assessment and management of low flow low … · assessment and management of low flow low gradient...

©2013 MFMER | 3289956-1

Assessment and Management of Low Flow Low Gradient AS with Preserved LV Systolic Function

Joseph F. Malouf MD, FACC, FAHA, FASE Director, Interventional Echocardiography

Professor of Medicine Mayo Clinic

No Disclosures

©2013 MFMER | 3289956-2

Objectives

• Describe potential reasons for discordant AS severity criteria

• Understand the pathophysiology of low flow low gradient (LG) “Severe” AS with preserved EF

• Review prevalence and clinical significance of LF LG “Severe” AS with preserved EF

©2013 MFMER | 3289956-3

1. Measurement errors

2. Small body size

3. Paradoxical LF severe AS

4. Intrinsic discrepancies in guidelines criteria

5. Any of the above

CP1283942-3

Question 1

In Aortic Stenosis with EF > 50%, possible reasons

for an AVA < 1 cm2 and mean gradient < 40 mm Hg

include:

©2013 MFMER | 3289956-4

Question #2 Which of following statements is NOT correct regarding paradoxical low flow low gradient

severe aortic stenosis?

1. Most studies show better outcomes compared to patients with high-gradient severe AS

2. There is a higher prevalence of heart failure (HFpEF)

3. Most studies show benefit from aortic valve replacement

4. Arterial and global afterload are increased

©2013 MFMER | 3289956-5

Question #3 What is your initial recommendation for treating

a 73 year old man with hypertension (160/94 mmHg), dyspnea, paradoxical LFLG severe AS,

and STS score of 6?

1. Vasodilator therapy

2. Surgical aortic valve replacement

3. TAVR

4. Decide after Dobutamine Stress Test

©2012

MFMER |

3200268v2(

2003)-5

88 yo female with progressive

DOE and no lung disease

or known CAD

EF 59%

LVMI 95 g/m2

RWT=0.57*

RVSP 60 mmHg

TR vel 3.4 m/s

Mild MR

MildTR

RWT= 2x PWed

LVEDD * ≥0.42

©2013 MFMER | 3289956-8

What would you recommend?

1. Aortic valve replacement

2. Discordant mean gradient and valve

area – repeat TTE

3. Dobutamine stress echo

4. Hemodynamic cardiac cath.

5. CT scan of the aortic valve

©2013 MFMER | 3289956-9

Grading Severity of

Aortic Stenosis

Mean gradient AVA

Mild <30 >1.5

Moderate 30-40 1.0-1.5

Severe >40 <1.0

CP1006390-34 AHA/ACC Valve Guidelines 2014

©2013 MFMER | 3289956-10

Discordant “Severe” AS by AVA and

MG in pts with nl LV EF

Mean gradient AVA

Mild-Mod <40

Severe <1.0

CP1006390-34

©2013 MFMER | 3289956-11

Aortic Valve Area by Echo Continuity Equation

©2012 MFMER |

slide-11

=

AVA x

LVOT Area LVOT TVI

AV TVI

STROKE VOLUME

©2013 MFMER | 3289956-12

1. Inaccurate LVOT diameter

2. Underestimated LVOT velocity/TVI

3. Underestimated AV peak velocity

4. SV (small LV , systolic function, SVR )

Measurement Errors

CP1283942-3

Michelena et al Heart 2013

©2013 MFMER | 3289956-14

The critical issue of LVOT diameter measurement

• Underestimation of LVOT diameter is ♯1 error leading to the false conclusion of severe AS

• This also leads to underestimation of stroke volume and to the false conclusion of “Low-Flow”

• LVOT diameter should be re-checked (several times) on closer examination

• TEE may be useful in case of poor image quality

LVEF = 60% (Biplane Simpson)

TVI LVOT= 12 cm

Stroke volume: 42 ml

Svi: 23ml/m² (32-58)

Mean gradient: 24 mmHg

AVA: 0.8 cm2 (0.45

cm²/m²)

Global longitudinal strain is markedly decreased

normal values ≥ -20%

GS -12% GS -10.9%

©2013 MFMER | 3289956-17

Herrmann S et al JACC 58:402, 2011

Low Flow Etiologies

Pibarot and Dumesnil Circulation 2013

Low flow, low gradient in severe aortic stenosis (AS) due to concomitant cardiovascular diseases.

Sorin V Pislaru, and Patricia A Pellikka Heart 2016;102:665-671

©2012 MFMER | 3200268v2(2003)-20

Severe AS with AV velocity < 4 m/sec ?

Velocity = 3.8 m/sec

Mean Gradient = 38 mmHg

From Apex

From Right Parastetnal position

Velocity = 5.6 m/sec

Mean Gradient = 72 mmHg

©2013 MFMER | 3289956-21

Optimal Doppler Velocity Location Depends on Aortic Root Angulation

• Overall, the highest AV velocity comes from RPS in 50%

• If the angle<115 degree, it is from RPS in 67%

• AS/MG is underestimated in 15% if only apex is used

©2011

MFMER |

slide-21 J. Thaden and J. Oh et al. ACC 2014

©2013 MFMER | 3289956-22

What is the Prevalence of Discordant Aortic

Stenosis Echo-Doppler derived measurements?

3,483 Echocardiographic Studies in

Patients with Aortic Valve Stenosis and

Normal Left Ventricular Function

Minners et al: EHJ 29:1043, 2008

2.0

1.5

1.0

0.5

0 20 40 60 80 100 120

39% 30%

Valv

e a

rea (

cm

2)

Mean pressure gradient (mm Hg)

1% 30%

Stroke Volume from 3,349 Echocardiographic

Studies in Patients with Aortic Valve Stenosis

Nl LV function; AVA 2

Consistent grading

AVA (cm2) 1

Pm (mm Hg) 40

n 983

Stroke volume (mL) 79±15*


Inconsistent grading

AVA (cm2) 1

Pm (mm Hg) >40

n 20



AVA (cm2) <1

Pm (mm Hg) 40

n 997


Consistent grading

AVA (cm2) <1

Pm (mm Hg) >40

n 1,338


Stroke Volume from 3,349 Echocardiographic

Studies in Patients with Aortic Valve Stenosis

Nl LV function; AVA 2



AVA (cm2) <1

Pm (mm Hg) 40

n 997


Consistent grading

AVA (cm2) <1

Pm (mm Hg) >40

n 1,338


©2013 MFMER | 3289956-27

What is the clinical significance of truly

discordant AS severity data?

©2013 MFMER | 3289956-28

Causes of True Discordance in Pts with Low Flow Low Gradient Severe AS

Paradoxical low flow, low gradient, severe AS

Inconsistency in guidelines criteria for severe AS

SV: 51 ml

AVA: 0.7 cm2

∆P: 25 mmHg

Normal Flow sAS

LVEF: 60%

SV: 69 ml

AVA: 0.7 cm2

∆P: 45 mmHg

LVEDV: 115 ml

Paradoxical Low Flow

sAS

LVEDV: 85 ml

Pibarot & Dumesnil JACCI 2009 Pibarot & Dumesnil JACC 2012

LVEF: 60%

Lancelloti et al JACC 2012;59:235

Clinical Outcome in Severe Asymptomatic AS (AVA <1cm2); LV EF ≥55%

LF=SV< 35 cc/m2

Aortic Valve Area vs Mean Gradient Based on Gorlin Equation

Carabello B. Aortic Stenosis NEJM 2002

©2013 MFMER | 3289956-33

50 53

352

1249

Flow Gradient Patterns in Severe AS (AVA<1 cm2) with Preserved EF

(n = 1704)

LF/HG (SVI<35, MG≥40)

LF/LG (SVI<35,MG<40)

NF/LG (SVI≥35, MG<40)

NF/HG (SVI≥35, MG≥40)

3%

21%

73%

3%

©2013 MFMER | 3289956-34

Survival to Death Under Medical Management

0

20

40

60

80

100

0 1 2 3

Su

rviv

al (%

)

At risk, no. (%)

NF/LG 190 (91.0) 112 (82.3) 65 (72.7)

NF/HG 223 (83.0) 108 (66.9) 56 (52.7)

LF/LG 23 (82.5) 8 (44.1) 3 (27.6)

LF/HG 8 (80.8) 5 (80.8) 1 (60.6)

NF/LG

NF/HG

LF/LG

LF/HG

Years

Eleid MF et al. Circulation 2013;128:1781-9.

P<0.0001

©2013 MFMER | 3289956-35

LF/LG Patient Characteristics

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Atrialfibrillation

Previousheartfailure

Obesity Anysymptoms

LF/LG

NF/LG

NF/HG

P < 0.0001 for all

Eleid MF et al. Circulation 2013;128:1781-9.

SVI is incrementally associated with Mortality

Eleid MF et al. Heart 2015;101:23-9.

©2013 MFMER | 3289956-38

0

20

40

60

80

100

0 1 2 3 4 5

Overall Survival in Patients with NF vs PLF Asymptomatic Severe AS

as a Function of the Type of Treatment Medical vs Surgical

Surv

ival (%

)

Follow-up (years)

P<0.001 (0.002; 0.017)

PLF surgical

NF surgical

NF medical

PLF medical

Hachicha Z et al Circulation 2007; 115:2856

Copyright © American Heart Association, Inc. All rights reserved. Dania Mohty et al. Circulation. 2013;128:S235-S242

AVR+/- CABG

Isolated AVR

Surgery or Conservative Management


AVR+/- CABG

Isolated AVR

Surgery or Conservative Management

Operative mortality

LFLGsAS=9.8%

NFHGsAS=3.8%

Mean FU 4.6 yrs


AVR vs Conservative Management in pts with LF-LG AVA≤ 1cm2 & EF>50%

LF=SV< 35 cc/m2

Le Ven et al JACC 2013

TAVR

67 year old woman with severe aortic stenosis

and heart failure came to Valve Clinic for AVR

Stroke volume = (1.9) 2 x 0.785 x 21 = 60 cc (SVI =30)

AVA = 60 / 76 = 0.79 cm2

MG 26 mmHg

LVOT D = 1.9 cm LVOT TVI = 21cm

Restrictive Diastolic Filling

Mitral inflow

Mitral Annulus

E/e’ =25

E’ = 4cm/sec

Hachicha et al. Circulation. 2007;115:2856-64

AKA Valvulo-Arterial Impedance

Characterization of 512 Consecutive Patients with Severe AS

(IAVA<0.6 cm2/m2)&EF>50%

Group 1

“Normal flow, high gradient”

SVi >35 mL/m2

Gradient >40 mmHg

n=152 (30%)

Indexed AVA=0.4±0.1 cm2/m2

LVEDD=48±5 mm

LVEDVI=59±13 mL/m2

ZVA=4.2±0.8 mmHg/mL/m2

AVR=80%

Group 2

“Normal flow, low gradient”

SVi >35 mL/m2

Gradient 40 mmHg

n=193 (38%)


LVEDD=48±5 mm

LVEDVI=58±13 mL/m2


AVR=53%

Group 3

“Low flow, high gradient”

SVi 35 mL/m2

Gradient >40 mmHg

n=44 (8%)


LVEDD=43±5 mm

LVEDVI=48±12 mL/m2


AVR=68%

Group 4

“Low flow, low gradient”

SVi 35 mL/m2

Gradient 40 mmHg

n=123 (24%)


LVEDD=46±5 mm

LVEDVI=53±11 mL/m2


AVR=36%

Dumesnil et al: EHJ 31;281, 2010

Co

nc

ord

an

t g

rad

ing

D

isco

rda

nt g

rad

ing

Eleid MF et al. Circulation 2013

Jordi S Dahl et al. Heart 2015;101:1015-1023

RWT= 2x PWed

LVEDD

Serial changes LFLGsAS vs NFHGsAS vs NFLGsAS

LFLGsAS=78 pts; NFHGsAS=156pts

Jordi S Dahl et al. Heart 2015;101:1015-1023

Copyright © BMJ Publishing Group Ltd & British Cardiovascular Society. All rights reserved.

Serial changes LFLGsAS vs NFHGsAS vs NFLGsAS

LFLGsAS=78 pts; NFHGsAS=156pts

Development of severe aortic stenosis (AS).


Proposed systematic approach to diagnosis of low-flow/low-gradient severe aortic stenosis.


CP1303877-3

Schroeder et al EHJ 29: 531 2008

Indications for Aortic Valve Replacement in Patients With Aortic Stenosis

assessment and management of low flow low … · assessment and management of low flow low gradient...

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