A follow‐up survey of clinical practices for the use of heparin, warfarin, and aspirin

Abstract

To determine whether anticoagulation practices have changed when heparin and warfarin are used to treat cerebrovascular disease, and to determine the dosage of aspirin used to treat carotid territory transient ischemic attacks (TIAs). A 1987 study documented that neurologists and neurology house officers were using excessive amounts of heparin and warfarin. Recent studies have demonstrated the efficacy and safety of low-intensity anticoagulation for preventing strokes, but no data are available on how these findings have affected the treatment practices of clinicians. Questionnaires were sent to neurology staff at 10 medical centers. The questions dealt with the use of heparin, warfarin, and aspirin in stroke/transient ischemic attack patients. The nonparametric Wilcoxon rank sum test was used for analyzing the responses. Ninety-three physicians responded compared with 52 in the prior study. Most (56 of 92; 61%) did not use an IV heparin bolus. The mean partial thromboplastin time (PTT) was 55 seconds, which was significantly less than the mean PTT of 62 seconds (p = 0.006) in the prior study. The mean prothrombin time (PT) fell to 16.0 seconds (range, 12.5 to 20.0) compared with a mean of 19.9 seconds (range, 15.0 to 27.0; p < 0.001) in the earlier study. There was a significant fall in the mean PT ratio from 1.74 (range, 1.20 to 2.25) to 1.49 (range, 1.12 to 2.50; p < 0.001). Most respondents used 325 mg qd of aspirin for treating TIAs. At the centers studied, neurologists and neurology house officers are using less intense anticoagulation when treating stroke patients now than in 1986. This concurs with recent studies demonstrating the efficacy and safety of low-intensity anticoagulation in some clinical settings. The use of 325 mg/d of aspirin is common, although the data supporting its efficacy compared with higher doses are unclear.