Ribeiro Angela Henrique Silva, Wender Orlando Carlos Belmonte, de Almeida Adriana Silveira, Soares Luciana Eltz, Picon Paulo Dornelles
Clinical Medicine of the Federal University of Rio Grande do Sul (UFRGS), Av, Francisco Trein, 596, sala 201, Porto Alegre, RS 91350-200, Brazil.
BMC Cardiovasc Disord. 2014 Oct 18;14:146. doi: 10.1186/1471-2261-14-146.
The choice of prosthesis for mitral valve replacement still remains controversial. This study assessed mortality, bleeding events and reoperation in patients who underwent mitral valve replacement surgery with biological or mechanical substitutes.
A total of 352 patients who underwent mitral valve replacement surgery between 1990 and 2008 with 5 to 23 years of follow-up were retrospectively evaluated in a cohort study.
The 5, 10, 15 and 20 year survival rates after surgery using a mechanical substitute were 87.7%, 74.2%, 69.3% and 69.3%, respectively, while after surgery with a biological substitute, they were 87.6%, 71.0%, 64.2% and 56.6%, respectively. There was no significant difference between the two groups (p = 0.38). In the multivariate analysis, the factors associated with death were age, bleeding events and renal failure. The probabilities of remaining free of reoperation at 5, 10, 15 and 20 years after surgery using a mechanical substitute were 94.4%, 92.7%, 92.7% and 92.7%; after surgery with a bioprosthesis, they were 95.9%, 86.4%, 81.2% and 76.5%, respectively (p = 0.073). There was a significantly higher incidence of reoperation for the bioprosthetic valve replacement group (p = 0.008). The probabilities of remaining free of bleeding events at 5, 10, 15 and 20 years after surgery using a mechanical substitute were 95.0%, 91.0%, 89.6% and 89.6%, respectively, while after surgery with a bioprosthesis, they were 96.9%, 94.0%, 94.0% and 94.0%, (p = 0.267).
The authors concluded that: 1) mortality during follow-up was statistically similar for both groups; 2) there was a greater tendency to reoperation in the bioprosthesis group; 3) the probability of remaining free from reoperation remained unchanged after 10 years' follow-up for patients with mechanical substitute valves; 4) the probability of remaining fee from bleeding events remained unchanged after 10 years' follow-up for patients given bioprostheses; 5) the baseline characteristics of patients were the greatest determinants of later mortality after surgery; 6) the type of prosthesis was not an independent predictive factor of any of the outcomes tested in the multivariate analysis.
二尖瓣置换术假体的选择仍存在争议。本研究评估了接受生物或机械替代物二尖瓣置换手术患者的死亡率、出血事件及再次手术情况。
在一项队列研究中，对1990年至2008年间接受二尖瓣置换手术且随访5至23年的352例患者进行回顾性评估。
使用机械替代物手术后5年、10年、15年和20年的生存率分别为87.7%、74.2%、69.3%和69.3%，而使用生物替代物手术后的生存率分别为87.6%、71.0%、64.2%和56.6%。两组之间无显著差异（p = 0.38）。多因素分析中，与死亡相关的因素为年龄、出血事件和肾衰竭。使用机械替代物手术后5年、10年、15年和20年无需再次手术的概率分别为94.4%、92.7%、92.7%和92.7%；使用生物假体手术后分别为95.9%、86.4%、81.2%和76.5%（p = 0.073）。生物假体瓣膜置换组再次手术的发生率显著更高（p = 0.008）。使用机械替代物手术后5年、10年、15年和20年无出血事件的概率分别为95.0%、91.0%、89.6%和89.6%，而使用生物假体手术后分别为96.9%、94.0%、94.0%和94.0%（p = 0.267）。
作者得出结论：1）两组随访期间的死亡率在统计学上相似；2）生物假体组再次手术的倾向更大；3）使用机械替代瓣膜的患者随访10年后无需再次手术的概率保持不变；4）接受生物假体的患者随访10年后无出血事件的概率保持不变；5）患者的基线特征是术后后期死亡率的最大决定因素；6）假体类型不是多因素分析中所测试的任何结局的独立预测因素。
