Prosthetic valve dysfunction: stenosis or regurgitation

Transcription

1 Prosthetic valve dysfunction: stenosis or regurgitation Jean G. Dumesnil MD, FRCP(C), FACC, FASE(Hon) Quebec Heart and Lung Institute, Québec, Québec No disclosures

2 Possible Causes of High Gradients in Prosthetic Heart Valves Patient-Prosthesis Mismatch (i.e. too small a prosthesis in too large a patient) Overestimation due to central high velocity jet in bileaflet mechanical prosthesis Intrinsic Prosthesis Degeneration or Dysfunction (e.g. valve thrombosis)

3 Case Study #1 72 yr-old male patient History of severe AS and no CAD AVR with a Carbomedics #19 in October 2001 After operation: Remained in functional class II-III Persistent pulmonary hypertension (systolic PAP: 50 mmhg)

4 Case Study : High Doppler Gradient in Aortic Valve Prosthesis 72 y.o. patient with Carbomedic # 19 aortic prosthesis (3 years) Dumesnil & Pibarot, in Book: Transesophageal Echocardiography Multimedia Manual: 361, 2005 Max Gradient = 69 mm Hg Mean Gradient = 40 mmhg

5 Question no. 1 Could valve prosthesis-patient mismatch be a factor in this case?

6 Mismatch!!!

7 Dependence of Gradients on Indexed Valve EOA Mean Gradient (mmhg) Mismatch Rest r= Mismatch Exercise r=0.89 Stented Stentless Autograft Homograft Pibarot & Dumesnil JACC, 34, Indexed EOA at rest (cm 2 /m 2 )

8 Severity of PPM Based on Indexed EOA (cm²/m²) SEVERE MODERATE MILD/NONE (non significant) Aortic Mitral

9 Reference Values of EOAs for Most Currently Used Aortic Prostheses Pibarot and Dumesnil, Circulation 2009;119;

10 Answer: Calculate projected indexed EOA to exclude PPM 72 y.o. patient 3 Years post AVR Carbomedic # 19 Reference EOA for Carbomedic # 19 Aortic Prosthesis 1.00±0.40 BSA = 1.95 m 2 Projected Indexed EOA = 0.51 cm 2 /m 2

11 Case Study : High Doppler Gradient in Aortic Valve Prosthesis Reoperated 3 years postop. Dumesnil & Pibarot, in Book: Transesophageal Echocardiography Multimedia Manual: 361, 2005 Prosthesis is functioning normally

12 Intraoperative Echo after Prosthesis Implantation St. Jude Regent # 21 in supra-annular position (reference EOA: 2.0 cm 2 ) Stroke volume: 64 ml Heart rate: 98 bpm Peak gradient: 21 mmhg Mean gradient: 14 mmhg

13 Case Study #2 62 y.o. patient Early postop Carbomedics # 25 bi-leaflet aortic valve prosthesis Low output failure (ejection fraction = 25%)

14 Aortic Gradient 62 y.o. postop patient with Carbomedics # 25 bi-leaflet aortic prosthesis and low output failure Max Gradient = 18 mm Hg Mean Gradient = 12 mm Hg

15 Question #1 Are these gradients abnormally high for a patient with low output and could the prosthesis be obstructive thus contributing to patient s heart failure?

16 Calculation of Projected Indexed EOA to exclude PPM 62 y.o. postop patient with Carbomedics # 25 bi-leaflet aortic prosthesis and low output failure Reference EOA for Carbomedics # cm 2 BSA = 1.90 m 2 Projected Indexed EOA = 1.04 cm 2 /m 2

17 Dysfunction? : Calculate Actual EOA and Compare to Reference Value 62 y.o. postop patient with Carbomedics # 25 bi-leaflet aortic prosthesis and low output failure EOA= 0.75 cm² Reference value= 1.98 cm²!!

18 Question # 2 What is the cause of the small EOA in this patient? Intrinsic valve prosthesis dysfunction (e.g. thrombus, vegetation) Artefactual underestimation due to localized central high velocity jet in bileaflet mechanical prosthesis I don t know, I need more information

19 Bioprosthesis Design vs Bi-Leaflet Prosthesis From Pibarot and Dumesnil, Heart. 2006; 92(8):

20 Numerical Simulation of Flow Pattern in a Bi-leaflet Prosthesis Pibarot & Dumesnil, Circulation 119: , 2009 Central Orifice: 19 mm Hg, Lateral Orifice: 10 mm Hg

21 Pibarot & Dumesnil Circulation, 119: , 2009 Normal Function Inflow Outflow Doppler Peak Gradient 19 mmhg [real: 10 mmhg] Mild Dysfunction (25% restriction) 20 mmhg [real: 18 mmhg]

22 Answer More information needed: evaluate leaflet mobility using either valve fluoroscopy and/or TEE

23 TEE : Normal Leaflet Mobility

24 TEE : Superimposition of Low and High Velocity Jets through Prosthesis High velocity: Max gradient = 18 mm Hg, mean = 9mm Hg, EOA = 0.75 cm² Low velocity: Max gradient = 7 mm Hg, mean = 3 mm Hg, EOA = 1.78 cm²

25 Conclusion Prosthesis is not obstructive and does not contribute to patient s heart failure

26 Localized High Velocity Jet in Mitral Valve Prosthesis

27 Intermittent Leaflet Dysfunction in Bileaflet Mitral Valve Prosthesis

28 Dumesnil & Pibarot Curr Cardiol Rep (2011) 13:

29 Specifics for Doppler Evaluation of Mitral Valve Prostheses EOA calculated using continuity equation as follows : EOA= Ao SV /Mi VTI (Not valid if significant aortic or mitral regurgitation) Pressure half-time not valid to calculate EOA (grossly overestimates) but may be useful for serial comparisons or if delayed (>130 msec) Doppler Velocity Index: VTI mvp / VTI lvot (>2.2) E velocity (>1.9 m/sec)

30 Dumesnil et al., Am J Cardiol 1990;65:

31 Overestimation of EOA by PHT (240 pts with C-E bioprosthesis) Blower et al, JASE 2009

32 Doppler Evaluation of Regurgitations in Prosthetic Heart Valves Mild regurgitations, central or perivalvular are frequent, sometimes transient and rarely progressive Mechanical prostheses usually show small regurgitation due to normal closing volume Mitral regurgitation may be underestimated by TTE due to reverberations : look for indirect signs Severity: use same criteria as for native valves If significant regurgitation suspected, look for underlying pathology and proceed to TEE

33 Aortic Regurgitation in Bioprosthesis

34 Leakage Backflow Jets in Bileaflet Prosthesis

35 ASE Recommendations for Evaluation of Prosthetic Valves - JASE2009; 22:

36 Mitral Prosthesis Regurgitation: indirect signs High E velocity (2.2 m/sec) Proximal PISA Hyperdynamic LV

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38 Significant Regurgitation in Prosthetic Heart Valves- Key Points to Remember May be underestimated due to reverberations and shadowing Look for indirect signs: High gradients and/or E velocity PISA proximal to the valve Hyperdynamic and/or dilated LV (compare to previous) Perform TEE whenever in doubt

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