Fibrinogen Level As a Surrogate for the Outcome of Thrombolytic Therapy Using Tissue Plasminogen Activator for Acute Lower Extremity Intravascular Thrombosis

Purpose: Monitoring of fibrinogen level is used to predict bleeding during lower extremity tissue plasminogen activator (tPA) infusions for peripheral arterial or venous thrombolysis. This practice is not fully addressed in the literature.

Materials And Methods: We retrospectively reviewed fibrinogen levels and studied bleeding rate from charts of patients who underwent lower extremity tPA infusions at a single hospital from January 2010 to May 2012.

Results: The rate of thrombolytic success did not correlate with fibrinogen level (P = .53). The rate of major bleeding was significantly higher for patients with a fibrinogen level at or below 150 mg/dL (P = .01). Patients whose tPA infusion was terminated within 46 hours had significantly lower rates of major bleeding (P = .01) and thrombolytic failure (P < .01). Periprocedural systolic blood pressure above 160 mm Hg was a risk factor for major bleeding (P = .02). There was no association between concomitant aspirin use (P = .90, .51) or hourly tPA dose (P = .71, .62) and thrombolytic success or major bleeding, respectively.

Conclusion: Fibrinogen level ≤ 150 mg/dL is associated with increased risk of major bleeding during tPA infusions. We suggest serial fibrinogen measurement as a viable method to monitor bleeding risk during lower extremity tPA infusions.