Treatment of abnormal prothestic valves

GVHD : TS.BS LÊ THANH LIÊM
NTH: BS. LÊ QUỐC HƯNG

CONTENT (CONT.)
 THEO DÕI
 ĐIỀU TRỊ
 BIẾN CHỨNG & XỬ TRÍ

TEE
The physician evaluating a prosthetic device with TEE
should be aware of the range of abnormalities that are
possible in these devices and should match those
possibilities to the patient's presentation. Complications
of prosthetic valves detected by TEE include:
 Paravalvular leak
 Endocarditis
 Extrinsic interference of function (pannus, thrombus,
vegetation) resulting in obstruction or regurgitation
 Ball variance
 Strut fracture and component escape
 Leaflet tears of bioprosthesis
 Leaflet calcification/stenosis of bioprosthesis
Echocardiographic evaluation of prosthetic heart valves - Elyse Foster – Uptodate 2012

Echocardiographic evaluation of prosthetic heart valves - Elyse Foster – Uptodate 2012

THEO DÕI
- An initial TTE study is recommended in patients after
prosthetic valve implantation for evaluation of valve
hemodynamics (IB)
- Annual TTE is reasonable in patients with a bioprosthetic
valve after the first 10 years, even in the absence of a change
in clinical status. (Class IIa, Level of Evidence: C)
 The incidence of bioprosthetic valve dysfunction is low within 10
years of valve implantation but increases markedly after that
point. Earlier evaluation may also be prudent in selected patients
at increased risk of early bioprosthetic valve degeneration.
 In patients with mechanical valve prostheses, routine annual
echocardiographic evaluation is not needed if the postoperative
baseline study is normal in the absence of signs or symptoms of
valve dysfunction.
2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Prosthetic valves, p111

 An initial TTE study is recommended in patients after
prosthetic valve implantation for evaluation of valve
hemodynamics (522-525). (Class I, Level of Evidence: B)
 An echocardiographic examination performed 6 weeks to 3
months after valve implantation is an essential component of
the first postoperative visit.
 Doppler TTE provides accurate measurements of
transvalvular velocities and pressure gradients as well as
detection and quantitation of valvular and paravalvular
regurgitation. Normal Doppler transvalvular velocities and
gradients vary among different types and sizes of prosthetic
valves but are also affected by patient-specific factors,
including body size and cardiac output. In addition to
imaging and Doppler flow data for the prosthetic valve, TTE
provides assessment of other disease(s).

 Repeat TTE is recommended in patients with
prosthetic heart valves if there is a change in
clinical symptoms or signs suggesting valve
dysfunction. (Class I, Level of Evidence: C)
 Bioprosthetic valves are prone to tissue degeneration
or pannus formation with development of valve
regurgitation and/or stenosis. Bioprosthetic valve
dysfunction typically presents with the insidious
onset of exertional dyspnea or with a louder systolic
murmur (MR or AS) or a new diastolic murmur (AR
or MS) on physical examination. More abrupt and
severe symptoms may occur with bioprosthetic valve
endocarditis or with degenerative rupture of a valve
cusp. 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Prosthetic valves, p111

 Mechanical valve dysfunction present with
symptoms of HF, systemic thromboembolism,
hemolysis, or a new murmur on auscultation.
 Signs or symptoms of mechanical valve
dysfunction are often acute or subacute because
of more abrupt impairment of leaflet occluder
opening or closing by thrombus or pannus.
 Acute or chronic paravalvular regurgitation may
also be seen due to IE or suture dehiscence.

 TEE is recommended when clinical symptoms or
signs suggest prosthetic valve dysfunction. (Class
I, Level of Evidence: C)
 TEE provides superior images of the left atrial side of
the mitral prosthesis and is accurate for diagnosis of
prosthetic mitral valve dysfunction.
 However, both TTE and TEE are needed for complete
evaluation in a patient with suspected prosthetic valve
dysfunction, particularly for those with prosthetic
aortic valves in whom the posterior aspect of the valve
is shadowed on the TTE approach and the anterior
aspect of the valve is shadowed on the TEE approach.

`

1. Continuation of VKA anticoagulation with a therapeutic
INR is recommended in patients with mechanical heart
valves undergoing minor procedures (such as dental
extractions or cataract removal) where bleeding is easily
controlled. (Class I, Level of Evidence: C)
2. Temporary interruption of VKA anticoagulation,
without bridging agents while the INR is subtherapeutic,
is recommended in patients with a bileaflet mechanical
AVR and no other risk factors for thrombosis who are
undergoing invasive or surgical procedures. (Level of
Evidence: C)
 VKA is stopped 2 to 4 days before the procedure (so the
INR falls to <1.5 for major surgical procedures) and
restarted as soon as bleeding risk allows, typically 12 to
24 hours after surgery. 2014 AHA/ACC Guideline for the Management of Patients With
Valvular Heart Disease, Prosthetic valves, p122 - 123

 Bridging anticoagulation with either intravenous UFH or
subcutaneous LMWH is recommended during the time
interval when the INR is subtherapeutic preoperatively in
patients who are undergoing invasive or surgical procedures
with a :
1) mechanical AVR and any thromboembolic risk factor
2) older-generation mechanical AVR, or
3) mechanical MVR.
(class I, Level of Evidence: C)
 Administration of fresh frozen plasma or prothrombin
complex concentrate is reasonable in patients with
mechanical valves receiving VKA therapy who require
emergency noncardiac surgery or invasive procedures.
(IIa, Level of evidence C)

- Excessive anticoagulation (INR ≥5)
greatly increases the risk of hemorrhage.
- High-dose vitamin K should not be
given routinely, because this may create a
hypercoagulable condition
- INR of 5 to 10, excessive anticoagulation
can be managed by withholding VKA and
monitoring the level of anticoagulation
with serial INR determinations
- In patients with an INR >10 who are not
bleeding, it is prudent to administer 1 mg
to 2.5 mg of oral vitamin K1
(phytonadione) in addition to holding
VKA therapy.
- In emergency situations, such as
uncontrollable bleeding, administration
of fresh frozen plasma or prothrombin
complex concentrate is reasonable .
Điều trị kháng đông ‘quá mức’
Guidelines on the management of valvular heart disease (version 2012), ESC, p34
-If the INR is .10, higher doses of oral
vitamin K (5 mg) should be
considered.
-The oral route should be favoured
over the intravenous route
- In the absence of bleeding, the
management depends on the target
INR, the actual INR, and the half-life
of the vitamin K antagonist used. It is
possible to stop oral anticoagulation
and to allow the INR to fall gradually
or to give oral vitamin K in increments
of 1 or 2 mg.
-Immediate reversal of anticoagulation
is required for severe bleeding causing
haemodynamic instability, or requiring
an emergency surgical procedure or
transfusion.

COMPLICATIONS
 Structural deterioration, particularly with bioprosthetic
valves
 Valve obstruction due to thrombosis or pannus formation
 Systemic embolization
 Bleeding
 Endocarditis and other infections
 Left ventricular systolic dysfunction, which may be pre-
existing
 Hemolytic anemia
Complications of prosthetic heart valves - William H Gaasch – Uptodate 2012

Structural deterioration
- Paravalvular leaks early after surgery, as detected
with (TEE) or (TTE), are common .
- The reported incidence ranges from 18 to 48 percent
of patients with a mitral or aortic prosthesis; the
majority of leaks are trivial or mild and do not
progress over a two to five year follow-up.
- the later development of new, often severe
regurgitation results from prosthetic valve
endocarditis or structural failure.

 A variety of factors can contribute to structural failure with
bioprosthetic valves, including:
- mechanical stress
- immunologic rejection
- endocarditis
- cusp tear leading to severe valvular regurgitation.
- The structural failure rate with bioprosthetic valves falls dramatically
with age

Valve obstruction
- Nguyên nhân:
Đ/v van cơ học: huyết khối, pannus, mảng sùi.
Đ/v van sinh học: xơ hóa và calci hóa lá van.
The clinical manifestations of prosthetic valve
obstruction include :
+ dyspnea,
+ heart failure, and with
+ thrombus formation
+ systemic embolization
2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Prosthetic valves, p130 - 131

Pannus is the ingrowth of fibrous tissue into the valve apparatus in case of prosthetic
valves, Pannus formation is more common in the aortic position
http://cardiophile.org/2012/04/pannus-formation-in-prosthetic-valves-2/

Prosthetic Valve thrombosis
- PVT can lead to valvular obstruction, occurs with equal
frequency in patients with bioprosthetic valves and in
those with mechanical valves who are treated with
anticoagulants.
- The reported annual incidence of PVT ranges from 0.03 to
5.7 percent; higher rates are observed in patients with
mitral prostheses (in some reports) and/or subtherapeutic
anticoagulation.
- In one report of PVT in mechanical valves, 70 percent of
patients with coagulation tests measured at the time of
PVT were receiving inadequate anticoagulant therapy
- The gold standard for the diagnosis of PVT is transesophageal
echocardiography (TEE) and/or cine-fluoroscopy to assess both
valve motion and clot burden

 Thrombolytic regimens include alteplase
(100 mg given as a 10 mg bolus followed by
90 mg as an infusion over 90 minutes) or
streptokinase (500,000 IU over 20 minutes
followed by 1.5 million IU over 10 hours).
 Intravenous heparin is typically given
concurrently to achieve an activated partial
thromboplastin time 1.5 to 2.0 times control.
Complications of prosthetic heart valves - William H Gaasch – Uptodate 2012 + 2006 ACC/AHA

2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Prosthetic valves

 Although fibrinolytic therapy of a left-sided obstructed prosthetic
heart valve is associated with an overall rate of thromboembolism
and bleeding of 17.8%, the degree of risk is directly related to
thrombus size.
 When thrombus area is measured in the 2D TEE view showing the
largest thrombus size, an area of 0.8 cm2 provides a useful
breakpoint.
 A mobile thrombus or a length >5 mm to 10 mm is also associated
with increased embolic risk. Patients with a small thrombus (<1.0
cm in diameter or 0.8 cm2 in area) have fewer thrombolysis-
related complications, whereas those with a large thrombus (>1.0
cm diameter or 0.8 cm2 in area) have a 2.4-fold rate of
complications per 1.0 cm2 increase in size.
 risk for adverse outcomes of fibrinolytic therapy : active internal
bleeding, history of hemorrhagic stroke, recent cranial trauma or
neoplasm, diabetic hemorrhagic retinopathy, large thrombi,
mobile thrombi, systemic hypertension (>200 mm Hg/120 mm
Hg), hypotension or shock, and NYHA class III to IV symptoms.

 With mild symptoms due to aortic or mitral valve
thrombosis with a small thrombus burden, it is prudent to
reassess after several days of intravenous UFH.
 If valve thrombosis persists, fibrinolysis with a
recombinant tissue plasminogen activator dose of a 10 mg
IV bolus followed by 90 mg infused IV over 2 hours is
reasonable.
 Heparin and glycoprotein IIb/IIIa inhibitors are held, but
aspirin can be continued.
 Alternatively, streptokinase may be used with a loading
dose of 500,000 IU in 20 minutes followed by 1,500,000 IU
over 10 hours.
 If fibrinolytic therapy is successful, it is followed by
intravenous UFH until VKA achieves an INR of 3.0 to 4.0
for aortic prosthetic valves and 3.5 to 4.5 for mitral
prosthetic valves

Guidelines on the management of valvular heart disease (version 2012), ESC, p 35

- DRUG THERAPY:
If embolic events have occurred despite a therapeutic
INR when other contraindications are not present :
-Increase the INR goal from 2.5 (range 2.0 to 3.0) to an INR goal
of 3.0 (range 2.5 to 3.5) for patients with an AVR
- Increase the INR goal from 3.0 (range 2.5 to 3.5) to an INR goal
of 4.0 (range 3.5 to 4.5) for patients with an MVR.
In patients with a bioprosthetic valve with embolic
events who are only on aspirin 75 mg to 100 mg daily, a
possible approach includes consideration of
anticoagulation with a VKA.

 TTE is indicated in patients with suspected PVT to
assess hemodynamic severity and follow resolution
of valve dysfunction (604, 605). (Level of Evidence:
B)
 TEE is indicated in patients with suspected PVT to
assess thrombus size and valve motion (605-607).
(Level of Evidence: B)
 Fluoroscopy or CT is reasonable in patients with
suspected valve thrombosis to assess valve motion.
(Level of Evidence: C)
Huyết khối tại van nhân tạo
2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Prosthetic valves, p126-127

Hẹp van nhân tạo
- Medical therapies :
 There are no medical therapies known to prevent
bioprosthetic valve degeneration other than those
integrated into the valve design.
 Medical therapy is not effective for treatment of
symptoms due to significant prosthetic valve
stenosis, except with valve thrombosis, but standard
medical therapy may help stabilize patients before
surgical intervention and may be used for palliative
care in patients who are not surgical candidates.
2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Prosthetic valves, p130 - 131
The indications for surgical intervention for prosthetic valve stenosis are the
same as those for native stenosis of the aortic or mitral valve

pathogenesis :
 Early infection - Microorganisms can reach the valve prosthesis by
direct contamination intraoperatively or via hematogenous spread
during the initial days and weeks after surgery. These pathogens have
direct access to the prosthesis-annulus interface and to perivalvular
tissue along suture pathways because the valve sewing ring, cardiac
annulus, and anchoring sutures are not endothelialized early after
valve implantation. These structures are coated with host proteins,
such as fibronectin and fibrinogen, to which some organisms can
adhere and initiate infection.
 Late infection - As the sewing ring, sutures, and adjacent tissues
become endothelialized over the months after valve replacement,
sites for adherence of microorganisms and access to host tissues
adjacent to the prosthesis are altered. The pathogenesis of late PVE
has been postulated to resemble native valve endocarditis (NVE).
Epidemiology, clinical manifestations, and diagnosis of prosthetic valve endocarditis, Adolf W Karchmer
Prosthetic Valve Endocarditis

Viêm nội tâm mạc nhiễm trùng (IE)

Viêm nội tâm mạc nhiễm trùng

Điều trị nội khoa

Điều trị can thiệp

LEFT VENTRICULAR SYSTOLIC
DYSFUNCTION
— Patients with prosthetic heart valves may develop LVSD with or
without HF. The factors may contribute :
 Preoperative left ventricular dysfunction that persists or partially
improves
 Perioperative myocardial infarction
 Progression of other valve disease
 Complications of the prosthetic valve
 An unrelated disorder such as coronary heart disease or
hypertension
 Appropriate testing in such patients includes transthoracic
Doppler echocardiography, TEE if necessary, or, if the cause
remains uncertain, cardiac catheterization with arteriography.
 Should be treated with standard medical therapy for systolic
heart failure . Such therapy should be continued even if left
ventricular function improves.
Complications of prosthetic heart valves - William H Gaasch – Uptodate

Hemolytic anemia
- Due to mechanical damage, is seen more commonly with prosthetic
mechanical heart valves than with bioprosthetic valves.
 Among patients with prosthetic mitral regurgitation, hemolysis is
associated with rapid acceleration and deceleration of the
regurgitant jet and/or high peak shear rates .
 Hemolysis is usually mild and subclinical, but is severe in up to 15
percent of patients with certain prostheses, such as ball-cage and
bileaflet valves, or those with paravalvular regurgitation .
 It is uncommon with tissue valves, although hemolytic anemia may
be the initial presentation of porcine valve failure .
 Presenting features may be subtle and include anemia, heart failure,
jaundice, dark urine, increasing serum LDH, and a new or changed
regurgitant murmur.
 The peripheral smear shows variable numbers of schistocytes and
smaller red cell fragments

 Oral iron replacement is effective in the majority of
patients, although transfusion may be required;
 The administration of erythropoietin may eliminate
the need for transfusion .
 Reoperation may be required, especially if hemolysis is
due to regurgitation from a paravalvular leak or valve
failure.
HEMOLYTIC ANEMIA

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