Sonoclot analysis in coronary artery surgery: a comparison between patients with unstable coronary artery disease treated with enoxaparin before surgery and patients with stable coronary artery disease not treated with enoxaparin

Abstract

Objectives: To investigate whether perioperative Sonoclot analyses could identify differences in hemostatic function between a group of patients with unstable coronary artery disease treated with low-molecular-weight heparin until the evening before surgery and a group of patients with stable coronary artery disease not treated with low-molecular-weight heparin.

Design: Prospective and observational investigation.

Setting: A university hospital, single institution.

Participants: Patients scheduled for coronary artery bypass surgery.

Interventions: Blood samples for Sonoclot analysis were drawn preoperatively, 5 minutes after the administration of heparin, immediately after and 20 minutes after cardiopulmonary bypass was established, and 30 minutes and 3 and 20 hours after the end of surgery in a group of patients with unstable coronary artery disease and a group of patients with stable coronary artery disease.

Measurements and main results: The Sonoclot variables sonACT, coagulation rate, time to peak, amplitude of the peak, and R3 were recorded. The sonACT was significantly lower in the enoxaparin group compared with the control group, whereas the coagulation rate was significantly higher in the enoxaparin group. There were no statistically significant differences in time to peak, amplitude of the peak, and R3 between the 2 study groups.

Conclusions: The presence of a hypercoagulable state in patients with unstable coronary artery disease is indicated by the significantly higher coagulation rate observed in this group compared with the control group. Further larger studies are needed for evaluation of the usefulness of Sonoclot analysis in the monitoring of hemostatic function in patients with unstable coronary artery disease.