Inhibition of clot formation process by treatment with the low-molecular-weight heparin nadroparin in patients with carotid artery disease undergoing angioplasty and stenting. A thromboelastography study on whole blood.

Low-molecular-weight heparins (LMWHs) have become the corner stone of antithrombotic treatment but their administration protocol needs to be optimized for certain groups of patients. In this paper, we studied the influence of nadroparin treatment on clot formation process assessed by thromboelastography in patients with carotid artery disease undergoing angioplasty and stenting. Standard thromboelastography assays (in-TEM and ex-TEM) and minimal TF-triggered thromboelastography assay in citrated whole blood were performed in normal volunteers (n = 20), in patients with carotid artery disease receiving only antiplatelet treatment (n = 30), and in patients undergoing angioplasty receiving nadroparin 5750 anti-Xa IU s.c. twice daily (n = 60). Blood samples were collected four hours after a second injection of nadroparin. In a subgroup of LMWH-patients (n = 18) blood samples were also obtained prior to first injection of LMWH. Antiplatelet treatment had no effect on any parameter of the thromboelastographic pattern. Nadroparin treatment resulted in significant prolongation of clotting time (CT) and clot formation time (CFT) and significantly reduced a -angle in minimal TF-triggered thromboelastography and 30 - 38% of nadroparin treated patients had thromboelastographic parameters beyond the normal maximum limit. In-TEM test revealed a significant prolongation of clotting time while ex-TEM was not modified, and 20 to 30% of the patients had thromboelastographic parameters beyond the normal maximum limit. Anti factor-Xa activity in platelet-poor plasma (PPP) was also measured, and statistical analysis showed that prolongation of CFT of minimal TF-triggered TEM was significantly correlated to the levels of anti-Xa activity in patients ' plasma (p = 0.04; r (2) = 0.7). There was no statistical correlation for any other parameter in all tests. In conclusion, the present study shows that nadroparin treatment in patients with carotid artery disease undergoing endovascular procedures induces significant modification of the thrombus kinetics assessed by minimal TF-triggered whole blood thromboelastography. The clinical relevance of these findings has to be evaluated in future studies.

[Multidisciplinary consultation for the prescription of danaparoid in suspected heparin-induced thrombocytopenia]. / Impact d'une organisation pluridisciplinaire pour la "juste prescription" du danaparoïde sodique en cas de suspicion de thrombopénie immuno-allergique à l'héparine.

INTRODUCTION: Heparin-induced thrombocytopenia (HIT) is a serious immune complication of heparin therapy and presents a risk of severe thromboembolic events. Withdrawal of heparin together with administration of an alternative antithrombotic agent is always necessary in patients with suspected HIT. Diagnosis of this complication, however, is often difficult, particularly in hospitalized patients. The aim of this study was to evaluate the impact of multidisciplinary consultation on the appropriate prescription of danaparoid, widely used as an alternative antithrombotic treatment in HIT. MATERIAL AND METHODS: Multidisciplinary consultation between clinician, hematologist, and pharmacist called for reassessment of the HIT diagnosis at day 3 and between day 3 and 10 after the beginning of danaparoid treatment. Continuation or stopping treatment depended on their joint conclusion. All danaparoid prescriptions were evaluated according to this procedure for one year. RESULTS: HIT was suspected in 26 in-patients. The multidisciplinary approach made it possible to reassess the HIT diagnosis on day 3 and stop the alternative treatment in 42.3% of cases. Danaparoid use decreased by 52% compared with the previous year. CONCLUSION: Multidisciplinary consultations between clinician, hematologist, and pharmacist appear useful for minimizing inappropriate prescription of this alternative treatment in cases of suspected HIT.