Aortic Valve Stenosis

Question 1

Aortic valve morphology indicating Stage B

Answer 1

• Mild to moderate leaflet calcification/ fibrosis of a bicuspid or trileaflet valve with some reduction in systolic motion.

or

• Rheumatic valve changes with commissural fusion

Question 2

What stage is Asymptomatic severe AS without LV Systolic dysfunction ?

Answer 2

Stage C1

• LV diastolic dysfunction
• Mild LV hypertrophy
• Normal LVEF

Question 3

What stage is asymptomatic severe aortic stenosis with evidence of LV systolic dysfunction?

Answer 3

Stage C2

Asymptomatic severe AS with LV systolic dysfunction

Question 4

Methods to assess low flow low gradient AS

Answer 4

• reduced LVEF (Stage D2), low-dose dobutamine stress testing with echocardiographic or invasive hemodynamic measurements is reasonable to further define severity and assess contractile reserve
• normal or reduced LVEF (Stages D2 and D3), calculation of the ratio of the outflow tract to aortic velocity is reasonable to further define the severity
• normal or reduced LVEF (Stages D2 and D3), measurement of aortic valve calcium score by CT imaging

Question 5

Interpretation of low flow / low EF AS with dobutamine stress:

Answer 5

1. Severe AS is characterized by a fixed valve area, resulting in an increase in transaortic velocity to >/=4 m/s (mean gradient >/=40 mmHg) at any flow rate, but with valve area remaining <1.0 cm2.
2. moderate AS and primary LV dysfunction (clinical efx due to reduced EF) there is an increase in valve area as volume flow rate increases, resulting in only a modest increase in transaortic velocity or gradient.
3. Some patients fail to show an increase in stroke volume >20% with dobutamine, referred to as “lack of contractile reserve” or “lack of flow reserve.”

Question 6

How to interpret the results of Dobutamine Stress Test :

resulting in an increase in transaortic velocity to >/=4 m/s (mean gradient >/=40 mmHg) at any flow rate

Answer 6

Results of Dobutamine Stress Test :

Severe AS

characterized by a fixed valve area, resulting in an increase in transaortic velocity to >/=4 m/s (mean gradient >/=40 mmHg) at any flow rate, but with valve area remaining <1.0 cm2.

Question 7

How to Interpret the Results of Dobutamine Stress Test :

resulting in only a modest increase in transaortic velocity or gradient.

Answer 7

Likely only moderate AS and primary LV dysfunction

(clinical efx due to reduced EF)

there is an increase in valve area as the volume flow rate increases, resulting in only a modest increase in transaortic velocity or gradient.

Question 8

LVOT area / aortic velocity consistent with AS

Answer 8

<0.25

Question 9

Calcium score specific for severe aortic stenosis

Answer 9

Sex-specific Agaston unit thresholds for diagnosis of severe AS are:

• 1300 in women
• 2000 in men.

Question 10

LVEF criteria for surgery in asymptomatic patients with severe AS?

Answer 10

In asymptomatic patients with severe AS and an LVEF <50% (Stage C2), AVR is indicated (8–11).

Question 11

Exercise stress test results indicating surgery for apparently asymptomatic patients with severe AS?

Answer 11

• Low Surgical Risk
• when an exercise test demonstrates either (or):
  
  1. decreased exercise tolerance (normalized for age and sex)
  2. f_all in systolic blood pressure of ‡10 mmHg from baseline_ to peak exercise

Question 12

BNP Level indicating surgery for apparently asymptomatic patients with severe AS (Stage C1)?

Answer 12

1. low surgical risk
2. B-type natriuretic peptide (BNP) level is >3 times normal

Question 13

How much increase in transvalvular velocity indicates surgical intervention in asymptomatic patients with high-gradient severe AS (Stage C1)?

Answer 13

AVR is reasonable when serial testing shows an increase in aortic velocity > 0.3 m/s per year.

Question 14

How much progressive decrease in LVEF should prompt AVR in asymptomatic severe AS

Answer 14

at least 3 serial imaging studies to <60%, AVR may be considered.

Question 15

General indications for surgery in asymptomatic patients with severe AS?

Answer 15

LVEF

1. LVEF < 50
2. LVEF progress to < 60 on three measurements

Velocity:

1. very severe > 5
2. increae in velocity > 0.3 m/s / year.

BNP > 3x normal

Question 16

Criteria for higher all-cause mortality in AS

Answer 16

V > 5, LVEF < 60%

Question 17

ECHO criteria for severe AI

Answer 17

Severe AR:

• Jet width > =65% of LVOT
• Vena contracta > 0.6 cm
• Holodiastolic flow reversal in the proximal abdominal aorta
• Regurgitant volume >=60 mL/beat
• Regurgitant fraction > =50%
• ERO >=0.3 cm2
• Angiography grade 3 to 4

Question 18

Jet width consistent with Severe AR

Answer 18

Jet width > =65% of LVOT

Question 19

Echo criteria for AI: Vena contracta?

Answer 19

Vena contracta > 0.6 cm

Question 20

Echo criteria for severe AI: Regurgitant volume?

Answer 20

Echo criteria for severe AI :

Regurgitant volume >=60 mL/beat

Question 21

Goal BP in patients with asympmatic AI ?

Answer 21

< 140 mmHg systolic

Question 22

Aortic Regurgitation:

Indications for surgey in asymptomatic patients.

Answer 22

• LVEF < 55%
  
  • surgery is indicated if no other cause identified.
• LVEF > 55%
  
  • LVESD > 50mm or inexed LVESD > 25
  • Progressive decline in LVEF on 3 serial measurments
  • Progressive increase in LV dilation (LVEDD > 65)