Association of thrombocytopenia and D-dimer elevation with in-hospital mortality in acute aortic dissection

Data on the association between the degree of platelet and coagulative-fibrinolytic variables abnormalities and the risk of in-hospital mortality in acute aortic dissection (AAD) are limited.
This multicentre retrospective cohort study included patients diagnosed with AAD by aortic computed tomographic angiography between 2010 and 2021 in five tertiary hospitals in China. The primary outcome was defined as all-cause mortality during hospitalization. Associations between platelet counts, coagulation-fibrinolytic parameters and all-cause in-hospital mortality were assessed using Cox proportional hazards regression models.
Among the 2567 participants, the median age was 54 years (interquartile range, IQR: 47–63); 531 (20.7%) were female, and the in-hospital mortality rate was 589 (23.0%). The Cox proportional hazards regression model indicated that lower platelet count, prothrombin activity (PTA), and fibrinogen levels and longer prothrombin time (PT) and thrombin time (TT) were linearly positively associated with an increased risk of in-hospital mortality (p < 0.05). A non-linear and positive association was confirmed between D-dimer levels and in-hospital mortality risk (p < 0.05). Additionally, a significant interaction between platelet counts and D-dimer levels was observed (p = 0.029). According to the subgroup analysis, compared to those in the reference group, those with thrombocytopenia (<140 × 109/L) and high D-dimer levels (>14.6 µg/mL) had a 3.59-fold increased risk of in-hospital mortality (HR, 3.59; 95% CI, 2.00–6.42).
Our analysis revealed associations between changes in platelet count, PT, PTA, TT, fibrinogen and D-dimer levels and outcomes in patients with AAD. Furthermore, the combined effect of thrombocytopenia and high D-dimer levels significantly increased the risk of in-hospital mortality.
Platelet count and coagulation-fibrinolysis system variables, including PT, PTA, TT, fibrinogen and D-dimer levels, are significantly associated with in-hospital mortality risk in acute aortic dissection (AAD) patients.
A significant interaction between platelet count and D-dimer level (p = 0.029) highlights that the combined effect of thrombocytopenia and elevated D-dimer levels significantly increases the risk of in-hospital mortality in AAD patients.
Prompt and repeated assessment of platelet counts and coagulation-fibrinolysis system variables upon admission can serve as pivotal biomarkers for risk stratification in AAD patients, facilitating timely and targeted interventions.