Heparin in the Treatment of Thromboembolic Stroke

Stroke is the single most important cause of neurological disability and the third most common cause of death in North America. The term stroke is used to describe the abrupt loss of function of a part of the central nervous system due to ischemia or hemorrhage which results in a focal neurological deficit that may be transient or prolonged. The majority of cerebral vascular strokes are thromboembolic in origin. It has been estimated that approximately 400,OOO persons in the United States suffer a form of thromboembolic stroke each year, of whom 40% die within the first 30 days. Of those patients who survive the first 30 days after a stroke, half have persistent neurological deficits and remain disabled and require long-term special care. Wolf et aL2 reported the results of a prospective population study carried out in Framingham, MA, in which the frequency of the development of stroke was examined. Over a 24-year period, 5184 people, aged 30 to 62 years, who were free of stroke at entry into the study were evaluated prospectively and examined every two years. After 24 years of follow-up, 345 strokes (6.7%) had occurred, 168 in men and 177 in women. Of these strokes, 82% were considered to be due to thromboembolic phenomena, 10% to subarachnoid hemorrhage, 5% to intracerebra1 hemorrhage, and the remaining 3% to miscellaneous causes. Of the total thromboembolic strokes, 72% were due to cerebral thrombosis, 17% were due to cerebral embolism with a demonstrated source such as the heart, and 11% were associated with transient ischemic attacks and presumably caused by emboli from carotid artery thrombi.