Abstract W P66: Elevated INR as a Manifestation of Post-Thrombolytic Coagulopathy in Acute Ischemic Stroke

Abstract

Background: A serious complication of intravenous tissue plasminogen activator (tPA) in acute ischemic stroke is hemorrhage. Alterations in fibrinogen and fibrinogen degradation products, labeled “early fibrinogen degradation coagulopathy” (EFDC), are well established after tPA. However, tPA is not recognized to cause markedly abnormal international normalized ratio (INR). Methods: With IRB approval, we retrospectively reviewed 338 acute ischemic stroke patients who received tPA. We defined post-tPA coagulopathy as a documented elevation of INR ≥ 1.5 after IVtPA within 24 hours of tPA without a known cause. Patients with recent warfarin use (within 3 weeks of presentation) were excluded. Results: Among the 328 acute ischemic stroke patients who had received tPA, we identified 21 (7.4%) patients with an elevated INR post-thrombolysis. The mean age was 68.3 years (SD +/- 11.9) and 57% were male. The mean initial NIHSS (pre-tPA) was 15.8 (range, 4 to 35). Liver disease or alcohol abuse was noted in 19%. There were 2 tPA protocol violations who received >90mg tPA. The mean post-tPA INR was 2.03 (range, 1.5 to 4.7) and the elevation in INR was documented within a mean 5.4 hours (range, 1 to 15) after tPA initiation. Repeat INR levels returned to normal during their hospital stay in 19 patients. Hypofibrinogenemia was noted in 10 of 12 patients who had fibrinogen levels drawn within 48 hours after tPA initiation (7 of these fibrinogen levels were drawn the same time as the elevated INR). Among the 6 patients with bleeding complications, 2 patients had symptomatic intracerebral hemorrhage. Conclusions: We report an under-recognized early transient coagulopathy associated with elevated INR in stroke patients after treatment with tPA. Post-thrombolytic INR elevation may represent a severe manifestation on the spectrum of EDFC rather than a distinct phenomenon