Prognosis after aortic valve replacement with St. Jude Medical bileaflet prostheses: impact on outcome of varying thromboembolic and bleeding hazards

Abstract

Aims Prognosis after aortic valve replacement (AVR) with mechanical prostheses depends on multiple inter-related factors. Investigation into these factors is complicated by limited knowledge on outcome after AVR and by the varying therapeutic ranges of International Normalized Ratio employed worldwide. Meta-analysis was combined with microsimulation to calculate evidence-based, age-specific outcomes after AVR with St. Jude Medical (SJM) prostheses (St. Jude Medical, Inc., St. Paul, MN, U.S.A.). Method and results Eight studies were included in a meta-analysis of published results of primary isolated AVR with SJM prostheses (2986 patients, 16,163 patient-years) in order to estimate the hazard of postoperative valve-related events. Using microsimulation, calculated life expectancy and event-free life expectancy were 22 and 16 years in males aged 35 years, and 7 and 5 years in males aged 75 years, respectively. Calculated lifetime risks for thromboembolic and bleeding events were 22% and 15% in males aged 35 years, and 7% and 37% in males aged 75 years, respectively. Varying thromboembolic and bleeding hazards resulted in considerable shifts in lifetime risks and deaths associated with these events. Conclusion Meta-analysis combined with microsimulation is a powerful tool with which to calculate reliable estimates of long-term prognosis, and allows detailed insight into the occurrence of valve-related events. Thromboembolism and bleeding occur frequently after AVR with mechanical prostheses and have an important impact on survival. Optimal control of International Normalized Ratio is therefore of utmost importance.