We read with interest the comments of M. Sturzenegger about our case observation [1]. We agree that it is unknown whether the relationship between anticoagulation and delayed carotid occlusion is causal rather than coincidental. However, colleagues from Geneva and Berlin made similar observations [2,3,4]. We agree that arterial thromboembolism is the main pathogenetic mechanism in cerebral ischaemia due to carotid dissection.
However, we disagree with the conclusion that delayed carotid occlusion during anticoagulation is clinically irrelevant for all dissection patients. Among 5 patients with delayed occlusion of the internal carotid artery during heparin therapy reported by Dreier et al. [4], one developed a watershed infarction. He was the only one without sufficient collateralisation at the circle of Willis, suggesting a haemodynamic stroke mechanism. This observation shows that anticoagulation indeed can be harmful in some patients with carotid dissection. Thus, the question remains whether in patients with carotid artery dissection antiplatelets are inferior to anticoagulants and therefore all patients should be anticoagulated as widely advocated [5]. Evidence from randomised trials on the efficacy of this therapy is missing [6,7]. Still, a Cochrane review across case series showed no difference between antiplatelets and anticoagulation [6,7]. Therefore, in order to balance risks and benefits of both options, a randomised controlled trial is necessary to solve the question of antiplatelets versus anticoagulants in carotid dissection. Whether such a trial is feasible remains to be shown. In the meantime, we recommend tailoring antithrombotic treatment decisions individually, based on distinct clinical and paraclinical characteristics [8].
References
- Fluri F, Lyrer PA, Steck AJ, Engelter ST. Internal carotid artery dissection with occlusion during heparin therapy. Schweiz Arch Neurol Psychiatr. 2007; 158:331–3.
- Perren F, Bocquet L, Saulnier F, Landis T, Sztajzel R. Does anticoagulation harm in acute cervical artery dissection? Cerebrovasc Dis. 2006;21(4):146.
- Perren F, Landis T, Sztajzel R. Does anticoagulation harm in acute “spontaneous” cervical artery dissection? Presentation at the 11th Meeting of Cerebrovascular Working Group of Switzerland. Aarau, January 24, 2008. http://kongress2.imk.ch/ZAS2008/ Programm?language=de.
- Dreier JP, Lurtzing F, Kappmeier M, Bohner G, Klingebiel R, Leistner S, et al. Delayed occlusion after internal carotid artery dissection under heparin. Cerebrovasc Dis. 2004;18(4):296–303.
- Brandt T, Stögbauer F, Ringelstein EB, Sitzer M. Dissektion hirnversorgender Arterien. In: Diener HC, Hacke W, Forsting M, Herausgeber. Schlaganfall: Referenzreihe Neurologie – Klinische Neurologie. 1. Auflage. Stuttgart, New York: Thieme; 2004. S. 176–81.
- Lyrer P, Engelter S. Antithrombotic drugs for carotid artery dissection. Stroke. 2004;35(2):613–4.
- Lyrer P, Engelter S. Antithrombotic drugs for carotid artery dissection. Cochrane Database Syst Rev. 2003;(3):CD000255.
- Engelter ST, Brandt T, Debette S, Caso V, Lichy C,Pezzini A, et al., for the Cervical Artery Dissection in Ischemic Stroke Patients (CADISP)-Study Group. Antiplatelets versus anticoagulation in cervical artery dissection – a review. Stroke. 2007;38:2605–11.
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (CC BY-NC-ND) 4.0 License.