A large body of scientific literature has documented that higher calcium scores are associated with higher risk of significantly blocked coronary arteries and of heart attack.
Apparently this is one of the best scans you can have to screen for subclinical atherosclerosis. If you're taking a preventative approach then you would want to know how your heart is doing prior to a cardiac event.
The calcium score can be utilized (in a manner similar to the carotid IMT and plaque) to help determine whether a given individual has more advanced atherosclerosis than we would predict based on their risk factor profile. A score of zero is consistent with a very low risk of significantly blocked arteries and confers an excellent prognosis. On the other hand, scores of >400 indicate extensive atherosclerotic plaque burde , high risk of heart attack, and high likelihood of a significantly blocked coronary artery.
This specific score along with the inflammation hsCRP test can give a strong indication of heart attack risk in the future. In fact it provides a better indication than lifestyle/age predictors and hsCRP in particular provides a better indicator than LDL cholesterol in specific.
The hsCRP is a test for inflammation which acts an indicator for artery health. When arteries are injured they become inflamed and for that reason the hsCRP score typically is higher.
Experts who study blood vessels, plaque, and heart attacks in minute detail have been developing an inflammatory explanation for heart attacks. They've described a process quite different from the clogged plumbing analogy. Blood vessels aren't solid pipes, but slender tubes of layered, living tissue, some of it quite delicate. LDL cholesterol doesn't simply lodge in arterial walls-it injures them. And like injuries elsewhere in the body, this stirs up an inflammatory response. Swarms of cytokines, macrophages, and other cells swoop in. They enlarge and transform deposits of LDL cholesterol into accumulations of fat-laden foam cells sealed by fibrous caps of collagen.
A forty-something year old man came to see me for palpitations. He had a stress echo which was normal except for the development of frequent PVCs and a brief run of non sustained ventricular tachycardia. His risk factor profile was not particularly bad: no diabetes, hypertension, or cigarette smoking and an average lipid profile. When I calculated his 10 year risk of ASCVD using my iPhone app it came out at 7%: below the level at which statin treatment would be recommended. Because his father had a coronary stent in his fifties (this does not qualify as a family history of heart disease according to the new guideline, by the way) I recommended he get a CAC test done.
His CAC score came back markedly elevated, almost 1000. . A subsequent cardiac catheterization demonstrated a very high-grade coronary blockage iwhich was subsequently stented. I started him on high intensity statin therapy and he has done well.
And for this reason it is a good idea to find out your CAC score if a CAC test is available to you. Either you will discover you're at high risk in which case something can be done early or you may discover you're at low risk in which case you can rest easy.