Prosthetic valve dysfunction: stenosis or regurgitation Jean G. Dumesnil MD, FRCP(C), FACC, FASE(Hon) Quebec Heart and Lung Institute, Québec, Québec No disclosures
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)
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)
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
Question no. 1 Could valve prosthesis-patient mismatch be a factor in this case?
Mismatch!!!
Dependence of Gradients on Indexed Valve EOA Mean Gradient (mmhg) 50 40 30 20 Mismatch Rest r=0.81 60 50 40 30 20 Mismatch Exercise r=0.89 Stented Stentless Autograft Homograft 10 10 0 0 0.85 1.35 1.85 2.35 2.85 0.35 0.85 1.35 1.85 2.35 2.85 Pibarot & Dumesnil JACC, 34, 2000. Indexed EOA at rest (cm 2 /m 2 )
Severity of PPM Based on Indexed EOA (cm²/m²) SEVERE MODERATE MILD/NONE (non significant) Aortic Mitral 0.65 0.90 0.85 1.20
Reference Values of EOAs for Most Currently Used Aortic Prostheses Pibarot and Dumesnil, Circulation 2009;119;1034-1048
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
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
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
Case Study #2 62 y.o. patient Early postop Carbomedics # 25 bi-leaflet aortic valve prosthesis Low output failure (ejection fraction = 25%)
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
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?
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 #25 1.98 cm 2 BSA = 1.90 m 2 Projected Indexed EOA = 1.04 cm 2 /m 2
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!!
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
Bioprosthesis Design vs Bi-Leaflet Prosthesis From Pibarot and Dumesnil, Heart. 2006; 92(8):1022-9.
Numerical Simulation of Flow Pattern in a Bi-leaflet Prosthesis Pibarot & Dumesnil, Circulation 119:1034-48, 2009 Central Orifice: 19 mm Hg, Lateral Orifice: 10 mm Hg
Pibarot & Dumesnil Circulation, 119:1034-1048, 2009 Normal Function Inflow Outflow Doppler Peak Gradient 19 mmhg [real: 10 mmhg] Mild Dysfunction (25% restriction) 20 mmhg [real: 18 mmhg]
Answer More information needed: evaluate leaflet mobility using either valve fluoroscopy and/or TEE
TEE : Normal Leaflet Mobility
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
Conclusion Prosthesis is not obstructive and does not contribute to patient s heart failure
Localized High Velocity Jet in Mitral Valve Prosthesis
Intermittent Leaflet Dysfunction in Bileaflet Mitral Valve Prosthesis
Dumesnil & Pibarot Curr Cardiol Rep (2011) 13:250 257
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)
Dumesnil et al., Am J Cardiol 1990;65:1443-8.
Overestimation of EOA by PHT (240 pts with C-E bioprosthesis) Blower et al, JASE 2009
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
Aortic Regurgitation in Bioprosthesis
Leakage Backflow Jets in Bileaflet Prosthesis
ASE Recommendations for Evaluation of Prosthetic Valves - JASE2009; 22: 975 1014
Mitral Prosthesis Regurgitation: indirect signs High E velocity (2.2 m/sec) Proximal PISA Hyperdynamic LV
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