Structural Heart/Valve Clinic
About Aortic Stenosis
Aortic stenosis occurs when the aortic heart valve narrows or becomes obstructed as a result of calcium deposits on the valve’s leaflets; this results in the inability of the valve to open and close properly. This often leads to debilitating symptoms that can restrict normal day-to-day activities, such as walking short distances or climbing stairs. Aortic stenosis is common, with 7% of the U.S. population over the age of 65 having this condition. Data suggests that these patients may benefit from surgical valve replacement – the gold standard treatment for severe aortic stenosis; however, only about two-thirds of them undergo the procedure each year. Often, patients are not referred for surgery because they are older or have other medical conditions increasing their surgical risk.
Patients who do not receive an aortic valve replacement (AVR) have no effective, long-term treatment option to prevent or delay their disease progression. Without treatment, severe symptomatic aortic stenosis is life-threatening. In fact, previous studies have indicated that 50 percent of untreated patients with the condition will not survive more than two to three years.
Overview of the Disease
A healthy aortic heart valve allows oxygen-rich blood from the lungs to flow from the left ventricle of the heart to the aorta, where it continues to the brain and the rest of the body.
Severe aortic stenosis is the narrowing or obstruction of the aortic valve and is most often due to the accumulation of calcium deposits on the valve’s leaflets (flaps of tissue that open and close to regulate the flow of blood in one direction through the valve). The resulting stenosis impairs the valve’s ability to open and close properly. When the leaflets don’t fully open, the heart must work harder to push blood through the calcified aortic valve. Eventually, the heart muscle weakens, increasing the patient’s risk of heart failure.
The prevalence of aortic stenosis increases with age. Today, build up of calcium on the leaflets that occurs with age (called senile degenerative aortic stenosis) is the most common cause of acquired aortic stenosis. It usually occurs in patients older than 75 years of age.
|Fig. 1 depicts the leaflets of a healthy aortic heart valve which open wide to allow oxygen-rich blood to flow unobstructed in one direction. The blood flows through the valve into the aorta where it then flows out to the rest of the body.||Fig. 2 depicts the leaflets of a stenotic or calcified aortic valve unable to open wide, obstructing blood flow from the left ventricle into the aorta. The narrowed valve allows less blood to flow through and as a result, less oxygen-rich blood is pumped out to the body, which may cause symptoms like severe shortness of breath.|
- Severe shortness of breath leading to gasping – even at rest
- Chest pain or tightness
- Extreme fatigue
- Difficulty exercising
- Rapid or irregular heartbeat
Identification of severe aortic stenosis can be confirmed by examining the heart, listening for the heart murmur that is typical of the disease and/or by performing an echocardiogram, electrocardiogram (ECG or EKG), chest x-ray or ultrasound. Making the correct diagnosis is critical, because once patients begin exhibiting symptoms, the disease progresses at a steady rate and can be life-threatening. Due to the high risks associated with leaving this condition untreated, aortic valve replacement (AVR) should be performed without delay after initial diagnosis of symptoms.
Aortic Stenosis Facts and Figures
U.S. Aortic Stenosis Disease Prevalence & Treatment Statistics
Heart disease is the leading cause of death in the U.S., killing more than 600,000 Americans each year.1
- More than five million Americans are diagnosed with heart valve disease each year.2
- Heart valve disease can occur in any single valve or a combination of the four valves, but diseases of the aortic and mitral valves are the most common.
- Calcific aortic stenosis is the most common cause of aortic stenosis (AS).3
- While up to 1.5 million people in the U.S. suffer from AS, approximately 500,000 within this group of patients suffer from severe AS. An estimated 250,000 patients with severe AS are symptomatic.4-6
- An echocardiogram (echo) is the primary imaging test used to diagnose severe AS.
- Without an aortic valve replacement (AVR), as many as 50 percent of patients with severe AS will not survive more than an average of two years after the onset of symptoms.7
- The predicted survival of inoperable patients with severe AS who are treated with standard non-surgical therapy is lower than with certain metastatic cancers.8
- Studies show that severe AS is undertreated. At many hospitals, more than 50 percent of patients that receive an echo and show the presence of the disease are not referred to a surgeon to be evaluated for an AVR. The absence of chest pain symptoms and overestimating risks associated with the AVR procedure have been identified as some of the reasons lack of patient referrals occur.9-11
- An estimated 80,000-85,000 AVR procedures are performed every year in the U.S.
- Miniño AM, Murphy SL, Xu J, Kochanek KD. Deaths: Final data for 2008. National Vital Statistics Reports; vol 59 no 10. Hyattsville, MD: National Center for Health Statistics. 2011.
- Nkomo V, Gardin M, Sktelton T, et al. Burden of valvular heart diseases: a population-based study (part 2). Lancet: 2006:1005-11.
- Roberts WC, Ko JM. Frequency by decades of unicuspid, bicuspid, and tricuspid aortic valves in adults having isolated aortic valve replacement for aortic stenosis, with or without associated aortic regurgitation. Circulation. 2005;111:920–925.
- Bach D, Radeva J, Birnbaum H, et al. Prevalence, Referral Patterns, Testing, and Surgery in Aortic Valve Disease: Leaving Women and Elderly Patients Behind. J Heart Valve Disease. 2007:362-9.
- Iivanainen A, Lindroos M, Tilvis R, et al. Natural History of Aortic Valve Stenosis of Varying Severity in the Elderly. Am J Cardiol. 1996:97-101.
- Aronow W, Ahn C, Kronzon I. Comparison of Echocardiographic Abnormalities in African-American, Hispanic, and White Men and Women Aged >60 Years. Am J Cardiol. 2001:1131-3.
- Otto, CM. Timing of Aortic Valve Surgery. Heart 2000;84(2):211-8.
- Leon M, Smith C, Mack M, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363(17):1597-1607.
- Bach DS, Siao D, Girard SE, et al. Evalation of patients with severe symptomatic aortic stenosis who do not undergo aortic valve replacement: The potential role of subjectively overestimated operative risk. Circ Cardiovasc Qual Outcomes 2009;2:533-539.
- Bach DS. Prevalence and Characteristics of Unoperated Patients with Severe Aortic Stenosis. J Heart Valve Dis 2011;20:284-291.
- Xu JQ, Kochanek KD, Murphy SL, et al. Deaths: final data for 2007. [PDF - 3.41MB] National Vital Statistics Reports 2010;58(19).