Association between platelet levels and bleeding events in patients with acute-on-chronic liver failure treated with an artificial liver support system

Background Platelet reduction is associated with an increased risk of bleeding in patients with chronic liver disease. However, the association between platelet levels and bleeding events in patients with liver failure treated with an artificial liver support system (ALSS) remains unclear. Methods This retrospective study included patients with acute-on-chronic liver failure (ACLF) who received ALSS treatment. Logistic and linear regression analyses were employed to assess the association between platelet levels and bleeding events during hospitalization and the relationship between sessions of ALSS treatment and platelet reduction rates. Results We included 262 patients, of whom 56 (21.4%) experienced bleeding events during hospitalization. Baseline platelet levels in patients with bleeding events were significantly lower than those in patients without bleeding events (59.0 (39.0 ~ 89.3) × 10 9 /L vs. 88.5 (57.0 ~ 121.0) × 10 9 /L; p < 0.001). Baseline platelet levels were negatively associated with bleeding events (adjusted OR, 0.986; 95% CI, 0.976–0.996; p = 0.006), whereas platelet reduction rates and final platelet levels were not significantly associated with bleeding events (all p > 0.05). Compared to patients with baseline platelet grade 0, the risk of bleeding was significantly higher compared to those with baseline platelet grade 1 (adjusted OR: 3.21, 95% CI: 1.20 ~ 8.59, p = 0.002) and grade 2 (adjusted OR: 7.20, 95% CI: 2.28 ~ 21.43, p = 0.001), as well as in the combined group of grades 2 and 3 (adjusted OR: 8.43, 95% CI: 2.96 ~ 23.99, p < 0.001). The number of ALSS treatment sessions was not significantly associated with platelet reduction rates ( p > 0.05). Conclusion Patients with ACLF who underwent ALSS treatment with lower baseline platelet levels were at an increased risk of bleeding during hospitalization, whereas the platelet reduction rate was not independently associated with bleeding risk. These findings underscore the importance of baseline platelet count rather than platelet reduction for early risk stratification in patients with ACLF.