Tleyjeh Imad M, Ghomrawi Hassan M K, Steckelberg James M, Hoskin Tanya L, Mirzoyev Zaur, Anavekar Nandan S, Enders Felicity, Moustafa Sherif, Mookadam Farouk, Huskins W Charles, Wilson Walter R, Baddour Larry M
Division of Infectious Diseases, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minn, USA.
Circulation. 2007 Apr 3;115(13):1721-8. doi: 10.1161/CIRCULATIONAHA.106.658831. Epub 2007 Mar 19.
The role of valve surgery in left-sided infective endocarditis has not been evaluated in randomized controlled trials. We examined the association between valve surgery and all-cause 6-month mortality among patients with left-sided infective endocarditis.
A total of 546 consecutive patients with left-sided infective endocarditis were included. To minimize selection bias, propensity score to undergo valve surgery was used to match patients in the surgical and nonsurgical groups. To adjust for survivor bias, we matched the follow-up time so that each patient in the nonsurgical group survived at least as long as the time to surgery in the respective surgically-treated patient. We also used valve surgery as a time-dependent covariate in different Cox models. A total of 129 (23.6%) patients underwent surgery within 30 days of diagnosis. Death occurred in 99 of the 417 patients (23.7%) in the nonsurgical group versus 35 deaths among the 129 patients (27.1%) in the surgical group. Eighteen of 35 (51%) patients in the surgical group died within 7 days of valve surgery. In the subset of 186 cases (93 pairs of surgical versus nonsurgical cases) matched on the logit of their propensity score, diagnosis decade, and follow-up time, no significant association existed between surgery and mortality (adjusted hazard ratio, 1.3; 95% confidence interval, 0.5 to 3.1). With a Cox model that incorporated surgery as a time-dependent covariate, valve surgery was associated with an increase in the 6-month mortality with an adjusted hazard ratio of 1.9 (95% confidence interval, 1.1 to 3.2). Because the proportionality hazard assumption was violated in the time-dependent analysis, we performed a partitioning analysis. After adjustment for early (operative) mortality, surgery was not associated with a survival benefit (adjusted hazard ratio, 0.92; 95% confidence interval, 0.48 to 1.76).
The results of our study suggest that valve surgery in left-sided infective endocarditis is not associated with a survival benefit and could be associated with increased 6-month mortality, even after adjustment for selection and survivor biases as well as confounders. Given the disparity between the results of our study and those of other observational studies, well-designed prospective studies are needed to further evaluate the role of valve surgery in endocarditis management.
在随机对照试验中尚未评估瓣膜手术在左侧感染性心内膜炎中的作用。我们研究了左侧感染性心内膜炎患者瓣膜手术与全因6个月死亡率之间的关联。
共纳入546例连续的左侧感染性心内膜炎患者。为尽量减少选择偏倚，采用接受瓣膜手术的倾向评分对手术组和非手术组患者进行匹配。为校正生存偏倚，我们对随访时间进行匹配，以使非手术组的每名患者存活时间至少与相应手术治疗患者的手术时间一样长。我们还在不同的Cox模型中使用瓣膜手术作为时间依赖性协变量。共有129例（23.6%）患者在诊断后30天内接受了手术。非手术组417例患者中有99例（23.7%）死亡，而手术组129例患者中有35例死亡（27.1%）。手术组35例患者中有18例（51%）在瓣膜手术后7天内死亡。在根据倾向评分、诊断年代和随访时间的对数进行匹配的186例病例子集（93对手术与非手术病例）中，手术与死亡率之间无显著关联（校正风险比，为1.3；95%置信区间，0.5至3.1）。在将手术作为时间依赖性协变量纳入的Cox模型中，瓣膜手术与6个月死亡率增加相关，校正风险比为1.9（95%置信区间，1.1至3.2）。由于在时间依赖性分析中违反了比例风险假设，我们进行了分层分析。在调整早期（手术）死亡率后，手术与生存获益无关（校正风险比，0.92；95%置信区间，0.48至1.76）。
我们的研究结果表明，左侧感染性心内膜炎的瓣膜手术与生存获益无关，即使在调整选择偏倚、生存偏倚以及混杂因素后，也可能与6个月死亡率增加相关。鉴于我们的研究结果与其他观察性研究结果存在差异，需要设计良好的前瞻性研究来进一步评估瓣膜手术在感染性心内膜炎治疗中的作用。
