The aortic valve regulates the flow of oxygen-rich blood from the heart’s left ventricle into the aorta, the body’s largest artery, ensuring efficient blood delivery to the body. Over time, this valve can stiffen and narrow due to calcification. This calcification impedes the valve’s ability to open fully, affecting the heart’s efficiency.
The Pathophysiology of Aortic Valve Calcification
Aortic valve calcification is an active biological disease, similar to atherosclerosis. It involves the accumulation of calcium deposits within the valve’s leaflets, the delicate flaps that open and close with each heartbeat. Specialized cells within the valve, called valve interstitial cells, can transform into bone-like cells, contributing to this mineral buildup. These deposits stiffen the valve leaflets, reducing their flexibility.
As deposits grow, they prevent the leaflets from opening completely during the heart’s pumping phase. This stiffening and thickening reduce the valve’s opening area, forcing the heart to work harder to push blood through the narrowed passage. Inflammation and lipid accumulation often precede calcium deposition.
Primary Causes and Risk Factors
Advancing age is the most significant factor contributing to aortic valve calcification. Its prevalence increases with each decade of life, becoming more common in individuals over 65.
Several medical conditions and lifestyle choices accelerate calcification. High blood pressure places increased mechanical stress on the valve. Elevated low-density lipoprotein (LDL) cholesterol contributes to inflammatory and degenerative changes. Smoking promotes inflammation and oxidative stress, which are detrimental to valve health.
Chronic kidney disease is another risk factor, as it disrupts the body’s mineral balance, leading to increased calcium and phosphate levels that can deposit in soft tissues. Genetic predispositions also play a role. For example, a bicuspid aortic valve, a congenital condition with two leaflets instead of three, is prone to calcification and stenosis at a younger age.
Recognizing Symptoms and Diagnostic Procedures
Early aortic valve calcification often has no noticeable symptoms. As calcification progresses and the valve opening narrows, symptoms emerge due to the heart’s increased workload. Patients may experience chest pain, especially during physical exertion, as the heart struggles to pump enough blood. Shortness of breath, particularly with activity or when lying flat, is another common symptom, indicating fluid buildup in the lungs.
Fatigue and lightheadedness are frequent complaints, resulting from insufficient blood flow to the brain and other organs. In severe cases, individuals might experience fainting spells when blood flow to the brain is critically reduced, often triggered by exertion. These symptoms worsen gradually as the valve stiffens.
Diagnosis primarily relies on an echocardiogram, a non-invasive ultrasound of the heart. This imaging technique visualizes the valve’s structure, assesses calcification, and measures blood flow. A cardiac CT scan can provide more detailed three-dimensional images of the valve.
Progression and Complications
If left unmanaged, aortic valve calcification progresses to aortic stenosis, a severe narrowing of the valve opening. This creates a substantial obstruction to blood flow from the heart. The degree of narrowing relates directly to the amount of calcium buildup.
The primary complication is increased strain on the left ventricle, the heart’s main pumping chamber. To overcome the narrowed valve’s resistance, the left ventricle must generate higher pressure to eject blood. This sustained workload causes the heart muscle to thicken, a condition called left ventricular hypertrophy. Initially, this thickening helps maintain blood flow, but over time, the muscle can become stiff and less efficient.
Eventually, prolonged strain can lead to the heart muscle weakening and dilating, signifying heart failure. At this stage, the heart cannot pump enough blood, leading to severe fatigue, swelling, and shortness of breath, even at rest.
Treatment and Management Strategies
For individuals with mild to moderate aortic valve calcification who do not have significant symptoms, management involves “watchful waiting.” This includes regular echocardiograms, usually every one to two years, to track calcification progression and valve function. During this period, managing co-existing risk factors is important.
Controlling high blood pressure through lifestyle changes and medication is a primary focus, as is managing high cholesterol levels, often with statins. Quitting smoking and managing chronic kidney disease are also important. These measures do not reverse existing calcification but may help slow its progression and reduce cardiovascular risk.
For patients with severe aortic stenosis and symptoms, intervention is necessary. The primary treatment involves replacing the diseased valve. Surgical Aortic Valve Replacement (SAVR) is a traditional open-heart surgery where the diseased valve is removed and replaced with a prosthetic valve.
A less invasive option is Transcatheter Aortic Valve Replacement (TAVR). This involves inserting a new valve through a catheter, often via an artery in the leg, and expanding it within the diseased valve. TAVR is often preferred for older patients or those with other health conditions that make open-heart surgery too risky. Both procedures restore normal blood flow from the heart, relieving symptoms and improving cardiac function.
References
1. Aortic Valve Calcification: An Active Biological Disease. [https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.118.037038](https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.118.037038)
2. Risk factors for aortic valve calcification. [https://pmc.ncbi.nlm.nih.gov/articles/PMC4035174/](https://pmc.ncbi.nlm.nih.gov/articles/PMC4035174/)
3. Aortic Valve Stenosis. [https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.119.043003](https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.119.043003)
4. Progression of Aortic Stenosis. [https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.118.038162](https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.118.038162)
5. Management of Aortic Stenosis. [https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.119.043003](https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.119.043003)