SAN DIEGO—IV treatment with t-PA within 4.5 hours of stroke onset and endovascular treatment within six hours of stroke onset may have equivalent efficacy in patients with acute cervical internal carotid artery occlusion, according to research presented at the 2014 International Stroke Conference. Although endovascular treatment entails a higher rate of intracranial bleeding than IV t-PA does, it may not result in an increased overall mortality rate. Rates of severe disability and death appear to be similar for both treatments.
“In view of the nonrandomized design of this study … these results should be interpreted with caution,” said Maurizio Paciaroni, MD, of the Stroke Unit and Division of Cardiovascular Medicine at the University of Perugia, Italy. “In the future, we look forward to confirming these results in a larger randomized study.”
A Case–Control Study of Patients With Ischemic Stroke
Dr. Paciaroni and colleagues conducted a case–control study to compare IV t-PA with endovascular treatment in patients with acute ischemic stroke and extracranial internal carotid artery occlusion. The researchers analyzed prospectively collected data from 648 patients treated at 37 stroke units from 2010 to 2013. Consecutive patients treated with endovascular procedures were classified as cases, and patients treated with IV t-PA were controls. Physicians used ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA), or angiography to diagnose the internal carotid artery occlusions before treatment. Cases and controls were matched for age, gender, and severity of stroke.
The study’s primary outcome measure was disability at 90 days, as assessed using the modified Rankin scale (mRS). Patients were categorized as having a favorable outcome (ie, mRS score of 0 to 2) or an unfavorable outcome (ie, mRS score of 3 to 6). The safety outcomes were overall mortality at 90 days, intracranial bleeding, fatal intracranial bleeding, and other serious adverse events.
Rates of Good Outcome Were Similar Between Groups
The risk factors were balanced between the two treatment groups, and patients’ median NIH Stroke Scale score was 16. Of the 161 patients treated with IV t-PA who underwent an intracranial study with CTA or MRA, 13% had tandem occlusions. In addition, 13% of patients with intra-arterial procedures had tandem occlusions.
Approximately 32% of patients treated with intra-arterial procedures had a good outcome, compared with 27% of patients treated with IV t-PA. The absolute risk difference of 5% was not statistically significant after an adjusted analysis. Intracranial hemorrhage was more common among patients treated with the intra-arterial procedure, compared with patients treated with IV procedures.
Mortality was 17.6% in patients treated with intra-arterial procedures and 23.1% in patients treated with IV t-PA. The 5.5% absolute risk difference was statistically significant after the adjusted analysis. Malignant edema and stroke progression were more common causes of death in patients treated with IV t-PA, and fatal hemorrhagic transformations were common causes of death in patients treated with intra-arterial procedures. There were no differences between the groups for the other causes of death.