Kok Wouter
Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
Diagnostics (Basel). 2024 Jul 22;14(14):1578. doi: 10.3390/diagnostics14141578.
Previous guidelines for endocarditis have suggested repeating blood cultures until they become negative, with limited evidence.
Literature reviews were conducted (1) on the incidence of persistent bacteremia and association with outcome and (2) on timing of valve culture negativization to examine the claim for prolongation of antibiotic therapy starting from negative blood cultures.
Persistent bacteremia and fever may be present in the first 3 days of endocarditis, despite treatment, and are more common in Staphylococcus (especially MRSA) and Enterococcus species. Persistent bacteremia (48-72 h), persistent infection (day 7), and new onset septic shock are related and predict in-hospital mortality. It is, however, persistent infection at day 7 and septic shock that primarily determine the infectious course of endocarditis, and not persistent bacteremia. Valve cultures at surgery become negative in most cases (>85-90%) after 14-21 days of antibiotic therapy, with no calculated benefit for prolonging therapy after 21 days.
Persistent infection at 7 days after appropriate antibiotic therapy is a better key event for prognosis then positive or negative blood cultures at 48-72 h. Therapy prolongation from the day of negative blood cultures is not reasonable. There is no need to survey blood cultures in endocarditis patients after starting therapy.
既往心内膜炎指南建议重复进行血培养直至结果呈阴性，但证据有限。
进行了文献综述，（1）关于持续性菌血症的发生率及其与预后的关联，以及（2）关于瓣膜培养转阴的时间，以检验从血培养阴性开始延长抗生素治疗的主张。
尽管进行了治疗，但心内膜炎的头3天可能出现持续性菌血症和发热，在葡萄球菌（尤其是耐甲氧西林金黄色葡萄球菌）和肠球菌属中更为常见。持续性菌血症（48 - 72小时）、持续性感染（第7天）和新发感染性休克相关，并可预测住院死亡率。然而，主要决定心内膜炎感染病程的是第7天的持续性感染和感染性休克，而非持续性菌血症。抗生素治疗14 - 21天后，大多数病例（>85 - 90%）手术时的瓣膜培养结果会转阴，延长治疗至21天以上未显示出益处。
适当抗生素治疗7天后的持续性感染对预后而言是比48 - 72小时血培养阳性或阴性更好的关键事件。从血培养阴性之日起延长治疗不合理。开始治疗后无需对心内膜炎患者进行血培养检查。
