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 (<i>p</i> &lt; 0.05). A non-linear and positive association was confirmed between D-dimer levels and in-hospital mortality risk (<i>p</i> &lt; 0.05). Additionally, a significant interaction between platelet counts and D-dimer levels was observed (<i>p</i> = 0.029). According to the subgroup analysis, compared to those in the reference group, those with thrombocytopenia (&lt;140 × 10⁹/L) and high D-dimer levels (&gt;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 (<i>p</i> = 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.

目前关于急性主动脉夹层（acute aortic dissection, AAD）患者血小板与凝血纤溶指标异常程度与院内死亡风险的关联研究较为有限。
本研究为一项多中心回顾性队列研究，纳入了2010年至2021年间中国5家三级医院经主动脉计算机断层血管造影（aortic computed tomographic angiography）确诊的AAD患者。本研究的主要结局为住院期间的全因死亡率。采用Cox比例风险回归模型（Cox proportional hazards regression models）评估血小板计数、凝血纤溶参数与全因住院死亡率之间的关联。
共纳入2567例受试者，中位年龄为54岁（四分位距（interquartile range, IQR）：47~63）；其中女性531例（20.7%），院内死亡人数为589例，死亡率达23.0%。
Cox比例风险回归分析显示，血小板计数降低、凝血酶原活动度（prothrombin activity, PTA）与纤维蛋白原水平下降，以及凝血酶原时间（prothrombin time, PT）和凝血酶时间（thrombin time, TT）延长，均与院内死亡风险升高呈线性正相关（P<0.05）。D-二聚体（D-dimer）水平与院内死亡风险则呈非线性正相关（P<0.05）。此外，研究观察到血小板计数与D-二聚体水平之间存在显著交互作用（P=0.029）。
亚组分析结果表明，与参照组相比，伴血小板减少症（thrombocytopenia，<140×10^9/L）且D-二聚体水平升高（>14.6μg/mL）的患者，其院内死亡风险升高3.59倍（风险比（hazard ratio, HR）=3.59；95%置信区间（95% CI）：2.00~6.42）。
本研究分析显示，AAD患者的血小板计数、PT、PTA、TT、纤维蛋白原及D-二聚体水平变化与临床结局存在关联。进一步发现，血小板减少症与高D-二聚体水平的联合效应可显著升高院内死亡风险。血小板计数及凝血纤溶系统指标（包括PT、PTA、TT、纤维蛋白原及D-二聚体水平）与AAD患者的院内死亡风险显著相关。血小板计数与D-二聚体水平间的显著交互作用（P=0.029）提示，血小板减少症与D-二聚体水平升高的联合效应可显著升高AAD患者的院内死亡风险。入院时及时且重复评估血小板计数及凝血纤溶系统指标，可作为AAD患者风险分层的关键生物标志物，助力实现及时且针对性的干预措施。