What is the Significance of a Borderline Stress Test and What Is The Value of a Coronary Calcium Score after a Stress Test?

A reader asks me the following question:

I’m 35 years old male and was positive for myocardial ischemia during stress test. The cardiologist said that my result was borderline. I’m not sure what does he meant by “borderline”. Also does it help if I do CAC score since my stress test already came out with positive MI?

Good questions.
First off, to understand what any stress test means we have to know the pre-test probability of disease. For example, in 35 year old males without chest pain the likelihood of any significantly blocked coronary artery is very low. This means that the vast majority of positive or borderline tests in this group are false positives, meaning the test is abnormal but there is no disease.
Even if we add exertional chest pain into the mix the probability of a tightly blocked coronary in a 35 year year old is incredibly low (but there are some congenital coronary anomalies that occur.)
The accuracy of stress tests varies depending on the type. The standard treadmill stress test with ECG monitoring is about 70% sensitive  and 70% specific. Adding on a nuclear imaging component improves the sensitivity (it makes it more likely we will pick up a blockage if it is present) to about 85% however, in the real world, the specificity (chance of a false positive) is still quite high. Accuracy varies a lot depending on how good the study is and how good the reader is.
Borderline for either the stress ECG the stress nuclear (or stress echo) means that the test wasn’t clearly abnormal but it wasn’t clearly normal. It is in a grey zone of uncertainty.
Given your low pre-test probability of disease it is highly likely your “borderline” test result is a false positive. Whether anything else needs to be done at this point depends on many factors (some from the stress test)  but most importantly, the nature of the symptoms that prompted the investigation in the first place.
If there are no symptoms and  you went for more than 9 minutes on the treadmill likely nothing needs to be done.
Would a coronary calcium scan add anything?
A very high score (>let’s say 100 for age 35) would raise substantial concerns that you have a coronary blockage.
A zero score would be expected in your age group and probably wouldn’t change recommendations .
A score of 1 up to let’s say 100  means you have a built up a lot more plaque than normal and should look at aggressive modification of risk factors but likely wouldn’t change other recommendations.
So the CAC might be helpful but most likely it would be a zero and not helpful.

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16 thoughts on “What is the Significance of a Borderline Stress Test and What Is The Value of a Coronary Calcium Score after a Stress Test?”

  1. Name: Luis Gonzalez
    Age: 39
    Smoker (For 20 years)
    Height: 5′ 11” – Weight 220 pounds

    Hi Dr. Anthony,

    My mom passed away a little over a month ago. It was a very stressful situation, she spent 45 days in the hospital fighting a hospital-acquired infection. A week before my mom passed I started having pain in many parts of my body, including my left and right chest area, as well as high blood pressure (150-160 over 95-105). The pain lasted for at least 2 weeks so I went to a cardiologist describing I’ve had occasional pain in my left chest area and he ordered an echo and a nuclear stress test. The echo was okay with a mild regurgitation of the pulmonic valve, but the nuclear stress test showed a reversible defect of mild intensity in the mid inferior and apical segments of mild to moderate intensity.

    A few days after the tests were performed the doctor saw me and he just mentioned I had some abnormalities in the nuclear stress test and he told me I needed a catheterization (invasive cardiac angiography) and wanted me to schedule the procedure right away without explaining anything. I stopped him and asked him if there was any other test that could be done to confirm these results before the catheterization and he said that there is not any other test to confirm this. I did not like this doctor’s attitude so I am planning to make an appointment with another cardiologist but my question is the following:

    Should I insist in getting a CT angiography to confirm diagnosis of ischemia before doing an invasive catheterization procedure?

    I know sooner or later I will have to do it but I want to find another cardiologist that is more empathetic and treats patients like humans and not numbers.

    Thank you Doc!

    Reply
  2. Hi Dr P,
    I have genetic elevated cholesterol (been taking Atorvastatin for 15 yrs or more, 10mg), SVT’s and palps. I’ve been working out vigorously for 40+ years. About 6 mos ago, I began to feel a bit winded with weak, heavy feeling in my legs. EKG was fine as was echo. Had stress test today and was diagnosed with1. Arrythmias: ocasional PACs 2. EKG changes: borderline ischemic EKG changes 3.Conclusions: The results suggest a low to intermediate likelihood for stress induced myocardial ischemia.
    I realize you don’t know me from a hall in the wall, but I wonder how concerned I should be. Haven’t spoken to my cardio yet but I’m already feeling resistant about doing any tests with injections or dyes. Do you think those are necessary? I’m happy to do CT of the heart or echo stress test. I’m 72 but very youthful. I’m very interested in your thoughts. Thank you so very much.

    Reply
    • Gail,
      If you prefer no testing with “injections or dyes” you should make this preference known to your doctor or cardiologist.
      The echo stress test can often be done with no contrast dye (the dye used in radiology procedures). Sometimes, a suspended solution of small bubbles is injected by vein in conjunction with the stress echo to improve accuracy. It would be my preference in the situation your are describing.
      A coronary artery calcium scan is a CT which does not involve injections or dyes and would yield information on the amount of plaque in your coronary arteries and your overall risk.
      A coronary Ct angio uses contrast dye injected into a vein and would not be unreasonable in your situation.

      Dr P

      Reply
  3. Comment re high calcium scan most interesting – three years ago my daughters’s partner died suddenly from a MI, so wife and daughter organised a heart review, including a calcium scan, for me. Despite a good treadmill stress test the 700 calcium score result was heralded as a harbinger of imminent doom – nothing was mentioned about the possibility of no ishaemia and no blocked arteries.
    As there were no clinical signs, I chose not to have any further investigations, but the high calcium score did play on my mind.
    So statins, weight loss and exercise a focus, as well as enjoying a loving family. And now a more positive outlook knowing there is a possibility that my arteries may not be blocked,so focus and effort on heart health are a very good risk management strategy.

    Reply
    • High CAC scores for age should not be viewed as the equivalent of “imminent doom” but as an early warning indicator. A strong motivator to get risk factors under control. Most high CAC scores will not need stents or CABG, just aggressive risk factor modification.

      Reply
  4. I don’t remember how I found your blog but I find it very informative, helpful and humorous. I am familiar with Gundry’s book, and I do feel it is good to have a healthy dose of skepticism. As a person interested in nutrition and health in general, I do read quite a bit and I come across so many claims that can be very unhealthy or just plain absurd. Sometimes there is an element of truth; it is just important not to swallow everything one reads.

    Reply
  5. I’m with you on Dr. Gundry Doc. The price of the supplements are absolutely ridiculous, not to mention useless.
    Wish there was some cancer info on your site–never ?
    Best in health.

    Reply
  6. Stress test. Timely for me. There was a question about Blood pressure spiking during work/exercise, so I went for it. Last week.
    There were several seemingly incongruous outcomes.
    I reached nearly 180 beats per minute and my blood pressure reached only 160/95. Yet I’m 74.
    I was told I’m clear on ischemia/heart disease. Yet I tallied more than 1,500 on my coronary artery calcium score a few years ago.
    The technician fearfully stopped the test because of an “arrhythmia” which the electrophysiologist later identified as a slight lag in one of the bundle branches (Left? Right?) when I reached that highest beat count. “Normal”. Well, normal enough, I guess?
    How does one rationalize such mixed signals?
    (BTW, notice I avoided acronyms? They’re a bane. Your man who asked the question might well be confusing myocardial ischemia with myocardial infarction. Rather different!
    Oh, and I’d already discounted Gundry and Esselstyn.)

    Reply
    • Not uncommon to have very high coronary calcium scan (>1000 or even 2000) with absolutely no ischemia and no significantly blocked (>70%) coronary arteries.
      arrhythmia-sounds more like aberrant conduction than a true “arrhythmia” . At high heart rates it is not uncommon to see one of the electrical pathways to the ventricles start to fail, so-called rate related bundle branch block. Usually not a sign of a problem.
      Acronyms-are everywhere in charts these days. MS to cardiologist is mitral stenosis to neurologist multiple sclerosis or mental status. I’m pretty sure the reader meant MI for myocardial ischemia but that is totally different from infarction.

      Reply
  7. “ Big Pharma “ has thousands of brilliant doctors of medicine , biochemistry, chemistry and many other disciplines who are competing fiercely for the next breakthrough.

    Reply

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