1. HK Core Cardiology Certificate Course
7 April 2019
Aortic Regurgitation
Dr. Yiu Siu Fung

2. Chronic AR Rheumatic Connective tissue disorders / autoimmune
Marfan’s syndrome
Ankylosing spondylitis
SLE
Aortitis
Syphilis
In the past, rheumatic fever was the main cause of aortic regurgitation. The use of antibiotics to treat strep infections has made rheumatic fever less common. Therefore, aortic regurgitation is more commonly due to other causes.
Congenital heart valve disease. You may have been born with an aortic valve that has only two cusps (bicuspid valve) or fused cusps rather than the normal three separate cusps. In some cases a valve may only have one cusp (unicuspid) or four cusps (quadricuspid), but this is less common.
These congenital heart defects put you at risk of developing aortic valve regurgitation at some time in your life. If you have a parent or sibling with a bicuspid valve, it increases the risk that you may have a bicuspid valve, but it can also occur if you don't have a family history of a bicuspid aortic valve.
Age-related changes to the heart. Calcium deposits can build up on the aortic valve over time, causing the aortic valve's cusps to stiffen. This can cause the aortic valve to become narrow, and it may also not close properly.
Endocarditis. The aortic valve may be damaged by endocarditis — an infection inside your heart that involves heart valves.
Rheumatic fever. Rheumatic fever — a complication of strep throat and once a common childhood illness in the United States — can damage the aortic valve. Rheumatic fever is still prevalent in developing countries but rare in the United States. Some older adults in the United States were exposed to rheumatic fever as children, although they may not have developed rheumatic heart disease.
Other diseases. Other rare conditions can enlarge the aorta and aortic valve and lead to regurgitation, including Marfan syndrome, a connective tissue disease. Some autoimmune conditions, such as lupus, also can lead to aortic valve regurgitation.
Trauma. Damage to the aorta near the site of the aortic valve, such as damage from injury to your chest or from a tear in the aorta, also can cause backward flow of blood through the valve.

3. Chronic AR Congenital Bicuspid AV VSD Sinus of Valsalva aneurysm
Others HT
Age related changes
Myxomatous degeneration
Myxoid degeneration of AV as isolated cause of AR is possible. Some can be Marfan, but this is a histological diagnosis – disruption of valve fibrosa and repalced by acid mucopolysaccharides and cystic changes.
Entity predominant in elderly males age 63 av with long standing hx of HT.

4. Acute AR Infective endocarditis Acute aortic dissection
Congenital rupture of sinus of Valsalva
Trauma

5. Identification of Etiology
PLAX + PSAX
AV morphology (cusp no, calcification, vegetations, cusp prolapse)
High / R parasternal + suprasternal
Thoracic aorta aneurysm + dissection
+/- TEE

6. Prolapse of non-coronary cusp AV
AV Cusp Prolapse
Poon Ka Shing 4:25:39 4:23:30
4:24:13
Prolapse of non-coronary cusp AV

7. Marfan’s Syndrome
Kwok Hong Pui 5:02:17 5:02:40

8. Perforation of Noncoronary Cusp due to SBE
AV Perforation
Cheng Koon Sang 3:25:20 3:25:24
Perforation of Noncoronary Cusp due to SBE

9. Presentation Chronic AR - usually no symptoms Heart murmur
Exertional SOB, chest tightness
Heart failure
Arrhythmia

10. MRI / CT in AR
CMR
Quantify RF when echo equivocal (RV = area under aortic flow vs time curve)
EF, LV volumes
Aortic dilatation – max diameter
FU aortic dimension (CT better than MRI – inner to inner edge technique at end diastole on strictly transverse plane by double oblique reconstruction perpendicular to axis of blood flow, NB echo: leading to leading edge)
Cardiac MRI is well suited for the examination of aortic regurgitation because it can accurately quantifiy the regurgitant volume, and left ventricular size and function. It is totally non-invasive and does not require contrast.
Short and long axis SSFP images are obtained to quantify end-diastolic and end-systolic LV volumes from which one can calculate the ejection fraction.
Phase-contrast images are obtained perpendicular to the aorta just distal to the aortic valve
To assess valve anatomy such as the number of cusps, SSFP images are acquired through the valve perpendicular to the aortic root.
The simplest and most direct way to determine the regurgitant volume is by integrating the area under the aortic flow vs. time curve during diastole.

11. Echo – comprehensive approach
? Bicuspid AV
AR jet – eccentric ? (LAX), central / commisure ? (SAX)
LV size, function (small size patient – indexing LV dimension to BSA)
Aortic root / AsAo size – annulus, SOV, STJ, AsAo – leading to leading edge at end diastole, except annulus at mid systole
3 phenotypes of AsAo (1) aortic root aneurysm SOV > 45mm (2) tubular AsAo (SOV < 40-45mm) (3) isolated AR (all diameters < 40mm)
? AV repair / valve sparing surgery of aortic root (may need preop TEE)
Intraop TEE must if AV sparing surgery / AV repair

12. Functional Significance
Left ventricular size and function (chronic AR)
M-mode
Simpson’s biplane
LVESD > 50mm
LVEF < 50%

13. AR Severity - Semiquantitative Methods
Color Doppler
Height ratio (AR jet width / LVOT diameter in LAX)
Area ratio (AR jet area / LVOT area in SAX)
Important : AR jet length into LV bears no correlation to AR severity

14. Color Doppler LAX / Height Ratio
Chan Kam Loi 3:06:04 Kong Kin Leung 10:54:46
2/4 AR TTE
4/4 AR TEE

15. Color Doppler SAX / Area Ratio
Chan Kam Loi 3:11:36 Kong Kin Leung 10:51:11
2/4 AR TTE
4/4 AR TEE

16. AR Severity - Semiquantitative Methods
Width of Vena Contracta
Measured from PLAX view
≥ 6mm  95% sensitive and 90% specific for diagnosing severe AR (ERO ≥ 30 mm2)
Regardless of jet direction (eccentric / central)
Circulation 2000; 102: 558

17. AR Severity - Semiquantitative Methods
PW Doppler
Descending thoracic aorta - diastolic flow reversal
Sample vol. - located near take off point of L subclavian artery
AS A “QUICK AND DIRTY” METHOD, HOWEVER IS ONE OF THE MOST USEFUL SIGNS OF SIGNIFICANT REGURGITATION --- OTTO 1997

18. Descending Thoracic Aorta PW Doppler
Holodiastolic flow reversal – but frequent in > 60yrs subjects without severe AR (sensitivity 100% specificity 75%)
TVI > 15 cm
Peak velocity > 60 cm/s
↑ regurgitant fraction 77% (sensitivity 100% specificity 92%)
J Heart Valve Dis Sep;2(5):585-94
End diastolic reversal velocity > cm/s
J Am Soc Echocardiogr 1996;9:675-83

19. End-Diastolic Flow Velocity
RF (%)
Mean ± SD (cm/s)
< 20
6.3 ± 5.2
20 – 40
12.2 ± 4.3
41 – 60
22.1 ± 5.7
> 60
34.3 ± 9.3
Tribouilloy C et al: Br Heart J Jan;65(1):37-40

20. Holo Diastolic Flow Reversal
Wong Yuk Ling 12:18:24 12:17:41
Chan Chung Sing 2:33:27 2:32:56 (cannot find)

21. AR Severity - Semiquantitative Methods
CW Doppler
Dense signal
PHT
If 2 separate slopes of AR velocity curve obtained - PHT should not be measured from initial steeper slope
Peak early diastolic velocity > 4m/s for accuracy
Why PHT decreases with severe AR?

22. Acute 4/4 AR due to aortic root abscess – dense signal and short PHT
CW Doppler
Chan Kam Loi 3:15:40 Kong Kin Leung 10:35:36
Acute 4/4 AR due to aortic root abscess – dense signal and short PHT
Chronic 2/4 AR

23. Pressure Curves in Chronic vs. Acute AR
Solid line – chronic AR Dashed line – acute AR
100 Ao LV
With chronic AR, large pressure difference between LV and Ao throughout diastole
With acute AR, aortic pressure falls rapidly while LVEDP elevates rapidly at end diastole → rapid equilibration of Ao and LV pressures → short PHT

24. AR Severity - Quantitative Methods
PISA
Quantitative Doppler

25. AR – Criteria of Severity
Mild
Severe
AR width / LVOT diameter ratio (%)
≤ 30
≥ 60
AR jet area / LVOT area ratio (%)
PHT (ms)
≥ 500
≤ 300
CW Doppler Density
Faint
Dense
Diastolic flow reversal
Early diastolic
Holodiastolic TVI ≥ 15cm
RV (cc)
ERO (mm2)
< 10
≥ 30
RF (%)
< 30
≥ 55

26. AR and PISA ERO RV Fundamental parameter
Dependent on loading conditions
Proportional to
Pressure gradient across Ao-LV
Duration of diastole

27. Criteria of Severity – MR vs. AR
ERO (mm2)
RV (cc) MR
> 40
> 60 AR
> 30

28. AR and PISA AR MS

29. AR and PISA - Underestimation
Marked underestimation of ERO with angle of inverted aortic valvular funnel ≥ 2200
e.g. large fusiform dilatation of Ao root
No trend of underestimation with a flat angle of flow convergence < 2200

30. Angle of Inverted AV Funnel ≥ 2200
Kwok Hong Pui 5:02:17
Marfan syndrome with aortic root dilatation

31. No single angle planar correction
AR and PISA
No single angle planar correction
Complex nonplanar geometry of aorta
3D angles
Difficult on line measurement
High interobserver variability
Classification
Angle < 2200
Angle ≥ 2200

32. AR and PISA
Not easy to master
High feasibility
Reliable with eccentric jet

33. Example of AR Quantification
Tsang Yuk Keung 3:45:08 3:47:15
Grade 4/4 eccentric AR by color Doppler + high velocity holodiastolic flow reversal descending thoracic aorta (TVI = 32cm) + severe LV dilatation (49/71mm)

34. Continuity Equation Mitral annulus diameter 3.2cm
Mitral inflow TVI 13cm
Tsang Yuk Keung 3:37:20 3:38:33 3:42:52 3:34:51
LVOT diameter 2.9cm
LVOT TVI 51cm

35. Continuity Equation Mitral inflow stroke volume =
mitral annular diameter2 x x mitral inflow TVI =
3.22 x x 13 = 104 cc
LVOT stroke volume =
LVOT diameter2 x x LVOT TVI =
2.92 x x 51 = 337 cc
RV = 337 – 104 cc = 233 cc
Regurgitant fraction = RV ÷ LVOT SV
= 233 ÷ 337 x 100 = 69%

36. PISA Apical LAX view with zoom up of AR orifice and jet
Tsang Yuk Keung 3:17:38 3:18:32
Apical LAX view with zoom up of AR orifice and jet
Upward (not downward) baseline shift of color flow map which makes the PISA larger

37. PISA
Tsang Yuk Keung 3:18:32 3:28:24
r = 1.31cm
Vr = 52 cm/s
VAR = 486cm/s
TVI = 204 cm
ERO = (6.28 x x 52) ÷ 486 = 1.13 cm2
RV = ERO x AR TVI = 1.13 x 204 = 232 cc

38. Assessment of AR severity
REMINDER
All modalities have their limitations. An accurate assessment and evaluation of AR requires one to incorporate all of the available tools echocardiography provides.

39. Natural History of Severe AR
Asymptomatic Patients + Good LV Function
Excellent long term prognosis
n = 99
90% asymptomatic at 3 yrs
81% at 5 yrs
75% at 7 yrs
AVR < 4% per yr
Bonow et al Circulation 1983; 68:
n = 50, EF > 50%, median FU 44 months
symptomatic or LV dysfunction 4 ± 3% per yr
Ann Intern Med 1989; 110:

40. Natural History of Severe AR
n = 104, normal LV function, average FU 8 yrs
Death / symptoms / LV dysfunction
LVESD > 50mm 19%
LVESD 40-49mm 6%
LVESD < 40mm 0%
2 sudden death with LVESD > 55mm
Bonow et al Circulation 1991; 84:
N = 104 FU 7.4 ± 3.7 yrs
AVR / asymptomatic excessive LV ↑ / sudden death = 6.2% per yr (similar to earlier studies)
Circulation 1998; 97:

41. Natural History of Severe AR
Asymptomatic Patients + Impaired LV Function
66% require surgery within 2-3 yrs
Bonow et al Herz 1984; 9:
Circulation 1980; 61:
Bonow et al AJC 1982; 50:
Symptomatic Patients
Poor prognosis
Only 4% alive at 10 yrs with NYHA class III or IV symptoms of CHF Henry et al Circulation 1980; 61:
In general symptomatic CHF - dies within 2 yrs without surgery
Right sided heart failure - very poor prognosis < 10% alive at 4 yrs J Thorac Cardiovasc Surg 1981; 82: 114

42. Natural History of AR Asymptomatic + normal LV function
Progression to symptoms or LV dysfunction
< 6% / yr
Progression to asymptomatic LV dysfunction
< 3.5% / yr
Sudden death
< 0.2% / yr
Asymptomatic + LV systolic dysfunction
Progression to cardiac symptoms
> 25% / yr
Symptomatic
Mortality rate
> 10% / yr

43. Afterload Reduction in Chronic Severe AR
Incidence of AVR (%)
p < 0.001
Years after randomization
Randomized trial of nifedipine vs. digoxin in 143 patients with chronic asymptomatic severe AR
NEJM 1994; 331:

44. Timing of Operation in AR
Previous Criteria
(1) Functional Class III
(2) Significant LV dysfunction
Based on higher operative mortality in the past

45. Modern Philosophy – Earlier Surgery
Based on
Enhanced understanding of natural history of AR
Lower operative risk than in the past
Newer surgical options which do not involve implantation of synthetic or non-human material

46. Newer Surgical Options – Role of Echo
Aortic valve repair
Feasible only in 10% of AR (70% in MR)
Echo for selection
AV not thickened, retracted, calcified or restricted in motion
Diastolic leaflet prolapse of either tri- or bicuspid AV - best candidates
Aortic root dilation with otherwise normal leaflets and annulus
separating valve flaps (cusps) that have fused, reshaping or removing excess valve tissue so that the cusps can close tightly, or patching holes in a valve.

47. Aortic homograft Aortic homograft Ideal for IE, small aortic root
Never widely used – lack of tissue donars + difficulty of OT
Echo planning OT - limited availability of valves of any given size by determining size of aortic annulus
Concerns of homograft valve failure

48. Indications for surgery with severe AR
Symptomatic – irrespective of LVEF

49. Indications for surgery with severe AR
Asymptomatic –
EF </= 50%
LVESD > 50mm
LVEDD > 70mm
small body size LVESD index to BSA – 25mm/m2
Serial rapid progression LV size or decline in EF

50. Indications for surgery with dilated aorta
Best defined with Marfan syndrome
Irrespective of the severity of AR

51. Indications for surgery with dilated aorta Marfan Syndrome
Management differs from primary AR
Root aneurysm  root replacement +/- AV preservation, but definitely with coronary reimplantation
Tubular AsAo aneurysm  supracommissural tube graft replacement without coronary reimplantation
Optimal medical Px – β blockade (↓ stress on aortic wall) more important than afterload reduction

52. Indications for surgery with dilated aorta Marfan Syndrome
Surgery if (without significant AR)
rate (> 5% annual change)
ALL patients – aortic diameter >/=50mm
TGFBR1 or TGFBR2 mutation – aortic diameter >/= 45mm

53. Indications for surgery with dilated aorta Bicuspid AV
Surgery if aortic dimension >/= 55mm or >/= 50mm if other risk factors or COA
Effects of medical treatment on aortic enlargement with bicuspid AV needs to be studied

54. Severe AR with aortic root disease
Patients with indication for AV surgery, concomitant surgery of aortic root / AsAo should be undertaken if
aortic diameter >/=45 mm

55. ^bSurgery should also be considered if significant changes in LV or aortic size occur during follow-up (see table of recommendations on indications for surgery in severe aortic regurgitation and aortic root disease in section 4.2).
Unless provided in the caption above, the following copyright applies to the content of this slide: © 2017 The European Society of Cardiology. For permissions please The article has been co-published with permission in the European Heart Journal [ /eurheartj/ehx391] on behalf of the European Society of Cardiology and the European Journal of Cardio-Thoracic Surgery [ /ejcts/ezx324] on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved in respect of European Heart Journal, © European Society of Cardiology The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Either citation can be used when citing this article.
European Journal of Cardio-Thoracic Surgery, Volume 52, Issue 4, 26 August 2017, Pages 616–664, 55

56. Serial follow up Mild to moderate AR – echo every 2 yrs
Severe AR – approaching thresholds for surgery – echo every 9 months
Inconclusive cases, BNP may be helpful. Elevation during FU  LV dysfunction
If AsAo > 40mm  obtain baseline CT/ CMR  then follow up with echo  any increase > 3mm should be validated with CT / CMR

57. Take Home Message Strongest indicator for valve surgery in severe AR
Symptoms
and / or documentation of LVEF < 50% and /or LVESD > 50mm
Dilated aorta – accurate measurements of aortic diameters are crucial to guide timing and type of surgery