Diagnostic and prognostic value of Ang-2 in ARDS: a systemic review and meta-analysis

To investigate the diagnostic and prognostic value of angiopoietin-2 (Ang-2) for acute respiratory distress syndrome (ARDS). Seven databases (4 English and 3 Chinese databases) were searched, the quality was evaluated by QUADAS-2 and GRADE profile. The bivariate model was employed to combine area under the curve (AUC), pooled sensitivity (pSEN) and pooled specificity (pSPE), the Fagan’s nomogram was employed for evaluating clinical utility. This study was registered in PROSPERO (NO.CRD42022371488). 18 eligible studies comprising 27 datasets (12 diagnostic and 15 prognostic datasets) were included for meta-analysis. For diagnostic analysis, Ang-2 yielded an AUC of 0.82, with a pSEN of 0.78 and a pSPE of 0.74; in clinical utility analysis, a pretest probability of 50% regulated the post probability positive (PPP) of 75% and the post probability negative (PPN) of 23%. In prognostic analysis, Ang-2 yielded an AUC of 0.83, with a pSEN of 0.69, a pSPE of 0.81, and good clinical utility (a pretest probability of 50% regulated the PPP of 79% and the PPN of 28%). Heterogeneity existed in both diagnostic and prognostic analysis. Ang-2 demonstrates promising diagnostic and prognostic capabilities as a noninvasive circulating biomarker for ARDS, especially in the Chinese population. It is advisable to dynamically monitor Ang-2 in critically ill patients both suspected and with confirmed ARDS.