Emergency physician-directed treatment of patients with acute stroke using tissue plasminogen activator (t-PA) is as safe as treatment directed by an acute stroke team, according to the results of a retrospective study presented at the American Heart Association's (AHA's) International Stroke Conference 2007 in San Francisco, Calif.
IV t-PA use was assessed over a 10-year period (from January 1, 1996, to January 1, 2005) in stroke patients treated in the emergency departments of 4 southeastern Michigan hospitals without a dedicated acute thrombolytic stroke team.
During this period, 95 individual emergency physicians used t-PA to treat 273 patients with acute strokes. The mean age of the patients was 68 years and 55% were men. The average time from symptom onset to treatment was 154 minutes. The treated patients' characteristics were similar to those of patients treated in the seminal 1996 National Institute of Neurological Disorders and Stroke (NINDS) study in which the safety and efficacy of IV t-PA for the treatment of acute ischemic stroke was established.
Mortality at 1 year, the primary end point of the study, was 27.8%, which was consistent with both the treatment and placebo groups in the NINDS study (P=.046). The relative risk of mortality was 1.16 (95% CI, 0.88–1.52) compared with the NINDS group of patients who received treatment, and 1.00 (95% CI, 0.77–1.30) compared with the NINDS placebo recipients, both nonsignificant differences.
"Secondary safety measures were also consistent with the experience of the NINDS trial," said Phillip A Scott, MD, assistant professor, department of emergency medicine, University of Michigan, Ann Arbor. The rate of any intracerebral hemorrhage (ICH) within 36 hours of treatment was 9.9% (RR=0.94; 95% CI, 058–1.51) compared with patients treated with t-PA in the NINDS study. The rate of symptomatic/significant ICH by CT criteria was 6.6% (RR=1.03; 95% CI, 0.56–1.90) compared with the NINDS t-PA group.
Protocol violations occurred in the emergency department in 26% of patients. Of these violations, 61% were for treatment beyond 3 hours. Among the patients treated beyond 3 hours, the median time to treatment from symptom onset was 195 minutes. The rate of protocol violations "represents an opportunity for improvement through systems of quality management and continuing education," Dr Scott said. "While a third of the out-of-window treatments were less than 5 minutes beyond the window... many were substantially greater. Given the other safety measures, the clinical implications of these violations seem limited, but suggest a potential need for continued monitoring."