Tiny amounts of calcified coronary plaque associated with heart disease risk.
Even small amounts of calcified coronary plaque puts adults under the age of 50 years at an increased risk of developing clinical coronary heart disease.
In a study published inJAMA Cardiology, investigators found that individuals with the highest coronary artery calcium (CAC) scores had a more than 20% chance of dying from a heart-related issue over the same time period.
Prior research has long shown the association between CAC and coronary heart disease and cardiovascular disease. However, prognostic data on CAC has been limited in younger adults in their 30s and 40s, especially women and African Americans.
“We always thought you had to have a certain amount of this plaque before you were at risk of having events,” said lead author Jeffrey Carr, MD, MSc. “What we showed was that, for younger people, any amount of coronary artery calcium or dramatically and statistically significantly increased risk of clinical heart disease.
“Any measurable CAC in early middle age—–scores of less than 100, and even less than 20––has a 10% risk of heart attack or acute myocardial infarction, both fatal and non-fatal, over the next decade beyond standard risk factors.”
For the study, investigators used data from the National Heart, Lung and Blood Institute Coronary Artery Risk Development in Young Adults (CARDIA) study. The longitudinal, community-based CARDIA study included 5115 black and white adults aged 18 to 30 years from Oakland; Minneapolis; Chicago; and Birmingham, Alabama. The study began in 1985 and participants were followed for 30 years.
During the current study, the investigators performed CT scans that measured CAC scores on 3330 participants. The mean follow-up period was 12.5 years. According to the investigators, CAC of any amount was observed in 30% of that group.
The goal of the study was to determine whether a simple presence of CAC on a chest CT could inform clinical practice, and if a CAC score higher than 100 was associated with premature death. The investigators found that both questions were true.
“The presence of any coronary artery calcification, even the lowest score, was associated with between a 2.6 and 10-fold increase in clinical events over the next 12.5 years,” Carr said. “And when it comes to those with high CAC scores (100 or above), the incidence of death was 22%, or approximately 1 in 5. Very few times do you get a biomarker, be it genetic or imaging, that predicts death at a level of 22% over 12.5 years.”
According to the authors, CAC could be used as a very specific imaging biomarker for identifying individuals who are at risk of heart disease earlier in life, and who may also benefit from interventions such as cholesterol and blood pressure management.
“The person may not be at risk for a heart attack tomorrow or next month, but they are at very high risk over the next 10 years of their life,” Carr said. “For individuals at this elevated risk, we have proven interventions that could reduce their risk.”
Even if the amount of CAC is high or low, its presence is a signal that advanced coronary artery disease is present and enhanced prevention may be warranted, Carr said.
Additionally, Carr pointed out that a CAC can easily be identified on routine CT scans of the chest, and this small change in clinical practice could have a huge impact on care.
“For example, a 45-year-old women with a cough might receive a routine CT scan that shows the presence of a calcified plaque in her coronary arteries,” Carr said. “With this new information, the doctors don’t need to know the CAC score or do additional tests. With the information that any CAC is present, she and her health care team could assess her risk and determine the optimum prevention strategy.
“Our study provides strong evidence that an individual under age 50 with any amount of CAC is at markedly elevated risk for heart disease, and for health care providers and patients it should be viewed as a call to action to enhance cardiovascular disease prevention.”
The authors concluded, “A more targeted approach based on measuring risk factors in early adult life to predict individuals at high risk for developing CAC in whom the CT scan would have the greatest value can be considered. This strategy could reduce the number of people selected for additional testing with CT scans by 50%. The findings that CAC present by ages 32 to 46 years is associated with increased risk of premature coronary heart disease and death emphasizes the need for reduction of risk factors and primordial prevention beginning in early life.”