tPA and warfarin

The appropriate use of IV tissue plasminogen activator (tPA) for patients with acute ischemic stroke remains an area of active discussion among health care professionals. Since its approval in the United States by the Food and Drug Administration in 1996, the medical community has continued to review and discuss the risks vs benefits of this important therapy. Two recent publications^1,2 and accompanying editorials have refocused attention on the vexing issue of using IV tPA in patients taking warfarin. The Xian et al.¹ study found a 1.1% absolute increase in the risk of intracranial hemorrhage (ICH) with warfarin use (5.7% vs 4.6%), but this difference was no longer present once the analysis was adjusted for various risk factors. The Ruecker et al.² study reported a 20% risk of ICH, but the difference was barely significant (p = 0.044) once proper adjustments were made. It is important to consider that successful recanalization or reperfusion of the stroke is likely to have precipitated a hemorrhage in some of these cases.³ Therefore the reported measure (cerebral hemorrhage) might actually be consequent (in part) to the therapeutic intervention, and not solely related to therapy with warfarin.