- ACRONYMS AND DEFINITIONS
- ACCP - American College of Chest Physicians
- AHA - American Heart Association
- AR - Aortic regurgitation
- AS - Aortic stenosis
- AVR - Aortic valve replacement
- BAV - Bicuspid aortic valve
- ECHO - Echocardiography
- EF - Ejection fraction
- HFrEF - Heart failure with reduced ejection fraction
- IVC - Inferior Vena Cava
- LA - Left atrium
- LV - Left ventricle
- MR - Mitral regurgitation
- MS - Mitral stenosis
- NYHA - New York Heart Association heart failure classification
- PMBC - Percutaneous mitral balloon commissurotomy
- PR - Pulmonary regurgitation
- PS - Pulmonary stenosis
- RCT - Randomized controlled trial
- TAVR - Transcatheter aortic valve replacement
- TR - Tricuspid regurgitation
- TS - Tricuspid stenosis
- VHD - Valvular heart disease
- VKA - Vitamin K antagonist (e.g. warfarin)
- STAGES OF VALVULAR HEART DISEASE
- Overview
- Definitions for the stages of valvular heart disease (VHD) used in the AHA guidelines are presented in the table below
AHA stages of valvular heart disease | ||
---|---|---|
Stage | Definition | Description |
A | At risk | Patients with risk factors for development of VHD |
B | Progressive | Patients with progressive VHD (mild to moderate severity and asymptomatic) |
C | Asymptomatic severe |
Asymptomatic patients who have the criteria for severe VHD:
|
D | Symptomatic severe | Patients who have developed symptoms as a result of VHD |
- AORTIC STENOSIS
- Overview
- Anatomy/pathology
- The aortic valve is the valve that controls blood flow from the left ventricle into the aorta. During systole, the left ventricle contracts and blood is forced through the aortic valve into the aorta. The aortic valve then closes to prevent the backflow of blood from the aorta into the left ventricle (see aortic valve illustration).
- As people age, the valve can become calcified and thickened (aortic sclerosis). If aortic sclerosis progresses, it can cause the valve to lose its elasticity, and it becomes less compliant to opening. This leads to aortic stenosis.
- The normal aortic valve has three leaflets, but some people (1 - 2% of population) are born with a bicuspid, or two leaflet valve. Bicuspid valves have a much higher risk of developing aortic stenosis (see bicuspid aortic valves below)
- Prevalence
- Aortic stenosis is the most common valve disease requiring surgery in the U.S. and Europe
- Aortic stenosis occurs in 4 - 5% of people ≥ 65 years old
- Aortic sclerosis is present in 25% of 65 year-olds and 48% of people ≥ 75 years old
- Risk factors
- Advancing age
- Bicuspid aortic valves - found in 1 - 2% of the population, and is present in 50% of valve replacement surgeries
- Aortic sclerosis - 10% of patients with aortic sclerosis will progress to severe aortic stenosis over 5 years
- Rheumatic heart disease
- Unicuspid valve (one leaflet) - rare
- Symptoms and physical findings
- Symptoms: The most common presenting symptoms are exertional dyspnea and fatigue. Syncope or lightheadedness may also occur from elevated LV pressures that stimulate baroreceptors leading to bradycardia and arterial hypotension. As the disease progresses, heart failure and secondary pulmonary hypertension may develop.
- Heart murmur: loud (grade ≥ 3/6), late-peaking systolic murmur that radiates to the carotid arteries [1,2,3,4]
- ECHO measures
- The two most important ECHO parameters in diagnosing aortic stenosis are the aortic valve area (AVA) and measures of aortic valve pressure which include the mean aortic valve pressure gradient (A△P) and the maximum aortic velocity (AVmax)
- Aortic valve area (AVA) - surface area of the aortic valve. As stenosis worsens, the surface area decreases.
- Aortic valve pressure gradient (A△P) - difference in systolic pressure readings between the aorta and the left ventricle. As stenosis worsens, the systolic pressure in the left ventricle rises above the pressure in the aorta because the left ventricle must create more pressure to force blood across the stenosed valve.
- Maximum aortic velocity (AVmax) - maximum velocity of blood flow across the aortic valve. As valve stenosis worsens, velocity of blood flow increases. Also called aortic-jet velocity.
- Patients with left ventricular systolic dysfunction may have lower pressure readings despite significant stenosis due to decreased force and/or decreased stroke volume
STAGES OF AORTIC STENOSIS AND MONITORING RECOMMENDATIONS | ||
---|---|---|
Stage | ECHO findings | Recommended monitoring |
Normal |
|
N/A |
Mild (Stage B) |
|
ECHO every 3 - 5 years |
Moderate (Stage B) |
|
ECHO every 1 - 2 years |
Severe (Stage C1) |
✝ Patients with significant LV dysfunction (e.g. reduced EF, reduced stroke volume) may not meet criteria for A△P or AVmax even though they have severe stenosis |
ECHO every 6 - 12 months |
- Rate of progression
- There is wide patient variability in the rate of AS progression. Once moderate AS is present, the average rate of progression is an increase in velocity of 0.3 m/s per year, an increase in mean pressure gradient of 7 mmHg/year, and a decrease in valve area of 0.1 cm²/year.
- AHA 2020 AS medical treatment recommendations
- There is no medical therapy that has been proven to slow the progression of AS
- In patients at risk of developing AS (Stage A) and in patients with asymptomatic AS (Stages B and C), hypertension should be treated according to standard guidelines, started at a low dose, and gradually titrated upward as needed, with appropriate clinical monitoring
- In all patients with calcific AS, statin therapy is indicated for primary and secondary prevention of atherosclerosis on the basis of standard risk scores
- In patients who have undergone TAVR, renin–angiotensin system blocker therapy (ACE inhibitor or ARB) may be considered to reduce the long-term risk of all-cause mortality
- In patients with calcific AS (Stages B and C), statin therapy is not indicated for prevention of hemodynamic progression of AS. Despite the fact that AS is often marked by progressive tissue calcification similar to atherosclerosis, large randomized controlled trials have not shown statins to be beneficial in slowing disease progression or improving outcomes [1,2,3,17]
- Valve replacement types
- There are two ways to repair an aortic valve - open heart surgery with aortic valve replacement (surgical AVR) or transcatheter aortic valve replacement (TAVR)
- Transcatheter aortic valve replacement (TAVR) is a procedure where a bioprosthetic valve (made from cow or pig) is placed using a catheter that is run up the aorta and across the damaged valve. Once the catheter is in place, the prosthetic valve is expanded and the native valve is crushed against the wall (see TAVR video for a video demonstration of the procedure).
- TAVR has been compared to surgical AVR in a number of studies. See studies below.
- AHA 2020 AS intervention recommendations
- The AHA recommendations for interventional therapy in AS are available at the link below
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- AS intervention timing [section 3.2.3]
- AS choice of intervention [section 3.2.4]
- AHA antithrombotic recommendations after valve replacement
- Studies
- TAVR has been compared to surgical AVR in a number of studies. The studies have enrolled patients based on their risk of death within 30 days after surgery (low, intermediate, high) which has been calculated in trials using The Society of Thoracic Surgeons Risk Calculator. Links to the studies are given below. A study that compared early AVR to a conservative approach in patients with severe asymptomatic AS is also detailed below.
- Low-risk patients (30-day mortality risk after surgery < 4%)
- TAVR vs Aortic Valve Replacement in Low-risk Patients ≥ 70 Years Old, JAMA (2022) [PubMed abstract]
- TAVR with Balloon-expanding Valve vs Aortic Valve Replacement in Low-risk Patients, NEJM (2019) [PubMed abstract]
- TAVR with Self-expanding Valve vs Aortic Valve Replacement in Low-risk Patients, NEJM (2019) [PubMed abstract]
- Intermediate-risk patients (30-day mortality risk after surgery 4% - 8%)
- High-risk patients (30-day mortality risk after surgery ≥ 15%)
- STUDY
- Design: Randomized controlled trial (N=145 | length = 6.2 years) in patients with asymptomatic, severe AS
- Treatment: Early aortic valve replacement vs Conservative approach where surgery was performed if patients became symptomatic, EF became < 50%, or peak aortic jet velocity increased > 0.5 m/s/year
- Primary outcome: Composite of operative mortality or death from cardiovascular causes during the follow-up period (continuing until 4 years after the last patient was enrolled)
- Results:
- Primary outcome: Aortic valve replacement - 1%, Conservative care - 15% (p=0.003)
- In the Conservative Approach group, 74% of patients had aortic valve replacement during follow-up
- Findings: Among asymptomatic patients with very severe aortic stenosis, the incidence of the composite of operative mortality or death from cardiovascular causes during the follow-up period was significantly lower among those who underwent early aortic valve replacement surgery than among those who received conservative care.
- STUDY
- Design: Randomized controlled trial (N=157 | length = 32 months) in patients with asymptomatic severe aortic stenosis
- Treatment: Surgical aortic valve replacement (SAVR) vs Conservative treatment
- Primary outcome: Composite of all-cause mortality or major adverse cardiovascular events comprised of acute myocardial infarction, stroke and unplanned heart failure hospitalization needing intravenous treatment with diuretics or inotropes
- Results:
- Primary outcome: SAVR - 15.2%, Conservative - 34.7% (p=0.02)
- Overall mortality: SAVR - 4%, Conservative - 12.94% (HR 0.56, 95%CI [0.24 - 1.27])
- In the SAVR group, 7% of patients did not have surgery, and in the conservative group, 32% of patients had surgery.
- Findings: In asymptomatic patients with severe AS, early surgery reduced a primary composite of all-cause death, acute myocardial infarction, stroke or unplanned hospitalization for heart failure compared with conservative treatment. This randomized trial provides preliminary support for early SAVR once AS becomes severe, regardless of symptoms.
- AORTIC REGURGITATION (AR)
- Overview
- Anatomy/pathology
- The aortic valve is the valve that controls blood flow from the left ventricle into the aorta. During systole, the left ventricle contracts and blood is forced through the aortic valve into the aorta. The aortic valve then closes to prevent the backflow of blood from the aorta into the left ventricle (see aortic valve illustration).
- In aortic regurgitation, blood flows backwards (regurgitates) across the aortic valve during diastole. The regurgitated blood must then be pumped back out of the LV during the next systole. To compensate for the regurgitated blood, the left ventricle often dilates and hypertrophies in order to increase its stroke volume. This chronic adaptation may prevent AR from becoming symptomatic for many years.
- The most common cause of AR in developed nations is a bicuspid aortic valve (1 - 2% of the population) and valvular sclerosis (degenerative calcific changes). Diseases that are associated with dilation of the aortic root (e.g. aortitis, Marfan's syndrome, Turner syndrome, Ehlers–Danlos disease) may also cause AR because the dilation causes the valve leaflets to lose apposition.
- Prevalence
- The overall prevalence of AR is estimated to be around 5% with moderate-to-severe AR occurring in ∼ 0.5% of affected individuals
- In healthy individuals ≥ 50 years old, trace-to-mild AR has been detected on echocardiography in up to 23% of patients
- The peak incidence of significant AR occurs between 40 - 60 years of age with men affected more than women
- Risk factors
- Bicuspid aortic valves - seen in 1 - 2% of the population, and is one of the most common causes in developed nations
- Aortic sclerosis - common cause in developed nations
- Rheumatic heart disease - more common in developing nations
- Endocarditis
- Aortitis - seen in inflammatory conditions such as ankylosing spondylitis, Takayasu’s arteritis, giant cell arteritis, RA, SLE, and syphilis
- Aortic dissection
- Conditions affecting cartilage integrity - e.g. Marfan's syndrome, Turner syndrome, Ehlers–Danlos disease, osteogenesis imperfecta
- Symptoms and physical findings
- Symptoms: exertional dyspnea. In late stages, angina and overt heart failure may develop. AR may remain asymptomatic for a long time due to compensatory LV enlargement
- Heart murmur: blowing holodiastolic murmur heard loudest at the left sternal border. Murmur is best heard in the sitting, forward-bended position. [1,3,6,14]
- ECHO measures
- Jet width - width of the regurgitant jet of blood just below the aortic valve expressed as a percent of the left ventricular outflow tract (LVOT)
- Vena contracta - narrowest diameter of the jet that occurs at or just downstream from the orifice
- Regurgitant volume (RVol) - volume of blood that regurgitates
- Regurgitant fraction (RF) - estimated fraction of stroke volume that regurgitates
- Effective regurgitant orifice area (EROA) - narrowest area of regurgitant flow
- Left ventricular dilation - can be measured with the left ventricular end-systolic dimension (LVESD). Significant dilation (> 50 mm) indicates more severe disease.
STAGES OF AORTIC REGURGITATION AND MONITORING RECOMMENDATIONS | ||
---|---|---|
Stage | ECHO findings | Recommended monitoring |
Mild (Stage B) |
|
ECHO every 3 - 5 years |
Moderate (Stage B) |
|
ECHO every 1 - 2 years |
Severe (Stage C1) |
|
ECHO every 6 - 12 months Dilating LV: more frequently |
- Rate of progression
- In one study, patients with moderate AR had the following progression rates to severe AR:
- Patients with valve leaflet pathology - 1.4%/year
- Patients with aortic dilation - 3.7%/year
- AHA 2020 AR medical treatment recommendations
- In asymptomatic patients with chronic AR (Stages B and C), treatment of hypertension (systolic blood pressure > 140 mmHg) is recommended
- In patients with severe AR who have symptoms and/or LV systolic dysfunction (Stages C2 and D) but a prohibitive surgical risk, guideline-directed therapy for reduced LV EF with ACE inhibitors, ARBs, and/or sacubitril/valsartan is recommended [17]
- AHA 2020 AR intervention recommendations
- The AHA recommendations for the timing of interventional therapy in AR are available at the link below
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- AR intervention timing [section 4.3.3]
- AHA antithrombotic recommendations after valve replacement
- BICUSPID AORTIC VALVE (BAV)
- The normal aortic valve has three leaflets, but 1 - 2% of the population is born with a bicuspid, or two leaflet valve. Men are affected more than women (3:1), and there appears to be a genetic predisposition; bicuspid valves and/or associated aortopathy are found in 20 - 30% of relatives of affected individuals. Bicuspid valves have a much higher risk of developing aortic stenosis and/or aortic regurgitation. In studies, 12 - 37% of patients with a bicuspid aortic valve will go on to develop moderate or greater AS and 13 - 30% will develop AR. Aortopathy that includes dilation of the aortic sinuses, the ascending aorta, and/or the aortic arch is seen in 20 - 40% of affected individuals.
- Patients with a bicuspid aortic valve should be followed with periodic ECHOs. The frequency depends upon the severity of any aortopathy that may be present. First-degree relatives of patients with bicuspid valves may benefit from screening. [3,4,17]
- The AHA published recommendations for monitoring and treating bicuspid aortic valves in 2020. A link to those recommendations is provided below.
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- BAV initial diagnosis [section 5.1.1.1]
- BAV routine follow-up [section 5.1.1.2]
- BAV replacement of the aorta [section 5.1.2.1]
- BAV repair or replacement of the aortic valve [section 5.1.2.2]
- MITRAL STENOSIS (MS)
- Overview
- Anatomy/pathology
- The mitral valve is the valve between the left atrium and the left ventricle. During diastole, the valve opens to allow blood to flow from the left atrium into the left ventricle. The valve then closes during systole to prevent blood from regurgitating back into the left atrium. The mitral valve has two leaflets (see mitral valve illustration).
- Mitral valve stenosis occurs when the valve becomes damaged and fails to open properly. The most common cause of mitral valve stenosis is rheumatic heart disease, a sequelae of rheumatic fever. Rheumatic heart disease is thought to occur because of antibodies that cross-react with streptococcal proteins and heart tissue. The cross-reactive antibodies stimulate an inflammatory reaction that causes the valve leaflets to fuse, thicken, and fibrose. Patients who have had rheumatic fever should receive prophylactic antibiotics to prevent a recurrent episode (see rheumatic fever prevention). Mitral valve stenosis may also occur because of valvular degenerative calcification which starts with calcification of the mitral annulus.
- Mitral valve stenosis greatly increases the risk of developing atrial fibrillation because left atrial dilation and hypertrophy often occur
- Incidence
- The incidence of mitral stenosis has decreased greatly in developed nations due to the treatment of streptococcal infections
- In developed nations, the incidence of rheumatic heart disease is about 0.2 - 0.3 cases/1000 persons. In developing nations, the incidence of rheumatic heart disease is around 5.5 - 5.7/1000 persons
- In developed nations, mitral stenosis is now primarily encountered in elderly patients with degenerative calcific disease
- Risk factors
- Rheumatic heart disease - most common cause worldwide
- Advanced age - degenerative calcific disease
- Marfan's syndrome
- Chronic kidney disease
- Autoimmune disease (e.g. RA, SLE) - rare
- Congenital metabolic disorders (e.g. Fabry disease)
- Carcinoid tumors
- Symptoms and physical findings
- Symptoms: exertional dyspnea; exercise intolerance; atrial fibrillation; pulmonary edema; in severe cases, right heart failure
- Heart murmur: low-pitched rumbling diastolic murmur (typically holodiastolic, decrescendo with a presystolic accentuation in sinus rhythm) [1,2,3,4]
- ECHO measures
- Mitral valve area (MVA) - surface area of the mitral valve. As stenosis worsens, the surface area decreases.
- Diastolic half-time - amount of time it takes the transmitral pressure gradient to go from maximal pressure (early diastole) to half maximal pressure. This value is used in calculating the mitral valve area.
STAGES OF MITRAL STENOSIS AND MONITORING RECOMMENDATIONS | ||
---|---|---|
Stage | ECHO findings | Recommended monitoring |
Normal |
|
N/A |
Mild to moderate (Stage B) |
|
ECHO every 3 - 5 years |
Severe (Stage C1) |
|
MVA: 1.0 - 1.5 cm² ECHO every 1 - 2 years MVA: < 1.0 cm² ECHO yearly |
- Rate of progression
- There is wide patient variability in the rate of MS progression. In general, stenosis progresses at a rate of 0.1 - 0.3 cm²/year.
- AHA 2020 MS medical treatment recommendations
- Anticoagulation with VKA (INR 2 - 3) is recommended in patients with rheumatic MS and any of the following:
- Atrial fibrillation
- Prior embolic event
- Left atrial thrombus
- In patients with rheumatic MS and atrial fibrillation with a rapid ventricular response, heart rate control can be beneficial
- In patients with rheumatic MS in normal sinus rhythm with symptomatic resting or exertional sinus tachycardia, heart rate control can be beneficial to manage symptoms [17]
- Valve replacement/repair types
- MS can be treated with valve replacement or a procedure called percutaneous mitral balloon commissurotomy (PMBC)
- During PMBC, a catheter with a deflated balloon is advanced across the mitral valve. The balloon is then inflated and the fused leaflets are split. PMBC has a very high success rate and is the preferred treatment in most cases. [1,3]
- AHA 2020 MS intervention recommendations
- The AHA recommendations for interventional therapy in MS are available at the link below
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- MS intervention recommendations [sections 6.2.3 and 6.3]
- AHA antithrombotic recommendations after valve replacement
- MITRAL REGURGITATION (MR)
- Overview
- Anatomy/pathology
- The mitral valve is the valve between the left atrium and the left ventricle. During diastole, the valve opens to allow blood to flow from the left atrium into the left ventricle. The valve then closes during systole to prevent blood from regurgitating back into the left atrium. The mitral valve has two leaflets which are supported by ligaments in the left ventricle called the chordae tendineae. The chordae tendineae are attached to papillary muscles which contract during systole to help support the mitral valve against the forces of left ventricular contraction (see mitral valve illustration).
- In mitral regurgitation, blood flows backwards (regurgitates) across the mitral valve during systole. MR is caused by two different mechanisms which have different sequelae and treatments.
- Primary MR
- In primary MR, the mitral valve and/or its supporting structures are diseased or defective
- Causes of primary MR include the following:
- Degenerative changes with aging that lead to annular calcification, loss of valve elasticity, and prolapse
- Mitral valve prolapse syndrome - syndrome marked by myxomatous degeneration of the mitral valve that leads to valve thickening and prolapse. The syndrome may be inherited genetically in an autosomal dominant pattern, but most affected patients have no family history.
- Connective tissue disorders (e.g. Marfan's syndrome, Ehlers–Danlos syndromes) that lead to a floppy valve
- Rupture of the chordae tendineae or papillary muscles - may occur from endocarditis, ischemic heart disease, or degenerative disease
- Rheumatic heart disease - autoimmune syndrome that directly damages the valve
- Secondary MR
- In secondary MR, the mitral valve and its supporting structures are normal and MR develops secondary to changes in the left ventricle (e.g. hypertrophy, dilation) which result in distortion of the mitral leaflets and/or their supporting structures
- Causes of secondary MR include the following:
- Cardiomyopathy
- Ischemic heart disease
- LV hypertrophy and dilation from any cause
- Myocarditis
- Prevalence
- MR is the most common valvular heart disease in the U.S., and it is the second most common reason for heart valve surgery behind aortic stenosis
- Trace-to-mild MR has been detected on echocardiography in up to 39% of healthy individuals < 50 years old, and up to 58% of healthy individuals ≥ 50 years old
- The mitral valve prolapse syndrome is present in about 2.5% of the general population
- Symptoms and physical findings
- Symptoms: exertional dyspnea; decreased exercise capacity; atrial fibrillation
- Heart murmur: systolic high-pitched murmur, loudest at the apex with mid- or late systolic click, generated by the tensing of the chordae and billowing of the mitral leaflets [1,3,11,12,14]
- ECHO measures
- Central jet - width of the regurgitant jet of blood just below the mitral valve expressed as a percent of the left atrium
- Vena contracta - narrowest diameter of the jet that occurs at or just downstream from the orifice
- Regurgitant volume (RVol) - volume of blood that regurgitates
- Regurgitant fraction (RF) - estimated fraction of stroke volume that regurgitates
- Effective regurgitant orifice (ERO) - narrowest area of regurgitant flow
STAGES OF PRIMARY MITRAL REGURGITATION AND MONITORING RECOMMENDATIONS | ||
---|---|---|
Stage | ECHO findings | Recommended monitoring |
Mild to moderate (Stage B) |
|
Mild: ECHO every 3 - 5 years
Moderate: ECHO every 1 - 2 years |
Severe (Stage C1) |
|
ECHO every 6 - 12 months Dilating LV: more frequently |
STAGES OF SECONDARY MITRAL REGURGITATION AND MONITORING RECOMMENDATIONS | ||
---|---|---|
Stage | ECHO findings | Recommended monitoring |
Mild to moderate (Stage B) |
|
Mild: ECHO every 3 - 5 years
Moderate: ECHO every 1 - 2 years |
Severe (Stage C1) |
|
ECHO every 6 - 12 months Dilating LV: more frequently |
- Rate of progression
- Primary MR
- In one study, the rate of progression of primary MR was as follows:
- RVol - 7.4 ml/year
- RF - 2.9%/year
- ERO - 0.059 cm²/year
- Secondary MR
- The rate of progression of secondary MR is highly variable and dependent on the severity of the underlying condition
- AHA 2020 MR medical treatment recommendations
- Primary MR
- In symptomatic or asymptomatic patients with severe primary MR and LV systolic dysfunction (Stages C2 and D) in whom surgery is not possible or must be delayed, guideline-directed treatment for systolic dysfunction is reasonable
- In asymptomatic patients with primary MR and normal LV systolic function (Stages B and C1), vasodilator therapy is not indicated if the patient is normotensive [17]
- Secondary MR
- Patients with chronic severe secondary MR (Stages C and D) and HFrEF should receive standard guideline-directed treatment for heart failure, including ACE inhibitors, ARBs, beta blockers, aldosterone antagonists, and/or sacubitril/valsartan, and biventricular pacing as indicated
- In patients with chronic severe secondary MR and HFrEF, a cardiologist expert in the management of patients with heart failure and LV systolic dysfunction should be the primary provider responsible for implementing and monitoring optimal therapy [17]
- Valve replacement/repair
- In primary MR, valve repair techniques, including removing the flail part of the valve and repairing ruptured chordae tendineae, are preferred over valve replacement surgery
- In secondary MR, valve surgery has a limited role, and its benefits are mostly unproven
- A device called the MitraClip is FDA-approved for primary and secondary MR. A video of how the device works can be viewed here - MitraClip video. Two studies that compared the device to medical therapy in secondary MR are detailed below (see studies).
- AHA 2020 MR intervention recommendations
- The AHA recommendations for interventional therapy in MR are available at the link below
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- Primary MR intervention recommendations [sections 7.2.4]
- Secondary MR intervention recommendations [sections 7.3.4]
- AHA antithrombotic recommendations after valve replacement
- STUDY
- Design: Randomized, controlled trial (N=304, length = 12 months) in patients with severe secondary MR
- Treatment: Transcatheter mitral-valve repair with MitraClip + medical therapy vs Medical therapy alone
- Primary outcome: Composite of death from any cause or unplanned hospitalization for heart failure at 12 months
- Results:
- Primary outcome: Repair + medical therapy - 54.6%, Medical therapy - 51.3% (p=0.53)
- Findings: Among patients with severe secondary mitral regurgitation, the rate of death or unplanned hospitalization for heart failure at 1 year did not differ significantly between patients who underwent percutaneous mitral-valve repair in addition to receiving medical therapy and those who received medical therapy alone
- STUDY
- Design: Randomized, controlled trial (N=614, length = 24 months) in patients with moderate-to-severe secondary MR
- Treatment: Transcatheter mitral-valve repair with MitraClip + medical therapy vs Medical therapy alone
- Primary outcome: All hospitalizations for heart failure within 24 months of follow-up
- Results:
- Primary outcome: Repair + medical therapy - 35.8%, Medical therapy - 67.9% (p<0.001)
- Findings: Among patients with heart failure and moderate-to-severe or severe secondary mitral regurgitation who remained symptomatic despite the use of maximal doses of guideline-directed medical therapy, transcatheter mitral-valve repair resulted in a lower rate of hospitalization for heart failure and lower all-cause mortality within 24 months of follow-up than medical therapy alone. The rate of freedom from device-related complications exceeded a prespecified safety threshold.
- Follow-up results: results from 5 years of follow-up - PMID 36876756
- TRICUSPID VALVE DISEASE
- Overview
- Anatomy
- The tricuspid valve is the valve between the right atrium and the right ventricle. During diastole, the valve opens to allow blood to flow from the right atrium into the right ventricle. The valve then closes during systole to prevent blood from regurgitating back into the right atrium. As the name implies, the tricuspid valve has three leaflets which are supported by ligaments in the left ventricle called the chordae tendineae. The chordae tendineae are attached to papillary muscles which contract during systole to help support the tricuspid valve against the forces of right ventricular contraction (see tricuspid valve illustration).
- Tricuspid regurgitation (TR)
- In tricuspid regurgitation, blood flows backwards (regurgitates) across the tricuspid valve during systole
- Trace-to-mild TR is often seen on echocardiography, and it has no significant physiologic consequence
- Moderate-to-severe TR is most often secondary to right ventricular pathology and is rarely the result of primary valve disease
- Causes of primary TR include endocarditis, rheumatic heart disease, carcinoid syndrome, myxomatous disease, endomyocardial fibrosis, Ebstein’s anomaly (see Ebstein's anomaly illustration), and trauma.
- Tricuspid stenosis (TS)
- In TS, the tricuspid valve is diseased and fails to open properly
- TS is a rare condition that is almost always secondary to rheumatic heart disease. TS frequently occurs with TR and mitral valve disease.
- Prevalence
- In one population study, the prevalence of TR was as follows
- Trace TR - up to 73% of adults < 60 years old
- Mild TR - 18% of adults
- Moderate-to-severe TR - 1.5% of adults [13]
- Symptoms and physical findings
- Symptoms: exertional dyspnea; fatigue; in severe disease, right-sided heart failure may develop
- Heart murmur: TR - soft holosystolic murmur best heard along the left sternal border; TS - diastolic murmur of low intensity that increases with inspiration, preceded by a subtle opening snap [1,3,13]
- ECHO measures
- Central jet - area of the regurgitant jet of blood
- Vena contracta - narrowest diameter of the jet that occurs at or just downstream from the orifice
- Pressure half-time - amount of time it takes the transtricuspid pressure gradient to go from maximal pressure (early diastole) to half maximal pressure.
STAGES OF TR AND TS AND MONITORING RECOMMENDATIONS | ||
---|---|---|
Stage | ECHO findings | Recommended monitoring |
Mild TR (Stage B) |
|
N/A |
Moderate TR (Stage B) |
|
N/A |
Severe TR (Stage C) |
|
N/A |
Severe TS (Stage C) |
|
N/A |
- Rate of progression
- There is limited data on the rate of progression of TR and TS. Severe, primary TR is has a poor prognosis. The course of secondary TR is highly dependent on the underlying condition. In cases where right ventricular dysfunction is successfully treated, secondary TR may improve or resolve.
- AHA 2020 TR medical treatment recommendations
- In patients with signs and symptoms of right-sided heart failure attributable to severe TR (Stages C and D), diuretics can be useful
- In patients with signs and symptoms of right-sided heart failure attributable to severe secondary TR (Stages C and D), therapies to treat the primary cause of heart failure (eg, pulmonary vasodilators to reduce elevated pulmonary artery pressures, guideline-directed therapy for heart failure with reduced LVEF, or rhythm control of AF) can be useful. [17]
- AHA 2020 TR intervention recommendations
- The AHA recommendations for interventional therapy in TR are available at the link below
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- TR timing of intervention recommendations [sections 8.2.3]
- AHA 2014 TS intervention recommendations
- Tricuspid valve surgery is recommended for patients with severe TS at the time of operation for left-sided valve disease
- Tricuspid valve surgery is recommended for patients with isolated, symptomatic severe TS
- Percutaneous balloon tricuspid commissurotomy might be considered in patients with isolated, symptomatic severe TS without accompanying TR [1]
- PULMONARY VALVE DISEASE
- Anatomy
- The pulmonary valve is the valve that controls blood flow from the right ventricle into the pulmonary artery. During systole, the right ventricle contracts and blood is forced through the pulmonary valve into the pulmonary artery. The pulmonary valve then closes to prevent the backflow of blood from the pulmonary artery into the right ventricle. (see pulmonary valve illustration).
- Pulmonary stenosis (PS)
- In PS, the pulmonary valve is defective and it does not open properly during systole
- Pulmonary stenosis is primarily a congenital disease and is not covered here [1]
- Pulmonary regurgitation (PR)
- In PR, blood flows backwards (regurgitates) across the pulmonary valve during diastole. The regurgitated blood must then be pumped back out of the right ventricle during the next systole.
- Mild-to-moderate pulmonary PR is a common finding on echocardiography. In the setting of normal right ventricular size and function, it has no clinical consequence and does not require follow-up.
- Primary, severe PR is rare and typically only encountered in patients who have undergone surgery for congenital heart disease (e.g. tetralogy of Fallot)
- Secondary, severe PR from chronic pulmonary hypertension is rare today. The underlying cause of pulmonary hypertension should be the focus of treatment.
- PROSTHETIC HEART VALVES
- Valve types
- Prosthetic heart valve - general term for a device that it used to replace the native heart valve. Prosthetic heart valves include both mechanical heart valves and bioprosthetic heart valves.
- Mechanical heart valve - mechanical heart valves are valves that are manufactured and include metal parts. The main advantage of mechanical heart valves is that they are more durable than bioprosthetic valves. The main disadvantage is that they require lifelong anticoagulation with a VKA. The most common type of valve used today is the bileaflet valve (bileaflet illustration). Other valve types include tilting-disk valves (tilting-disc illustration) and caged-ball valves (caged-ball illustration).
- Bioprosthetic heart valve
- Bioprosthetic heart valves are valves that are made from pig (porcine) or cow (bovine) heart tissue. Porcine valves are similar to human valves, and the intact valve is removed from the pig. Bovine valves are made from the pericardium of the cow heart. Valve tissue is treated to reduce its immunogenicity, and it is then sewn into plastic or metal frames/stents that are covered with fabric. Stentless valves that are housed within the native aorta do exist, but are much less common.
- The main advantage of bioprosthetic valves is that they do not require lifelong anticoagulation. The main disadvantage is that they are not as durable due to their immunogenicity which leads to calcification and deterioration.
- Valve deterioration occurs more rapidly in younger patients, possibly because they have more robust immune systems (see valve type recs below). In patients who receive aortic valves at age > 65 years, valve failure rates are < 10% at 10 years compared to 20% in patients who receive their valves before age 40. Valve position also plays a role in deterioration with mitral valves having higher failure rates in all age groups when compared to atrial valves.
- Valves used in transcatheter aortic valve replacement (TAVR) are constructed from bovine or porcine pericardium
- Homografts and autografts - homograft valves are valves that are obtained from human cadavers. Autografts are valves that come from the individual who is being treated. In the Ross procedure, a diseased aortic valve is replaced with the patient's own pulmonary valve (autograft). A pulmonary valve from a cadaver (homograft) is then used to replace the pulmonary valve. The Ross procedure is primarily performed in children. [1,3,15,16]
Factors to consider when choosing a valve type | |
---|---|
Favors Mechanical Valve | Favors Bioprosthetic Valve |
Age < 50 years
|
Age > 65 years
|
Patient preference (avoid risk of reintervention) | Patient preference (avoid risk and inconvenience of anticoagulation) |
Low risk of complications with long-term anticoagulation | High risk of complications with long-term anticoagulation |
Compliant patient with access to INR monitoring | Limited access to medical care or inability to regulate VKA |
Other indications for anticoagulation (e.g. atrial fib) | Access to surgical centers with low reoperation mortality rate |
High-risk reintervention (e.g. porcelain aorta, prior radiation therapy) | Access to transcatheter valve-in-valve replacement |
Small aortic root size for AVR (may preclude valve-in-valve procedure in future) | TAVR valves have larger effective orifice areas for smaller valve sizes (avoid patient–prosthesis mismatch) |
- AHA 2020 recommendations for choosing a valve type
- The AHA recommendations for choosing a valve type are available at the link below
- 2020 AHA Guideline for the Management of Patients With Valvular Heart Disease (pdf)
- Selection of valve type [sections 11.1.2]
- ANTITHROMBOTIC RECOMMENDATIONS
- Mechanical heart valves
- Warfarin is the anticoagulant of choice for people with mechanical heart valves. Dabigatran, a direct thrombin inhibitor, was compared to warfarin in patients with bileaflet mechanical valves, and the trial was stopped early because dabigatran was clearly inferior. [PMID 23991661] After this study, the manufacturers of dabigatran and Factor Xa inhibitors (e.g. Xarelto, Eliquis) recommended their products not be used in patients with prosthetic heart valves.
- The table below gives the recommended INR for different mechanical valve types.
AHA recommendations for antithrombotic therapy in patients with mechanical heart valves | |
---|---|
Valve type / Patient factors | Target INR (range) |
|
2.5 (2 - 3) |
|
3 (2.5 - 3.5) |
|
3 (2.5 - 3.5) |
|
3 (2.5 - 3.5) |
|
Target of 1.5 - 2.0 may be reasonable✝ |
Antiplatelet therapy | |
|
- Bioprosthetic heart valves (AHA 2020 recommendations)
- All patients
- For all patients with a bioprosthetic surgical AVR or mitral valve replacement, aspirin 75 to 100 mg daily is reasonable in the absence of other indications for oral anticoagulants
- For patients with a bioprosthetic surgical AVR or mitral valve replacement who are at low risk of bleeding, anticoagulation with a VKA to achieve an INR of 2.5 is reasonable for at least 3 months and for as long as 6 months after surgical replacement [17]
- Patients with atrial fibrillation
- For patients with atrial fibrillation and native valve heart disease (except rheumatic mitral stenosis) or who received a bioprosthetic valve > 3 months ago, a non–vitamin K oral anticoagulant is an effective alternative to VKA anticoagulation and should be administered on the basis of the patient’s CHA2DS2-VASc score.
- For patients with new-onset atrial fibrillation ≤ 3 months after surgical or transcatheter bioprosthetic valve replacement, anticoagulation with a VKA is reasonable [17]
- Studies
- Transcatheter aortic valve replacement (AHA 2020 recommendations)
- All patients
- For patients with a bioprosthetic TAVR, aspirin 75 to 100 mg daily is reasonable in the absence of other indications for oral anticoagulants
- For patients with a bioprosthetic TAVR who are at low risk of bleeding, anticoagulation with a VKA to achieve an INR of 2.5 may be reasonable for at least 3 months after valve implantation
- For patients with a bioprosthetic TAVR who are at low risk of bleeding, dual antiplatelet therapy with aspirin 75 to 100 mg and clopidogrel 75 mg may be reasonable for 3 to 6 months after valve implantation
- For patients with a bioprosthetic TAVR who are at low risk of bleeding, anticoagulation with a VKA to achieve an INR of 2.5 may be reasonable for at least 3 months after valve implantation
- For patients with bioprosthetic TAVR, treatment with low-dose rivaroxaban (10 mg daily) plus aspirin (75 – 100 mg) is contraindicated in the absence of other indications for oral anticoagulants [17]
- Patients with atrial fibrillation
- For patients with atrial fibrillation and native valve heart disease (except rheumatic mitral stenosis) or who received a bioprosthetic valve > 3 months ago, a non–vitamin K oral anticoagulant is an effective alternative to VKA anticoagulation and should be administered on the basis of the patient’s CHA2DS2-VASc score.
- For patients with new-onset atrial fibrillation ≤ 3 months after surgical or transcatheter bioprosthetic valve replacement, anticoagulation with a VKA is reasonable [17]
- Studies
- Patients with an indication for chronic anticoagulation
- Edoxaban vs Vitamin K Antagonist after TAVR in Patients with A fib, NEJM (2021) [PubMed abstract]
- Anticoagulation Alone vs Anticoagulation + 3 Months of Clopidogrel after TAVR, NEJM (2020) [PubMed abstract]
- Patients without an indication for chronic anticoagulation
- Periprocedural management
- Recommendations for the periprocedural management of antithrombotics are available at the links below
- BIBLIOGRAPHY
- 1 - PMID 24589853 - 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Circulation (2014)
- 2 - PMID 28886619 - 2017 ESC/EACTS Guidelines for the management of valvular heart disease, European Heart Journal (2017)
- 3 - ESC CardioMed 3rd ed.
- 4 - PMID 15723989 - The bicuspid aortic valve: adverse outcomes from infancy to old age, Circulation (2005)
- 5 - PMID 28298458 - 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, Circulation (2017)
- 6 - PMID 16775114 - Aortic regurgitation, Heart (2006)
- 7 - PMID 23798207 - Mid-term echocardiographic progression of patients with moderate aortic regurgitation: implications for aortic valve surgery, J Heart Valve Dis (2013)
- 8 - Aetiology and epidemiology of mitral stenosis, European Society of Cardiology E-Journal, Vol 16 N 14, Jun 13, 2018
- 9 - PMID 22315272 - Antithrombotic and Thrombolytic Therapy for Valvular Disease, Chest (2012)
- 10 - PMID 10520803 - Progression of mitral regurgitation: a prospective Doppler echocardiographic study, JACC (1999)
- 11 - PMID 19356795 - Mitral regurgitation, Lancet (2009)
- 12 - PMID 19955526 - Mitral-Valve Repair for Mitral-Valve Prolapse, NEJM (2009)
- 13 - PMID 10190406 - Prevalence and clinical determinants of mitral, tricuspid, and aortic regurgitation (the Framingham Heart Study), Am J Cardiol (1999)
- 14 - PMID 2310593 - Age-related prevalence of valvular regurgitation in normal subjects: a comprehensive color flow examination of 118 volunteers, J Am Soc Echocardiogr (1990)
- 15 - PMID 19683642 - Antithrombotic management of patients with prosthetic heart valves: current evidence and future trends, Lancet (2009)
- 16 - PMID 26190838 - Xenograft bioprosthetic heart valves: Past, present and future, Int J Surg (2015)
- 17 - PMID 33332150 - 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines, Circulation (2020)