Main»Aortic Valve Disease

Aortic Valve Disease

Aortic Valve Disease

1. Morphology

A. Calcified Aortic Stenosis
1) Congenitally bicuspid or unicuspid, fused commissures, heavy calcification, age 50-70
B. Rheumatic Aortic Stenosis
1) Fibrous thickening, 3-cusp valve, mild calcification, rheumatic fever history in 1/2
C. Degenerative Aortic Stenosis
1) Diffuse nodular calcification, 3-cusp valve, no commissural fusion

2. Aortic Valve Incompetence

A. Cusp prolapse or cicatricial shortening of cusps with rolled edges
B. Annulo-aortic ectasia is a disease of the aorta rather than the valve itself
C. Dilation of sinus aorta, cystic medial necrosis, failure of coaptation of cusps

3. Symptoms and Diagnosis and indications for surgery

A. Aortic Stenosis
1) Dyspnea, angina, syncope in 1/3
2) Angina more common with CAD
3) Severe AS = LV to Ao gradient greater than 50 mmHg or aortic valve area less than 1.2 cm2/M2
4)what is a heart murmur of aortic stenosis:it is a harsh ejection systolic murmur which can radiate to the neck
B. Aortic Incompetence
1) CHF symptoms, angina 1/4, syncope rare
2) Severe AI = LV enlargement, calculated LV end systolic pressure greater than 50mm Hg, EF less than 40%, calculated fiber shortening less than 0.6 cm/sec

4. Natural History - Stenosis

A. Hemodynamically severe, symptomatic or asymptomatic
1) Sudden death risk high
2) Immediate operation is indicated
B. Hemodynamically mild or moderate, asymptomatic
1) 50% event free for 4 years
2) Operation is not urgent, but patients should be followed carefully as the disease advances rapidly
C. Hemodynamically mild or moderate, symptomatic
1) One-third will die within 4 years
2) Prompt operation is indicated

5. Natural History - Incompetence

A. Latent period to cardiac decompensation is long
1) Sudden death is not common
2) Once deterioration begins, the LV fails rapidly
C. Symptomatic patient with CHF, angina, syncope
1) Prompt operation is indicated
C. Asymptomatic patient
1) Follow carefully for LV enlargement or decreased LV function by ECHO or MUGA
2) Operate at an appropriate time

6. Associated Coronary Artery Disease

A. Treat significant coronary artery disease at the time of surgery even if asymptomatic
B. CABG reduces risk of AVR and improves long-term survival
C. Coronary angiography is indicated in all patients older than 45 years who will be having AVR

7. Ventricular Performance After AVR

A. AVR may improve LV performance
B. Pre-op LV dysfunction is the strongest predictor of post-op dysfunction (60%)
C. Microscopic changes in myocardium may persist despite improvement in symptoms and reduction in heart size

8. Age and AVR

A. Advanced age most common predictor of survival and cardiac events
B. AVR very effective treatment even in patients over age 70 or 80
C. Even the best patients over age 80 have reduced reserve

9. Choice of Replacement Device

A. Age less than 55 years - Aortic allograft or pulmonary autograft
B. Age between 55-75 years - Mechanical prosthesis
C. Age greater than 75 years - Porcine heterograft, stented or stentless
D. Allografts and autografts enlarge the orifice by about 2 mm, porcine heterografts reduce valve size by about 2 mm, and mechanical valves reduce valve size by about 5-8 mm

10. Size of Prosthesis for AVR

A. 19 mm
1) Prohibitively high LV/Ao gradient
2) Enlarge the aortic root or perform Ross procedure instead
B. 21 mm
1) Adequate size if BSA 1.5-1.7 M2 and patient is sedentary
2) If BSA greater than 1.7 M2 = enlarge the aortic root (10 year survival 80% vs 60%)
C. 23 mm or larger
1) Acceptable LV/Ao gradient in all patients

11. Survival After AVR

A. Early (hospital) death - 3-6%
B. Time-related survival
1) 5 years - 75%
2) 10 years - 60%
3) 15 years - 40%
C. Mode of death
1) Early due to CHF, hemorrhage, infection, CVA
2) Sudden - 20%
3) Device related - 20%

12. Risk Factors for Survival after AVR

A. Advanced age
B. Functional status (NHYA class)
C. Depressed LV function (aortic incompetence)
D. Coronary artery disease
E. Presence of endocarditis
F. Aneurysm of ascending aorta
G. Mismatch of prosthesis and body size