BACKGROUND Bacterial growth in cultures of resected heart valves of patients with infective endocarditis (IE) is influenced by pre-operative antibiotic treatment (preop-AT). OBJECTIVES This study sought to evaluate the time dependency of valve culture results (positive valve culture [PVC] vs. negative valve culture) on preop-AT. METHODS A total of 352 IE episodes in 344 adult patients of our tertiary referral hospital were retrospectively investigated (2005 to 2016). The primary endpoint was PVC results. The study used a logistic additive model adjusted for bacterial species, the McCabe-Jackson classification, and the existence of foreign valve material as covariables. RESULTS The 231 included IE cases (187 [81%] men, median age 62 years, 153 [66%] native valves) comprised 58 (25%) PVC results and 173 (75%) negative valve culture results. A multivariable analysis adjusted for bacterial species, McCabe-Jackson classification, and valve type resulted in odds ratios for PVC of 6.35 (95% confidence interval [CI]: 1.94 to 20.78; p = 0.002) and 3.93 (95% CI: 1.57 to 9.84; p = 0.003) for Enterococcus spp. and Staphylococcus spp., respectively. Model-based odds ratios for PVC risk reduction in 2-day intervals of preop-AT ranged from 0.64 (95% CI: 0.61 to 0.68) at day 7 to 0.74 (95% CI: 0.70 to 0.78) at day 13 and 0.98 (95% CI: 0.93 to 1.02) at day 21. CONCLUSIONS In IE cases treated with valve surgery, Staphylococcus aureus and Enterococcus spp. were associated with valve culture growth. After 7 days of antibiotic treatment, the additional effect of preop-AT on valve culture results per 2-day interval was minor. Antibiotic treatment beyond 21 days had no influence on culture results.

中文翻译：

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感染性心内膜炎患者术前抗生素治疗的持续时间和培养结果

背景 感染性心内膜炎 (IE) 患者切除的心脏瓣膜培养物中的细菌生长受术前抗生素治疗 (preop-AT) 的影响。目的 本研究旨在评估瓣膜培养结果（瓣膜培养阳性 [PVC] 与瓣膜培养阴性）对术前 AT 的时间依赖性。方法 回顾性调查了我们三级转诊医院 344 名成年患者的 352 次 IE 发作（2005 年至 2016 年）。主要终点是 PVC 结果。该研究使用对细菌种类、McCabe-Jackson 分类和作为协变量的外来瓣膜材料的存在进行调整的逻辑可加模型。结果 231 例 IE 病例（187 [81%] 名男性，中位年龄 62 岁，153 [66%] 个自体瓣膜）包括 58 (25%) 个 PVC 结果和 173 (75%) 个阴性瓣膜培养结果。针对细菌种类、McCabe-Jackson 分类和瓣膜类型调整的多变量分析导致 PVC 的优势比为 6.35（95% 置信区间 [CI]：1.94 至 20.78；p = 0.002）和 3.93（95% CI：1.57 至9.84；p = 0.003）对于肠球菌属。和葡萄球菌属。在术前 AT 的 2 天间隔内，基于模型的 PVC 风险降低的优势比范围从第 7 天的 0.64（95% CI：0.61 至 0.68）到第 13 天的 0.74（95% CI：0.70 至 0.78）和 0.98（ 95% CI：0.93 到 1.02）在第 21 天。结论 在用瓣膜手术治疗的 IE 病例中，金黄色葡萄球菌和肠球菌属。与瓣膜培养生长有关。抗生素治疗 7 天后，术前 AT 对每 2 天间隔的瓣膜培养结果的额外影响很小。抗生素治疗超过 21 天对培养结果没有影响。