Preoperative Thromboelastographic Profile of Patients with Congenital Heart Disease: Association of Hypercoagulability and Decreased Heparin Response

Abstract

Objective: To describe the demographic and thromboelastographic characteristics of patients with congenital heart disease presenting with decreased heparin response before cardiac surgery.

Design: Retrospective, observational study.

Setting: Single institution, tertiary, academic, university hospital.

Participants: The study comprised 496 pediatric and adult patients undergoing cardiac surgery for congenital heart disease.

Interventions: Retrospective review of medical records.

Measurements and main results: Data on preoperative thromboelastography (TEG), demographics, and response to heparin were collected retrospectively. Logistic regression analysis was used to study the association between TEG and response to heparin. Decreased heparin response (defined as activated clotting time <480 s initial bolus of 300 U/kg heparin) was observed in 23.6% of patients presenting for surgery. Age distribution and preoperative coagulation profiles were similar for both nonresponders and responders to heparin. Preoperatively, nonresponders demonstrated all thromboelastrographic characteristics consistent with a hypercoagulable profile (shorter reaction time, K value, wider angle, and maximum amplitude). Univariate logistic regression identified all TEG variables significantly associated with decreased heparin response. After adjustment for age, procedure type, and the presence of cyanosis, a multivariate logistic regression model identified the TEG variable K (≤1.3 min) as being significantly associated with decreased heparin response (odds ratio 3.7; confidence interval 2.3-5.8; p < 0.0001).

Conclusions: Decreased response to heparin before cardiac surgery in patients with congenital heart disease is associated with preoperative hypercoagulability identified using a viscoelastic test. Additional studies are needed to better understand the etiology of decreased heparin response and potential clinical strategies to improve anticoagulation management.

Keywords: congenital heart disease; heparin resistance; hypercoagulability; pediatric cardiac surgery; thromboelastography.