Heart valve disease in general practice: a clinical overview

WHEN TO SUSPECT VALVE DISEASE

Auscultation is a good screen and should be performed in patients with exertional chest pain, breathlessness, or syncope and also non-specifically reduced exercise capacity. Any first-degree relative of someone with a bicuspid aortic valve has a 10% chance of having either a bicuspid valve or dilated aorta and should be offered echocardiography. Valve disease was thought to be the cause of heart failure in just under one-third of patients in the EuroHeart Failure survey⁴ for which echocardiography is already indicated. Anyone from countries with a high prevalence of rheumatic disease (for example, India, Sub-Saharan Africa, or South America) should have auscultation as part of their routine assessment. Similarly, patients aged ≥75 years are also at high risk and should ideally have auscultation at their annual check.⁵

HOW TO INTERPRET AN ECHO REPORT

Mild mitral, tricuspid, and pulmonary regurgitation are never clinically important and mild aortic valve thickening or regurgitation in older people require no further investigation. A subaortic septal bulge is common in older people, although in the majority of cases is not haemodynamically significant. Trivial pericardial fluid is common and usually normal.

In asymptomatic severe valve disease, surgery is indicated for either left ventricular impairment or raised pulmonary artery pressures.² In the presence of significant aortic or mitral regurgitation the ejection fraction should be high because of offloading, and so a left ventricular ejection fraction <60% in severe mitral regurgitation or <50% in severe aortic regurgitation represent left ventricular impairment. Valve disease that appears moderate according to the gradient may still be clinically significant if the left ventricular ejection fraction is low. Therefore, in aortic stenosis the effective orifice area may be more reliable than the gradient because it is relatively independent of flow. Surgery may also be considered for aortic dilatation.²

TYPES OF SURGICAL INTERVENTION AVAILABLE

In mitral prolapse, repair is preferable to replacement. For aortic valve disease mechanical valves are usually recommended in those aged <60 years and biological valves in those aged >65 years. Transcatheter techniques are established for aortic stenosis in patients at excessive risk from conventional valve replacement. Transcatheter mitral replacements and annuloplasty techniques are being developed.

WHAT MEDICAL THERAPY IS INDICATED?

No medical therapy reduces the rate of progression of any valve disease.⁶ However, there is evidence that beta-blockers or angiotensin-receptor blockers reduce progression and complications of a dilated aorta in Marfan syndrome.⁷,⁸ This treatment is extrapolated to patients with bicuspid aortic valve disease. In inoperable heart failure secondary to valve disease, angiotensin-converting enzyme inhibitors and beta-blockers are indicated, as for any patient with systolic heart failure. Atrial fibrillation (AF) in mitral valve disease is treated with rate control and, importantly, anticoagulation with warfarin as these patients have a high risk of thromboembolic complications. Anticoagulation should also be considered for patients with severe mitral stenosis and large atria (usually taken as a left atrial diameter >55 mm) even when in sinus rhythm. The novel anticoagulants (dabigatran, apixaban, and rivaroxaban) are contraindicated in the presence of significant mitral stenosis or replacement heart valves.

LIFESTYLE ADVICE

Competitive and contact sports are usually not advisable in any patient with moderate or severe valve disease. The only sports categorised as safe in European guidelines are bowling, cricket, golf, and shooting in patients with moderate or severe mitral stenosis, moderate aortic stenosis, or moderate aortic regurgitation without aortic dilatation.⁹ These are also safe after valve replacement and repair. Driving is not usually contraindicated in uncomplicated asymptomatic valve disease and travel depends on individual factors including available healthcare provision in the event of decompensation.

ANTIBIOTIC PROPHYLAXIS

Antibiotics are not needed before dental work in any patients with native valve disease who have not undergone either valve replacement or repair. There is controversy over high-risk patients with previous infective endocarditis and replacement heart valves or valve repair surgery. Although the National Institute for Health and Care Excellence (NICE) does not recommend antibiotics in these high-risk patients, all international guidelines do and most cardiologists and cardiac surgeons follow these rather than NICE. Dental surveillance and optimal oral hygiene should be encouraged in all patients with native or operated heart valve disease.

WHEN TO SUSPECT INFECTIVE ENDOCARDITIS?

Endocarditis is rare and symptoms are often non-specific, but an unexplained fever, malaise, or weight loss should suggest the diagnosis especially in patients with heart valve disease or pacemakers. High-risk groups are patients with diabetes, HIV, or those having haemodialysis. Fever with stroke or peripheral embolism is strongly suggestive of endocarditis. It is important to take blood cultures before contemplating antibiotics because prior therapy is the cause of about 50% of culture-negative endocarditis.

CONCLUSION

It is important to consider the possibility of valve disease, particularly in older patients with exertional symptoms. Echocardiography is the definitive first investigation and best practice is to refer cases with moderate or severe valve disease to a specialist valve clinic for further evaluation and advice regarding surveillance or intervention as appropriate.