[Anticoagulation in acute cerebral infarct. Benefits, risks, therapeutic failures]

Abstract

We studied 2 groups of ischemic stroke patients who received therapeutic heparinization during the acute phase in order to prevent thromboembolic reinfarction. 530 patients were studied retrospectively (Group B) and 127 prospectively (Group A). Doses of 24,000-38,000 IE/24 h of heparin were given i.v., resulting in a partial thromboplastin time 2-3 times that of normal controls. Three patients from Group A suffered a massive intracranial hemorrhage. All of them had a large infarction (greater than 5 cm in diameter). They had been given anticoagulants within the first 12 h. Two of them presented with uncontrollable hypertension (systolic BP up to 240 mm Hg). Ischemic reinfarction during the first two weeks occurred in 2.3% and 2.4% of subgroups, respectively. This was less than would have been expected from the literature (approx. 14-15%). Features of these patients were 1.) insufficient heparin dosage, 2.) progression of hemodynamically relevant internal carotid artery lesions leading to critical low-flow or 3.) embolization of a floating thrombus from the internal carotid artery in the middle cerebral artery. It appears that therapeutic heparinization reduces the rate of reinfarction within the acute phase of ischemic strokes. This type of treatment should, however, be confined to patients with an embolic stroke mechanism. Careful surveillance of blood pressure and PTT are prerequisites. Anticoagulation should be avoided in patients with massive infarctions (greater than 5 cm in diameter) or uncontrollable hypertension.