Letter: Aortic valvular disease and valve replacement.
D001021:Aortic Valve / Q000601:surgery*; D001022:Aortic Valve Insufficiency / Q000401:mortality / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D006801:Humans; D008396:Maryland; D010414:Pennsylvania; D011379:Prognosis