Arterial vascular calcification is the accumulation of calcium phosphate deposits within the walls of arteries, which carry oxygen-rich blood from the heart. This buildup causes the flexible arterial walls to stiffen and lose elasticity, a process referred to as “hardening of the arteries.” This process narrows the space for blood flow and can lead to a variety of health issues.
Underlying Causes of Arterial Hardening
Arterial calcification is an active process, not a passive accumulation of calcium. It involves cellular events where smooth muscle cells in artery walls transform into cells resembling bone-forming osteoblasts. This transformation is triggered by several factors. Chronic kidney disease is a primary cause, as failing kidneys disrupt the body’s calcium and phosphate balance. Diabetes mellitus also promotes this process through high blood sugar and inflammation that damage the arterial lining. Other contributing factors include advanced age, high cholesterol, and smoking, which worsen the inflammatory responses underlying the transformation.
Calcification can manifest in two patterns. Intimal calcification occurs in the artery’s innermost layer and is associated with atherosclerosis, the plaque buildup that causes blockages. Medial calcification affects the middle, muscular layer of the artery wall. This form is linked to aging, diabetes, and chronic kidney disease and contributes to generalized arterial stiffness.
Locations of Calcification and Related Complications
When calcification develops in the coronary arteries, which supply blood to the heart, it contributes to coronary artery disease. The mineral deposits are a component of atherosclerotic plaques that narrow these arteries and restrict blood flow. If a plaque ruptures, it can trigger a blood clot that completely blocks an artery, causing a heart attack.
Calcification in the peripheral arteries, mainly in the legs, leads to peripheral artery disease (PAD). The hardening and narrowing of these vessels reduce blood flow to the limbs, causing muscle pain during physical activity (claudication). Severe PAD can lead to chronic limb-threatening ischemia, marked by constant pain, non-healing sores, and may ultimately necessitate amputation.
The aorta, the body’s largest artery, is also susceptible to calcification. When the aortic wall stiffens, it loses its ability to expand and recoil with each heartbeat. This loss of elasticity forces the heart to work harder, which can increase systolic blood pressure. Over time, this elevated workload and pressure can contribute to heart failure.
Diagnostic Imaging and Screening
Physicians use several imaging techniques to detect and quantify arterial calcification. A primary method for the heart’s arteries is a coronary artery calcium (CAC) scan, a non-invasive computed tomography (CT) scan. This test produces detailed images of the coronary arteries, allowing for the direct visualization and measurement of calcium deposits.
The results of a CAC scan are given as a numerical score. This CAC score reflects the total amount of calcified plaque in the coronary arteries. A score of zero indicates no detectable calcification and a very low risk of a future heart attack. As the score increases, so does the predicted risk, helping doctors assess cardiovascular risk and guide preventive treatment.
Other imaging methods can identify calcification elsewhere. An X-ray can reveal severe calcification in major arteries like the aorta. Vascular ultrasound is useful for examining peripheral arteries in the legs and carotid arteries in the neck, as it can show plaque buildup and calcification that may obstruct blood flow.
Current Management Strategies
As there is no treatment to reverse existing arterial calcification, management focuses on slowing its progression and mitigating cardiovascular risks. Lifestyle modifications are the foundation of this approach. A balanced diet, low in processed foods and saturated fats, is recommended. Adequate intake of vitamin K2 may also play a role in inhibiting calcification by helping direct calcium toward bones.
Regular physical activity is another component of management, as it helps control weight, lower blood pressure, and improve cholesterol levels. For individuals who smoke, cessation is an impactful change. Quitting smoking helps lower inflammation and reduce further damage to the arterial walls, slowing the calcification process.
In conjunction with lifestyle changes, medications are used to control the underlying conditions that promote calcification. Statins are prescribed to lower LDL (“bad”) cholesterol, a component of the atherosclerotic plaques where calcification occurs. For patients with high blood pressure or diabetes, medications to control these conditions are central to protecting the arteries. In patients with chronic kidney disease, physicians may prescribe phosphate binders to lower phosphate levels in the blood, reducing its deposition in arteries.