The medical management of valvar heart disease.

Although there is very little high quality evidence to guide the medical treatment of valve disease, this is an important area of cardiology for two reasons. Firstly, there are many frail older people with symptomatic degenerative valve disease in whom the risks of surgical intervention are prohibitive and medical treatment is the only realistic option. Secondly, there is a real and exciting prospect of using medical treatment to influence the natural history of some forms of valve disease, thereby delaying or even avoiding the need for surgery. Left ventricular systolic dysfunction caused by ischaemic heart disease was the underlying problem in the vast majority of patients who took part in the landmark trials of medical treatment (angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor antagonists, vasodilators, β blockers, and spironolactone) for heart failure. However, some of these trials included patients with valve disease and the principles that have been learned may be widely applicable. Thus, it seems reasonable to assume that a small dose of spironolactone will benefit most patients with severe congestive cardiac failure including those with valvar heart disease. On the other hand it seems clear that the characteristic haemodynamic problems associated with individual valve lesions may influence the relative benefits and hazards of specific treatments. For example, vasodilator treatment may be unwise in patients with severe aortic stenosis because there is a risk that this will reduce aortic pressure and coronary perfusion without an equivalent reduction in the left ventricular afterload. In contrast, vasodilators may be particularly beneficial in patients with aortic or mitral regurgitation because they might be expected to reduce the regurgitant fraction and increase forward flow. Similarly, by prolonging diastole and left ventricular filling, β blockers may harm patients with aortic regurgitation but benefit patients with mitral stenosis. Medical treatment might be able to alter the natural history of valve disease in two ways. Firstly, it is conceivable that outcome might be improved by treatments that suppress the disease process in the valve itself—for example, it may be possible to restrict fibrosis, scarring and calcification by using anti-inflammatory treatments in some forms of degenerative and rheumatic valve disease. Secondly, it may be possible to prevent or ameliorate the deleterious effects of secondary heart muscle disease—for example, vasodilator treatment may help to protect the myocardium in patients with left ventricular volume overload caused by chronic aortic or mitral regurgitation. This article will review the medical treatment of the four major left heart valve lesions (aortic stenosis, mitral stenosis, aortic regurgitation, and mitral regurgitation). The optimum timing of surgery, the role of anticoagulants, and the prophylaxis of infective endocarditis have been covered in separate reviews in this series.