Aortic valve stenosis

From Citizendium, the Citizens' Compendium
Jump to: navigation, search
This article is developing and not approved.
Main Article
Talk
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.

In medicine, aortic valve stenosis is an abnormality of the aortic valve in the heart.[1]

Diagnosis

A systematic review by the Rational Clinical Examination addresses diagnosis with the history and physical examination.[2] Since publication of the systematic review, a clinical prediction rule may help detecting moderate to severe aortic valve stenosis (defined as a valve area of 1.2 cm2or less, or a peak instantaneous gradient of 25 mm Hg or greater):[3]

  • If the heart murmur does not radiate to the right neck, moderate aortic stenosis was very unlikely
  • If the heart murmur has at least three of the following signs, moderate stenosis was likely:
    • slow carotid artery upstroke (other studies suggest more than 200 msec is abnormal[4])
    • reduced carotid artery volume
    • heart murmur loudest at the second right intercostal space
    • reduced intensity of the second heart sound

Echocardiography

According to joint clinical practice guidelines by the American College of Cardiology and the American Heart Association, echocardiography should be obtained when:[5]

  • Systolic heart murmur that is grade 3/6 or greater
  • Single S2 heart sound
  • Symptoms that might be due to aortic valve stenosis

It is not clear why the guidelines did not include radiation of the murmur to the right neck and the presence of an abnormal carotid pulse among the indications for echocardiography as the value of these signs have been previously shown in a systematic review.[2]

Grading the degree of stenosis

According to joint clinical practice guidelines by the American College of Cardiology and the American Heart Association:[5]

  • "Mild (area 1.5 cm2, mean gradient less than 25 mm Hg, or jet velocity less than 3.0 m per second)"
  • "Moderate (area 1.0 to 1.5 cm2, mean gradient 25–40 mm Hg, or jet velocity 3.0–4.0 m per second)"
  • "Severe (area less than 1.0 cm2, mean gradient greater than 40 mm Hg or jet velocity greater than 4.0 m per second)"

Treatment

Joint clinical practice guidelines by the American College of Cardiology and the American Heart Association address treatment[5]

Surgery

According to the ACC/AHA guidelines:[5] Class I recommendations

  1. Aortic valve replacement "AVR is indicated for symptomatic patients with severe AS."
  2. "AVR is indicated for patients with severe AS* undergoing coronary artery bypass graft surgery (CABG)."
  3. "AVR is indicated for patients with severe AS* undergoing surgery on the aorta or other heart valves."
  4. "AVR is recommended for patients with severe AS* and LV systolic dysfunction (ejection fraction less than 0.50). "

Class IIa recommendations

  1. "AVR is reasonable for patients with moderate AS* undergoing CABG or surgery on the aorta or other heart valves."

Class IIb recommendations

  1. "AVR may be considered for asymptomatic patients with severe AS* and abnormal response to exercise (e.g., development of symptoms or asymptomatic hypotension)."
  2. "AVR may be considered for adults with severe asymptomatic AS* if there is a high likelihood of rapid progression (age, calcification, and CAD) or if surgery might be delayed at the time of symptom onset."
  3. "AVR may be considered in patients undergoing CABG who have mild AS* when there is evidence, such as moderate to severe valve calcification, that progression may be rapid."
  4. "AVR may be considered for asymptomatic patients with extremely severe AS (aortic valve area less than 0.6 cm2, mean gradient greater than 60 mm Hg, and jet velocity greater than 5.0 m per second) when the patient’s expected operative mortality is 1.0% or less."

Prognosis

Among asymptomatic patients, risks factors for progression are "moderate or severe valvular calcification, together with a rapid increase in aortic-jet velocity."[6]

Outcomes after 41 months among asymptomatic patients with very severe aortic stenosis (peak aortic jet velocity ≥ 5.0 m/s)[7]
Peak aortic jet velocity No valve replacement of death
1 year 2 years 3 years 4 years
5.0 and 5.5 m/s 76% 43% 33% 17%
≥ 5.5 m/s 44% 25% 11% 4%

A clinical prediction rule consisting of aortic-jet velocity, gender, and brain natriuretic peptide is available for prognosticating which asymptomatic patients will become symptomatic:[8]

References

  1. Carabello BA. Clinical practice. Aortic stenosis. N Engl J Med. 2002 Feb 28;346(9):677-82. Review. No abstract available. PMID 11870246
  2. 2.0 2.1 Etchells E, Bell C, Robb K (February 1997). "Does this patient have an abnormal systolic murmur?". JAMA : the Journal of the American Medical Association 277 (7): 564–71. PMID 9032164[e] Full text at OVID
  3. Etchells E, Glenns V, Shadowitz S, Bell C, Siu S (October 1998). "A bedside clinical prediction rule for detecting moderate or severe aortic stenosis". Journal of general internal medicine : official journal of the Society for Research and Education in Primary Care Internal Medicine 13 (10): 699–704. PMID 9798818. PMC 1500900[e] PubMed Central
  4. Flohr KH, Weir EK, Chesler E (May 1981). "Diagnosis of aortic stenosis in older age groups using external carotid pulse recording and phonocardiography". British heart journal 45 (5): 577–82. PMID 7236464. PMC 482567[e]
  5. 5.0 5.1 5.2 5.3 Bonow RO, Carabello BA, Kanu C, de Leon AC Jr, Faxon DP, Freed MD, Gaasch WH, Lytle BW, Nishimura RA, O'Gara PT, O'Rourke RA, Otto CM, Shah PM, Shanewise JS, Smith SC Jr, Jacobs AK, Adams CD, Anderson JL, Antman EM, Faxon DP, Fuster V, Halperin JL, Hiratzka LF, Hunt SA, Lytle BW, Nishimura R, Page RL, Riegel B.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (writing committee to revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons.Circulation. 2006 Aug 1;114(5):e84-231. PMID 16880336 (see page 462 for indications for replacement)
  6. Rosenhek R, Binder T, Porenta G, Lang I, Christ G, Schemper M, Maurer G, Baumgartner H.Predictors of outcome in severe, asymptomatic aortic stenosis.N Engl J Med. 2000 Aug 31;343(9):611-7. PMID 10965007
  7. Rosenhek R, Zilberszac R, Schemper M, Czerny M, Mundigler G, Graf S et al. (2010). "Natural history of very severe aortic stenosis.". Circulation 121 (1): 151-6. DOI:10.1161/CIRCULATIONAHA.109.894170. PMID 20026771. Research Blogging.
  8. Monin JL, Lancellotti P, Monchi M, Lim P, Weiss E, Piérard L et al. (2009). "Risk score for predicting outcome in patients with asymptomatic aortic stenosis.". Circulation 120 (1): 69-75. DOI:10.1161/CIRCULATIONAHA.108.808857. PMID 19546391. Research Blogging.