NEW ORLEANS — The administration of tissue plasminogen activator to acute ischemic stroke patients with blood pressure values above the cutoff recommended by current guidelines is associated with significantly higher odds of developing a symptomatic intracerebral hemorrhage, according to a retrospective study.
The study is one of the first to corroborate the recommended cutoff values of a systolic BP of less than 185 mm Hg and a diastolic BP of less than 110 mm for Hg for treatment with intravenous tissue plasminogen activator (TPA), Dr. Georgios K. Tsivgoulis reported at the International Stroke Conference 2008.
These thresholds, part of the American Heart Association/American Stroke Association guidelines on the early management of adults with ischemic stroke (Stroke 2007;38:1655–711), advise against use of TPA in patients with BP greater than those values, said Dr. Tsivgoulis of the University of Alabama at Birmingham Comprehensive Stroke Research Center at the conference, which was sponsored by the American Stroke Association.
In a review of 510 patients with acute ischemic stroke who received intravenous TPA at a single center during 1996–2005, Dr. Tsivgoulis and his colleagues found 63 (12%) patients received TPA when their blood pressure was above the cutoff. They used blood pressure measurements that were taken closest in time before the TPA bolus was administered. Overall, the patients had a median onset-to-treatment time of 125 minutes and a median baseline National Institutes of Health Stroke Scale score of 9.
Compared with patients who did not hemorrhage after receiving TPA, the 31 (6%) patients who developed a symptomatic intracerebral hemorrhage had significantly higher mean prebolus systolic BP (169 mm Hg in the bleeders vs. 156 mm Hg in the others) but similar prebolus diastolic BP (85 mm Hg vs. 82 mm Hg). The investigators defined a symptomatic intracerebral hemorrhage by brain-imaging evidence of the hemorrhage and neurological worsening of 4 or more points on the NIHSS within 36 hours of receiving the bolus.
Pretreatment BP protocol violations also were more common in patients who had a symptomatic intracerebral hemorrhage than in those who did not (26% vs. 12%). The absolute risk of developing a symptomatic intracerebral hemorrhage also was significantly greater in patients with a pretreatment BP protocol violation than in those without such a violation (12.7% vs. 5.1%). However, the patients with and without pretreatment BP protocol violations had similar mortality (7.9% vs. 5.8%, respectively).
The occurrence of a pretreatment blood pressure protocol violation was associated with about 2.5 times higher odds of developing a symptomatic intracerebral hemorrhage than in the absence of any blood pressure protocol violation, after adjustment for demographics, stroke risk factors, baseline stroke severity, and onset-to-treatment time.