THE MONOSTRUT PROSTHETIC VALVE - PREDICTORS FOR VALVE-RELATED EVENTS DURING AN 8 YEARS EXPERIENCE

All postoperative complications, including transient ischaemic attacks (TIA) and cerebrovascular accidents (CVA) of 259 patients, in whom a total of 301 Monostrut tilting-disc valves were implanted between Janu ary 1985 and December 1991 were evaluated retrospectively. The follow- up was maximally 8 years, with a mean of 3.5 years, and totaled 914 pa tient-years. In this study we found no mechanical deterioration of the Monostrut valve and demonstrated the elimination of valve thrombosis in patients receiving adequate anticoagulation. The actuarial probabil ity of being free of thrombo-embolism was 94.7% +/- 1.7% and free of a nticoagulant related hemorrhage 95.4% +/- 1.5% at 8-years. In comparis on with earlier reports by others, our findings show a lower ratio of thromboembolic and hemorrhagic events. We demonstrated a correlation ( p < 0.05) between thrombo-embolic and hemorrhagic complications. In ad dition, a lower incidence of CVA's (0.22 per 100 patient-years), but a higher incidence of TIA's (0.66 per 100 patient-years) in comparison with the general Dutch population was found. At eight years follow-up, all patients were In Class I or II of the New York Heart Association Classification. Although the overall valve related event-free survival at eight years was only 47.9%, 93.5% of the patient were satisfied wi th their operative result. Predictive factors for late mortality were the occurrence of paravalvular leakage (p < 0.01), the age of the pati ent at the time of operation (p < 0.01) and the number of diseases cor onary arteries(p < 0.01). In conclusion, our study shows that the Mono strut tilting-disc valve seems to be, during the studied 8-years perio d, a more reliable prosthesis than the earlier Bjork-Shiley convex-con cave model.