Isolated mitral valve replacement with the Kay-Shiley prosthesis. Long- term follow-up and recommendations

Eighty patients underwent isolated mitral valve replacement with the Kay-Shiley prosthesis during a 6 year period (September, 1966, in October, 1972) at Walter Reed Army Medical Center. One-hundred percent follow-up has been achieved with this group. Sixty-four percent of this group have experienced one or more thromboembolic episodes (TEEs), for a TEE rate of 28.7 episodes per 1,000 patient months at risk. The 5 year survival rate is 45%. Eleven of 43 (25%) late deaths resulted from TEEs, and 13 of 43 (30%) late deaths were secondary in the hemorrhagic complications of long-term anticoagulant therapy. The dismal TEE rate prompted as to initiate a policy of elective replacement of all Kay-Shiley mitral prostheses. Eighteen of the 26 survivors underwent replacement of the Kay-Shiley mitral prosthesis. The other eight patients either declined reoperation or were not considered suitable candidates. The reoperative mortality rate was 22% (4/18). Fifteen of 18 explained prostheses revealed a yellow disclored, grooved occluder disc with loosely adherent clot. We recommend elective replacement of Kay-Shiley mitral prostheses in all patients in whom the risk of operation is reasonable.