Heparin Sensitivity and Postoperative Blood Loss in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass

Background

Heparin-associated coagulation disorder is an important factor related to postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass. Currently, the relationship between heparin sensitivity and postoperative bleeding is unknown.

Objective

To investigate the relationship between individual heparin sensitivity and postoperative blood loss in patients undergoing cardiac surgery.

Design

Prospective controlled study.

Setting

Tertiary teaching hospital, Urumqi, Xinjiang, PR China. The study was conducted from January 2016 to August 2018.

Patients

A total of 195 adult patients undergoing cardiac valve replacement surgery were included.

Intervention

After initial heparin dosing (2.5 mg kg⁻¹), patients were divided into three groups according to the whole blood activated clotting time (ACT): group A, insensitive group (ACT < 480 s); group B, sensitive group (480 s < ACT < 750 s); group C, hypersensitive group (ACT > 750 s).

Main Outcome Measures

First, intra-operative and 24-h postoperative blood loss. Second, antithrombin (AT) and factor X mRNA levels. Third, the plasma levels of AT-III and factor X. Fourth, heparin sensitivity index.

Results

Blood loss was approximately 20 to 25% lower in group B than in groups A and C, which was statistically significant (P < 0.01). The AT-III mRNA levels increased from groups A to C and was positively associated with heparin sensitivity; the factor X mRNA levels changed in the opposite direction; a significant difference was observed between groups A and C (P < 0.05). The factor X plasma level showed the same trend as its mRNA. The AT-III plasma level was significantly lower in group B than in groups A and C (P < 0.05).

Conclusion

Postoperative blood loss is related to heparin sensitivity in patients undergoing cardiac surgery, and the moderately sensitive patients have the least postoperative bleeding. Individual variation in heparin sensitivity is related to the mRNA and plasma levels of AT-III and factor X.