Antithrombin as a Predictor of Heparin Resistance in Cardiac Surgery With Cardiopulmonary Bypass
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 300
- 试验地点
- 1
- 主要终点
- Heparin resistance
研究概览
简要总结
This study aims to investigate whether the level of antithrombin (AT) in the blood before cardiac surgery can predict how well patients respond to heparin, a medication used to prevent blood clotting during surgery with a heart-lung machine (cardiopulmonary bypass).
Heparin requires antithrombin to work effectively. Some patients have lower levels of antithrombin, which may result in reduced response to heparin, a condition known as heparin resistance. This can lead to difficulties achieving adequate anticoagulation during surgery and may require additional medication or adjustments in treatment.
In this study, an additional blood sample will be taken after anesthesia induction but before the administration of heparin. No changes will be made to the patient's treatment or care. Clinical data, including laboratory values, heparin dosing, and surgical outcomes, will be collected from routine medical records.
The goal is to identify a clinically useful antithrombin threshold that can help detect patients at risk of heparin resistance. This may improve patient safety, optimize treatment strategies, and reduce unnecessary use of antithrombin therapy in the future.
详细描述
This prospective observational cohort study aims to evaluate whether preoperative antithrombin (AT) levels can predict heparin resistance in adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) at Sahlgrenska University Hospital, Sweden.
Heparin is routinely administered during CPB to prevent thrombus formation in the extracorporeal circuit. Its anticoagulant effect depends on the presence of antithrombin, a key endogenous inhibitor of coagulation. Reduced levels of antithrombin are known to impair the anticoagulant response to heparin and may result in heparin resistance. Clinically, this can lead to repeated heparin dosing, delays in achieving adequate anticoagulation, and increased use of antithrombin supplementation. However, there is currently no well-established threshold for antithrombin levels that can reliably identify patients at risk prior to heparin administration.
The study is designed as a non-interventional investigation in which all patients are managed according to standard clinical practice. A single additional blood sample for measurement of antithrombin will be obtained after induction of anesthesia and prior to administration of heparin. This timing is chosen to ensure standardized conditions and to minimize the influence of hemodilution and perioperative physiological changes.
Clinical and perioperative data will be collected from routine medical records, including anesthesia records, perfusion protocols, and laboratory systems. These data will be used to assess the relationship between preoperative antithrombin levels and the anticoagulant response to heparin during CPB, as well as associated perioperative outcomes.
The primary objective is to determine whether antithrombin levels can serve as a clinically useful predictor of heparin resistance. The analysis will focus on evaluating the discriminative ability of antithrombin and identifying a threshold value that may be useful for clinical decision-making. Secondary analyses will explore the association between antithrombin levels, heparin dosing requirements, and perioperative outcomes.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age ≥18 years
- •Planned cardiac surgery with cardiopulmonary bypass
- •Ability to provide informed consent
排除标准
- •Emergency cardiac surgery
- •Ongoing antithrombin supplementation prior to surgery
- •Known severe congenital coagulation disorder affecting interpretation of outcomes
- •Severe liver failure
- •Missing key data required to define heparin resistance (e.g., missing heparin dose or ACT values)
研究组 & 干预措施
Patients undergoing cardiac surgery with cardiopulmonary bypass
Adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) at Sahlgrenska University Hospital, Sweden. All patients are managed according to standard clinical practice. A preoperative blood sample is collected to measure antithrombin levels, and clinical data are collected to assess the relationship between antithrombin levels and heparin resistance. No study-specific intervention is performed.
干预措施: No intervention (observational study) (Other)
结局指标
主要结局
Heparin resistance
时间窗: Intraoperative (immediately after initial heparin administration)
Heparin resistance defined as failure to achieve an activated clotting time (ACT) ≥480 seconds after administration of an initial heparin dose of 350 IU/kg, according to standard clinical practice.
次要结局
- Activated clotting time after initial heparin dose(Intraoperative (after initial heparin administration))
- Total heparin dose(Intraoperative)
- Antithrombin supplementation(Intraoperative)
研究者
Anna Corderfeldt Keiller
Senior Perfusionist, PhD
Sahlgrenska University Hospital