FLUSH HEPARIN DURING CARDIAC-CATHETERIZATION PREVENTS LONG-TERM COAGULATION ACTIVATION IN CHILDREN WITHOUT APC-RESISTANCE - PRELIMINARY-RESULTS

This study was designed to prospectively evaluate haemostatic activati on in 75 children undergoing cardiac catheterisation with intermittent flush heparin (10 IU/ml saline) and to relate these data to clinical findings and inherited risk factors for thrombophilia. In addition to flush heparin in infants <6 months of age in whom additional arterial catheterisation was performed (n=5) or patients with thrombophilia, he parin (300-400 IU/kg/d) was administered for a further 24 h. APTT was prolonged and anti Xa activity was significantly increased at the end of catheterisation and returned to normal 24 hours later. Whereas thro mbin generation (F1+2) showed a significant coagulation activation at the end of catheterisation, no concomitant fibrinolytic activation (D- Dimer) was observed. Four children showed resistance to APC: one of th em in whom stroke had occurred before and one additional child heteroz ygous for APCR received further prophylactic heparin. Two neonates wit h APCR and flush heparin only suffered from thrombosis after catheteri sation. No further thrombotic events occurred. This study indicates th at low-dose flush heparin during catheterisation may prevent long-term haemostatic activation in children without thrombophilia. Whether fur ther heparin after cardiac catheterisation in children with APCR preve nts vascular insults requires a more intensive study.