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Cardiology - Valvular Disease - Fast Facts | NEJM Resident 360

The most common forms of valvular heart disease encountered on the general inpatient service are aortic stenosis (AS), mitral regurgitation (MR), and infective endocarditis (IE).

Aortic Stenosis and Mitral Regurgitation

Intervention

The central issue with management of AS is when to intervene. Intervention involves either surgical aortic valve replacement (AVR) or percutaneous transcatheter aortic valve replacement (TAVR).  

The decision to intervene can be made based on the following findings:

• Symptoms: The most common are dyspnea on exertion, chest pain, and syncope. AVR is not generally recommended for asymptomatic patients (except in patients with very severe AS). In sedentary patients, exercise stress testing may be indicated to confirm the absence of symptoms. 

• Maximum aortic velocity (V_max) on Doppler echocardiogram: AVR should be considered in symptomatic patients with V_max ≥4.0 m/sec.

• Aortic valve area (AVA) calculated from the patient’s echocardiogram: The AVA should be ≤1.0 cm² to confirm the diagnosis of severe AS.

• Ejection fraction (EF): Patients with reduced EF (<50%) may have severe AS without a V_max ≥4.0 m/sec.

• Dobutamine stress echocardiography (DSE): For patients with reduced EF, an increase in V_max ≥4.0 m/sec with an AVA remaining ≤1.0 cm² on DSE is consistent with severe AS.

TAVR has replaced surgical AVR for patients at high- or prohibitive-surgical risk. Studies also demonstrate that, in the short term, TAVR is noninferior to surgery for patients at intermediate- or low-surgical risk, although longer-term outcomes for such patients are still being evaluated.

Indications taken into account when considering mitral valve surgery (repair or replacement):

• Severity of disease: Generally, mitral valve surgery is indicated only in patients with severe MR, as defined by Doppler echocardiography.

• Symptoms: Mitral valve surgery is indicated in patients with dyspnea or fatigue who have severe MR.

• Left ventricular (LV) dilatation or dysfunction: Mitral valve surgery is recommended for asymptomatic patients with severe MR if they have an EF ≤60% and/or an LV end-systolic dimension (LVESD) ≥40 mm.

• Severely reduced LV function or severe LV dilatation (LVESD >55 mm): Patients with severely reduced LV function (EF <30%) or severe LV dilatation (LVESD >55 mm) may not benefit from mitral valve surgery.

• Pulmonary hypertension: Consider mitral valve surgery in the asymptomatic patient with severe MR and a pulmonary artery (PA) systolic pressure >50 mm Hg at rest.

• New-onset atrial fibrillation (AF): In asymptomatic patients with severe MR, AF is an indication for surgery if it is known to be new or if it is present at the time of diagnosis of severe MR.

Transcatheter mitral valve repair, using the percutaneous mitral-valve clip, has been compared to medical therapy in twotrials in patients with moderate-to-severe mitral regurgitation and heart failure; the two trials came to different conclusions and the role of the procedure in this setting remains uncertain but can be considered in patients with an indication for mitral valve repair who are at high surgical risk.

More details on the decision for surgery in AS and MR can be found in the reference section.

Aortic Stenosis Disease Stages

(Source: Aortic-Valve Stenosis — From Patients at Risk to Severe Valve Obstruction. N Engl J Med 2014.)

Infective Endocarditis

Diagnosis is made using the Duke criteria.

Treatment: For patients with IE who are not acutely ill, obtain blood culture data and await culture results before deciding which therapy is appropriate. For acutely ill patients, empiric therapy may be necessary; vancomycin is usually recommended for such patients.

Early surgery for IE should be considered for patients with the following conditions:

• heart failure

• annular or aortic abscess

• heart block

• recurrent emboli on appropriate antibiotic therapy

• infections resistant to antibiotic therapy

• fungal endocarditis

• persistent infection (>5-7 days)

Indications for Echocardiography in Suspected Endocarditis

Indications for echocardiography in suspected infective endocarditis. IE, infective endocarditis; TTE, transthoracic echocardiography; TOE, transoesophageal echocardiography. TOE is not mandatory in isolated right-sided native valve IE with good quality TTE examination and unequivocal echocardiographic findings.

Empirical Antibiotic Treatment Regimens for Infective Endocarditis

(Source: Guidelines for the Diagnosis and Antibiotic Treatment of Endocarditis in Adults: A Report of the Working Party of the British Society for Antimicrobial Chemotherapy, J Antimicrob Chemother 2012. Reprinted with permission of British Society for Antimicrobial Chemotherapy.)

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