This document discusses patient-prosthesis mismatch (PPM) after aortic valve replacement (AVR). PPM occurs when the effective orifice area (EOA) of the implanted prosthetic valve is too small relative to the patient's body size, leading to higher-than-expected gradients. PPM is associated with worse outcomes including reduced exercise capacity, less regression of left ventricular hypertrophy, and reduced long-term survival. The document outlines methods for assessing and differentiating PPM from valve stenosis using echocardiography parameters. It also discusses strategies for preventing PPM including proper valve sizing and the potential role of transcatheter valve-in-valve procedures for treating PPM in failed biopro
5. What is PPM?
• Literally, a mismatch between the patient and implanted prosthesis
• Remember, Gradient (or Velocity) = Flow (volume per unit time) ➗
Area (AVA)
• Flow, in any given haemodynamic environment, is proportional to
metabolic needs
• Hyperdynamic states (high flow): anaemia, fever, thyrotoxicosis, exercise
• Resting metabolic requirements: size of the patient (obesity paradox BMI >
30kg/m2)
• Hence Velocity/Gradient increases when (1) flow increases, or (2)
area decreases
6. Why is PPM so important?
• 2-20% of AVR patients may have severe PPM (defined as indexed EOA
< 0.65cm2/m2)
• Patients with severe PPM:
• Worse functional class and exercise capacity
• Reduced regression of LVH
• More HF related rehospitalization
• Reduced medium to long term survival
• Faster structural degeneration of bioprosthetic SAVR
• TAVR (esp self-expanding version) a/w less PPM than SAVR, but >
pacemaker and PVR
8. Tasca G et al. Impact of valve prosthesis-patient mismatch on left ventricular mass regression
following aortic valve replacement. Ann Thorac Surg 2005;79:505–10.
9. Head S et al. The impact of prosthesis-patient mismatch on long term survival after aortic valve replacement: a systematic review and meta-
analysis of 34 observational studies comprising 27,186 patients with 133, 141 patient-years. Eur Heart J 2012;33:1518–29.
10. Fallon JM, DeSimone JP, Brennan JM, et al. The incidence and consequence of prosthesis-patient
mismatch after surgical aortic valve replacement. Ann Thorac Surg 2018;106:14–22.
11. Fallon JM, DeSimone JP, Brennan JM, et al. The incidence and consequence of prosthesis-patient
mismatch after surgical aortic valve replacement. Ann Thorac Surg 2018;106:14–22.
12. Fallon JM, DeSimone JP, Brennan JM, et al. The incidence and consequence of prosthesis-patient
mismatch after surgical aortic valve replacement. Ann Thorac Surg 2018;106:14–22.
13. Fallon JM, DeSimone JP, Brennan JM, et al. The incidence and consequence of prosthesis-patient
mismatch after surgical aortic valve replacement. Ann Thorac Surg 2018;106:14–22.
15. Bleiziffer S, Eichinger WB, Hettich I, et al. Impact of prosthesis-patient mismatch on exercise
capacity in patients after bioprosthetic aortic valve replacement. Heart 2008;94:637–41.
17. Pibarot et al. Incidence and sequelae of prosthesis-patient mismatch in transcatheter versus surgical
valve replacement in high-risk patients with severe aortic stenosis: a PARTNER trial cohort A
analysis. J Am Coll Cardiol 2014;64:1323–34.
18. Takagi H, Yamamoto H, Iwata K, Goto SN, Umemoto T. A meta-analysis of effects of prosthesis-
patient mismatch after aortic valve replacement on late mortality. Int J Cardiol 2012; 159:150–4.
24. Dayan V et al. Predictors and outcomes of prosthesis patient mismatch after aortic valve replacement. J Am Coll Cardiol Img 2016;9: 924–33.
25. How to prevent PPM?
• Knowledge of size and model of prosthesis → reference against
published EOA values (EACVI 2016) → divide this EOA by patient’s BSA
Lancellotti P, Pibarot P, Chambers J, et al. Recommendations for the imaging assessment of prosthetic heart valves: a report from the European
Association of Cardiovascular Imaging endorsed by the Chinese Society of Echocardiography, the Interamerican Society of Echocardiography
and the Brazilian Department of Cardiovascular Imaging. Eur Heart J Cardiovasc Imaging 2016;17:589–90.
26. What to do if predicted iEOA = PPM?
1. Change to another model of prosthetic valve with larger predicted
iEOA
2. Enlarge aortic root / annulus to accommodate larger sized valve
(depends on anatomy of aortic root)
3. TAVR instead of SAVR
• Again, need to predict iEOA pre-op
• 3D TEE or MDCT to identify pts with small Ao annulus whereby mod-large
sized valve may be difficult even after debridement
27. TAVR – “1-size-fits-all”
• Final TAVR prosthesis size is determined by native annular size and not
TAVR size itself
• A single-size transcatheter valve can be implanted across a range of
different annular sizes, and expanded to fill the annular space
• Any given model/label size of a TAVR valve thus provides a larger EOA when
fully deployed in a larger annulus
• Reference the normal values
Hahn RT, Leipsic J, Douglas PS, et al. Comprehensive echocardiographic assessment of normal transcatheter
valve function. J Am Coll Cardiol Img 2018 Jun 13.
31. Beware the Russian Doll
• Transcatheter valve-in-valve procedure for degenerative bioprosthesis
have shown positive results in functional, haemodynamic and clinical
outcomes
• However, if high gradient was due to PPM in the first place,
telescoping another valve inside the prosthesis will not solve the PPM
oKey is to distinguish etiology of elevated gradient: stenosis / valve
degeneration, regurgitation, PPM, or combination of above
oUsage of oversized non-compliant balloon to fracture pre-existing
bioprosthetic stent to accommodate larger TAVR valve
oNewer gen SAVR valves have expandable frame (e.g. INSPIRIS Resilia AV,
Edwards LifeSciences), which does not require frame breaking
oTAVR valve with supra-annular design: high implant depth (0-2mm below
bioprosth stent) may also help increase EOA post TAVR
32.
33. Pibarot P, Simonato M, Barbanti M, et al. Impact of pre-existing prosthesis-patient mismatch on survival following aortic valve-
in- valve procedures. J Am Coll Cardiol Intv 2018;11: 133–41.
34. Pibarot P, Simonato M, Barbanti M, et al. Impact of pre-existing prosthesis-patient mismatch on survival following aortic valve-
in- valve procedures. J Am Coll Cardiol Intv 2018;11: 133–41.
35. Simonato M, Azadani AN, Webb J, et al. In vitro evaluation of implantation depth in valve-in-valve using different transcatheter
heart valves. EuroIntervention 2016;12:909–17.
36. Simonato M et al. Transcatheter replacement of failed bioprosthetic valves: Large multicenter assessment of the effect of
implantation depth on hemodynamics after aortic valve-in-valve. Circ Cardiovasc Interv 2016; 9:e003651.
37. Simonato M et al. Transcatheter replacement of failed bioprosthetic valves: Large multicenter assessment of the effect of
implantation depth on hemodynamics after aortic valve-in-valve. Circ Cardiovasc Interv 2016; 9:e003651.
38. Simonato M et al. Transcatheter replacement of failed bioprosthetic valves: Large multicenter assessment of the effect of
implantation depth on hemodynamics after aortic valve-in-valve. Circ Cardiovasc Interv 2016; 9:e003651.
43. Lancellotti P, Pibarot P, Chambers J, et al. Recommendations for the imaging assessment of prosthetic heart valves: a report from the Euro-
pean Association of Cardiovascular Imaging endorsed by the Chinese Society of Echocardiog- raphy, the Interamerican Society of Echocardiog-
raphy and the Brazilian Department of Cardiovascular Imaging. Eur Heart J Cardiovasc Imaging 2016;17:589–90.
44. Doppler Parameters
• Accurate derivation of the EOA from continuity equation MANDATES
the precise measurements of LVOT diameter and position of PW
sample of LVOT VTI
LVOT diameter measured from outer border to outer border of stent/ring
PW sample immediately below apical border of stent (no opening/closing
clicks should be seen)
• Multi-modality imaging – CT measurement of LVOT area
45. Doppler Parameters
• Measured EOA difference
If >0.3cm2 difference between measured and reference value → suspect
stenosis
If >0.6cm2 difference between measured and reference value → sig stenosis
• Doppler Velocity Index (DVI): ratio of LVOT VTI to AV VTI
<0.35 → mild to mod stenosis
<0.25 → severe stenosis
• Ratio of accel time to ejection time
<0.32 → PPM
>0.32 → stenosis
46. Serial Changes
• Compare velocity and gradients to baseline measurements post op
(pre-discharge echo)
Recommended 1 month post AVR
PPM → at valve implantation →stable over time;
PrAV stenosis → post op increase in gradient / velocity over time
• Post op increase in MPG, with stable or increase in EOA and DVI →
likely from systolic function recovery and improved flow (do not
misinterpret this as stenosis)
• Remember that PPM and PrAV stenosis are not mutually exclusive –
both can co-exist in the same patient
51. Management of PPM
• Consider valve reintervention when
PPM severe
MPG > 30mmHg
HF
Drop in LVEF
• Options
Re-do SAVR with larger sized prosthesis
Transcatheter ViV with self-expanding valve and supra-annular design +
fracturing of first SAVR valve
52. Summary
• PREVENTION
• Understand PPM – strategize pre-operatively to avoid it by sizing the
prosthesis appropriately
• DETECTION
• Recognize PPM and differentiate it from valve stenosis
• INTERVENTION
• Emerging role of ViV TAVR in managing PrAV PPM
53. Causes of High MPG
Obstruction High Flow PPM Pressure
Recovery
Gradients ↑ ↑ ↑ ↑
DVI ↓ Normal Normal ↓
EOA ↓ Normal Normal ↓
iEOA ↓ Normal ↓ ↓
Change in EOA
or DVI over
baseline?
Yes No No No
Abnormal
leaflet motion
Yes No No No