Infectious Endocarditis - TotalCardiology · Click to edit Master title style What are the commonest clinically significant valvular abnormalities? •1. Aortic stenosis and mitral

Click to edit Master title style

Infectious Endocarditis


Relationships with Financial Sponsors:

- Grants or Research Support: None

- Speakers Honoraria: None

- Consulting Fees: Circle CVI Circle International

- Patents: None

- Other: None

Faculty Presenter Disclosure

Cardiology for the Non-Cardiologist

Faculty: Neil Filipchuk


Potential for conflicts of interest: None

Disclosure of Financial Support

Cardiology for the Non-Cardiologist has received financial support from Pharmaceutical companies Bayer, Bristol-Meyers Squibb/Pfizer, Servier, Novartis, Amgen, AstraZeneca and Merck in the form of unrestricted educational grants.


• While we have received unrestricted educational grants from several pharmaceutical companies, most presentations have no mention of specific products and are unrelated to the supporting companies or their products. No specific presentations will be supported or sponsored by a specific company.

• Information on specific products will be presented in the context of an unbiased overview of all products related to treating patients.

• All scientific research related to, reported or used in this CME activity in support or justification of patient care recommendations conforms to the generally accepted standards.

• Clinical medicine is based in evidence that is accepted within the profession.

Mitigating Potential Bias

Click to edit Master title stylePre-Test:Which is False?

1) Infectious endocarditis is an uncommon disease

2) Infectious endocarditis is a serious disease with a high morbidity and mortality

3) Antibiotic prophylaxis at the time of dental procedures prevents most cases of endocarditis

4) We have a pretty good idea of what structural cardiac abnormalities predispose a patient to endocarditis

5) We have a pretty good idea of what organisms cause endocarditis

Click to edit Master title stylePreamble: Infectious Endocarditis

• It’s an uncommon but serious disease. From an English study:

• Incidence is 36 / million persons / year

• Mortality is 6 / million persons / year (17%)

• Its incidence is increasing.

• Who gets endocarditis?

• How does a patient get endocarditis?

• Can endocarditis be prevented?

• Does antibiotic prophylaxis work?

• Can we trust the guidelines?

• What might we do better?

Click to edit Master title styleWho gets endocarditis?

• The risk depends on the presence or absence of an underlying structural cardiac abnormality

• International guidelines group individuals into risk categories

• ESC uses high, moderate and unknown risk

• New observational evidence has become available since publication of the major guidelines that has more than 1 possible interpretation:

• We missed or misclassified some predisposing conditions

• The epidemiology of this disease may be changing


Click to edit Master title styleHow Does A Patient Get Endocarditis?

• It’s associated with dental work or invasive procedures in a minority of cases

• That limits the opportunity for effective antibiotic prophylaxis



Click to edit Master title styleCan We Prevent Infectious Endocarditis? Antibiotic Prophylaxis

• History of the Guidelines

• There are no randomized controlled trials to inform our practice

• Guidelines are primarily based on observational studies and expert opinion

• The quality of evidence is weak

• The evidence is subject to interpretation

• Rationale

• Give antibiotic prophylaxis to patients who:

• Have structural heart disease that predisposes them to endocarditis

• Are having a procedure (e.g. dental surgery) that is known to cause endocarditis

• Are at an increased risk of a poor outcome if they develop endocarditis.

• International guidelines changed in 2007 to decrease the amount of prophylactic antibiotic use.

• AHA, ESC and NICE guidelines differ substantially even though they are all based on the same evidence.

Click to edit Master title styleThe Guidelines

• AHA• Prior endocarditis

• Prosthetic valves

• Valvulopathy associated with heart transplantation

• Cyanotic congenital heart disease

• NICE• Not recommended routinely

• Involve patient in decision after informing them of risks and potential benefits

• ESC• Prior endocarditis

• Prosthetic valves

• Valves repaired with prosthetic materials

• Unrepaired cyanotic congenital heart disease

• Congenital heart disease repaired with prosthetic material

• Congenital heart condition with palliative shunt or conduit


Has the incidence of endocarditis increased now that we are prophylaxing fewer patients?

• Yes BUT

• Oral organisms are only causal in about 15% of cases

• Most patients are not being infected as a result of dental work

• The drugs we traditionally use for prophylaxis will not prevent infection with most of the 85% of causal organisms.

• There is no clear cut-off in risk between high and low-moderate risk groups.

• Endocarditis in patients with bicuspid aortic valve and mitral valve prolapse

• Comprises about 5% of all cases of endocarditis

• Considering the high prevalence of BAV and MVP, the per case risk is small

• 45% are infected with oral organisms

• Have a poor outcome

Click to edit Master title styleWhat might we do better based on new evidence?

• Consider antibiotic prophylaxis of patients with bicuspid aortic valve and mitral valve prolapse prior to dental procedures

• Take into consideration the expanded list of procedures known to cause endocarditis, like bronchoscopy


What is your strategy for advising your next patient with a heart murmur who needs a tooth filled

1) I know what to do

2) I am going to follow international guidelines realizing they are flawed

3) I am going to explain the risks and benefits of antibiotic prophylaxis and decide together with my patient what to do

4) I am not going to recommend antibiotic prophylaxis because it doesn’t work

Click to edit Master title styleWhat are the commonest clinically significant valvular abnormalities?

• 1. Aortic stenosis and mitral regurgitation

• 2. Mitral and tricuspid regurgitation

• 3. Bicuspid aortic valve and mitral valve prolapse

• 4. Pulmonary stenosis and aortic regurgitation

• 5. Flail mitral leaflet and aortic stenosis

Click to edit Master title styleAortic stenosis

• What % of patients over 75 have moderate or severe aortic stenosis?

• 1. 1%

• 2. 3%

• 3. 7%

• 4. 12%

• 5. 21%

Click to edit Master title styleAortic stenosis – General concepts

• Definitions:• Aortic stenosis is obstruction to blood flow through the aortic valve

• Aortic sclerosis is an aortic valve murmur without obstruction to blood flow

• Although it’s a disease associated with aging, its incidence is increasing faster than the population is aging

• The number of valve replacements has increased 26% in the last 18 years

• In one referral center its cause was:• Degenerative in 50%

• Congenital bicuspid aortic valve 35%

• Rheumatic in 9%

Click to edit Master title styleClinical presentation

• Symptoms

• Heart failure (50% mortality in 2 years without valve replacement)

• Syncope (50% mortality in 3 years without valve replacement)

• Angina (50% die in 5 years without valve replacement)

• Physical findings

• Pulsus parvus et tardus

• Absence of aortic second sound

• Ejection systolic murmur that takes more than 220 milliseconds to peak

• ECG

• LVH in 80% of cases

Click to edit Master title styleDiagnostic tests

• Echocardiogram is the mainstay of testing

• To confirm the diagnosis

• To assess the severity of stenosis

• To look for left ventricular dysfunction

• Is quite accurate when the reader is proficient

• Invasive heart catheterization and coronary angiography

• Prior to aortic valve replacement

• To confirm the severity of stenosis

• To look for co-morbid coronary artery disease

• The severity of aortic stenosis is assessed according to aortic valve area

• Mild: valve area is 1.5 – 3 cm2

• Moderate: valve area is 1-1.5 cm2

• Severe: valve area is < 1 cm2

Click to edit Master title styleManagement strategy

• There is no safe or effective medical therapy to treat aortic stenosis

• Diuretics and beta blockers can be used to treat hypertension

• Vasodilators and digoxin are contraindicated in severe aortic stenosis

• Ca++ antagonists (amlodipine, diltiazem, verapamil)

• All ACEI, ARB, aliskiren

• Nitroglycerine

• Hydralazine

• The patient is considered for surgery or TAVR when symptoms develop

• The risk of dyeing from the disease is less than the risk of dyeing from surgery until symptoms develop.

• Risk increases quickly when symptoms are present

• The stenosis must be severe before valve replacement is considered

Click to edit Master title style2 ways to replace the aortic valve

• TAVR

• Transcatheter aortic valve replacement

• The artificial valve is “folded” onto the end of a catheter so its small enough to be introduced via the femoral artery or directly across the left ventricular apex via a mini thorascotomy

• Its use is approved for patients at an intermediate or high risk of death or complications from surgical valve replacement

• Its not used in patients who have a low surgical risk because there are still questions about the durability of these valves but thus far they have exceeded expectations.

• SAVR

• Surgical aortic replacement

• Outcomes have been compared in moderate to high risk patients

• No difference in death or stroke at 1 year


Click to edit Master title styleWhich is True Re: Mitral Regurgitation?

• Mitral regurgitation is an uncommon problem

• Mitral regurgitation is usually a serious problem requiring treatment

• Mitral regurgitation may be a complication of a heart attack

• Most people with mitral regurgitation acquire it as they grow older and are not born with it

• Most patients with severe mitral regurgitation will benefit from surgery

Click to edit Master title styleChronic mitral regurgitation

• Definition and cause:

• Primary mitral regurgitation – something is wrong with the valve

• Secondary mitral regurgitation – something is wrong with the left ventricle – the valve is stretched so the leaflets don’t touch, to allow the valve to close

• These are 2 different diseases

• Fixing or replacing the valve surgically is an option in primary regurgitation

• There is no consensus about the benefit of valve surgery in secondary regurgitation

• Efforts should be focused on decreasing left ventricular size

Click to edit Master title styleCauses of mitral regurgitation

• Primary mitral regurgitation

• Myxomatous disease of the mitral valve leaflets and/or chordae tendinae

• Rheumatic mitral valve disease

• Endocarditis

• Papillary muscle dysfunction or rupture

• Secondary mitral regurgitation

• Coronary artery disease

• Dilated non-ischemic cardiomyopathy

Click to edit Master title styleClinical presentation

• Symptoms

• Patients may be asymptomatic, even when regurgitation is severe and the left ventricle is irreversibly damaged

• Heart failure symptoms may be present

• Physical findings

• Holosystolic murmur

• Signs of heart failure

• Increased JVP

• 3rd heart sound

• ECG

• Is often normal

Click to edit Master title styleDiagnostic tests

• Echocardiography is again the mainstay of testing

• To confirm the diagnosis

• To evaluate left ventricular size and function

• To identify patients who need surgery

• Assessing the severity of mitral regurgitation and indications for surgery by echocardiography challenges even the best echo doctors

• The need for surgery is informed by the volume of blood regurgitating through the valve, left ventricular volume and left ventricular function

• Echocardiography:

• Cannot accurately measure heart volume, is fair at measuring change in volume over time

• Can get in the ballpark measuring LVEF if the reader is proficient

• Cannot accurately measure the volume of regurgitation

• Multiple criteria are applied in each case to provide clinical guidance

Click to edit Master title styleMore diagnostic tests

• Uncertainty and conflicting clinical or imaging findings may persist despite careful echocardiographic assessment.

• CMR can accurately assess a patient who is in sinus rhythm

• Very accurate assessment of:

• Left ventricular volume

• Left ventricular ejection fraction

• Volume of regurgitation. Regurgitant fraction of > 50% is considered severe

• It’s less accurate, even potentially unreliable in atrial fibrillation.

Click to edit Master title styleManagement strategy

• Medical intervention (e.g. afterload reduction) is of uncertain value

• Complex algorithm but, to summarize:

• To treat symptoms:

• repair or, if repair is not possible, replace valve if symptomatic severe mitral regurgitation

• To protect the left ventricle from irreparable damage whether the patient is symptomatic or asymptomatic:

• monitor left ventricular size and function. If they are abnormal or deteriorating in the presence of and presumably due to severe mitral regurgitation, repair or if repair is not possible replace the valve

• The complexity of the algorithm is driven by inaccuracy of diagnostic tests and lack of sufficiently large randomized controlled trials.

• Einstein: Beyond complexity lies simplicity.


Documents

Infectious Endocarditis - TotalCardiology · Click to edit Master title style What are the commonest clinically significant valvular abnormalities? •1. Aortic stenosis and mitral