Introduction:
Ischemic stroke prognosis given standard therapy differs according to the underlying pathophysiology. In contrast, the impact of ischemic stroke subtype on clinical outcome in patients treated with intravenous tissue-type plasminogen activator (IV-tPA) is less clear.
Objectives:
We examined the association between ischemic stroke subtype and clinical outcome in magnetic resonance imaging (MRI)-selected patients treated with IV-tPA.
Methods:
We included consecutive MRI-evaluated patients treated with IV-tPA in a Danish stroke center between 2004 and 2010. Patients with DWI lesions >1/3 of the middle cerebral artery territory were excluded from treatment. The TOAST criteria were used to classify patients into a stroke subtype based on the results of the complete diagnostic work-up available at three months. A favorable 90-day outcome was defined as a modified Rankin Scale score of 0 to 1. Early neurological improvement was defined as complete remission of the neurologic deficit or an improvement of ≥4 on the NIHSS at 24 hours. Multivariable logistic regression analyses were used to compare outcomes among stroke subtypes adjusted for clinical and imaging characteristics.
Results:
A total of 557 patients were analyzed: 202 (36%) had large vessel disease, 153 (27%) had cardioembolic stroke, 109 (20%) had small vessel disease and 93 (17%) were of other or undetermined etiology. A favorable outcome was achieved by 361 (64.8%) patients. Patients with cardioembolic strokes were more likely to achieve a favorable outcome as opposed to large vessel disease patients (adjusted OR, 2.9 (95% confidence interval, 1.1-7.4)). Similarly, the probability of an early neurological improvement was increased in cardioembolic stroke patients in comparison with large vessel disease patients (adjusted OR, 3.5 (95% confidence interval, 1.6-7.6)).
Conclusions:
The ischemic stroke subtype influenced early as well as late clinical outcome after treatment with IV-tPA in MRI-selected patients. Our findings argue for a potentially more successful IV-tPA-induced recanalization in strokes of cardioembolic origin in comparison with large vessel disease strokes.
Recurrent stroke after transient ischaemic attack or minor ischaemic stroke: does the distinction between small and large vessel disease remain true to type? Dutch TIA Trial Study Group.
