Two-thirds of stroke patients fail to benefit from intravenous thrombolysis
MedWire News: Less than a third of stroke patients treated in clinical practice achieve recanalization with intravenous (iv) thrombolysis, say researchers who call for "timely" endovascular intervention.
The findings emerge from a study of the Calgary Stroke Program computed tomography angiogram database, which contains data on 1341 patients treated between 2002 and 2009.
From these patients, Rohit Bhatia (All India Institute of Medical Sciences, New Delhi) and Canadian colleagues identified 127 who had proximal intracranial vessel occlusions and underwent repeat imaging to assess recanalization.
Just 27 (21.25%) patients achieved recanalization, the team reports in the journal Stroke.
These patients, however, were as least twice as likely to achieve good functional outcomes (modified Rankin Scale ≤2) as those who did not recanalize, after accounting for age and stroke severity.
"Because early recanalization is an important determinant of good outcome, assessment for the same is critical after thrombolytic therapy," say Bhatia et al.
"Timely endovascular recanalization may be a strong consideration when the target vessel occluded is a proximal T-occlusion or basilar artery occlusion, both of which have a low rate of recanalization after systemic thrombolysis in a given patient."
Patients with occlusions in the M1 or M2 segments of the middle cerebral artery were most likely to achieve recanalization, at 32.3% and 30.8%, respectively. In contrast, recanalization occurred in just 4.4% of patients with distal internal carotid artery occlusions and 4.0% of those with basilar artery occlusions.
More than three-quarters of patients who achieved recanalization with iv thrombolysis had good 3-month outcomes, compared with 52.5% of those who recanalized later with endovascular treatment, and 24.4% of those who did not recanalize.
Compared with patients who did not recanalize, those who achieved recanalization on iv and endovascular treatment were, respectively, 2.7 and 2.0 times more likely to have good functional outcomes.
Patients who underwent successful endovascular treatment achieved recanalization almost 90 minutes later than those who achieved recanalization with iv thrombolysis, which the team says may explain lower rate of good outcomes in the former group.
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By Eleanor McDermid