timing for pvr

Massimo Chessa

Department of Pediatric Cardiology

&

Adult with Congenital Heart Disease

IRCCS- Policlinico San Donato

San Donato Milanese – Milano

[email protected]

Managing the RVOT

Indications andTiming

Department of Pediatric Cardiology & Adult with Congenital Heart Disease

…………….severe pulmonary regurgitation alone,

requiring valve insertion, is uncommon……..

World Congress of Paediatric Cardiology 1989


Natural History of PR

One of the reason for the lack of appreciation of the

impact of PR is its very long preclinical natural history

At age 20 years, only 6% of the pt had symptoms, but the

incidence increased to 29% at age 40 years

Shimazaki Y Thorac Cardiovasc Surg1984;32:257-9



At the time of ToF repair the RV is hypertrophied and its

compliance is low; the diameters of the central PA are

either hypoplastic or low-normal, and their capacitance is

low.

The heart rate is relatively high, which leads to a relatively

short duration of diastole

The combination of these factors

limits the degree of pulmonary regurgitation.



Combined with a longer duration of diastole as HR

decreases with age, these changes lead to progressive

increase in the degree of PR

Over time the increase in RV

stroke volume leads to

progressive rise in the size and

compliance of the central PA

and to increased RV

compliance


The number of pts free of reinterventions for PVR

decrease during the 3rd-4th decade


During the past 2 decades it has become apparent that

PR is a key driver

of RV failure

but

the Timing for PVR remains Controversial


Criteria for PV Replacement

Pt with symptoms Exercise intollerance

Heart failure

sVT

syncope

PVR surgically

or

transcatheter


Criteria for PV Replacement

Pt asymptomatic with PR ≥ 25-35% + at least 2 criteria

RV EDVi ≥ 150 mL/m2 or RV/LV >1.5

RV ESVi ≥ 80 mL/m2

RV EF ≤ 45%

CPET ≤ 65% of the predicted VO2 max

RV volumes and function

QRS ≥ 180 msec (better before 180 because no improvments after PVR)

TR ++ Residual VSD RVOTO (RVP 2/3 LVP or ΔP ≥ 50 mmHg

LV Dysfunction AR ++


Why timing is so important?

Why timing is so difficult?

What do we know OR DON’T know?

Which are possible future directions?



In a pt with a PR

although there is a normal

pattern of ejection during

pressure rise and pressure

fall, there is increase in

volume during the

isovolumic relaxation

period.

Redington AN Br Heart J 1988;60:57-65



There is a linear

relationship between the

amount of pulmonary

incompetence measured

during the isovolumic

relaxation period and the

end diastolic volume

Redington AN Br Heart J 1988;60:57-65


Once the compensatory mechanisms begin to fail

RV Mass-to-Volume ratio decreases

End-Systolic Volume increases

Ejection Fraction decreases


Samyn et al, J Magn Reson Imaging 2007 Geva et al, J Am Coll Cardiol 2004,


RV Structure and Function

More afterload dependent than the LV

Very modest increases in PVR – one component of afterload

- may result in substantial declines in RV stroke volume


For determining the optimal timing of

pulmonary valve replacement

we must know the

Natural History

ant the

Adverse Clinical Outcomes


One of the key point influencing the RV modifications

related to the PR is the RV Diastolic Performance

While this appears to be disadvantageous in the early

postoperative period, restrictive physiology has many

potential advantages during late postoperative follow-up


For determining the optimal timing of pulmonary valve

replacement we must know the

Natural History

ant the

Adverse Clinical Outcomes


• Mortality rate triples during the 3rd postoperative decade

There are three major categories of outcome predictors

on the risk of death in survivors of ToF repair

1. History (syncope, older age at repair)

2. Electrophysiologic markers (prolonged QRS duration,

sVT, positive ventricular stimulation study)

3. Hemodynamic sequelae (RV dilatation, Ventricular

dysfunction)


How to Investigate


How to Investigate

12


How to Investigate


Certainly PVR should be performed when patients develop

first symptoms as dyspnea, but it is not infrequent that they

may have advanced RV dysfunction by the time complain of

symptoms

The Timing!

Serial exercise testing and/or CPE test may help to delineate

subtle changes in exercise capacity before the pt becomes

symptomatic.


The Timing!

RV Size and function

TR functional or mechanic

Symptomatic atrial and ventricular arrhythmias

Coexistent PS


The most recent RV EDV “cut-off ” proposed has moved

even lower than 150 ml/m2

but

Non consistent improvement in RVEF was observed!!

Dave HH 2005;80:1615-20

Frigiola A 2008;34:576-82

The Timing!

Maybe the Focus should be on the

preservation of RVEF rather than RV volume


The Timing!

In asymptomatic children after repair of ToF,

pulmonary regurgitation is associated with

impaired regional systolic RV deformation indices

(Cadiac Doppler Myocardial Imaging)

not

demonstrate by routine RVEF


The Timing!




Coexistent PS


Tricuspid Valve Repair


The Timing!




Coexistent PS


QRS duration may be a “proxy”for RV function

A bad RV is associated with an increased risk for VT and SD

PVR alone does not usually result in shortening of the QRS

duration

Harrild DM 2009;119:445-451

It is possible that in both groups, the RV size and

dysfunction were already advanced and surgery was too

late to confer a survival advantage

Warnes CA JACC 2009;54:1903-10

The Timing!


Conclusions

We are probably still operating too late because the

limited life expectancy of all valves inserted in the

pulmonary position….

…. but further development of transcatheter

techniques for implantation and re-implantation

may lower the threshold for PVR

I Thank you for your attention……

timing for pvr

Health & Medicine