Thrombolytic therapy for acute ischemic stroke after recent transient ischemic attack.

Background and aim Safety and efficacy of intravenous thrombolysis in stroke patients with recent transient ischemic attack are hotly debated. Patients suffering transient ischemic attack may present with diffusion-weighted imaging lesions, and although normal computed tomography would not preclude thrombolysis, the concern is that they may be at higher risk for hemorrhage post-thrombolysis treatment. Prior ipsilateral transient ischemic attack might provide protection due to ischemic preconditioning. We assessed post-thrombolysis outcomes in stroke patients who had prior transient ischemic attack. Methods Multicentered prospective study of consecutive acute stroke patients treated with intravenous tissue plasminogen activator (tPA). Ipsilateral transient ischemic attack, baseline characteristics, risk factors, etiology, and time-lapse to treatment were recorded. National Institutes of Health Stroke Scale at seven-days and modified Rankin Scale at three-months, symptomatic intracranial hemorrhage, and mortality were compared in patients with and without transient ischemic attack. Results There were 877 patients included, 60 (6·84%) had previous ipsilateral transient ischemic attack within one-month prior to the current stroke (65% in the previous 24 h). Transient ischemic attack patients were more frequently men (70% vs. 53%; P = 0·011), younger (63 vs. 71 years of age; P = 0·011), smokers (37% vs. 25%; P = 0·043), and with large vessel disease (40% vs. 25%; P = 0·011). Severity of stroke at onset was similar to those with and without prior transient ischemic attack (median National Institutes of Health Stroke Scale score 12 vs. 14 P = 0·134). Those with previous transient ischemic attack were treated earlier (117 ± 52 vs. 144 ± 38 mins; P < 0·005). After adjustment for confounding variables, regression analysis showed that previous transient ischemic attack was not associated with differences in stroke outcome such as independence (modified Rankin Scale 0–2) (odds ratios: 1·035 (0·57–1·93) P = 0·91), mortality (odds ratios: 0·99 (0·37–2·67) P = 0·99), or symptomatic intracranial hemorrhage (odds ratios: 2·04 (0·45–9·32) P = 0·36). Conclusions Transient ischemic attack preceding ischemic stroke does not appear to have a major influence on outcomes following thrombolysis. Patients with prior ipsilateral transient ischemic attack appear not to be at higher risk of bleeding complications.