0-10 MINIMAL CALCIFIED PLAQUE
11-100 MILD CALCIFIED PLAQUE
101- 400 MODERATE CALCIFIED PLAQUE
OVER 400 ADVANCED CORONARY PLAQUE
Out of the 1,000+ patients that I have personally screened, 14
patients had scores over 3,000, with an all-time record of 6,900. But
many patients with a zero score got a good dose of reassurance.
Only one of the patients with a score over 3,000 did not have
obstructive, flow-limiting disease on angiography. This individual,
with unexplained dyspnea on exertion, had multiple 50% to 60%
coronary artery lesions that were fractional flow reserve (FFR)
negative and he was treated medically. FFR is measured with flow
wire above and below the stenoses. A negative value correlates
with safer avoidance of immediate revascularization with ongoing
medical therapy.
All of the others were already on anti-ischemic therapy and had
significant silent ischemia, nuclear imagining or FFR-positive large
vessel disease. They required interventional therapy or surgical
revascularization for symptom relief. Interestingly, none of these
patients had typical angina–not one. The majority had dyspnea or
atypical chest pain. Several complained only of fatigue and tiredness,
thinking they were just getting old, and trying to ignore the
symptoms.
Anyone with typical angina would not require a screening test if
they fit with the appropriate age and risk factor group. They would
require medical therapy with a follow-up functional assessment or
consideration for invasive coronary angiography.
Calcified plaque in the left anterior descending and
diagonal, total score = 270
GETTING TO THE HEART OF MEDICINE
The patient with the score over 6,000 is still living and doing
well, asymptomatic on medical therapy after two coronary stents five
years ago (a severely diseased left anterior descending with a 100%
chronically occluded right coronary artery, that was depending on
collaterals from the left anterior descending). Surprisingly, he had
no chest pain and thought he was short of breath taking out the
garbage cans, just because he was getting older. After treatment,
these symptoms fully resolved.
His dyspnea on exertion was what we label as an “ischemic
equivalent.” He did not think he would have heart disease. The
simple calcium scan convinced him otherwise, and he went straight
to a cardiac catheterization after I saw him in the office–no need for
a nuclear stress test given that score and his unexplained dyspnea
on exertion.
A score of zero is also extremely helpful. Many of my CAC=0
patients, including some who were complaining of side effects from
statin therapy, could be told they were at low risk (not zero risk).
After an informed/shared decision process, some could elect to
stop it. The exceptions: even with a CAC=0 score, people who are
smokers, diabetics or individuals with family history of premature
coronary artery disease should not stop statin treatment.
Patients with a score of zero are at very low risk but not at zero
risk. Recent studies estimate that fewer than 10% of people could
have soft, non-calcified plaque which is not visible on CT. I have
seen an appropriately concerned 50-year-old lady who was having
unresolved atypical chest pain. Both of her parents had either heart
attacks or bypass surgery in their early 60s. She was reluctant to take
a statin for moderate LDL cholesterol elevation, but also worried if
she didn’t, because of her family history. Ten or 20 years ago, given
the prominent family history, I may have ordered an expensive
nuclear stress test, costing over $7,000, given her multiple coronary
risk factors and concerning family history and symptoms.
However with a $99 out-of-pocket CAC, I could explain to her
that there is still a small chance that she may have additional soft,
non-calcified coronary plaque, but with an excellent prognosis, less
than 2% for a stenosis over 50%. 1
This led to an inexpensive basic treadmill stress test, as opposed
to an expensive nuclear one (which carries perhaps 14 to 18 mSv of
radiation, a more significant exposure). Her stress test was normal,
and I placed her on an H-2 blocker trial. She was very relieved; we
focused on lifestyle changes and positive steps she can take herself,
for her mildly elevated LDL.
At UofL, our radiologists not only describe the score in each
vessel but also the specific locations of coronary plaque: if all of
the plaque is in the proximal left anterior descending, this may be
more of a risk than if it is diffusely distributed or in the distal LAD.
They comment on lung parenchyma and nodules, hiatal hernia if
present, and measure the thoracic aorta, to exclude aortic aneurysm
(4 cm or less is normal). Over six years, we have screened 200-250
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