I just saw this article with Recommendations to cardiologists about aortic stenosis (AS). Some of you might find it interesting because it summarizes a bunch of stuff about AS including:
--the frequency of AS in the population
--rate of AS progression
--diagnosis of AS
--measurements that define AS through Echos like mean gradient and valve area
--when surgery is warranted
outcomes of AS (with or without surgery).
Here is a review of the article by Dr David Bach, MD in Journal of the American College of Cardiologists.
Click here for link
Conclusions: Calcific aortic stenosis (AS) is a common and morbid disease. Although there are clear surgical indications for aortic valve replacement among patients with severe AS and symptoms of angina, dyspnea, heart failure, or syncope, the optimal management of asymptomatic patients is less well established. This review article summarizes available literature and makes recommendations in keeping with the American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) guidelines for the evaluation and management of asymptomatic patients with severe AS.
Ten points to remember from this state-of-the-art paper are:
1. Prevalence and pathogenesis: Aortic sclerosis and AS are common; approximately 25% of people in North America >65 years of age have aortic sclerosis; and more than 4% of people ≥75 years of age have AS. Both aortic sclerosis and AS share risk factors with atherosclerotic disease. Probably in response to endothelial damage caused by blood flow and shear stress, the disease begins at the bases of the aortic cusps, with subsequent inflammatory cell infiltration, lipid and calcium deposition, and activation of osteoblast-like cells. Calcification spreads to the commissural edges of cusps, leading to thickening, stiffening, and restricted mobility of the valve. In response to increased afterload, the left ventricle adapts with concentric hypertrophy.
2. Prognosis: Patients with severe AS and symptoms of angina, dyspnea, heart failure, or syncope have a very poor prognosis without intervention, but a good prognosis after aortic valve replacement. Asymptomatic patients with severe AS in general appear to have a good prognosis, but may progress to the development of symptoms, and also have a small risk of death without intervention.
3. AS progression: In patients with moderate AS, the peak velocity across the aortic valve progresses on average at a rate of 0.3 m/s/y, with an associated increase in mean gradient of 7 mm Hg/y and decrease in valve area of 0.1 cm2/y. Progression occurs more quickly among patients with congenital AS (most commonly bicuspid aortic valve).
4. Diagnosis and quantitation: Echocardiography with Doppler is the dominant means for the assessment of AS presence and severity. Invasive assessment of hemodynamics should be performed only among patients undergoing coronary angiography in whom noninvasive assessment of AS fails to correlate with historical or physical findings. AS is mild if jet velocity is <3.0 m/s, mean gradient is <25 mm Hg, and valve area is >1.5 cm2; AS is moderate if jet velocity is 3.0-4.0 m/s, mean gradient is 25-40 mm Hg, and valve area is 1.5-1.0 cm2; AS is severe if jet velocity is >4.0 m/s, mean gradient is >40 mm Hg, and valve area is <1.0 cm2.
5. Asymptomatic AS: A substantial proportion of patients with severe AS do not have cardinal symptoms of angina, dyspnea, heart failure, or syncope. Several observational studies have reported outcomes for asymptomatic patients. Although methodological specifics vary between studies, they agree in their major findings in that: a substantial number of asymptomatic patients progress to developing symptoms or requiring aortic valve replacement; survival in unoperated asymptomatic patients tends to be good and risk of sudden death is low; and there may be predictors of disease progression or clinical outcomes.
6. Predicting progression to symptoms: Progression from asymptomatic severe AS to the development of symptoms associated with AS may be predicted by AS severity (Vmax >4.5 m/s; relative risk 1.26 for each 0.2 cm2 decrease in valve area), response to exercise testing (dizziness more predictive than dyspnea or exertional chest tightness), and serum levels of B-type natriuretic peptide (BNP, ≥130 pg/ml) or N-terminal BNP (≥80 pmol/L).
7. Predicting clinical outcome: Clinical endpoints (including cardiac death and requirement for aortic valve replacement) in asymptomatic patients may be predicted in part by clinical factors (advanced age, baseline functional status), echocardiographic criteria (Vmax >4.0 or 4.5 m/s; ∆ Vmax over time; aortic valve area; left ventricular systolic dysfunction [ejection fraction <50%]; moderate or severe valve calcification; stroke work loss [defined as the ratio of mean gradient to left ventricular pressure, >26%]), functional testing with or without echocardiography/Doppler imaging, and degree of valve calcification on electron beam computed tomography (relative risk 1.06 per 100 Agatston unit increase).
8. Indications for surgical intervention: Among patients with severe AS, surgery is indicated (in accordance with ACC/AHA and ESC guidelines) in the setting of symptoms or left ventricular systolic dysfunction, or at the time of coronary bypass or another cardiac surgical procedure. Exercise testing is recommended if symptomatic status is uncertain, with consideration for intervention based on exercise-induced symptoms, blood pressure decline, or complex ventricular ectopy. Aortic valve replacement also may be considered in asymptomatic patients thought to be at high risk based on presence of coronary artery disease, heavy valve calcification, very severe AS (mean gradient >60 mm Hg, valve area <0.6 cm2), or elevated BNP.
9. Nonsurgical patient management: Patients who are not referred for surgery should be educated about the nature and significance of new symptoms of dyspnea, angina, heart failure, or syncope; and cautioned to seek medical attention without delay with symptom onset. Regular follow-up should be arranged, including echocardiography/Doppler imaging to assess AS progression. Hypertension should be aggressively controlled, and consideration given (based on conflicting available data) for statin therapy.
10. Special cases: Patients with bicuspid aortic valve have a predisposition for aortic root enlargement independent of AS severity, and should be followed for this. Concomitant aortic root repair is recommended at the time of aortic valve replacement if the aorta measures >4.5 cm in diameter, and concomitant aortic valve replacement is recommended in the setting of at least moderate valve disease at the time of aortic root repair. Patients with low-flow low-gradient AS should be evaluated to differentiate severe from pseudo-severe AS; surgical aortic valve replacement is not contraindicated based solely on the absence of left ventricular contractile reserve.
Perspective: This is a nice review that summarizes existing data guiding the management of asymptomatic patients with severe AS. Recommendations are in keeping with current ACC/AHA and ESC guidelines. With more freedom to ad lib, personal experience suggests the following two points: 1) Probably based on lifestyle adaptation and denial, many patients who are purportedly asymptomatic develop symptoms on objective functional testing, leading to a rationale for broader use of exercise testing in asymptomatic patients who would be suitable candidates for aortic valve replacement; and 2) despite absent proof of efficacy, risk-benefit analysis may favor the use of statins in patients who seek to delay progression of AS (i.e., absent evidence of efficacy is not the same as evidence of absent efficacy; if the risk is small, then why not treat?). David S. Bach, M.D., F.A.C.C.
Here is the abstract
Once there click on the link to the right to get the full article for $15.
Or call your library or local hospital library and if they don't have it ask them to do an "Interlibrary loan" for a copy of the article.
Here's the reference:
Title: Management of Asymptomatic Severe Aortic Stenosis
Topic: Noninvasive Cardiology
Date Posted: 10/31/2008
Author(s): Dal-Bianco JP, Khandheria BK, Mookadam F, Gentile F, Sengupta PP.
Citation: J Am Coll Cardiol 2008;52:1279-1292.
--the frequency of AS in the population
--rate of AS progression
--diagnosis of AS
--measurements that define AS through Echos like mean gradient and valve area
--when surgery is warranted
outcomes of AS (with or without surgery).
Here is a review of the article by Dr David Bach, MD in Journal of the American College of Cardiologists.
Click here for link
Conclusions: Calcific aortic stenosis (AS) is a common and morbid disease. Although there are clear surgical indications for aortic valve replacement among patients with severe AS and symptoms of angina, dyspnea, heart failure, or syncope, the optimal management of asymptomatic patients is less well established. This review article summarizes available literature and makes recommendations in keeping with the American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) guidelines for the evaluation and management of asymptomatic patients with severe AS.
Ten points to remember from this state-of-the-art paper are:
1. Prevalence and pathogenesis: Aortic sclerosis and AS are common; approximately 25% of people in North America >65 years of age have aortic sclerosis; and more than 4% of people ≥75 years of age have AS. Both aortic sclerosis and AS share risk factors with atherosclerotic disease. Probably in response to endothelial damage caused by blood flow and shear stress, the disease begins at the bases of the aortic cusps, with subsequent inflammatory cell infiltration, lipid and calcium deposition, and activation of osteoblast-like cells. Calcification spreads to the commissural edges of cusps, leading to thickening, stiffening, and restricted mobility of the valve. In response to increased afterload, the left ventricle adapts with concentric hypertrophy.
2. Prognosis: Patients with severe AS and symptoms of angina, dyspnea, heart failure, or syncope have a very poor prognosis without intervention, but a good prognosis after aortic valve replacement. Asymptomatic patients with severe AS in general appear to have a good prognosis, but may progress to the development of symptoms, and also have a small risk of death without intervention.
3. AS progression: In patients with moderate AS, the peak velocity across the aortic valve progresses on average at a rate of 0.3 m/s/y, with an associated increase in mean gradient of 7 mm Hg/y and decrease in valve area of 0.1 cm2/y. Progression occurs more quickly among patients with congenital AS (most commonly bicuspid aortic valve).
4. Diagnosis and quantitation: Echocardiography with Doppler is the dominant means for the assessment of AS presence and severity. Invasive assessment of hemodynamics should be performed only among patients undergoing coronary angiography in whom noninvasive assessment of AS fails to correlate with historical or physical findings. AS is mild if jet velocity is <3.0 m/s, mean gradient is <25 mm Hg, and valve area is >1.5 cm2; AS is moderate if jet velocity is 3.0-4.0 m/s, mean gradient is 25-40 mm Hg, and valve area is 1.5-1.0 cm2; AS is severe if jet velocity is >4.0 m/s, mean gradient is >40 mm Hg, and valve area is <1.0 cm2.
5. Asymptomatic AS: A substantial proportion of patients with severe AS do not have cardinal symptoms of angina, dyspnea, heart failure, or syncope. Several observational studies have reported outcomes for asymptomatic patients. Although methodological specifics vary between studies, they agree in their major findings in that: a substantial number of asymptomatic patients progress to developing symptoms or requiring aortic valve replacement; survival in unoperated asymptomatic patients tends to be good and risk of sudden death is low; and there may be predictors of disease progression or clinical outcomes.
6. Predicting progression to symptoms: Progression from asymptomatic severe AS to the development of symptoms associated with AS may be predicted by AS severity (Vmax >4.5 m/s; relative risk 1.26 for each 0.2 cm2 decrease in valve area), response to exercise testing (dizziness more predictive than dyspnea or exertional chest tightness), and serum levels of B-type natriuretic peptide (BNP, ≥130 pg/ml) or N-terminal BNP (≥80 pmol/L).
7. Predicting clinical outcome: Clinical endpoints (including cardiac death and requirement for aortic valve replacement) in asymptomatic patients may be predicted in part by clinical factors (advanced age, baseline functional status), echocardiographic criteria (Vmax >4.0 or 4.5 m/s; ∆ Vmax over time; aortic valve area; left ventricular systolic dysfunction [ejection fraction <50%]; moderate or severe valve calcification; stroke work loss [defined as the ratio of mean gradient to left ventricular pressure, >26%]), functional testing with or without echocardiography/Doppler imaging, and degree of valve calcification on electron beam computed tomography (relative risk 1.06 per 100 Agatston unit increase).
8. Indications for surgical intervention: Among patients with severe AS, surgery is indicated (in accordance with ACC/AHA and ESC guidelines) in the setting of symptoms or left ventricular systolic dysfunction, or at the time of coronary bypass or another cardiac surgical procedure. Exercise testing is recommended if symptomatic status is uncertain, with consideration for intervention based on exercise-induced symptoms, blood pressure decline, or complex ventricular ectopy. Aortic valve replacement also may be considered in asymptomatic patients thought to be at high risk based on presence of coronary artery disease, heavy valve calcification, very severe AS (mean gradient >60 mm Hg, valve area <0.6 cm2), or elevated BNP.
9. Nonsurgical patient management: Patients who are not referred for surgery should be educated about the nature and significance of new symptoms of dyspnea, angina, heart failure, or syncope; and cautioned to seek medical attention without delay with symptom onset. Regular follow-up should be arranged, including echocardiography/Doppler imaging to assess AS progression. Hypertension should be aggressively controlled, and consideration given (based on conflicting available data) for statin therapy.
10. Special cases: Patients with bicuspid aortic valve have a predisposition for aortic root enlargement independent of AS severity, and should be followed for this. Concomitant aortic root repair is recommended at the time of aortic valve replacement if the aorta measures >4.5 cm in diameter, and concomitant aortic valve replacement is recommended in the setting of at least moderate valve disease at the time of aortic root repair. Patients with low-flow low-gradient AS should be evaluated to differentiate severe from pseudo-severe AS; surgical aortic valve replacement is not contraindicated based solely on the absence of left ventricular contractile reserve.
Perspective: This is a nice review that summarizes existing data guiding the management of asymptomatic patients with severe AS. Recommendations are in keeping with current ACC/AHA and ESC guidelines. With more freedom to ad lib, personal experience suggests the following two points: 1) Probably based on lifestyle adaptation and denial, many patients who are purportedly asymptomatic develop symptoms on objective functional testing, leading to a rationale for broader use of exercise testing in asymptomatic patients who would be suitable candidates for aortic valve replacement; and 2) despite absent proof of efficacy, risk-benefit analysis may favor the use of statins in patients who seek to delay progression of AS (i.e., absent evidence of efficacy is not the same as evidence of absent efficacy; if the risk is small, then why not treat?). David S. Bach, M.D., F.A.C.C.
Here is the abstract
Once there click on the link to the right to get the full article for $15.
Or call your library or local hospital library and if they don't have it ask them to do an "Interlibrary loan" for a copy of the article.
Here's the reference:
Title: Management of Asymptomatic Severe Aortic Stenosis
Topic: Noninvasive Cardiology
Date Posted: 10/31/2008
Author(s): Dal-Bianco JP, Khandheria BK, Mookadam F, Gentile F, Sengupta PP.
Citation: J Am Coll Cardiol 2008;52:1279-1292.
