Supplementary Material for: Utility of echocardiogram in neutropenic patients with gram positive bacteremia – a retrospective study

Introduction: Hemato-oncology patients are vulnerable to bloodstream infections due to immunocompromised state and use of intravascular catheters. Data regarding risk of infective endocarditis (IE) among those with gram positive bacteremia is limited.
We aimed to evaluate the incidence of IE among neutropenic hemato-oncology patients, and to explore the yield of echocardiogram in this population.
Methods: we conducted a single retrospective study of all hospitalized hemato-oncology neutropenic patients with gram positive blood cultures between 2007 and 2021. Data regarding Patients’ characteristics, blood cultures and echocardiogram was collected.
Results: Study included 241 patients, with 283 isolates. Coagulase negative staphylococcus (CONS) were the most commonly isolates found, followed by streptococcus viridans. Trans thoracic echocardiography (TTE) was performed in 45% of patients overall, of which 5.8% had additional Trans esophageal echocardiogram (TEE).
Only a single case of IE was identified; 47 y/o multiple myeloma patient with neutropenic fever, streptococcus viridans bacteremia, and stroke caused by septic emboli. TTE and TEE failed to demonstrate valvular pathology consistent with IE.
Conclusion In our experience, the yield of echocardiogram in hemato-oncological neutropenic patients with bacteremia is extremely low, owing to reduced probability of IE in this population, and thus could be avoided in most cases.

引言：血液肿瘤患者因免疫功能低下状态及血管内导管的使用，极易发生血流感染。目前针对革兰阳性菌血症患者罹患感染性心内膜炎（infective endocarditis，IE）风险的相关研究数据较为有限。本研究旨在评估中性粒细胞减少性血液肿瘤患者中IE的发生率，并探讨该人群中心脏超声检查的检出价值。
方法：本研究为单中心回顾性研究，纳入2007年至2021年间所有住院的、血液肿瘤合并中性粒细胞减少且血培养呈革兰阳性的患者。研究收集了患者的基线特征、血培养结果及心脏超声检查相关数据。
结果：本研究共纳入241例患者，分离得到283株病原菌。凝固酶阴性葡萄球菌（coagulase negative staphylococcus，CONS）为最常见分离菌株，其次为草绿色链球菌。总体而言，45%的患者接受了经胸超声心动图（trans thoracic echocardiography，TTE）检查，其中5.8%的患者进一步接受了经食管超声心动图（trans esophageal echocardiography，TEE）。本研究仅确诊1例IE患者：该患者为47岁多发性骨髓瘤合并中性粒细胞减少性发热患者，血培养检出草绿色链球菌，并发脓毒性栓子所致脑卒中。经胸超声心动图及经食管超声心动图均未发现与IE相符的瓣膜病变。
结论：基于本研究经验，在合并菌血症的中性粒细胞减少性血液肿瘤患者中，心脏超声检查的检出价值极低。究其原因，该人群罹患IE的概率本就较低，因此多数情况下无需开展此类检查。