Association between prothrombin time activity and short-term outcomes in patients with infective endocarditis

Abstract Background Coagulopathy, a frequent complication of infectious diseases, is strongly associated with adverse clinical outcomes. This study aimed to investigate the prognostic value of prothrombin time activity (PTA) in patients with infective endocarditis (IE). Methods A total of 1,533 IE patients were stratified into four groups based on quartiles of PTA at admission: 1) < 73% (n = 366); 2) 73%-83% (n = 381); 3) 84%-92% (n = 370); and 4) ≥ 93% (n = 416). Receiver operating characteristic (ROC) analysis was used to identify the optimal PTA cut-off for predicting in-hospital mortality. Multivariable regression and subgroup analyses were conducted to assess the association between PTA and 6-month mortality. Results The in-hospital mortality was higher in IE patients with lower PTA (15.8% vs. 5.8% vs. 4.6% vs. 2.9%; P < 0.001). PTA was independently associated with in-hospital death (odds ratio: 0.98; 95% CI: 0.97-0.99; P < 0.001). ROC curve analysis identified 78% as the optimal PTA cut-off value for predicting in-hospital mortality, with a sensitivity of 67.8% and specificity of 66.1% (AUC: 0.704; P < 0.001). In multivariable Cox regression analysis, PTA < 78% was an independent predictor of 6-month mortality, with a 2.27-fold increased risk after adjusting for potential confounders (95% CI: 1.63-3.17; P = 0.025). The predictive performance of PTA was robust across subgroups stratified by infection site, disease severity, and organ dysfunction. Conclusion PTA < 78% at admission is an independent predictor of poor short-term outcomes in patients with IE. This novel finding highlights the importance of coagulation assessment in IE and facilitates early risk stratification in IE management.