Safety and outcome after thrombolytic treatment in ischemic stroke patients with high-risk cardioembolic sources and prior subtherapeutic warfarin use

Background: Hemorrhage is a major complication of thrombolytic treatment. Concerns have been raised about the risk of hemorrhage in patients having received warfarin. Therefore, different indications for thrombolytic treatment are in use for stroke patients on warfarin. However, it remains uncertain whether the prior warfarin use actually increases their risk of bleeding in patients treated with thrombolysis. Methods: This study included 179 consecutive patients who had high-risk cardioembolic sources and received thrombolytic treatment. Patients were treated with intravenous thrombolytic agents, or underwent intraarterial thrombolysis if their international normalized ratio (INR) was ≤ 1.7. We compared the frequency of bleeding complications between patients with prior warfarin use and those without. We also investigated whether there were differences in functional outcome and recanalization rates between them. Results: A prior warfarin use was present in 28 patients (15.6%). Although INR levels were higher in the prior warfarin group, the frequency of bleeding complications was not different between patients who received prior warfarin and those who did not. No differences were observed in patients with or without prior warfarin use, for successful recanalization rate (Thrombolysis in Myocardial Infarction grade 2 or 3), mortality, or modified Rankin score (≤ 2) at 3 months. Conclusions: Thrombolytic therapy for patients who previously received warfarin and had an INR ≤ 1.7 did not affect bleeding risk, clinical outcome, or recanalization rate. Our data suggest that patients with a history of prior warfarin use may be safely treated with thrombolytic agents when their INR levels are low.