Coronary Artery Calcification

Excerpt

Calcium is the most abundant mineral in the human body. Although most calcium is found in teeth and bone, approximately 1% is dissolved in the bloodstream. As the human body ages, calcium is deposited in various body parts. Arterial calcification is closely related to vascular injury, inflammation, and repair. Calcification occurs very early in atherosclerosis; it is only detectable through imaging modalities when it accumulates in tissue and vasculature. This accumulation typically occurs after age 40, and most individuals older than 60 have diffuse calcification.

A close relationship exists between coronary calcium burden and atherosclerosis despite not all plaques being calcified. The presence and extent of coronary artery calcification (CAC) provides direct evidence of coronary artery disease. Unstable angina is characterized by lesions with smaller calcium deposits described as spotty or speckled; fewer, larger calcium deposits often characterize stable angina. Lesions without calcium are usually nonocclusive (<25% stenosis). CAC independently predicts future major adverse cardiovascular events (MACE) more than other noninvasive modalities. Scoring CAC can also guide management strategies for primary prevention in patients unsure about statin use. Computed tomography (CT) angiography is useful for imaging CAC as a surrogate for clinically significant atherosclerosis.