Unravelling low-flow low-gradient aortic stenosisFabian Nietlispach, MD PhDHead TAVI

Disclosures

• Consultant for• Edwards Lifesciences• Direct Flow Medical• Medtronic• St. Jude Medical

Case vignette

• 81 y/o htn, dyslip, female in AFib• Presents in NYHA III-IV• Previous CABG x2 and AVR (CE); LVEF 40%

LVEF 40%, aortic P-mean 21mmHgRHC: CI 2.1; PA 69/29/45; PCW 40

Aortic stenosis:the ‘easy’ valve pathology?

• Simple anatomy…

Piazza N et al. Circ Cardiovasc Interv. 2008

• …not so simple pathophysiology• Gorlin Formula:

• Continuity equation

Aortic stenosis:the ‘easy’ valve pathology?

Baumgartner at al., JASE 2009

• …not so simple pathophysiology• Gorlin Formula (with CO 6, HR 80, SEP 0.33):

– AVA 1cm2 Pmean = 26mmHg– AVA 0.8 cm2 Pmean = 41mmHg– AVA 0.7 cm2 Pmean = 53mmHg

Aortic stenosis:the ‘easy’ valve pathology?

Courtesy C. Seiler

• …not so simple pathophysiology• Continuity equation

Aortic stenosis:the ‘easy’ valve pathology?

Baumgartner at al., JASE 2009 Piazza N et al. Circ cv Interv. 2008 Zamorano et al. EHJ 2014

• …not so simple clinical management

Aortic stenosis:the ‘easy’ valve pathology?

Calcification

Rapid increase in jet velocity

Rosenhek et al, NEJM 1996

• …not so simple clinical management

Aortic stenosis:the ‘easy’ valve pathology?

Circulation 2012

Low-flow low-gradient AS

• Classification

Pibarot, JACC 2012

5-10%

Poor prognosis

High operative risk10-20%

small cavities

advanced diast. Dysf.

Normal LVEFNormal-FlowLOW-GRADIENT

Small body size indexedAVA 1cm2 Pmean 26mmHg

Pseudo-AS

AVA = 0.8 CO 2l/min gradient: 19mmHg

Low-flow low-gradient AS

modest changes in flow relevant reduction in gradient

• Definition• Low EF LFLG severe AS:

– LVEF <40%, Gradient <40mmHg, Low Flow: SVI <35 (or CI <3)

• Normal EF LFLG AS– LVEF >50%, Gradient <40mmHg, Low Flow: SVI <35 (or CI <3)

• Pseudo-AS– LVEF <40%, Gradient <40mmHg, Low Flow: SVI <35 (or CI <3)

• Normal EF NFLG AS– LVEF >50%, Gradient <40mmHg, Flow: SVI >35

Diagnostic challenges

• Stroke volume indexReduced even in HIGH-gradient AS

O’Sullivan, EHJ 2013

Gradient ‘per se’ not suited for AS quantification

Gradient: marker for myocardial function / risk assessment

AVA-calculations come with many confounders

Diagnostic challenges

• Low EF LFLG without contractile reserve

With contractile reserve (SV increase >20%)- Dobutamine SE

- AVA <1 severe AS- AVA >1 Pseudo AS

Without contractile reserve (SV increase <20%)- Severe AS? Pseudo AS?

Highest surgical risk

Is the distinction important?

• …maybe not so much…!

Group I: contractile reserveGroup II: no contractile reserve

Monin et al, Circulation 2003

Should patients with pseudo-AS undergo AVR??

Pseudo with (T)AVR?

Adapted from Fougeres et al, EHJ 2012

(T)AVR facilitating myocardial recovery?

(T)AVR slowing down myocardial deterioration?

Therapeutic options

• Medical therapy

Normal EF LFLG AS benefits from AVR

Prognosis of Low EF LFLG AS with MedTx is dismal

Hachicha et al, Circulation 2007

Therapeutic options

• Surgical valve replacement

Excess of 30-day mortality for LGLF (6.3%)

(Odds Ratio for PLF: 3)

Excess 10year mortality for Low EF LGLF

Clavel et al, JACC 2015

Therapeutic options

• Transcatheter Aortic Vave Implantation– Theoretical advantages

• Less invasive faster recovery, suited for high-risk pts• No extracorporal circulation

– suited for hypertrophic LV’s with diastolic dysfunction– Suited for failing LV’s with systolic dysfunction

• Better hemodynamics– Less risk of PPM

Smith C et al, PARTNER A, NEJM

Faster recovery

Day 1 post TAVI

Pibarot et al, JACC 2014

Less PPM

d/t larger valve areas

TAVI in LFLG

30d MACCE

O’Sullivan, EHJ 2013

cvDeath @ 30d and 1year

O’Sullivan, EHJ 2013

Symptomatic benefit

O’Sullivan, EHJ 2013

Randomized data(with 1st generation TAVI device)

• Low EF LFLG

Herrmann et al, Circ 2013

Randomized data(with 1st generation TAVI device)

• Normal EF LFLG

Herrmann et al, Circ 2013

• Main advantage: faster recovery

Herrmann et al, Circ 2013

Case vignette

• Decision:• TAVI Valve in valve• MitraClip• Left Atrial Appendage Closure

Follow-up after 3 and 6mts

• Patient doing well• NYHA I• P-mean 10mmHg• Mild mitral regurgitation

Complex patients

• Diagnostic challenge• Do we have the right cut-off values?

• Clinical challenge• When to treat?

– Earlier d/t concomitant myocardial disease ( additional benefit)

• How to treat?– SAVR versus TAVI

Thank you