is your monster.
Pros: you just lie there; no holes, no poking, no healing; greater detail in your readout.
Cons: radiation (which as Citrus says, don't make a habit of it and you ought to be okay), if you need a stent, you'll have to undergo catheterization anyway.

My gut says to go with non-invasive over invasive and greater information gathering techniques.

I am still not a doctor.
posted by oreonax at 1:34 PM on August 13, 2008

Get the CT angio. see how much better you did with exercise and diet. If better: yay, keep up the good work. If worse/same: follow doctors recommendations (likely get a cardiac cath to prevent possible death.)
posted by ruwan at 2:20 PM on August 13, 2008

Not a doctor, not even a heart patient, although I've had many, many CT scans, a cerebral angiogram and was with my mom for her cardio angios and stents.

I'd say get the CT. It doesn't mean you'll have to get the angio and/or stent done. But it will give you, your cardiologist, and any other professionals whose advice you seek a better idea of what's lurking in there. A couple CTs are fine. If you're getting one every month for years, then I'd worry. And compared to the angio, the CT is a piece of cake.

CTs are pretty standard, because they're easy and doctors like knowing what they're dealing with. Maybe they request them more they they should, and there are obviously cases when they were found to not be necessary after all, but they're erroring on the side of your health. Taking pictures of the problem is the easiest way to see what the problem actually is, short of seeing it with your eyes.

As for the angio, if you do get one and they realize you do need a stent, they'll put it in at the same time. (Or at least they did for both my mom's.) Conversely, they won't if it's not necessary. My mom went in for her latest angiogram with the understanding they'd be putting in another stent as well given the results of her CTs and stress tests. Once they got in there however, they saw there was only a 50% blockage and they decided against the stent for the time being.

But no matter what the situation, there's no harm in getting a second or even third opinion.
posted by cgg at 2:20 PM on August 13, 2008

I vote for the CT. As a matter of fact, I would vote for non-invasive techniques if I was ever given a choice. Worse case, you'll have to have a heart cath anyways.

Depending on which stress test you received, Its normal to have that tightness in your chest as they're injecting the meds. (this is what our nuclear tech who handles stress tests in the office tells me)

DO NOT be afraid to tell your doctor you don't want a heart cath. I feel that sometimes the docs will quickly opt for a heart cath if the patient fits the criteria, but it is what they have been trained to do. Go for a second opinion and/or discuss possible alternatives with your cardiologist

IANAD, but i do work at a cardiology practice and get to observe a lot of these situations.
posted by aGee at 2:27 PM on August 13, 2008

I had a heart attack in 1999, in the rack with Sandy from San Antone; she surely was rambunctious. I wasn't sure of it (the heart attack -- I was pretty dang sure about Sandy), and I was in such good shape that I was doubtful of it. So I went to my doc, he took an ekg, didn't find anything, sent me to The Austin Heart Hospital, and they put me on a stress test, and listened with their little stethoscopes in a very doctorly way, or whatever it is they did. What they didn't do was find anything wrong.

There was plenty wrong. And had they done a CT test they'd have seen it, or at least they might have, thus precluded what happened in July 2004.

Are you interested in death?

Myself, I've always been interested in death, the whole NDE thing and all, it sounds cute, sortof fun, almost, zooming around over peoples heads, life review, The White Light, that whole thing. And depression -- yeah, sure, there's times I've considered leaping off a building, or what have you. But actually dying and stuff? It was somewhere after "Going to the coast" on the list of things I wanted to do, after that but before "Listening to rap music".

But I did die.

You can too.

I just can't recommend this.

Some stuff has shown up on your ekg -- you do have issues. Other than that pesky hereditary defect in my cardiac artery I was healthy as a horse.

It's your call, for sure. Though you might want to include your loved ones, sortof let them in on this decision, as they do have a stake in it. And you might want to consider your favorite painting, or your very favorite poem, or how much you enjoy watching the sun rise, or set, or just how beautiful it is to watch a full moon rise at dusk, rich ivory turning pale as it rises the sky. Which is to say: This thing is beautiful. Don't check out early, or even risk it -- I even wear seat belts now.

And don't go to San Antone until after you're fixed up, if you catch my drift...
posted by dancestoblue at 7:29 PM on August 13, 2008 [2 favorites]

Were I in your position, I might ask for the diagnostic angiogram that has already been offered - not the CT angiogram, the actual invasive femoral-stick angiogram where they thread a catheter into your coronary arteries and squirt dye in under X-ray guidance. That test is the gold standard for identifying a structural lesion in the coronary vessel. There is no law saying the cardiologist has to angioplasty or stent you while you're on the table; a cardiac angiogram can be purely diagnostic. But if there's a lesion, there is the option to fix it right then.

The stress test can detect actual ischemia, which the angiogram can't. Ischemia means the end organ, in this case the heart muscle, isn't getting as much blood as it needs. Ischemia means: too late. It's great to test for that, but boy, once it's there the horse is out of the barn. Often heart muscle has started dying, hardening, thickening, remodeling, doing everything but what you would like it to do by the time ischemia is present.

MRI stress tests are perfusion tests for ischemia, but the stress is usually pharmacologic - a drug to make your heart beat faster is dripping into you during the study. Sometimes these drugs can cause chest feelings that aren't angina. A regular treadmill-EKG stress test is stll first-line here in the States; I dunno how you guys do business up in Canada.
posted by ikkyu2 at 12:30 AM on August 14, 2008

I have a bit of a personal bias against coronary CT, which as of yet in my opinion is neither well-enough studied as a diagnostic modality nor incorporated into any of the major guidelines or algorithms for diagnosis and management of coronary artery disease by societies like the ACC/AHA etc. So take what I say with a grain of salt as a non-cardiologist, but practicing physician in the US.

An exercise stress test with your findings along with exertional chest pressure is already highly suggestive of coronary artery disease and possibly mild angina. That's pretty much all the risk stratification one needs to determine what medications you need to reduce your risk of an event (ie a heart attack and heart failure). There is no well tested modality to determine how or when such an event may occur in a patient with known coronary artery disease (which it sounds like you may be). Consequently at risk patients are typically treated with the same bevy of medications (aspirin, beta-blockers, ACE inhibitors, statins, etc.) because in large prospective, randomized controlled studies these agents have all been shown to essentially reduce the risk of major cardiovascular events and death in high risk patients.

Angiography and stenting in relatively asymptomatic patients has not been shown to provide any tangible benefit in terms of mortality or morbidity as compared to conservative management (see the COURAGE trial), perhaps with the exception of the subset of patients who have severe multivessel or left main coronary disease with evidence of systolic heart failure. What this means to me is that the only thing worth knowing is whether you are in this select group or not because that additional risk stratification would make you a good candidate for stenting or bypass grafts. Otherwise if a study that exposes you to radiation or an invasive procedure isn't going to change your medical care in any way, there's no point in doing it. Also do bare in mind that if you and your doctor agree that further testing is appropriate, as ikkyu2 points out, the old invasive angiography is still the gold standard. And I agree personally, that it's a better option for another reason: if the idea is to find out if you have a stent-appropriate type of disease, then angiography allows for the potential of performing the intervention at that time. If an alternative modality is used, you're still going to need the angiogram anyway to get the stenting done if necessary.

So my recommendations would be:

1) Ask your doctor how the diagnostic test is going to change your management and why he or she favors it over alternatives (ie standard angiography).

2) If the answer is simply to stent whatever is stentable, make sure to ask if your doctor thinks that stenting is going to either reduce your risk of heart attacks or death. There's an exuberance amongst the interventionalists to stent any significant occlusion because of a belief that it may reduce symptomatic angina, but as I noted invasive interventions have only been shown to improve hard outcomes like mortality in certain specific patterns of disease or shortly following heart attacks.

3) Seek a second opinion if the answer you receive is unsatisfactory.

4) At your age, and with your suggestive heart disease, you should probably be much, much less concerned about the radiation from a CT scan or angiography as compared to the concern for keeling over from a massive heart attack. I'm not saying don't worry about it. Certainly avoid radiation exposure if it isn't going to change anything. But if such a study does ultimately yield information that may lead to an intervention that adds years to your life, then you need to put aside what may be irrational fears about "radiation" and do what's best for you.
posted by drpynchon at 8:07 AM on August 14, 2008