Advances in scanning and screening are informing an increasing number of Americans that their arteries are calcified. But what causes calcium deposits, at what point do they become problematic, and how can you get rid of calcium deposits or slow their progression? Bottom Line Health asked interventional cardiologist Jay Mohan, DO, for details.
How much calcification is too much
We need calcium—it’s the most abundant mineral in the human body and is necessary for bone health. But when calcium from the blood forms deposits on the walls of the arteries, it can narrow them, impeding blood flow and increasing the risk of cardiac events. If you’ve reached normal retirement age, this is probably already is happening to your arteries whether or not you’ve been diagnosed with this problem. Arterial calcification is found in more than 90 percent of men and more than 67 percent of women ages 70 and up, according to a study published in the Journal of Geriatric Cardiology. Women are at a lower risk of calcification than men for most of their lives due to their significantly higher estrogen levels, but that advantage slowly fades once women’s estrogen levels fall following menopause.
Coronary artery calcification is most commonly caused by atherosclerosis, a slow accumulation of plaque deposits inside the arteries, a condition often referred to as hardening of the arteries. The good news is that the presence of coronary artery calcification does not necessarily point to impending heart attacks. The amount of calcification is the crucial factor.
If a patient is believed to be at elevated risk of calcification based on his or her age, blood pressure, cholesterol, or other factors and symptoms, a CT scan might be ordered. The extent of the calcification revealed by this scan then will be used to compute an “Agatston score,” or potentially another, similar, score.
Patients are considered to have “extensive” signs of calcification, suggesting greatly increased risk of a cardiac event in the following years, only if their Agatston scores exceed 400. An Agatston score between 100 and 400 is considered “moderate” and is associated with a somewhat increased risk of cardiac event. Because calcification tends to increase with age, an elevated Agatston score can be particularly problematic in someone who is still relatively young. As a result, a patient’s Agatston score also is likely to be considered problematic if it’s higher than those of 75 percent of people of that patient’s age and gender.
Helpful: If you haven’t had a CT scan for the purpose of calcium scoring, use an ASCVD Risk Estimation calculator to gauge your risk of cardiac events. These calculators are available on numerous medical websites, including that of the American College of Cardiology.
The five major modifiable risk factors
Certain aspects of coronary artery calcification risk are out of your control. For example, there’s a significant genetic component. If your mother, father, sister and/or brother had it, then you’re at elevated risk, too. If you have chronic kidney disease, that also significantly increases your risk of developing coronary artery calcification. Impaired phosphate excretion by the kidneys is likely to lead to excess phosphate in your blood, and that phosphate can combine with the calcium in the blood to form arterial deposits. But there also are coronary artery calcification risk factors that are within people’s control, at least to a degree.
High blood pressure
Hypertension is a major risk factor for atherosclerosis and, in turn, coronary artery calcification. Fortunately, there are numerous ways to bring high blood pressure under control, including eating a heart-healthy diet, exercising regularly, getting sufficient sleep, and/or taking prescription blood pressure medications.
High cholesterol
Hyperlipidemia—that is, high levels of low-density lipoprotein “LDL” cholesterol—also is correlated with increased risk of calcification. The progression of calcification is likely to be significantly reduced if statins or other prescription medications are used to control cholesterol levels.
Patients who have coronary artery calcification problems typically are advised to try to keep their LDL cholesterol levels below 70 mg/dL, but a more ambitious target is likely on the horizon. The European Society of Cardiology has lowered its target to below 55 mg/dL.
Diabetes
The hyperglycemia, inflammation, and oxidative stress caused by diabetes all have been linked to increased coronary artery calcification risk. If you’re wondering why diabetes is listed as a “modifiable” risk factor, that’s because how well diabetics control their diabetes significantly affects the degree to which diabetes increases their arterial calcification risk. Unfortunately, all diabetics face some degree of increased risk even if they manage their diabetes very well.
Smoking
No single behavior accelerates coronary artery calcification more than smoking. Calcification differences between smokers and non-smokers often can be measured in decades. If two people have very similar genetics but one is a chronic smoker and the other isn’t, the smoker might start to develop calcification at 45, the non-smoker at 65. The good news is that quitting smoking does appear to significantly slow calcification’s progression, even among people who previously smoked quite heavily.
Obesity
Being substantially overweight is linked to higher rates of coronary artery calcification, as are the often-related factors of having a sedentary lifestyle and consuming a diet high in saturated fats. Losing weight via lifestyle changes and/or weight loss drugs can reduce this calcification risk.
Treatment options and the latest advances
The most effective treatment option for coronary artery calcification often is treating the modifiable risk factors cited above, such as taking statins to control high LDL cholesterol.
If you have a high Agatston score, there’s a good chance that your doctor will recommend taking a low-dose aspirin every day as well. Recent research has called into question the effectiveness of taking aspirin to control the risk of cardiac events, but those questions relate to the usefulness of aspirin for people who have no known cardiovascular issues. The evidence in favor of taking daily low-dose aspirin remains very strong for people who have been diagnosed with coronary artery disease and/or high levels of coronary artery calcification.
If calcification of a coronary artery has dramatically reduced blood flow, it might be necessary to surgically install a mesh tube, known as a stent, into that artery. Stents have historically been more effective in arteries blocked by fatty deposits than in hardened, highly calcified arteries. A mesh tube isn’t very effective at expanding an artery that’s become hardened into a virtual stovepipe. Fortunately, a new procedure called intravascular lithotripsy has improved the effectiveness of stents in hardened arteries. This innovative technique uses acoustic pressure waves to break up calcifications before the stent is deployed.
There’s a good chance that additional coronary artery calcification-related treatment options will become available by the end of this decade. One of these advances likely will be drugs that reduce inflammation. Inflammation is considered a major risk factor for atherosclerosis and coronary artery calcification, but pharmaceutical treatment options have been limited.
There was some hope that the gout medication colchicine would help, but research in this area has produced disappointing results. A new generation of inflammation-fighting drugs appear to be are on the horizon, however, and it seems likely that one or more of these will be both effective and available within five years.
The next five years also is likely to bring substantial improvements when it comes to the interpretation of the CT scans that are used to calculate Agatston scores. Medical scan interpretation appears to be a task that AI can perform better than humans. Soon patients likely will receive increasingly accurate scores, leading to improved guidance about whether or not their arterial calcification poses an immediate risk and which treatments, if any, are appropriate.
