Low-molecular-weight heparin-coated cardiopulmonary bypass: coagulatory and clinical findings

Introduction

The aim of the study was to evaluate clinical and coagulatory effects of low-molecular-weight heparin-coated extracorporeal circulation (ECC) in coronary artery bypass grafting (CABG).

Method

CABG was performed in 287 patients, who were included in a prospective, randomized study. In patients treated using heparin coated technology (AOTHEL^®; AOT, Bad Oeynhausen, Germany), low-molecular-weight heparin coating was employed. Conventional roller pumps and coronary suction were used, and operations were performed in conditions of moderate hypothermia, with application of intermittent aortic cross-clamping. Patients were divided into three groups. Group A (n = 97) had a standard uncoated ECC set and intravenous heparin was administered at an initial dose of 400 IE/kg body weight; during ECC activated clotting time (ACT) was kept at 480 s or greater. Group B (n = 94) had the same ECC set but completely coated with low-molecular-weight heparin, and intravenous heparin was administered at the same dose as that employed in group A; ACT was kept at the same level. Group C (n = 96) had the same coated ECC set as group B, but intravenous heparin was reduced to 150 IE/kg, and during ECC ACT was set to be 240 s or greater. Coagulatory effects were measured in a consecutive subset of 119 patients.

Results

The coagulatory and clinical findings are presented in Tables 1 and 2, respectively.

Table 1 Coagulatory findings during ECC

Table 2 Clinical findings

Conclusion

CABG can be performed effectively employing heparin-coated ECC. Thrombin generation is significantly elevated by low intravenous heparinization at ECC durations greater than 60 min, but fibrinolysis is not increased. Platelet activation is less and there are few clinical complications, even if intravenous heparin is greatly reduced. Significantly less postoperative bleeding and need for blood replacement occurs only if coated ECC technology is combined with low-dose systemic heparin.