Valvular Heart Disease
2012: The Year of the Valve
Robert H. McQueen, MD, FACC
Mountain States Medical Group – Cardiology
January 27, 2012
2
• Structural abnormalities and disorders of cardiac
valve function result in valvular heart disease
• Disruption in the anatomic integrity of cardiac valves
may result in disorders of the valve surface, valvular
stenosis, valvular regurgitation, or mixed disease
with stenosis and regurgitation.
• Clinical understanding and experience of valvular
heart disease has changed dramatically in the past 5
decades, due to a number of factors:
– Recognition of nonrheumatic causes
– Reduction in incidence of rheumatic fever
– Increased life expectancy
– Development of new technology for Dx and Tx
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• Although there has been a dramatic reduction in
rheumatic valve disease in industrialized countries
over the past 50 years, there has not been a similar
reduction in valve surgery.
• Calcific aortic stenosis and mitral annular
calcification are common valvular abnormalities in
the elderly, and their incidence has increased due to
an increase in life expectancy.
• Valvular heart disease still constitutes a major health
problem even in industrialized countries, and will
continue to do so with aging populations.
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Valvular Disease
• Although the incidence of degenerative disease
increases with age, aging itself does not appear to be
the only factor.
• The initial lesion of calcified aortic valve disease
seems to involve an active process similar to that of
atherosclerosis, including lipid deposition,
macrophage infiltration, and production of other
proteins which negatively affect the valvular
structure
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Aortic Stenosis
• Over 300,000 patients have severe AS worldwide
• Most commonly caused by age-related progressive
calcification (> 50% of cases) usually occurs later,
70-80 yr of age. Some degree of calcification found
in 75% of people > 85.
• Congenital Bicuspid AS (30-40%) usually occurs
earlier, 40–50 yr of age. 1-1.5% of population have
bicuspid aortic valves
• Acute rheumatic fever (<10%)
• HTN, DM, Elevated Lipoproteins, and Uremia may
encourage/accelerate process
• Severe AS found in 2% over age 65, 3% over 75, and
4% over 85
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Severe AS Patients Not Undergoing AVR Have
a Shorter Life Expectancy Than Those
Receiving AVR
Survival of patients with severe AS with and without AVR
1yr
87%
Cumulative Survival
1
2yr
78%
P < 0.0001
5yr
68%
0.8
AVR n = 80
No AVR n = 197
0.6
0.4
1yr
52%
2yr
40%
0.2
5yr
22%
0
0
2
4
6
8
10
12
Time in Years
Number at risk
10
80
197
63
97
54
67
41
48
33
37
26
29
16
17
8
9
4
6
3
4
2
1
AVR group
No AVR group
1. Varadarajan P, Kapoor N, Bansal RC, Pai RG. Survival in elderly patients with severe aortic stenosis is dramatically improved by aortic
valve replacement: results from a cohort of 277 patients aged ≥ 80 years. Euro J Cardiothorac Surg. 2006;30:722-727.
Aortic Stenosis Symptoms
•
•
•
•
•
Degree dependent
Mild/Mod – Few if any symptoms
Severe – Syncope, CHF, and Angina
Most often AS presents with SOB/DOE
As gradient increases, concentric hypertrophy
develops as a result of excessive pressure loading
• Later progresses to LV dilation/thinning with ultimate
function deterioration and increased filling pressures
• CHF and AS = 2 year mortality of 50%
• Syncope (usually exertional) = 3 yr mortality of 50%
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Aortic Stenosis
• Angina occurs as LVH progresses and inability to
supply thickened myocardium with adequate
oxygenation.
• Angina = 50% 5 yr mortality
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Aortic Stenosis - Diagnosis
• Adequate H & P
• EKG = LVH with possible strain/ischemia if advanced
• CXR = Calcification of Aortic valve with possible
Cardiac enlargement secondary to LVH
• Echo (TTE or TEE) best non-invasive imaging
modality, 3D may provide additional information
• Cardiac Cath (R/L/LV/Root) remains gold standard for
exact gradient measurement and coronary
angiogram
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Aortic Stenosis – Medical Treatment
• In general, all medical therapies have poor effect on
AS, important to treat associated symptoms
– Angina = B-Blocker or Ca blocker
– Avoid peripheral vasodilators, unable to increase
C.O. to compensate
– (NTG, ACE/ARB, Alpha blockers, Hydralazine)
If no significant symptoms:
Mild/Mod stenosis = Echo every 1-2 yr, +/- GXT
Mod/Severe = Echo every 3-6 months, ? Stress
Valve replacement if symptoms, Echo changes
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Aortic Stenosis – Invasive options
• Balloon Valvuloplasty generally ineffective long-term
and used only for palliative treatment or as bridge to
subsequent procedure
• Surgical valve replacement remains the Gold
Standard for alleviation of symptoms and improved
survival
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Aortic Regurgitation
• Half of all cases due to aortic root dilation which is
usually idiopathic (> 80%) but may be secondary to
aging, syphilitic aortitis, osteogenesis imperfecta, or
dissection
• 15% of cases secondary to bicuspid AV
• 15% of cases secondary to rheumatic fever
• May accompany AS with post-stenotic dilation of AO
root and subsequent associated regurgitation
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Aortic Regurgitation
• Acute: Sudden increase in LV volume, less efficient
contraction (shifting Frank-Starling curve), increased
end-diastolic pressures resulting in pulmonary
edema
• Severe = life-threatening emergency associated with
high mortality if AVR not performed
• Chronic: LV hypertrophy and volume overload is
compensated for over time
• Eventual LV decompensation and filling pressures
escalate = SOB/CHF (PND, DOE)
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Aortic Regurgitation – Diagnostic Tools
• Adequate H & P
• EKG may suggest LVH if chronic
• CXR may show AV calcification with possible cardiac
enlargement +/- widened mediastinum
• Echo (TTE/TEE) remains best non-invasive tool
• Cardiac Cath with Root, Gold Standard
• CT may be helpful to R/O Dissection
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Aortic Regurgitation - Treatment
• Vasodilators preferred (ACE/ARB, Hydralazine) but
only if HTN present, for afterload reduction
• AVR indicated if:
– Any symptoms suggestive of CHF
– Fall in EF < 50% regardless of sxs
– Severe LV dilation or abnormal GXT
If stable without above findings:
Mild/Mod AI: Echo every 1-2 yr +/- GXT
Mod/Severe AI: Echo every 3-6 mos
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Mitral Stenosis
• Almost all cases are secondary to rheumatic fever
• Normally latent period @ 16 yrs. Once symptoms
develop, progression to stenosis @ 9 years.
• Little role of medical therapy other than symptomatic
support
• Patients with severe MS who refuse MV
replacement/repair, 44% survival @ 5 yr, 32% @ 10yr.
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Mitral Stenosis
• LA/LV gradient increases with increased HR or
Cardiac output
• As LA/LV gradient increases, the amount of time to
fill the LV increases, now relying on the “atrial kick”
• Ultimately diastolic filling is insufficient resulting in
decreased C.O. and elevated LA pressures =
pulmonary edema
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Mitral Stenosis - Diagnosis
•
•
•
•
•
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Adequate H & P
EKG = P mitralie (Broad notched P), possible AF
CXR = LAE, pulm edema
Echo = Best non-invasive test (TEE > TTE)
Cath (R/L with simultaneous LV/Wedge) – Gold
Standard
Mitral Stensis – Treatment Options
• If no symptoms, Echocardiographic monitoring
• If Symptoms:
– Mitral valve replacement/repair
– Mitral Valvuloplasty:
• Leaflet mobility
• Leaflet thickening
• Subvalvular thickening
• Amount of calcification present
Class III or IV only
If score > 8, surgery preferred
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Mitral Valvuloplasty
• Performed via femoral vein
• Requires trans-septal puncture
• Three stagged balloon
– 1st: Inflated in LV and pulled back against MV leaflets
– 2nd: Inflated in LA to secure leaflets in center
– 3rd: Center inflated to “crack” leaflets
Usually all performed in < 30 sec
Most serious complication is severe MR (torn leaflet or
subvalvular apparatus) requiring surgical repair
Requires vigilant F/U for restenosis:
70-75% free of restenosis @ 10 yr
40% free of restenosis @ 15 yr
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Mitral Regurgitation
• Most common form of valvular heart disease
• Problem with either papillary muscle or chordae
tendineae can produce sub-valvular MR
• Most common cause is papillary muscle fibrosis
(ischemic papillary muscle damage) after MI with
either shortening or lengthening and possible LV
dilation
• 50% of all infarcts have some involvement of the
papillary muscles
• Myxomatous degeneration most common form of
valvular regurgitation
• All result in failure in coaptation
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Mitral Regurgitation - Diagnosis
•
•
•
•
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Adequate H & P
EKG = LAE, LVH, ? AF
Echo (TEE/TTE) best diagnostic tool
Cardiac cath best invasive
Mitral Regurgitation – Treatment Options
• Medical treatment consist of After-load reduction
(ACE/Hydralazine)
• Acute management may require IABP, IV Nipride and
surgical repair of Valve
• Mitral Replacement or Repair +/- ring
• Replace when symptoms present, LV dysfunction
(EF<50), or LVESD > 45
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New Percutaneous Valvular
Therapies
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Aortic Stenosis - Percutaneous
Therapies
• Surgical Aortic valve replacement is not performed in
up to 1/3 of eligible pts due to advanced age, comorbidities, previous cardiac surgery, low EF,
Concomitant CAD and patient refusal
• Percutaneous treatment of CAD is now the treatment
of choice for most individuals, however, the
treatment of structural heart disease via a
percutaneous approach has been slower to evolve
30
• Transcatheter Aortic Valve Implantation (TAVI) allows
a less invasive means of valve replacement via a
transfemoral, transapical, or subclavian approach
with favorable results in terms of procedural
success, hemodynamic performance, periprocedural complications, and survival
• Currently in US, only Pulmonic valves are approved
(Melody – Medtronic)
• Outside US, 2 current platforms in use, Edwards
Sapian Valve and Medtronic Corevalve.
• Over 15,000 percutaneous valves implanted
worldwide since 2002
31
Edwards Sapian Valve
• 3 bovine pericardial leaflets hand-sewn to a stainless
steel balloon expandable stent with fabric covering
of the lower portion of the stent to facilitate formation
of a seal
• Valve leaflets undergo anticalcification treatment
during production in an attempt to maximize
longevity
• Currently produce in 3 sizes: 23,26, and 29 mm
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Transcatheter Valves
Three Primary Components:
1. Tissue Valve
2. Supporting Frame
3. Delivery System
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Medtronic CoreValve Revalving System
• Self-expanding nitinol stent (no balloon delivery)
• Delivered through a 18Fr system
• 2 Current sizes: 26 & 29mm
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CoreValve Experience
More than 10,000 implants in 34 countries
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Design & System Components
Design
• Transfemoral approach for beating-heart,
transcatheter aortic valve implantation (TAVI)
Components:
Over-the-wire 0.035 compatible
• 18Fr catheter delivery system
• Self-expanding multi-level Nitinol frame
• Porcine pericardial tissue valve
Caution: The CoreValve® System is not currently available in the USA for clinical trials or for sale. CoreValve is a
registered trademark of Medtronic CV Luxembourg S.a.r.l.
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Valve Design Features
Delivery Fixation Hoops
Nitinol Frame
Orientation Crowns
• Self-expanding frame
• Radiopaque design
• Memory shaping properties
Multi-Level Radial Forces
• Outflow Aspect
• Hoop Strength
• Inflow Aspect
Pericardial Porcine Tissue Valve
• Supra-annular valve function
• Tall commissures
Sealing Skirt
• Porcine pericardium
• Intra-annular sealing
Caution: The CoreValve® System is not currently available in the USA for clinical trials or for sale. CoreValve is a
registered trademark of Medtronic CV Luxembourg S.a.r.l.
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Position and Fixation
Inflow
Outflow
Caution: The CoreValve® System is not currently available in the USA for clinical trials or for sale. CoreValve is a
registered trademark of Medtronic CV Luxembourg S.a.r.l.
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TAVI Inclusion
• Severe symptomatic AS with Aortic valve area less
than 1 cm2 or mean gradient > 40mmHg, advanced
age > 80
• If age < 80 then one of the following: Liver cirrhosis,
Significant pulmonary HTN, previous cardiac
surgery, porcelain aorta, severe COPD, recent PE
• Aortic annulus sized by TEE or CT to avoid size
mismatch
42
TAVI Exclusion
• Bulky aortic calcification
• ? Bicuspid aortic valve
• Short Distance (< 8mm) between the aortic annulus
and the Left main coronary
43
TAVI Results
• 20% reduction in mortality with significant
improvement in Valve gradients, quality of life,
reduced hospitalizations compared with Med Rx
• Most common hospital complications were bleeding
(31%), CIN (18%), Vascular (16%), CVA (11%),
Coronary occlusion, Persistent AV block
• Most common long-term complication is Perivalvular leak, @ 75% mild and well tolerated, @ 20%
mod/severe and require either post-dilation,
placement of second valve, or surgery
• Causes: Prosthesis mismatch, valve malposition,
under expansion of stent, valve damage, operator
experience
• MSCT to evaluate annulus to Coronary distance
44
TAVI Results
• 1 year mortality after TAVI = 10% (Pt age, disease
states)
• MACE @ 30%
• Stroke after Surgical AVR
– 1.5% but increases to 2-4% in high-risk pts
– 1.5 – 6% at 1yr
At 1 year, TAVI and SAVR showed similar rates of
survival, although there were important
differences in periprocedural risks
? Long-term valve durability
Newer Generation Devices – fewer complications
45
TAVI Placement
High deployment:
– Device embolization
– Coronary ischemia owing to compromise of one
or both coronary ostia
– Aortic injury
Low Deployment:
- Impingement upon the AV node causing
bradycardia or BBB or MV apparatus resulting in
acute and ofter poorly tolerated MR
46
TAVI Summary
•
•
•
•
•
Team approach mandatory
Extensive pre-procedure planning/imaging
Family discussions
Intra-Cardiac Echo/TEE needed
Emergency back-up procedures in place
• No substitute for experience
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? Mitral Valve Replacement
• Percutaneous replacement of MV not currently
possible due to anatomic features of the MV that
make fixation and peri-valvular seal desires a
challenge
• Calcified aortic valve OK for TAVI, other locations
require prosthetic material to provide support for
Transcatheter stent-mounted valves
• Annuloplasty ring in Annulus may provide “landing
zone” for secure deployment
• Valve-in-Valve has been done successfully in animal
models
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Mitral Regurgitation
MitraClip – Abbott Vascular
• Edge-to-edge technique (Alfieri 1991, Double Orifice),
Open heart procedure that sutured free edge of
leaflets at site of MR which created 2 orifices
• Safe, effective, and durable
• Historically Open procedure - Min. invasive robotic
with direct (trans-atrial) off-pump suture based
approach – Percutaneous Clip
• 2003 first in Man
• Clip currently available in Europe and in trials in US
(Everest II) in high-risk pts with functional MR
50
MitraClip – Abbott Vascular
• 24Fr, trans-septal approach
• Cobalt/chromium clip
• Capture of MV leaflets at site of MR
51
Everest II Results
• At 12 months, the rates of primary end point for
efficacy were 55% MitraClip vs 73% Surgical
• Death: 6% each group
• Surgery for valve dysfunctin: 20% vs 2%
• Severe MR: 21% vs 20%
• Major adverse events: 15% vs 48% at 30 days
• At 12 months, both had improved LV size, functional
class, and QOL measures
Although percutaneous repair was less effective at
reducing MR, the procedure was associated with
superior safety and similar improvements in
outcomes
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