Elderly patients who develop symptomatic aortic valvular malfunctionhave a grave prognosis. Until recently they have not been seriouslyconsidered for active treatment, such as valvular surgery or balloonvalvuloplasty. Between January 1972 and July 1989, 88 patients over the ageof 80 years underwent aortic valve replacement and have been prospectivelyfollowed for a total of 185 patient-years. The majority were in New YorkHeart Association functional class III (48%) or IV (48%) preoperatively.Valvular pathology was pure aortic stenosis in 81%, regurgitation alone in6%, and mixed lesions in 13% of the cases. Before 1982 the majority ofpatients received mechanical valves, whereas tissue valves havepredominated since then (76% of total). Forty-three percent of the patientshad concomitant coronary artery bypass grafting. The overall operativemortality was 16%. Emergency surgery, isolated aortic valve replacement,advanced preoperative functional class, and female gender carried astatistically higher operative mortality. The overall actuarial survival(standard error) at 5 years was 64(7)%. Survival was significantly higherat 5 years for concomitant coronary bypass grafting than for isolatedaortic valve replacement, 70 (11)% versus 59(8%), and for males compared tofemales, 73(9)% versus 55(9)%. The 5-year event-free rates forvalve-related death and valve re-replacement were 97(2)% and 93(5)%,respectively. These data provide a firm basis for aortic valve replacementas the standard form of treatment in patients over 80.