Introduction In December 2023, the cardiac surgery team of Guangdong Provincial People's Hospital cooperated with Difei Medical and published a research paper in the journal Clinica Chimica Acta (IF=5.0).The article included 79 patients with left-sided infective endocarditis (LSIE) after valve surgery and conducted a prospective study. The patients' venous blood, arterial blood and valve samples were collected for culture and mNGS detection. The purpose is to explore the detection performance, influencing factors and bacterial flora distribution of mNGS in venous and arterial blood of patients with LSIE, and to provide favorable basis for the clinical application of mNGS.Research background Infective endocarditis (IE) is a disease that occurs on natural or artificial heart valves, endocardial surfaces or