People free of heart disease who have very high levels of calcium in the walls of the heart’s arteries are markedly more likely to have a heart attack, stroke and other heart-related events, or develop other health conditions compared with people who have less or no calcium buildup, according to a study published in 'Circulation'. Coronary artery calcium (CAC), measured on an imaging scan, is increasingly being used as a tool – in addition to standard risk calculators – to gauge how likely someone is to develop heart disease or have a heart attack or stroke. This score gives information that can help guide treatment decisions, such as the need to go on a statin or intensify lifestyle changes to lower their risk.
Higher CAC scores mean there is more evidence of calcium and thickening in the inside lining of the arteries. Researchers explain that people with CAC scores of >300 or >400 are generally considered to be at highest risk of developing heart disease or having an event such as a heart attack or stroke.
Researchers sought to investigate their risk compared with people who had lower CAC scores as it relates not only to cardiovascular events and deaths, but also for developing other chronic conditions. They included data from 6,814 participants (age 45-84 years) enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA), a community-based population study, sponsored by the National Heart, Lung, and Blood Institute, of diverse adults free of known cardiovascular disease and followed over many years.
People with CAC ≥1,000 were substantially more likely to have a cardiovascular event (for example, heart attack, stroke, chest pain due to blockages, or heart-related death) or to die of any cause compared with people who had no evidence of CAC or with CAC 400-999 after accounting for factors known to increase the risk of heart disease. As well, compared with people with CAC=0, those with the highest CAC had almost double the chance of developing other conditions including cancer, chronic kidney disease, pneumonia, chronic obstructive pulmonary disease (COPD) and hip fracture. Researchers said this finding supports the idea that CAC is not only a marker for atherosclerosis, but also older age and undetected organ injury.