Fast Antimicrobial Susceptibility Testing for Gram-Negative Bacteremia: The FAST Randomized Clinical Trial.

Background

To evaluate clinical outcomes of blood culture testing using a rapid AST method compared with standard AST in patients with BSIs caused by gram-negative bacilli in regions with high prevalenceof antimicrobial resistance.

在抗菌药物耐药性高发地区，评估使用快速AST方法进行血培养测试与标准AST方法在由革兰氏阴性杆菌引起的BSIs患者中的临床结果。

DESIGN, SETTING, AND PARTICIPANTS: Open-label randomized clinical trial that enrolled participants from December 2023 to May 2025 (final follow-up, June 18, 2025) at 7 medical centers in Greece (n = 2), India (n = 1), Israel (n = 3), and Spain (n = 1).

设计、设置和参与者：一项开放标签的随机临床试验，从2023年12月到2025年5月在希腊（2个中心）、印度（1个中心）、以色列（3个中心）和西班牙（1个中心）的7个医疗中心招募参与者（最终随访日期为2025年6月18日）。

Hospitalized patients (adults and children) with BSIs caused by gram-negative bacilli were eligible.

住院患者（成人和儿童）因革兰氏阴性杆菌引起的血流感染（BSIs）是符合条件的。

Statistical analysis was conducted from August 2025 to January 2026.

统计分析从2025年8月进行到2026年1月。

intervention

Patients were randomized to undergo blood culture evaluation using rapid, phenotypic AST directly from positive blood cultures plus standard susceptibility testing (n = 413) vs standard susceptibility testing alone (n = 437).

患者被随机分为两组，一组接受快速表型AST直接从阳性血培养中进行的血培养评估加上标准敏感性测试（n=413），另一组仅接受标准敏感性测试（n=437）。

Local antimicrobial stewardship teams reviewed all patients and provided treatment recommendations.

本地抗菌药物管理团队审查了所有患者，并提供了治疗建议。

main_outcomes_and_measures

The primary outcome was a desirability of outcome ranking (DOOR) at day 30, with 3 categories (alive without deleterious events, alive with deleterious events, and death).

主要结果是第30天的期望结果排名（DOOR），分为3个类别（无不良事件存活、有不良事件存活和死亡）。

The difference between rapid and standard testing was summarized as the probability that the DOOR outcomes were more desirable in the rapid testing group.

快速检测与标准检测之间的差异被总结为DOOR结果在快速检测组中更令人满意的概率。

Superiority was concluded if the lower limit of the 95% CI exceeded 50%.

如果95%置信区间的下限超过50%，则得出优越性的结论。

Secondary outcomes included 30-day mortality, length of hospitalization, intensive care unit admission, acquisition of hospital-acquired infections, time to effective antibiotic therapy within 3 days, and time to antibiotic escalation or deescalation within 3 days.

次要结果包括30天内的死亡率、住院时间、重症监护病房的入住率、获得医院获得性感染的情况、3天内有效抗生素治疗的时间以及3天内抗生素升级或降级的时间。

Results

Of the 899 patients randomized, 850 were included in the primary outcome analysis (median [IQR] age, 72 [21] years; 43% female).

在随机分配的899名患者中，有850名被纳入主要结果分析（中位数[四分位数间距]年龄为72[21]岁；女性占43%）。

The probability that DOOR outcomes were more favorable in the rapid testing group was 48.8% (95% CI, 45.3%-52.4%).

在快速检测组中，DOOR结果更有利的概率为48.8%（95%置信区间，45.3%-52.4%）。

Median time to effective antibiotic therapy was not different between the groups in the as-randomized population.

在按随机分配的人群中，两组之间有效抗生素治疗的中位时间没有差异。

Median time to antibiotic escalation or deescalation was faster in the rapid testing group by 14 hours (95% CI, 6-22) in the as-randomized population.

在随机化人群中，快速检测组的抗生素升级或降级的中位时间比对照组快14小时（95%置信区间，6-22小时）。

There were no differences between the groups in other secondary outcomes.

两组在其他次要结果方面没有差异。

In the prespecified subgroup with carbapenem-resistant infections, median time to effective therapy was 9.5 hours in the rapid testing group vs 28 hours in the standard testing group (difference, -18 hours [95% CI, -42 to 6]).

在预先设定的碳青霉烯类耐药感染亚组中，快速检测组的有效治疗中位时间为9.5小时，标准检测组为28小时（差异，-18小时 [95% 置信区间, -42到6]）。

conclusions_and_relevance

Among patients with gram-negative bacilli BSIs, rapid blood culture AST was not superior to standard testing by DOOR.

在革兰氏阴性杆菌血流感染的患者中，快速血培养药敏试验并不优于标准检测，以DOOR为评价标准。

When considered with other efficacy and safety outcomes, these findings may help inform the use of rapid susceptibility testing in clinical practice.

当与其他有效性和安全性结果一起考虑时，这些发现可能有助于指导快速敏感性测试在临床实践中的使用。

trial_registration

ClinicalTrials.gov Identifier: NCT06174649.

ClinicalTrials.gov 注册号：NCT06174649。