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people annually. Only the thorax goes into the scanner (feet first,
heads out). Prices in Louisville range from $99 to $150, though a
decade ago, the cost was $1,000.
RECOMMENDATIONS FOR CAC TESTING
At the present time, there are no Class 1 guidelines/recommendations
for coronary calcium scanning. Because it takes time for
coronary plaques to calcify, this type of testing is usually not recommended
for men less than 40 or women less than 50, unless there are
extensive premature risk factors such as childhood diabetes, heavy
smoking or very premature coronary disease in family members.
The 2018 Executive Summary from the American Heart Association/American
College of Cardiology (AHA/ACC) on management
of blood cholesterol discussed that calcium scanning may be most
helpful for intermediate-risk patients with 7.5% to 20% estimated
heart attack or stroke risk based on the AHA/ACC ASCVD 10-year
risk estimator. However, that risk estimator ignores family history
as a variable.
Drs. Schade D, Arora S, and Eaton PR, from the University of
New Mexico Health Sciences Center, have a stimulating article in
the American Journal of Medicine. 2 In this commentary, they point
out that there are 600,000 deaths per year from atherosclerotic heart
disease, and only 50,000 deaths per year from colon cancer. Yet
everyone is screened for colon cancer at a certain age, but there are
no recommendations or specific guidelines for coronary calcium
scanning. Their final sentence is, “As part of prevention of chronic
disease in our aging population, there is strong rationale for routine
calcium scanning starting at the age of 45 years, the same age as is
recommended for a routine colon cancer screening.”
This is a topic frequently debated by various groups of cardiologists
and internists, but I would support a similar recommendation.
For an opposing viewpoint, see a detailed article by local cardiologist,
Dr. John Mandrola, titled “The Case Against Coronary Artery
Calcium Scoring for Cardiovascular Risk Assessment.” 3
STRESS TESTING WITH CALCIFIC CORONARY PLAQUE
For symptomatic patients, whether it be chest pain, unexplained
dyspnea or unexplained fatigue, stress testing is recommended.
More controversial is the topic of stress testing for patients that are
asymptomatic with advanced calcified coronary plaque. There are
surely no randomized prospective studies that justify stress testing
in truly asymptomatic individuals with calcific CAD. One however,
must take a very careful and detailed history to make sure patients
are not minimizing or ignoring symptoms
My sense after talking with multiple cardiologists over a five-year
period is that that most are in agreement that no testing is indicated
for coronary calcium scores less than 100 without symptoms.
A small number of cardiologists have advocated consideration
for functional testing in individuals with moderate calcified plaque,
in the 100 to 400 score range. No proven data exists for this at this
time, however. I currently do not recommend this.
In individuals with advanced calcified coronary plaque, i.e.
scores over 400, an increasing number of cardiologists consider
stress testing, and discuss the pros and cons of functional testing,
although when I do this, I try to avoid nuclear imaging and radiation.
The rationale for this is that some people, especially diabetics,
have silent ischemia as evidenced by obstructive coronary disease
without typical or classic symptoms. However, there are no current
studies to support this as being cost-effective, and we in cardiology
are still seeking the Holy Grail of discovering an inexpensive test to
identify which coronary plaques are vulnerable to rupture and cause
heart attacks and if there’s any way we can prevent this.
Thus, the final answer is unknown and awaits a large scale
prospective and randomized trial: this might not ever happen due
to expense. I continue to follow some of the experts in the field
of preventive cardiology, such as Dr. Roger Blumenthal at Johns
Hopkins, Dr. Larry Sperling at the Emory University Preventive
Cardiology program, and other experts who usually make up the
part of the AHA/ACC task force.
I have also enjoyed well-written articles about some of the pros
and cons of calcium scanning, by cardiologist Dr. Anthony Pearson,
who practiced here in the 90s. Dr. Pearson has a thorough and
balanced summary of the opinions on both sides, in his review
“Should all patients with a high coronary calcium score undergo
stress testing?” He does not routinely recommend stress testing for
his patients with high CAC score, but acknowledges he has a low
threshold for stress testing with worrisome symptoms especially in
diabetic or sedentary individuals. 4
And for me personally, I am hoping that the three to five mile
weekend hikes, walks in Seneca Park on weekdays, taking 40 mg of
rosuvastatin for an LDL less than 70, having a CRP less than 1.0–and
some good luck and prayers–will help allow me to practice for a few
more years, enjoy life and travel for a few more years after that.
References:
1
Wang X. Le EPV ,Rajani, NK, et al. A zero coronary artery calcium score in
patients with stable chest pain is associated with a good medium-term prognosis,
despite risk of non-calcified plaque. Open Heart 2019 ;6e000945.dol:10.1136/
openheart-2018-000945.
2
American Journal of Medicine. February 2020, Vol 133,No 2: “Should Routine
Screening for Coronary Artery Disease Be Recommended? A Comparison with
Routine Screening for Colon Cancer.”
3
“The Case Against Coronary Artery Calcium Scoring for Cardiovascular Risk
Assessment” Ref: American Family Physician 2019 Dec 15:100 (12) 734-735.
4
“THE SKEPTICAL CARDIOLOGIST” March 15,2019.
Dr. Henry Sadlo is an Assistant Professor in the Division of Cardiovascular Medicine
at the University of Louisville School of Medicine.
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