Excluding patients from thrombolytic therapy on the basis of anticoagulation alone should be reconsidered according to researchers.
SAN FRANCISCO—IV thrombolysis can be safe and effective in patients with acute ischemic stroke who have had anticoagulation therapy, researchers reported at the 135th Annual Meeting of the American Neurological Association. The investigators recommend that clinicians reassess the practice of excluding patients from thrombolytic therapy on the basis of anticoagulation alone.
“Use of thrombolysis in these patients may enable a significantly greater number of patients to receive thrombolytic therapy, particularly at institutions where intra-arterial therapy is unavailable,” said Nobl Barazangi, MD, PhD, a neurologist at the California Pacific Medical Center in San Francisco and Clinical Instructor of Neurology, University of California, San Francisco.
Dr. Barazangi and colleagues conducted a retrospective analysis of patients who received IV t-PA and were taking warfarin, therapeutic heparin, or low-molecular weight heparin. Outcome was based on subjects’ initial and discharge NIH Stroke Scale (NIHSS) scores. Safety was determined by the presence of symptomatic intracranial and clinically significant systemic hemorrhage rates within 36 hours after treatment.
A total of 124 patients received IV t-PA during a two-year period—17 (4%) of subjects fulfilled the inclusion criteria. The mean age of the sample was 70 (range, 35 to 92), and 53% were female. Thirteen patients were receiving warfarin for atrial fibrillation, deep vein thrombosis, or mechanical heart valve replacement. The mean International Normalized Ratio (INR) for patients taking only warfarin was 2.1 (range, 1.8 to 3).
According to the researchers, two subjects were receiving heparin for cardiac stent placement or bridging for atrial fibrillation. Three patients were receiving low-molecular weight heparin for stroke or bridging therapy for known left atrial thrombus and atrial fibrillation, and one patient had a coagulopathy of unclear etiology. In addition, nine patients received 0.45 mg/kg t-PA and eight patients received 0.9 mg/kg t-PA based on estimated weight. Three patients also received intra-arterial t-PA following IV t-PA.
“The average NIHSS improved from 15 to 13,” stated Dr. Barazangi. “If the patient who expired due to unrelated causes was excluded, the average NIHSS improved from 15 to 11.”
One patient died from myocardial infarction unrelated to the stroke, and two patients died after comfort care measures were initiated on hospital day 2. The investigators observed no symptomatic intracranial hemorrhage and five asymptomatic intracerebral petechial hemorrhages. Two patients developed minor systemic bleeding in the form of small groin and neck hematomas.
“The use for intra-arterial therapy in anticoagulated patients needs to be reconsidered, given the generally longer time to treatment required for intra-arterial therapy,” concluded Dr. Barazangi. “Understanding the pathophysiology of why patients develop embolic strokes despite therapeutic anticoagulation may aid in the acute and long-term therapy of stroke patients.”
—Colby Stong