Abstract：
OBJECTIVE: The selection of valve prostheses for patients undergoing surgical aortic valve replacement (SAVR) remains controversial. In this study, we compared the long-term outcomes of patients undergoing aortic valve replacement with biological or mechanical aortic valve prostheses.
METHODS: We evaluated late results among 5,762 patients aged 45-74 years who underwent biological or mechanical aortic valve replacement with or without concomitant coronary artery bypass from 1989 to 2019 at four medical centers. The Cox proportional hazards model was used to compare late survival; the age-dependent effect of prosthesis type on long-term survival was evaluated by an interaction term between age and prosthesis type. Incidences of stroke, major bleeding, and reoperation on the aortic valve following the index procedure were compared between prosthesis groups.
RESULTS: Overall, 61% (n=3,508) of patients received a bioprosthesis. The 30-day mortality rate was 1.7% (n=58) in the bioprosthesis group and 1.5% (n=34) in the mechanical group (P=0.75). During a mean follow-up of 9.0 years, the adjusted risk of mortality was higher in the bioprosthesis group (HR=1.30, P<0.001). The long-term survival benefit associated with mechanical prosthesis persisted until 70 years of age. Bioprosthesis (vs mechanical prosthesis) was associated with a similar risk of stroke (P=0.20), lower risk of major bleeding (P<0.001), and higher risk of reoperation (P<0.001).
CONCLUSIONS: Compared to bioprostheses, mechanical aortic valves are associated with a lower adjusted risk of long-term mortality in patients aged 70 years or younger. Patients <70 years old undergoing SAVR should be informed of the potential survival benefit of mechanical valve substitutes.
METHODS: We evaluated late results among 5,762 patients aged 45-74 years who underwent biological or mechanical aortic valve replacement with or without concomitant coronary artery bypass from 1989 to 2019 at four medical centers. The Cox proportional hazards model was used to compare late survival; the age-dependent effect of prosthesis type on long-term survival was evaluated by an interaction term between age and prosthesis type. Incidences of stroke, major bleeding, and reoperation on the aortic valve following the index procedure were compared between prosthesis groups.
RESULTS: Overall, 61% (n=3,508) of patients received a bioprosthesis. The 30-day mortality rate was 1.7% (n=58) in the bioprosthesis group and 1.5% (n=34) in the mechanical group (P=0.75). During a mean follow-up of 9.0 years, the adjusted risk of mortality was higher in the bioprosthesis group (HR=1.30, P<0.001). The long-term survival benefit associated with mechanical prosthesis persisted until 70 years of age. Bioprosthesis (vs mechanical prosthesis) was associated with a similar risk of stroke (P=0.20), lower risk of major bleeding (P<0.001), and higher risk of reoperation (P<0.001).
CONCLUSIONS: Compared to bioprostheses, mechanical aortic valves are associated with a lower adjusted risk of long-term mortality in patients aged 70 years or younger. Patients <70 years old undergoing SAVR should be informed of the potential survival benefit of mechanical valve substitutes.
摘要：
目的：外科主动脉瓣置换术（SAVR）患者瓣膜假体的选择仍存在争议。在这项研究中,我们比较了接受主动脉瓣置换术和生物或机械主动脉瓣假体的患者的长期结局.
方法：我们评估了1989年至2019年在四个医疗中心接受生物或机械主动脉瓣置换术伴或不伴冠状动脉搭桥术的5,762例45-74岁患者的晚期结果。Cox比例风险模型用于比较晚期生存率；通过年龄和假体类型之间的相互作用项评估假体类型对长期生存率的年龄依赖性影响。中风的发生率，大出血,比较了造影术后主动脉瓣的再手术。
结果：总体而言，61%(n=3,508)的患者接受了生物假体。生物假体组30天死亡率为1.7%(n=58)，机械组为1.5%(n=34)(P=0.75)。在平均9.0年的随访中，生物假体组的校正后死亡风险较高(HR=1.30,P<0.001).与机械假体相关的长期生存益处持续到70岁。生物假体（相对于机械假体）与中风的风险相似（P=0.20），大出血风险较低（P<0.001），再次手术风险较高(P<0.001)。
结论：与生物假体相比，在70岁及以下的患者中,机械主动脉瓣与较低的调整后长期死亡风险相关.应告知<70岁接受SAVR的患者机械瓣膜替代品的潜在生存益处。
方法：我们评估了1989年至2019年在四个医疗中心接受生物或机械主动脉瓣置换术伴或不伴冠状动脉搭桥术的5,762例45-74岁患者的晚期结果。Cox比例风险模型用于比较晚期生存率；通过年龄和假体类型之间的相互作用项评估假体类型对长期生存率的年龄依赖性影响。中风的发生率，大出血,比较了造影术后主动脉瓣的再手术。
结果：总体而言，61%(n=3,508)的患者接受了生物假体。生物假体组30天死亡率为1.7%(n=58)，机械组为1.5%(n=34)(P=0.75)。在平均9.0年的随访中，生物假体组的校正后死亡风险较高(HR=1.30,P<0.001).与机械假体相关的长期生存益处持续到70岁。生物假体（相对于机械假体）与中风的风险相似（P=0.20），大出血风险较低（P<0.001），再次手术风险较高(P<0.001)。
结论：与生物假体相比，在70岁及以下的患者中,机械主动脉瓣与较低的调整后长期死亡风险相关.应告知<70岁接受SAVR的患者机械瓣膜替代品的潜在生存益处。
