Published by the Students of Johns Hopkins since 1896
August 11, 2022

Calcium levels can indicate coronary artery disease

By RACHEL HUANG | November 29, 2018



Coronary calcium levels can be used to calculate various types of heart disease risk scores.

Doctors often discuss the benefits of calcium intake for the body. Not only is calcium beneficial for bone health, but it’s also required for the heart, muscles and nerves to function properly. More recently, a study presented at the 2018 American Heart Association Scientific Session conference in Chicago found that measuring calcium levels can also provide insight in predicting the risk of developing coronary heart disease (CHD).

According to the Centers for Disease Control and Prevention (CDC), about 610,000 people die of heart disease in the United States every year.

CHD, the most common type of heart disease, is the narrowing of the coronary arteries — major blood vessels on the surface of the heart that supply the heart with blood, oxygen and nutrients — due to an accumulation of plaque in the arterial walls. 

The plaque that’s usually the culprit for coronary artery disease differs from the plaque that is found on teeth. Instead of a sticky biofilm of growing bacteria, as is the case on teeth, the plaque that builds up in the arteries is composed of cholesterol, fat, calcium and other substances. As the plaque builds, the coronary arteries become more and more narrow, and blood flow to the heart becomes restricted. 

As a result of the limited blood flow to the heart, patients of CHD may experience angina pectoris, chest pain caused by lack of blood to the heart.

Heart attacks, medically termed myocardial infarctions, occur when there’s a lack of oxygen arriving at the heart muscle. Under these poor-oxygenated circumstances, the muscle dies and a heart attack occurs. In most cases, the heart attack is caused by a coronary thrombosis — or a blood clot — formed from a plaque large enough to obstruct blood flow to the heart.

CHD cannot be cured, but it can be managed. Because of this, prevention is highly stressed by doctors. CHD can be prevented by controlling blood cholesterol levels through physical activity and by maintaining a healthy diet. Smoking increases the risk of developing CHD because tobacco can cause more cholesterol to build up in the coronary arteries. Other risk factors for CHD include age, genetics and high blood pressure.

Jeffrey L. Anderson, a cardiologist and cardiovascular researcher at the Intermountain Medical Center Heart Institute explained the lack of knowledge about heart disease. 

“Cardiovascular disease remains the greatest cause of morbidity and mortality in the United States, and determining who’s most at risk continues to be suboptimal,” he wrote in a press release. 

In their recent study, Anderson and his team extended beyond the standard set of risk factors and determined a new way to screen for patients with a high risk for developing CHD. By looking at and measuring the coronary calcium levels, three different cardiovascular disease risk scores were able to be calculated: the standard Pooled Cohort Equation, the Multi-Ethnic Study of Atherosclerosis (MESA) Risk Score and the Coronary Calcium Score.

The Pooled Cohort Equation calculated the risk of CHD by measuring the standard risk factors such as age, blood pressure and gender. The Coronary Calcium Score alone calculated the risk by measuring coronary calcium levels. MESA, which was found to produce the best results, combined both approaches to better predict the risk of CHD.

Anderson commented on the results of their study. 

“With coronary calcium, we’re looking at a marker indicating the actual presence of anatomic disease — [although] calcium in the artery doesn’t tell you the extent of soft plaque, it does mark that disease is present,” Anderson wrote. “These results tell us that coronary calcium adds importantly to probability estimates.”

With the new coronary calcium test as way to predict the risk of CHD, Anderson believes that not only will the number of overtreated low-risk patients decrease, but also the number of high-risk patients getting treated earlier will also increase, potentially decreasing the prevalence of CHD.

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