Current Treatment and Future
Trends
Anthony J. Palazzo, M.D.F.A.C.S.
Objectives
 Brief discussion of most common pathologic valvular
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disease involving aortic and mitral valves
Focus on aortic stenosis and mitral regurgitation
Indications for surgical intervention
Best choice of prosthetic device
Current and future trends
Aortic Stenosis
Etiology
•Degenerative (Calcification)
•Bicuspid
•Rheumatic
Aortic Stenosis - Classification
Indicator
Mild
Moderate
Severe
Jet Velocity (m/s)
< 3.0
3.0-4.0
>4.0
Mean Gradient
(mm Hg)
<25
25-40
>40
Aortic Valve Area
(cm²)
>1.5
1.0-1.5
<1.0
Normal Aortic Valve Area 2-4 cm²
Aortic Stenosis-Pathophysiology
 Increased transvalvular gradient
 Increased left ventricular afterload
 Leads to development of LVH
Aortic Stenosis-Natural History
 Multiple echocardiographic studies have
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demonstrated that the average rate of decrease in
aortic valve area is approximately 0.12 cm² per year
Ross and Braunwald study (1968)- landmark paper
revealing natural history as it relates to symptoms
average survival with angina/syncope 3 yrs
average survival with dyspnea
2 yrs
average survival with CHF
1.5 yrs
Aortic Stenosis-Natural History
 Loma Lima study
 Retrospective review of 453 patients with documented
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severe aortic stenosis on ECHO
Treated non-surgically
Survival at 1, 5, and 10 years was 62%, 32% and 18%
Demonstrated grave prognosis of patients with severe
aortic stenosis
AnnThorSurg, 2006
Aortic Stenosis-Indications for
Surgery
 Patients with symptoms
 Asymptomatic patients with evidence of diminished
left ventricular function (EF < 50%)
 Asymptomatic patients with normal ventricular
function should be followed closely with serial
echocardiography every 6 months due to known
history of progression of 0.1-0.12 cm² and risk of death
of 1-3% per year
Aortic Stenosis-Salient Points
 Once diagnosis is suspected echocardiogram is single
best non-invasive diagnostic test to determine aortic
valve morphology, gradient and jet velocity
 Symptomatic patients should be referred for surgical
evaluation
 Asymptomatic patients need to be followed closely for
natural progression of disease
 Asymptomatic patients with diminished left
ventricular function should be referred for surgery
Aortic Regurgitation-Etiology
•Calcific degeneration (mixed lesion with stenosis)
•Bicuspid aortic valve
•Connective tissue disease (Marfan’s)
•Aortic aneursym
•Aortic dissection
•Endocarditis
Aortic RegurgitationPathophysiology
 Increased left ventricular overload
 Left ventricular dilatation
 Diminishing left ventricular function
Aortic Regurgitation-Indications for
Surgery
 Symptomatic patients with severe aortic regurgitation
patients with angina have >10% mortality/year
>20% mortality/year with CHF
 Endocarditis with hemodynamic decompensation
 Asymptomatic patients
•surgery for patients with EF <50%
•surgery for patients with evidence of left
ventricular distension (end-diastolic dimension > 75 mm
and end-systolic dimension > 55 m)
Mitral Stenosis
•Normal mitral valve area 4-6 cm²
•Rheumatic heart disease most common cause
•prevalence decreased significantly
•Thickening and calcification of leaflets
•Thickening of subvalvular structures (chords)
•May have mixed lesions-MS/MR
•Stenosis tends to progress slowly
Mitral Stenosis-Classification
Indicator
Mild
Moderate
Severe
Mean Gradient
(mm Hg)
<5
5-10
>10
PA systolic
pressure (mm Hg)
<30
30-50
>50
Mitral Valve Area
(cm²)
>1.5
1.0-1.5
<1.0
Normal mitral valve area = 4-6 cm²
Mitral Stenosis-Indications for
Surgery
 Patients with severe mitral stenosis with class NYHA
class III and IV symptoms who are not candidates for
percutaneous balloon mitral valvulotomy (patients
with mixed lesions or heavy calcification)
 Asymptomatic patients with severe MS and severe
pulmonary hypertension (PAP > 60 mm Hg)
 No therapy recommended in asymptomatic patients
without evidence of severe pulmonary hypertension
Mitral Regurgitation-Etiology
 Degenerative
“myxomatous”
isolated leaflet prolapse
Barlow’s disease
 Ischemic
acute- ruptured papillary muscle/chord 2° AMI
chronic- chronic myocardial ischemia
 Endocarditis
Mitral Regurgitation-Etiology
 Isolated “P-2” segmental prolapse
Mitral Regurgitation-Etiology
Barlow’s disease
Ischemic Mitral Regurgitation
Chronic ischemic mitral regurgitation
annular dilatation
papillary muscle retraction
Mitral Regurgitation-Diagnosis
 ECHO most informative non-invasive diagnostic test
 Assess leaflet morphology
 Chordal rupture
 Leaflet prolapse
 Regurgitant jets
 Ejection fraction
Mitral Regurgitation-Indications for
Surgery (Class I indications)
 Symptomatic acute mitral regurgitation
ruptured chord
ruptured papillary muscle
 Symptomatic patients with chronic severe MR as long
as EF > 30%
 Acute endocarditis with hemodynamic compromise,
persistent sepsis, annular abscess, recurrent emboli
 Asymptomatic patients with severe MR and EF 3060%
Mitral Regurgitation-Class IIa and
IIb Indications
 Patients with severe MR with class III-IV symptoms
and EF < 30% and/or end-systolic dimension > 55 mm
and if a repair is highly likely
 There are 2 class IIb indications with asymptomatic
patients with severe MR with EF > 60% who develop
new onset atrial fibrillation and/or pulmonary
hypertension (PAP > 50 mm Hg)
Mitral Regurgitation-Asymptomatic
 Asymptomatic patients with severe MR should be
followed closely with ECHO every 6 months
 If there is evidence of left ventricular dysfunction with
a decreased EF < 60 %, patients should be referred for
surgery
 Preoperative EF important predictor of long term
survival after mitral valve surgery
Effect of preoperative EF
 Long term postoperative prognosis is related to
preoperative EF
Pre-op EF
Normal EF
EF 50-60%
EF < 50%
10 yr survival
73 %
53 %
32 %
Circulation, 1995
Mitral Regurgitation-Salient Points
 In asymptomatic patients with severe mitral
regurgitation ventricular function should be followed
closely
 If EF decreases to < 60% or left ventricular end systolic
diameter dimension exceeds 40 mm patient should be
referred for surgery
 Mitral valve repair is the ideal procedure
Prosthetic Valves
 No “perfect” prosthetic valve
 Bioprosthetic valves versus mechanical
bioprosthetic
mechanical
Avoids longterm
anticoagulation
Long-term
anticoagulation
Limited
durability
Excellent
durability
Prosthetic Valves
porcine
bovine pericardial
mechanical
Prosthetic Valves-Selection
 Generally, if patient is > 65 a tissue valve is
recommended
 Due improvements in the manufacturing process
tissue valves have increased durability
demineralization to prevent calcification
“zero pressure” tissue fixation
 General trend to place tissue valves in younger patients
 Ultimate decision is patient’s
Prosthetic Valve Selection
 Some tissue valves have demonstrated 85% 15 year
structural free deterioration
 Some evidence to suggest antiplatelet therapy may be
sufficient anticoagulation in select patients with
mechanical AVR (not a guideline)
select cohort
normal LV function
normal sinus rhythym
bileaflet mechanical valve
ongoing clinical trails to determine efficiacy
Early Anticoagulation in
bioprosthetic valves
 Historically “early” anticoagulation recommended in
immediate postoperative period for tissue valves is
warfarin for 3 months (AHA/ACC guidelines)
 Expanding clinical evidence to support use of
antiplatelet therapy alone after aortic tissue valve
placement in early postoperative period unless there is
some other indication for warfarin¹΄²
1. JTCS,2005
2. JTCS,2010
Percutaneous Therapy
 TAVI (transcatheter aortic valve implantation)
 Reserved for patients with severe aortic stenosis who
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are not surgical candidates for open procedure
Recently FDA approved
Likely will be regulated
Should involve societal (STS) oversights and database
Should be collaborative, multidisciplinary approach
Percutaneous Aortic Valve
•? Long term durability
•Aortic insufficiency
• equivalent 1 year survival¹
compared to open surgery
in some studies
1. NEJM, 2010