Heparin‐induced thrombocytopenia in patients with cerebrovascular ischemic disease

Abstract

We studied 137 patients who were treated with heparin for cerebral infarction (73), partially reversible ischemic neurologic deficit (22), or transient ischemic attack (42). Platelet counts were performed before therapy, twice weekly, and at cessation of therapy. Platelets decreased in 118 patients (86%). In 21 (15.3%), platelets dropped greater than or equal to 40%; 9 of 14 new ischemic events and three of six deaths occurred in this group of patients. Because there was a significant association between poor outcome and platelet drop greater than or equal to 40% (p less than 0.001), we believe that platelets should be monitored frequently when patients are treated with heparin for ischemic cerebrovascular disease.

Heparin-Induced Thrombocytopenia: A Serious Complication of Heparin Therapy for Acute Stroke

“…At the National Cardiovascular Center (Osaka, Japan), in addition to being administered to prevent DVT and PE during the acute phase of stroke, UFH is given to: acute stroke patients having embologenic heart diseases or superimposed thrombi on the carotid plaque to prevent embolic complications; patients with particular stroke etiologies, including cerebral arterial dissection and vasculitis, and patients with embolic stroke of unknown origin until the presence of heart diseases is excluded using prolonged electrocardiography and transesophageal echocardiography [9]. A previous study of 137 stroke patients treated with UFH reported that 21 patients (15.3%) developed thrombocytopenia, and 5 of these 21 patients had a recurrent ischemic stroke [10]. In another study, of 18 patients who developed carotid arterial occlusion following endarterectomy, 6 (33%) had an associated heparin-induced coagulation disorder [11].…”

Is Anticoagulant Therapy Too Frequently Used in Ischemic Stroke?

“…This suggests that platelets become activated and are consumed. In the prospective study of Ramirez-Lassepas et al [ 19], 9 of 14 new ischemic events and 3 of 6 deaths occurred among patients whose platelet count decreased by ^40%. To prevent this kind of thrombotic complications, it has been suggested that all patients receiving heparin have serial platelet counts.…”

“…The true frequency of this phenomenon is difficult to establish since it depends on how thrombocy topenia is defined. In a prospective study of 137 patients treated with heparin for cerebral infarction or TIA, a decrease in platelet count was observed in 118 patients (86%) and in 21 (15%), platelets dropped ^40% [19]. Severe (< 100,000 platelets/pl) heparin-induced throm bocytopenia probably occurs in 5-10% of patients and it varies with different types of heparin preparations.…”

Prevention and management of stroke

“…If heparin therapy is chosen for such patients, it should be undertaken with the following caveats: a high resolution CT scan should be taken to exclude haemorrhage; lumbar puncture is not necessary to detect haemorrhage if a high-resolution CT is negative; it is logical to begin heparin with an initial bolus of 1000 units followed by a constant infusion of 800-1200 units per hour in order to produce an immediate 1.5 to 2.0 times prolongation of the partial thromboplastin time; and the platelet count should be measured daily.to detect heparin-induced thrombocytopenia which may lead to systemic vascular occlusion. 34 Heparin should be stopped if the platelet count falls substantially. The optimal duration of heparin treatment is not known, but it should be carefully withdrawn only after the patient has been stable for 72 hours and re-introduced if further deterioration occurs.…”