Incorporating the identification of Class 1 dynamic trajectory significantly improved the predictive performance for 30-day mortality (area under the curve = 0.824, <i>P</i> = 0.0015).<h4>Conclusions</h4>This prospective cohort study uncovers heterogeneity in AT III trajectories among IAI-induced sepsis, which were closely associated with the disease severity over time. Here, SERPINC1 is linked to Sepsis.