| Abstract | OBJECTIVES: The administration of unfractionated heparin (UFH) prior to carotid clamping during carotid endarterectomy (CEA) transiently increases the platelet aggregation response to arachidonic acid (AA) despite the use of aspirin. We hypothesized that this phenomenon might be reduced by using low molecular weight heparin (LMWH) resulting in fewer emboli in the early post-operative period. METHODS: 183 aspirinated patients undergoing CEA were randomised to 5000 IU UFH (n=91) or 2500 IU LMWH (dalteparin, n=92) prior to carotid clamping. End-points were: transcranial Doppler (TCD) measurement of embolisation, effect on bleeding and platelet aggregation to AA and adenosine 5'-diphosphate (ADP). RESULTS: Patients randomised to UFH had twice the odds of experiencing a higher number of emboli in the first 3h after CEA, than those randomised to LMWH (p=0.04). This was not associated with increased bleeding (mean time from flow restoration to operation end: 23 min (UFH) vs. 24 min (LMWH), p=0.18). Platelet aggregation to AA increased significantly following heparinisation, but was unaffected by heparin type (p=0.90). The platelets of patients randomised to LMWH exhibited significantly lower aggregation to ADP compared to UFH (p<0.0001). CONCLUSIONS: Intravenous LMWH is associated with a significant reduction in post-operative embolisation without increased bleeding. The higher rate of embolisation seen with UFH may be mediated by increased platelet aggregation to ADP, rather than to AA. |
| Authors | G S McMahon, S E Webster, P D Hayes, C I Jones, A H Goodall, A R Naylor
(Affiliation: Department of Cardiovascular Sciences, University of Leicester, Leicester Royal Infirmary, Leicester, UK. gregmcmahon at hotmail.com)
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| Journal | European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery
(Eur J Vasc Endovasc Surg)
Vol. 37
Issue 6
Pg. 633-9
(Jun 2009)
ISSN: 1532-2165 [Electronic] England |
| PMID | 19328023
(Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
|
| Chemical References |
- Anticoagulants
- Dalteparin
- Platelet Aggregation Inhibitors
- Aspirin
- Arachidonic Acid
- Adenosine Diphosphate
- Heparin
|
| Topics |
- Adenosine Diphosphate
(diagnostic use)
- Aged
- Anticoagulants
(administration & dosage, adverse effects, therapeutic use)
- Arachidonic Acid
(diagnostic use)
- Aspirin
(therapeutic use)
- Carotid Artery Diseases
(blood, mortality, surgery, ultrasonography)
- Dalteparin
(administration & dosage, adverse effects, therapeutic use)
- Double-Blind Method
- Drug Therapy, Combination
- Endarterectomy, Carotid
(adverse effects, mortality)
- Female
- Hemorrhage
(chemically induced)
- Heparin
(administration & dosage, adverse effects, therapeutic use)
- Humans
- Infusions, Intravenous
- Intracranial Embolism
(blood, etiology, mortality, prevention & control, ultrasonography)
- Male
- Middle Aged
- Odds Ratio
- Platelet Aggregation
(drug effects)
- Platelet Aggregation Inhibitors
(therapeutic use)
- Risk Assessment
- Stroke
(blood, etiology, mortality, prevention & control, ultrasonography)
- Time Factors
- Treatment Outcome
- Ultrasonography, Doppler, Transcranial
|
