• Clinical science

Aortic valve stenosis

Summary

Aortic stenosis (AS) is a valvular heart disease characterized by narrowing of the aortic valve. As a result, the outflow of blood from the left ventricle into the aorta is obstructed. This leads to chronic and progressive excess load on the left ventricle and potentially left ventricular failure. The patient may remain asymptomatic for long periods of time; for this reason, AS is often detected late, i.e., when it first becomes symptomatic (dyspnea on exertion, angina pectoris, or syncope). Auscultation reveals a harsh, crescendo-decrescendo murmur in systole that radiates to the carotids, and pulses are delayed with diminished carotid upstrokes. Echocardiography is the gold standard for diagnosis. Patients with asymptomatic aortic stenosis are treated conservatively. Symptomatic patients or those with severe aortic valve stenosis require valve replacement.

Epidemiology

  • Most common valvular heart disease in industrialized countries
  • Prevalence:
    • Increases with age
    • May reach up to 12.4% among individuals ≥ 75 years

References:[1][2]

Epidemiological data refers to the US, unless otherwise specified.

Classification

By location of obstruction

  • Valvular: most common
  • Supravalvular
  • Subvalvular

By etiology

  • Congenital:
    • Bicuspid aortic valve: caused by a fusion of two of the three aortic-valve leaflets in utero
      • Most common congenital heart defect, 3:1 predominance
      • Predisposes the valve to dystrophic calcification and degeneration
      • Patients present with symptoms of aortic stenosis earlier than in regular aortic valve calcification
  • Acquired
    • Calcific aortic stenosis: most common cause of aortic stenosis
    • Rheumatic fever is a rare cause of AS in developed countries, but continues to remain a significant cause in developing countries.

References:[3][4][5][6]

Pathophysiology

References:[3][7]

Clinical features

SAD (syncope, angina, dyspnea)

Without definite treatment (surgery), more than 50% of the symptomatic patients with severe aortic stenosis will die within the first 2 years of diagnosis!

References:[3][8][4]

Diagnostics

References:[3][9][10]

Treatment

  • Conservative management: regular follow-ups indicated for asymptomatic patients with mild aortic stenosis
  • Surgical (see heart valve prostheses)
    • Indications
      • Symptomatic patients
      • Asymptomatic patients with severe AS and either significantly ↓ LV EF or those undergoing cardiac surgery
    • Aortic valve replacement (AVR): 3 possible approaches
      • Surgical AVR: patients with low surgical risk.
      • Transcatheter AVR (TAVR): patients with high surgical risk or contraindication
      • Catheter balloon valvuloplasty: children without AV calcification

The presence of exertional symptoms (dyspnea on exertion, angina pectoris, syncope) is an indication for surgery!
References:[8]

Prognosis

  • Asymptomatic patients: The mortality rate is < 1% in a given year.
  • Symptomatic patients: The mortality rate in the first 2 years is > 50%.

References:[8]

  • 1. Mohty D, Pislaru S. Valvular heart disease in elderly adults. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/valvular-heart-disease-in-elderly-adults. Last updated December 22, 2016. Accessed November 28, 2017.
  • 2. Osnabrugge RLJ, Mylotte D, Head SJ, et al. Aortic stenosis in the elderly: disease prevalence and number of candidates for transcatheter aortic valve replacement: A meta-analysis and modeling study. J Am Coll Cardiol. 2013; 62(11): pp. 1002–1012. doi: 10.1016/j.jacc.2013.05.015.
  • 3. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. New York, NY: McGraw-Hill Education; 2015.
  • 4. Crawford MH. Current Diagnosis and Treatment: Cardiology. Lange; 2013.
  • 5. Stritzke J, Linsel-nitschke P, Markus MR, et al. Association between degenerative aortic valve disease and long-term exposure to cardiovascular risk factors: results of the longitudinal population-based KORA/MONICA survey. Eur Heart J. 2009; 30(16): pp. 2044–2053. doi: 10.1093/eurheartj/ehp287.
  • 6. Siu SC, Silversides CK. Bicuspid aortic valve disease. J Am Coll Cardiol. 2010; 55(25): pp. 2789–2800. doi: 10.1016/j.jacc.2009.12.068.
  • 7. Otto CM. Clinical manifestations and diagnosis of aortic stenosis in adults. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-aortic-stenosis-in-adults. Last updated October 24, 2016. Accessed October 4, 2017.
  • 8. Ren X. Aortic Stenosis. In: Aortic Stenosis. New York, NY: WebMD. http://emedicine.medscape.com/article/150638. Updated December 11, 2016. Accessed February 26, 2017.
  • 9. Saikrishnan N, Kumar G, Sawaya FJ, Lerakis S, Yoganathan AP. Accurate assessment of aortic stenosis: a review of diagnostic modalities and hemodynamics. Circulation. 2014; 129(2): pp. 244–253. doi: 10.1161/CIRCULATIONAHA.113.002310.
  • 10. Cary T, Pearce J. Aortic Stenosis: Pathophysiology, Diagnosis, and Medical Management of Nonsurgical Patients. https://www.ncbi.nlm.nih.gov/pubmed/23547127. Updated February 13, 2017. Accessed March 21, 2018.
last updated 12/11/2019
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