Results five to seven years after aortic valve replacement with the original Delrin disc model Björk-Shiley prosthesis.

Isolated aortic valve replacement with the original Delrin disc model Björk-Shiley prosthesis was performed in 128 patients at the Thoracic Surgical Clinic, Karolinska Sjukhuset, Stockholm, Sweden, during the period 1969--71. No patient was lost at follow-up 5--7 years after surgery. The early mortality rate was 5% (6/128) and the actuarial late death rate at 5 years was 13% (16/122). This late survival rate represents a significant improvement over the natural history of symptomatic aortic valvular disease. Age at operation and the particular size of prosthetic valve inserted had no bearing on late mortality, while large heart size and aortic incompetence were associated with a higher incidence of late deaths. There was only one death due to thromboembolism and no case of mechanical prosthetic valve dysfunction. The incidence of thrombo-embolism was 0.7 per 100 patient years with continuous anticoagulation therapy during sinus rhythm, but increased during atrial fibrillation and after discontinuation of anticoagulation. Survival without complications was 75% at 5 years among the 122 patients discharged from hospital.