Peronace B, Cornelli U, Marcazzan E, Pellegrini A
G Ital Cardiol. 1980;10(9):1179-85.
304 patients have been studied between 1972 and 1977 after mitral valve replacement. 133 patients had a Starr-Edwards prosthesis and 171 patients had a Björk-Shiley prosthesis; both groups presented similar risk factors. The follow-up varied between a 6 months and a 72 months period for both types of prosthesis with a mean period of 3.2 years. The statistical results were based on the cluster system and he outcomes helped us to realise curves of homogeneous groups of patients who underwent mitral valve replacement with Starr and Björd prosthesis. One observed that 4 years from date of surgery the survival percentage is 84% for those patients with the Starr prosthesis and 78% for Björk prosthesis; with regards to the log rank test this difference is insignificant. Considering the probability of embolism one observed a percentage of 10% of the patients with the Björk prosthesis and of 18% with the Starr prosthesis; this difference is insignificant from the statistical point of view. The cluster analysis of the considered parameters (age, type of valve defect, NYHA class, duration of symptoms before surgery, C/T, size of left atrium) did not evince real and proper risk factors at least not such to condition the long term results. The only observed relationship is the one between the major incidence of embolism and great left atrium. One may conclude that not exist differences in long term results between both prostheses when placed in mitral valve.
1972年至1977年间，对304例二尖瓣置换术后患者进行了研究。133例患者植入了Starr-Edwards人工瓣膜，171例患者植入了Björk-Shiley人工瓣膜；两组的危险因素相似。两种人工瓣膜的随访时间在6个月至72个月之间，平均为3.2年。统计结果基于聚类系统，结果帮助我们绘制了使用Starr和Björd人工瓣膜进行二尖瓣置换的同质患者组曲线。可以观察到，术后4年，植入Starr人工瓣膜的患者生存率为84%，植入Björk人工瓣膜的患者生存率为78%；就对数秩检验而言，这种差异不显著。考虑到栓塞的概率，观察到植入Björk人工瓣膜的患者中有10%发生栓塞，植入Starr人工瓣膜的患者中有18%发生栓塞；从统计学角度来看，这种差异不显著。对所考虑的参数（年龄、瓣膜缺损类型、纽约心脏协会分级、术前症状持续时间、C/T、左心房大小）进行聚类分析，未发现真正合适的危险因素，至少没有足以影响长期结果的危险因素。唯一观察到的关系是栓塞的主要发生率与左心房增大之间的关系。可以得出结论，两种人工瓣膜用于二尖瓣置换时，长期结果不存在差异。
