The Presence of a Right-to-Left Shunt Is Associated With Dramatic Improvement After Thrombolytic Therapy in Patients With Acute Ischemic Stroke

Background and Purpose— The efficacy of pharmacological thrombolysis using tissue plasminogen activator depends on the relative fibrin content of the thrombus. We investigated whether patients with stroke with a right-to-left shunt (RLS), whose embolic source was associated with fibrin-rich thrombus formed in the venous system, were more likely to improve dramatically after thrombolytic therapy than those without RLS. Methods— Patients with acute stroke treated with tissue plasminogen activator were assessed prospectively to determine the clinical factors associated with “dramatic improvement” after tissue plasminogen activator administration. “Dramatic improvement” was defined as a ≥10-point reduction in the total National Institutes of Health Stroke Scale score or a total National Institutes of Health Stroke Scale score of 0 or 1 at 7 days. The presence of an RLS was determined using contrast transcranial Doppler within 6 hours of stroke onset. Results— Forty-four patients (26 males; mean age; 73.0±10.7...