The traditional measures to gauge heart disease risk, such as blood pressure, cholesterol, and blood sugar levels, don’t always tell the whole story. Sometimes you and your doctor need more information.
An increasingly used test to predict your chance of heart attack or stroke is a coronary artery calcium (CAC) scan. It measures the amount of calcified plaque in the heart’s arteries, high levels of which suggest higher overall plaque buildup.
“The CAC results can help identify a person’s possible risk, even if that person doesn’t have obvious risk factors or symptoms,” says Dr. Ron Blankstein, associate director of the cardiovascular imaging program at Harvard-affiliated Brigham and Women’s Hospital.
A CAC scan uses a special CT scanner. You lie on your back with electrodes placed on your chest to also record an electrocardiogram. The scanner takes several pictures of your heart in less than 10 seconds. The scanner emits low-dose radiation similar to that used for a mammogram.
Plaque sometimes calcifies, and the calcium shows up as tiny white specks on the scan. The amount of calcification is scored on a scale from zero to 400 and sometimes higher. In general, the lower the score, the lower the likelihood of a future heart attack or stroke.
“The result can show that plaque buildup is present and offer an estimate of future risk, but does not specifically pinpoint which heart arteries have plaques that are more likely to rupture and cause a heart attack,” says Dr. Blankstein.
For example, a score of zero indicates the absence of plaque and a low chance of having a heart attack or stroke over the next 10 years, while a score higher than 400 suggests there is a large amount of plaque and a risk that may be 10 times greater (see “CAC scores”).
Your CAC score also can help you and your doctor decide the best course of treatment. “While lifestyle and drug therapies cannot reverse calcified plaques, the CAC score could mean you need additional treatment to stop new plaque formation and keep existing plaques stable to reduce your risk of a heart attack,” says Dr. Blankstein.
According to the 2018 American College of Cardiology/American Heart Association cholesterol guidelines, people with a CAC score of 1 to 100, especially those over age 55, should consider statin therapy in addition to lifestyle changes. A moderate or severe amount of plaque — a CAC score higher than 100 — suggests the need for even greater efforts to lose weight if needed, eat a plant-based diet and exercise more. Usually the high CAC score also means high-dose statin therapy as tolerated, possibly daily low-dose aspirin, and perhaps a lower blood pressure goal, says Dr. Blankstein.
|SCORE||PRESENCE OF PLAQUE|
|No evidence. Heart attack risk is very low.|
|1 to 10||A small amount. Heart attack risk is low.|
|11 to 100||Enough to indicate mild heart disease. Heart attack risk is moderate.|
|101 to 400||A moderate amount, possibly with some artery blockage. Heart attack risk is moderate to high.|
|401 and higher||A large amount, with a 90% chance of some artery blockage. Heart attack risk is high.|
Who should get one?
For people with evident heart disease — like those who’ve had a heart attack or stent — a CAC scan isn’t necessary, since they already need to be on maximal therapy to prevent their disease from progressing.
“A CAC scan is most beneficial for people who have borderline or intermediate risk of atherosclerotic cardiovascular disease [ASCVD] in the next 10 years,” says Dr. Blankstein. (You can calculate your estimated 10-year risk of ASCVD using a calculator from the American College of Cardiology, available at /ascvd.)
People who are unsure of their risk also may benefit from a CAC. For example, this might include someone with good blood pressure and cholesterol levels, but a family history of heart disease (a father, sibling, or uncle who had a heart attack before age 55), or someone with average cholesterol levels and borderline blood pressure who quit smoking five to 10 years ago. Certain conditions also may merit a CAC scan, particularly inflammatory diseases like psoriasis, lupus, or rheumatoid arthritis.
Whether or not you need a follow-up scan depends on your initial score. “If your CAC score is elevated, beginning on the right preventive therapies will be important, and repeat testing is unlikely to be helpful,” says Dr. Blankstein. “On the other hand, if your score is zero, it may be reasonable to repeat the test in about four to eight years.”
Bible verses for today’s meditation and inspiration: Matthew E. McLaren
Yours, Lord, is the greatness and the power and the glory and the majesty and the splendor, for everything in heaven and earth is yours. Yours, Lord, is the kingdom; you are exalted as head over all. 1 Chronicles 29:11 NIV
Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength. Mark 12:30 NIV
Now to him who is able to do immeasurably more than all we ask or imagine, according to his power that is at work within us, to him be glory in the church and in Christ Jesus throughout all generations, for ever and ever! Amen. Ephesians 3:20-21 NIV
So he said to me, “This is the word of the Lord to Zerubbabel: ‘Not by might nor by power, but by my Spirit,’ says the Lord Almighty.” Zechariah 4:6 NIV
For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. 1 Corinthians 1:18 NIV
For who is God besides the Lord? And who is the Rock except our God? Psalm 18:31 NIV
It was not by their sword that they won the land, nor did their arm bring them victory; it was your right hand, your arm, and the light of your face, for you loved them. Psalm 44:3 NIV
For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse. Romans 1:20 NIV
For in Christ all the fullness of the Deity lives in bodily form, and in Christ you have been brought to fullness. He is the head over every power and authority. Colossians 2:9-10 NIV
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