SHA24/008003

High Gradient Post Mitral Valve Replacement: Surgeon’s Perspectives Ahmed A Arifi; MD,FRCS,FCSHK,FHKAM,MBA Consultant cardiac surgery King Abdulaziz Cardiac Sciences KAMC

Outline • • • • •

What is in the name?

Echocardiographic evaluation Causes of High Gradient Patient related factors Prosthesis related factors & Prosthesis dysfunction • Patient /Prosthesis mismatch

What is in the name?

2. Prosthesis related 1. Patient related

3. Patient prosthesis mismatch

Hyperdynamic states HR and Rhythm Pulmonary hypertension LV dysfunction LVOT obstruction

High Gradient Prosthesis A high gradient should be taken in the Context of other parameters and diagnostic tests

Determination of Gradients Across the Prosthetic Mitral Valves • Pulse wave, continuous wave and color Doppler • Multiple views and angulations • Blood velocity across a prosthetic valve is dependent on several factors, including flow and valve size and type.

Simplified Bernoulli equation noninvasive calculation of pressure gradients across prosthetic valves

P= 4V2 P=pressure gradient V = the velocity of the jet in meters per second.

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound, JASE 2009 Volume 22 Number 9

Impact of Intra-operative Environment on Prosthetic Valve Evaluation o The period prior to cardiopulmonary bypass is usually associated with reduced preload and myocardial depression that accompanies the anesthetized state.* o Moreover, an open chest, open pericardial cavity, and positive pressure ventilation also influence loading conditions.** o The post bypass phase, on the other hand, is a labile period during which there are frequent changes in preload and afterload, inotropic and chronotropic drugs may be in effect, and the heart is frequently electrically paced.***

* Grewal KS, MalkowskiMJ, Piracha AR, et al. Effect of general anesthesia on the severity of mitral regurgitation by transesophageal echocardiography.

Am J Cardiol 2000;85:199-203. ** Kubitz JC, Annecke T, Kemming GI, et al. The influence of positive end expiratory .

The importance of the Effective Orifice Area (EOA) o The EOA of a prosthesis by the continuity equation is a better index of valve function than gradient alone o EOA = stroke volume / VTIPrV o General mechanical prosthesis tend to have a larger EOA than bioprosthesis, except stentless bioprosthesis o Even within the same category of prosthesis, performance can vary considerably from one manufacturer to the other

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound, JASE 2009 Volume 22 Number 9

Normal Reference Values of EOAs for the Mitral Prosthesis Prosthetic Valve Size, mm 25 mm

27 mm

29 mm

31 mm

33 mm

Reference

Medtronic Mosaic

1.5±0.4

1.7±0.5

1.9±0.5

1.9±0.5

...

15, 28

Hancock II

1.5±0.4

1.8±0.5

1.9±0.5

2.6±0.5

2.60.7

29

Carpentier-Edwards Perimount*

1.6±0.4

1.8±0.4

2.1±0.5

...

...

28

Stented bioprosthesis

Mechanical prostheses

St Jude Medical Standard

1.5±0.3

1.7±0.4

1.8±0.4

2.0±0.5

2.0±0.5

28

MCRI On-X†

2.2±0.9

2.2±0.9

2.2±0.9

2.2±0.9

2.2±0.9

28

EOA is expressed as mean values available in the literature. *These results are based on a limited number of patients and thus should be interpreted with caution. †The strut and leaflets of the MCRI On-X valve are identical for all sizes (25 to 33 mm).

Prosthetic Heart Valves: selection of the optimal prosthesis and long term management: Philippe Pibarot and Jean G.Dumesil; circulation 2009:1034-1048

Evaluation of Prosthetic Valve Function PARAMENTERS

DOPPLER ECHOCARDIOGRAPHY OF THE VALVE

Contour of jet velocity signal Peak velocity and gradient Mean pressure gradient VTI of the jet DVI Pressure half time in MV and TV EOA Presence, location and severity of regurgitation

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound, JASE 2009 Volume 22 Number 9

Evaluation of Prosthetic Valve Function PARAMETERS OTHER ECHOCARDIOGRAPHIC DATA

LV and RV size, function, and hypertrophy LA and right atrial size Concommitant valvular disease Estimation of pulmonary artery pressure

PREVIOUS POST OPERATIVE STUDIES, WHEN AVAILABLE

Comparison of above parameters in suspected prosthetic valvular dysfunction

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound, JASE 2009 Volume 22 Number 9

Algorithm for the interpretation of high transprosthetic gradient

Pibarot P , Dumesnil J G Circulation 2009;119:1034-1048

Evaluating Mitral Prosthetic Valve Function • Exertional SOB after mitral valve replacement may be caused by – primary valve failure, LV and/or right ventricular (RV) dysfunction, pulmonary hypertension – Stress echocardiography considered if the diagnosis is not clear.

• Transmitral velocities and the tricuspid regurgitant signal.

• Obstruction or PPM is likely if the mean gradient rises above 18 mm Hg after exercise, even when the resting mean gradient is normal.

Reis G, Motta MS, Barbosa MM,. JAm Coll Cardiol 2004;43:393-401.

Doppler parameters of prosthetic mitral valve function/stenosis Normal*

Possible stenosis‡

Suggests significant stenosis* ‡

Peak velocity (m/s)†

<1.9

1.9-2.5

>2.5

Mean gradient (mm Hg)†

<6

6-10

>10

VTIPrMv/VTILVO

<2.2

2.2-2.5

>2.5

EOA (cm2)

>2

1-2

<1

PHT (ms)

<130

130-200

>200

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound, JASE 2009 Volume 22 Number 9

Alaa A Mohamed, Omran S Ahmed, Arifi Ahmed.

King Abdul-Aziz Cardiac center Riyadh, Saudi Arabia.

The Aim of this study: To assess whether 3D TEE can provide an incremental diagnostic and descriptive value as compared to 2D TEE, in assessment of various Prosthetic valve dysfunction.

o 27 cases were referred to our echo-lab for suspected prosthetic valve dysfunction, between Sept 2008-2009 ď&#x192;&#x2DC;Mitral prosthetic valve in 12 patients. ď&#x192;&#x2DC;Aortic Prosthetic valve in 9 patients. ď&#x192;&#x2DC;Mitral and Aortic Prosthetic valve in 6 patients.

PV in mitral position â&#x20AC;˘ 3D TEE gives unique views that can add extra morphological and anatomical information to 2D TEE assessment. â&#x20AC;˘ Off- line analysis of prosthetic MV allows inspection of the MV from both LA and LV views and it is helpful in assessment of PV obstruction due to pannus formation.

For Prosthetic mitral paravalvular leak  3D TEE can be very useful in the diagnosis and in guiding the percutaneous closure For PV in aortic position  Visualization of the prosthetic aortic valve is less than in mitral position.  However 3D TEE is still helpful in demonstrating obstruction of the AV by pannus.

Prosthetic Valve Dysfunction 1.

2.

3.

4.

5.

6.

7.

PPM Prosthetic Dehiscence Primary prosthetic valve dysfunction Prosthetic Thrombosis and thromboembolism Pannus formation Endocarditis Haemolysis

3D echo of the stuck mitral valve courtasy of Dr. Alla Mohamed, KACC.

Prosthetic Valve Obstruction Diagnosis ď&#x192;&#x2DC;Valve thrombosis should be suspected in any patient with any type of prosthetic valve who presents with a recent increase in dyspnea or fatigue ď&#x192;&#x2DC;Echocardiography should be done promptly and should include TEE

Thrombus Versus Pannus  Obstruction of prosthetic valves may be caused by 1. Thrombus formation 2. Pannus ingrowth  Pannus in growth alone may be encountered in both bioprosthesis and mechanical valves  Valve thrombosis is most often encountered in patients with mechanical valves and inadequate antithrombotic therapy

0.3% and 1.3% per patient-year in patients with mechanical valves.

Barbetseas J, Nagueh SF, J Am Coll Cardiol 1998;32:1410-7.

Prosthesis Thrombo-Embolism o 0.6 to 2.3% per patient year o It depends on:  Prosthesis type  Patient thrombogenicity  Patients risk factors  Antithrombotic treatment

o The first step in management is to assess the adequacy of anticaogulation

o Cerebral infarct >35%, with risk of haemorrhagic transformation, withhold warfarin and use IV heparin.

Prosthetic Heart Valve Thrombosis in Pregnancy o Currently available options Thrombolytic therapy Thrombectomy Prosthetic valve replacement

Surgery is usually favoured in the current guidelines o The reported operative mortality, depending on the functional class, can be as high as 69% Lengyel M. Diagnosis and treatment of left-sided prosthetic valve thrombosis. Expert Rev Cardiovasc Ther. 2008; 6: 85–93

Algorithm for the Management of Patients with Left-sided Prosthetic Valve Thrombosis

Pibarot P , Dumesnil J G Circulation 2009;119:1034-1048

Structural Valve Dysfunction(SVD) I. Mechanical valves: “ excellent durability” Strut fracture Leaflet escape Occluder dysfunction

II. Bioprosthetic valves: Dysfuntion increases over time over 7 to 8 years Stented bioprosthesis freedom from valve failure is 70%-90% at 10 years and 50 to 80% at 15years A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2006; 114: e84–e231

Structural Valve Dysfunction(SVD) Predictors of bioprosthetic valve failures o Young age o Mitral position o Renal insufficiency o hyperparathyroidism o Hypertension o Poor LV function Ruel M, Kulik A, Rubens FD, Bedard P, Masters RG, Pipe AL, Mesana TG. Late o Prosthesis size incidence and determinants of reoperation in patients with prosthetic heart valves. Eur J Cardiothorac Surg. 2004; 25: 364â&#x20AC;&#x201C;370

Treatment of SVD o SVD is the most frequent cause of Re-operative valve replacement in patients with a bioprosthesis. o Whenever possible, the Reoperative procedure should be performed early in the disease process before LV function and symptomatic status deteriorate significantly

Prosthetic Valve Endocarditis o â&#x2030;&#x2C6;0.5% per patient-year o Mortality rates (30% to 50%) o Positive blood cultures o Echocardiographic evidence of prosthetic infection including vegetation, paraprosthetic abscess, new paravalvular leak

Prosthetic Valve Endocarditis Management Guidelines

Paravalvular MR due to Dehiscence

Causes:  Infection  Suture dehiscence  Annular calcification o Small paravalvular regurgitant jets are frequently (10% to 25% of cases) seen on intraoperative TEE before cardiopulmonary bypass weaning

Paravalvular MR due to dehiscence o Moderate to sever early dehiscence is rare 1% to 2%, requires returning to cardiopulmonary bypass for immediate correction o Dehiscence of the prosthesis in the late postoperative period may be related to operative technical factors but is most often caused by endocarditis, in which case emergency surgical treatment is generally required.

Akins CW, Bitondo JM, Hilgenberg AD, Vlahakes GJ, Madsen JC, MacGillivray TE. Early and late results of the surgical correction of cardiac prosthetic paravalvular leaks. J Heart Valve Dis. 2005; 14: 792â&#x20AC;&#x201C;799

Conclusion o Evaluation of prosthetic valve function is very challenging. o High Gradient is just one piece of the puzzle. o Prevention and adequate post operative care should be the goal to prevent the prosthesis related complications .

Thank you