Detection of pathogens from venous or arterial blood of patients with left-sided infective endocarditis by metagenomic next-generation sequencing: a prospective study.

BACKGROUND: Infective endocarditis is a life-threatening uncommon infectious disease, and we aimed to explore the clinical utility of venous or arterial blood-based metagenomic next-generation sequencing (mNGS) approaches to diagnose left-sided infective endocarditis (LSIE).

METHODS: We prospectively studied 79 LSIE patients who received valvular surgery in our hospital. Results of blood culture, valve culture, venous blood-based mNGS, arterial blood-based mNGS, venous blood-based mNGS plus blood culture, and arterial blood-based mNGS plus blood culture were evaluated and compared.

RESULTS: Both venous blood- and arterial blood-based mNGS methods displayed significantly higher positive detection rates than blood culture and valve culture (43.0%, 49.4% vs. 32.9%, 19.0%; P<0.001). Strikingly, when combining blood-based mNGS and blood culture, the positive rate could be further improved to more than 60%. Moreover, we found mNGS LSIE detection was closely associated with preoperative leukocyte (P=0.027), neutrophil value (P=0.018), vegetation≥14 mm (P=0.043), and vegetations in aortic valve (P=0.048). In addition, we discovered that blood-based mNGS had a superior capacity over blood culture to detect gram-negative bacteria, fungi, Bartonella Quintana, and mixed infections than blood culture.

CONCLUSION: This study indicates that venous blood- and arterial blood-based mNGS displayed high positive rate in the rapid detection of pathogens in high-risk LSIE patients.