Kim Hyungjoo, Newman Joshua, Cassiere Hugh, Hartman Alan, Yu Pey-Jen
Department of Cardiovascular and Thoracic Surgery, Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York.
Ann Thorac Surg Short Rep. 2024 Feb 8;2(3):586-589. doi: 10.1016/j.atssr.2023.12.024. eCollection 2024 Sep.
Cardiac surgery patients are at increased risk for venous thromboembolism (VTE). Prevention is the most critical strategy to reduce VTE-associated morbidity and death. However, there is a lack of data on the optimal approach to VTE prophylaxis in this population of high-risk patients. This study aimed to assess whether the standard dose of enoxaparin, the subcutaneous injection of 40 mg of enoxaparin daily, achieves adequate anti-factor Xa (aFXa) levels for VTE prophylaxis in patients after open heart surgery.
All patients with open heart surgery with cardiopulmonary bypass from August to December 2022 who received at least 3 consecutive doses of subcutaneously administered enoxaparin were included in the study. Patients receiving therapeutic anticoagulation, patients who underwent cardiac transplantation or placement of ventricular assist device, and patients with renal insufficiency were excluded. Serum aFXa was measured 0.5 to 1 hour before the fourth dose to attain the steady-state trough levels.
Data were completed for 44 patients. The target aFXa level was between 0.10 and 0.20 IU/mL for the avoidance of both underanticoagulation (≤0.10 IU/mL) and overanticoagulation (>0.20 IU/mL). The mean was 0.049 IU/mL with SD of 0.026 IU/mL, which was statistically significantly lower than the lower end of the target aFXa values (0.10 IU/mL; = -13; < .001; = -1.9; 99% CI, -0.059 to -0.043).
The daily subcutaneous administration of 40 mg of enoxaparin leads to subprophylactic aFXa levels for most patients who undergo cardiac surgery. Further studies on the clinical relevance are warranted.
心脏手术患者发生静脉血栓栓塞（VTE）的风险增加。预防是降低VTE相关发病率和死亡率的最关键策略。然而，对于这一高危患者群体，缺乏关于VTE预防最佳方法的数据。本研究旨在评估依诺肝素标准剂量（每日皮下注射40mg依诺肝素）是否能在心脏直视手术后患者中达到足够的抗Xa因子（aFXa）水平以预防VTE。
纳入2022年8月至12月接受体外循环心脏直视手术且至少连续皮下注射3剂依诺肝素的所有患者。排除接受治疗性抗凝的患者、接受心脏移植或植入心室辅助装置的患者以及肾功能不全的患者。在第4剂前0.5至1小时测量血清aFXa，以获得稳态谷浓度。
44例患者的数据完整。为避免抗凝不足（≤0.10IU/mL）和抗凝过度（>0.20IU/mL），目标aFXa水平为0.10至0.20IU/mL。平均值为0.049IU/mL，标准差为0.026IU/mL，在统计学上显著低于目标aFXa值的下限（0.10IU/mL；t = -13；P <.001；效应量 = -1.9；99%CI，-0.059至-0.043）。
对于大多数接受心脏手术的患者，每日皮下注射40mg依诺肝素导致aFXa水平低于预防剂量。有必要进一步研究其临床相关性。
