Present status of prosthetic cardiac valves.

Cardiac prosthetic valves have not yet reached the point of reliability and durability to be used for other than remedial purposes. In mitral valve disease, the prime targets are patients in whom medical treatment could not successfully reverse progressive clinical disability, or in whom less drastic mitral valve operations have failed. In aortic stenosis, the prime targets are patients with substantial cardiac symptoms. In aortic regurgitation, earliest indications of disability provide the timing for valve replacement. In this lesion, prophylactic operations in the absence of symptoms are often proposed. Such operations should be given the most cautious considerations.