Aortic Valve Replacement in Octogenarians

Aortic Valve Replacement in Octogenarians

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Description: Aortic stenosis is the most common acquired valvular disorder found in developed countries. The prevalence of calcific aortic stenosis increases with age. Mild to severe is present in 2% to 4% of adults over age 65 years.

Aortic Sclerosis is a common disease affecting 25% of people 65 to 74 and 48% of people over 84. Risk Factors Associated with Calcific Aortic Stenosis are examined. No medical treatments proven to prevent or delay the disease process in aortic valve leaflets.

 
Author: Samir AbdAllah (Fellow) | Visits: 2711 | Page Views: 2739
Domain:  Medicine Category: Implants 
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Contents:
AORTIC VALVE REPLACEMENT in Octogenarians
Samir AbdAllah
Prof. of Cardiothoracic Surgery Cairo University

Prevalence and Surgical Incidence
Aortic stenosis is the most common acquired valvular disorder found in developed countries The prevalence of calcific aortic stenosis increases with age Mild to severe AS present in 2% to 4% of adults over age 65 years

Aortic Sclerosis: The Beginning
A common disease � 25% of people 65 to 74 � 48% of people over 84 Focal areas of valve thickening, typically in the leaflet center � Commissural sparing � Normal leaflet mobility y Valvular hemodynamics within normal limits � Antegrade velocity across the valve of 2.5 m/s. Systolic outflow murmur may be auscultated on physical examination No reliable clinical symptoms Associated with increased morbidity and mortality not caused by the valve pathology, even controlling for other risk factors � 40% increase in risk of myocardial infarction � 50% increase in risk of cardiovascular death

From Sclerosis to Stenosis
Largest study published in 2005 (n=2131) 16% developed aortic stenosis
� Large absolute numbers (25% of patients age 65-74 have aortic sclerosis)
10.5% Mild 2.9% Moderate 2.5% 2 5% Severe

Average time from diagnosis of aortic sclerosis to progression to severe stenosis was 8 years
� Number progressing to severe valve obstruction likely to increase with a longer follow-up

Close clinical follow-up and serial evaluation is required once aortic sclerosis is identified

Risk Factors Associated with Calcific Aortic Stenosis
Increasing age Elevated lipoprotein A Elevated LDL cholesterol l d h l l Smoking Hypertension Male gender Elevated C-reactive protein C reactive Note: lipids are a risk factor

Natural History
Prolonged latent period with very low morbidity and mortality Once moderate stenosis present, average present progression: Jet velocity: +0.3 m/s per year 0.3 Mean pressure gradient: +7 mm Hg per year Valve area: -0.1 cm2 per year Significant variation among individuals Regular Reg lar clinical follo -up is MANDATORY in all followfollow p patients with asymptomatic mild to moderate AS

No Medical Therapy Yet Proven
No medical treatments proven to prevent or delay the disease process in aortic valve leaflets A 3-year prospective, randomized, placebocontrolled trial of atorvastatin failed to slow the progression of calcific AS i f l ifi � Possible that disease was too advanced to be reversed � Lipid-lowering therapy in several small retrospective studies suggest a benefit from statins � Trials with less severe disease and longer follow-ups needed Modification of ca diac risk facto s is impo tant in cardiac isk factors important these patients to prevent concurrent CAD

Onset Of Symptoms y p
The Three Classic Symptoms of Aortic Stenosis St i
� Angina � Syncope � Heart failure

Symptoms may also be subtle and "often are not elicited by the physician in taking a routine clinical history" ti li i l hi t
� � � � Decreased exercise tolerance Exertional chest discomfort Dyspnea Lightheadedness

Onset Of Symptoms y p
After the onset of symptoms, average survival is 2 to 3 years with a high risk of sudden death "The development of symptoms identifies p y p a critical point in the natural history of AS...corrective surgery is generally recommended in patients with symptoms eco e ded pat e ts t sy pto s thought to be due to AS" --2006 ACC/AHA Guidelines

Sudden Death Known to occur in patients with severe AS Reported to occur without prior symptoms in older retrospective studies Rare in prospective p p echocardiographic studies Estimated at less than 1% per year

Purpose of Echocardiography in AS
Define the primary lesion in terms of cause and severity Define hemodynamics Define coexisting abnormalities Detect seco da y lesions etect secondary es o s Evaluate cardiac chamber size and function Establish E t bli h a reference point for future f i tf f t comparisons Re evaluate Re-evaluate the patient after an intervention Measurement of Aortic Annulus

Serial Evaluations
Many physicians perform an annual history and physical examination on patients with asymptomatic AS of any degree Because the rate of progression varies considerably, clinicians often perform an annual echocardiogram on patients known to have moderate to severe AS In patients with... � Severe AS: annual echocardiogram may be appropriate i t � Moderate AS: serial studies every 1 to 2 years � Mild AS: serial studies every 3 to 5 years Echocardiograms should be performed more frequently if there is a change in signs or symptoms

Cardiac Catheterization
Provides important information regarding � Presence and severity of valvular obstruction � Valvular regurgitation � Intracardiac shunting Not necessary in most patients with cardiac murmurs and normal or diagnostic echocardiograms Provides additional information for some patients in whom there is a discrepancy between echocardiographic and clinical

Cardiac Catheterization � Indications
Class I Cl Coronary angiography is recommended before AVR in patients with AS at risk for CAD Cardiac catheterization f hemodynamic C d h for h d measurements is recommended for assessment of severity of AS in symptomatic patients when noninvasive tests are inconclusive or when there is a discrepancy between noninvasive tests and clinical findings regarding severity of AS Coronary angiography is recommended before AVR in patients with AS for whom a pulmonary autograft (Ross procedure) is contemplated and if the origin of the coronary arteries was not identified by noninvasive y y technique

Cardiac Catheterization � Contraindications
Class III Cardiac catheterization for hemodynamic measurements i not recommended for t is t d df the assessment of severity of AS before AVR when noninvasive tests are adequate and concordant with clinical findings Cardiac catheterization for hemodynamic y measurements is not recommended for the assessment of LV function and severity of AS in asymptomatic patients

Exercise Testing g
Can provide valuable information in patients with valvular heart disease Especially valuable in patients whose symptoms are difficult to assess Can be combined with echocardiography, radionuclide angiography, and cardiac catheterization Proven track record of safety, even among asymptomatic patients with severe AS � Generall underutilized in this lly d ili d i hi population and should constitute an important component of the evaluation p p process

" Exercise testing in asymptomatic patients with AS may be considered to elicit exercise induced symptoms and exercise-induced abnormal blood pressure responses" " Exercise testing should not be performed in symptomatic patients with AS" ACC/AHA 2006 Guidelines

Dobutamine Stress Echo
Assessing Low-Flow/Low-Gradient AS May be useful to determine the transvalvular pressure gradient and to calculate valve area during a baseline state and again during exercise or low dose pharmacological (i e dobutamine low-dose (i.e., infusion) stress If a dobutamine infusion produces an increment in stroke volume and an increase in valve area greater than 0.2 cm2 and little change in gradient, it is likely that baseline evaluation overestimated the severity of stenosis. Patients who do not have true anatomically severe stenosis will exhibit an increase in the valve area and little change in gradient during an increase in stroke volume

Dobutamine Stress Echo
In contrast, patients with severe AS will have a fi d valve area with an increase in h fixed l ith i i stroke volume and an increase in gradient. These patients are likely to respond favorably to surgery surgery. Patients who fail to show an increase in stroke volume with dobutamine (less than 20%), referred to as "lack of contractile reserve," appear to have a very poor prognosis with either medical or surgical therapy Dobutamine stress testing in patients with AS should be performed only in centers with experience in pharmacological stress testing and with a cardiologist in attendance.

ACC/AHA 2006 Guidelines Low-Flow/Low-Gradient AS Class IIa 1. Dobutamine stress echocardiography is reasonable to evaluate patients with lowbl t l t ti t ith l flow/low-gradient AS and LV dysfunction 2. 2 Cardiac catheterization for hemodynamic measurements with infusion of dobutamine can be useful for evaluation of patients with lowflow/low-gradient AS and LV dysfunction fl /l di t d d f ti

Indications for Operation
Peak aortic valve gradient greater than 75mmHg with or without symptoms Peak aortic valve gradient greater than 50mmHg with symptoms Peak aortic valve gradient less than 50mmHg associated with � significant/progressive LV hypertrophy � heavy aortic valve calcification

Indications for Operations
Aortic valve area less than 0.75cm2 and symptoms Aortic valve area less than 0.75cm2 and no symptoms but "serious" LV dysfunction and serious progressive cardiomegaly "As artificial valves and surgical skills continue to As improve, it is likely that patients with severe AS will become candidates for operation at earlier stages in the natural history of their disease

Indications for Operation
Symptomatic patients with severe stenosis Patients with moderate or severe stenosis having operation for coronary artery disease, other valve disease, or aortic disease Asymptomatic patients with severe aortic stenosis LV systolic dysfunction Abnormal response to exercise (hypotension) Ab l t i (h t i ) Ventricular tachycardia Marked LV hypertrophy Aortic valve area less than 0.6cm2 From ACC/AHA Task Force on Practice Guidelines, , 1998

ACC/AHA 2006 Guidelines " AVR should be performed promptly after the onset of symptoms " " It is important to emphasize that symptoms may be subtle and often are not elicited by the physician in taking a routine clinical history "
� � � � Decreased exercise tolerance Exertional chest discomfort Dyspnea Lightheadedness

" AVR may be considered for asymptomatic patients with severe AS and abnormal response ti t ith d b l to exercise "

2006 ACC/AHA Guidelines � Highlights

In the absence of serious comorbid conditions, aortic valve replacement (AVR) is indicated in virtually all symptomatic patients with severe AS Because of the risk of sudden death AVR death, should be performed promptly after the onset of symptoms Age is not a contraindication to surgery

When Disease Is Not "Severe" Severe Class IIa "AVR is reasonable for patients with moderate AS undergoing CABG or surgery on the aorta or other heart valves" Class IIb Cl "AVR may be considered in patients undergoing CABG who have mild AS when there is evidence, such as moderate to severe valve calcification, that progression may be rapid"

When Patients Are Truly Asymptomatic Currently, AVR risk exceeds benefit in severe asymptomatic as mptomatic patients with normal LV function ith no mal f nction
� Improvements to valve substitutes and procedures could shift risk/benefit analysis to earlier i t li intervention ti

AVR recommended in severe asymptomatic patients with LV ejection fraction < 50% AVR may be considered if high likelihood of rapid progression or severe calcification AVR may be considered if surgery might be delayed at the time of symptom onset y y p

ACC/AHA 2006 Guidelines " Patients with asymptomatic AS require frequent monitoring for development of symptoms and progressive disease " ACC/AHA 2006 Guidelines Relating To Asymptomatic AS Patients Class IIa--AVR is reasonable for: Patients with moderate AS* undergoing CABG or surgery on the aorta or other heart valves Class IIb--AVR may be considered for: Asymptomatic patients with severe AS* and abnormal response to exercise (e.g., A t ti ti t ith d b l t i ( development of symptoms or asymptomatic hypotension) Adults with severe asymptomatic AS* if there is a high likelihood of rapid progression (age, calcification, and CAD) or if surgery might be delayed at the time of symptom onset y p Patients undergoing CABG who have mild AS* when there is evidence, such as moderate to severe valve calcification, that progression may be rapid Asymptomatic patients with extremely severe AS (aortic valve area less than 0.6 cm2, mean gradient greater than 60 mm Hg, and jet velocity greater than 5.0 m per second) when the patient s expected operative mortality is 1 0% or less patient's 1.0% Class III--AVR is not useful for: The prevention of sudden death in asymptomatic patients with AS who have none of the findings listed under the class IIa/IIb recommendations g /

Concerns with Asymptomatic Severe Aortic Stenosis

LV hypertrophy LV diastolic dysfunction LV systolic dysfunction Ventricular dysrhythmias Sudden death An increased LV mass index is associated with an increased operative mortality Reversal of LV interstitial fibrosis and accompanying diastolic dysfunction takes years after AVR ft

"... Only 59% of the patients who should have had valve y p replacement according to the practice guidelines were actually offered surgical treatment...mainly symptomatic patients under 80 years of age with a high gradient ..." "... In daily practice, elderly patients with clinically relevant symptomatic aortic stenosis are often denied surgical t ti ti t i ft d i d i l treatment ..." "... A surgical approach, especially where there is impaired systolic left ventricular function, is associated with better survival ..." Previous assumptions regarding surgery in the elderly need to be b revisited d t d i it d due to demographic shifts and i hi hift d improvements i t in technology

Various studies have shown that:
Life expectancy varies from ~8 years at 80 years old to ~6 years at 89 years ~40% of octogenarians have symptomatic CV disease, leading cause of death , g 17% of patients > 80 have severe aortic calcification l ifi ti 2%-4% of patients >75 have severe AS on p echo

A rational approach to cardiac surgery in octogenarians can bring survival rates closer to demographic norms
Principles c p es
Indications are broad for independent and motivated patients Select the simplest operation and accept incomplete repair Consider only symptomatic patients Highlights Hi hli ht AVR is well tolerated; post-op survival is similar to a control p p population Only severe comorbidities should contraindicate surgery Tissue valves are preferred Survival in symptomatic patients without operation is short

Contra-indications
CAD and EF 200�mol/L Decreased lung function (abnormal FEV1) g ( ) Neurological/psychiatric deficits which restrict independence or outside activity i d d t id ti it

Literature demonstrating excellent outcomes in elderly patients after undergoing AVR continuing to emerge AVR in elderly Author/year Chiappini, Chiappini 2004 Medalion, 1998 Gehlot, 1996 Tseng, 1997 T N/age (mean) 115/82.3

Survival
98% of patients were pleased with their choice Functional status improved from preoperative average NYHA score of 1.6 to a post-operative f average of 2.9 Due to faster progression of functional decline in the elderly, a AVA < 1.4 cm2 should be directed toward surgery

In a recent study at the Mayo Clinic of patients >80 years of age p >80 y g undergoing AVR
92% improved after surgery 60% survival at 5 years Mortality rate was 3.6% in those operated after 1995 (the mortality rate was >13% overall in a study covering ~3 decades of valve surgery)

Choice of valve type appears to be important in the outcomes elderly cohort of patients y p Stented bioprosthetic valves demonstrate better outcomes, likely attributable to: outcomes
Limited need for anticoagulation with fewer bleeding episodes Less frequent thromboembolic events from foreign surface Recent technological advances in valve design, R tt h l i l d i l d i easier to implant than stentless valves Mechanical valves are preferred in select cases characterized by
� Narrowed annulus � Impaired organ function � Atrial fibrillation

WHAT ARE OUR VALVE CHOICES?
Mechanical versus tissue 1st, 2nd, and 3rd generation valves Supra-annular versus intra-annular l i l Porcine (stentless) versus pericardial Ross Procedure Aortic Homografts And recently Trans-catheter Aortic Valve TransImplantation (TAVI)
Percutaneous Femoral Transapical

AVR in Octogenarians in Egypt
Population in Egypt is about 82 millions p gyp Age structure
0-14 years: 32.2% 32. 1515-64 years: 63.2% 63. >65 years: 4.6%

Life Expectancy at birth:
Total population: 71.5 years 71. Males : 69.04 years 69. Females: 74.22 years 74.

AVR in the 70s 70s
28 patients with calcific AS aging 707076 years (mean 73 years) had AVR during the period from 6/2005 to 12/2008, 12/2008, There were 20 males and 8 females

AVR in the 70s 70s
Type of prosthesis Carpentier-Edward' Carpentier-Edward's porcine aortic bioprosthesis used in 20 patients In 8 patients mechanical valves were used d

AVR in the 70s 70s
Mortality: One hospital mortality (3.5%) (3 Morbidity: 3 patients suffered heartblock One patient got permanent pacemaker. 3 patients had reoperation for bleeding One patient suffered renal failure

Conclusion
The true philosophic objective is to favor good years with good life for old patients with AS satisfactory results can at least be obtained with aortic valve replacement and AVR should not be based on age alone.

Thank You

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