ST 2025

Welcome to SIR Today, your guide to the events, programming and faculty that make the SIR annual meeting a memorable meeting for the interventional radiology community each year. Watch for more preview content to be published in the coming weeks, as well as daily previews and recaps of scientific sessions, award presentations, and during the week of the meeting in March. For the latest details on presenters, times and locations, refer to the SIR 2025 website and the annual meeting mobile app.

Is fibrinogen monitoring during CDT helpful or harmful?

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Abstract No. 162: Fibrinogen Monitoring Does Not Significantly Reduce Rates of Bleeding Complications During Catheter-Directed Thrombolysis

Fibrinogen monitoring during catheter-directed thrombolysis (CDT) may actually increase patient risk, according to a new study.

Fibrinogen Monitoring Does Not Significantly Reduce Rates of Bleeding Complications During Catheter-Directed Thrombolysis, one of the SIR 2025 Featured Abstracts, details the results of an investigation into whether fibrinogen monitoring during CDT lowered the risk of bleeding. What researchers found was that not only may it not lower bleeding risks, but it may open patients up to additional complications.

“The practice of monitoring fibrinogen post-thrombolysis has been in place at several institutions, including mine, for years, but there is insufficient evidence as to whether it is clinically indicated,” said Minh Nguyen, a medical student at OHSU and lead author of the study.

Fibrinogen levels often are used to assess hemorrhagic risk and guide dosage of alteplase (tPA), a thrombolytic agent. Along with co-author Claire Kaufman, MD, Nguyen conducted a retrospective study of 355 patients who underwent CDT for arterial, venous or pulmonary thrombosis between 2011 and 2023. The majority of patients (225) did not have fibrinogen monitoring during their procedures, while 130 did.

By reviewing rates of significant hemorrhages and premature tPA cessation, Nguyen found that there was no significant difference in bleeding rates—but premature tPA stoppage occurred more frequently in the fibrinogen group (16.9% vs. 2.22%). Of the cases where tPA was stopped prematurely, 81.5% of patients had residual clots that required further interventions.

“This study demonstrates that fibrinogen monitoring does not significantly reduce bleeding complications during CDT but is associated with higher rates of premature tPA cessation, leading to worse clinical outcomes,” Nguyen said. “These findings challenge the necessity of routine fibrinogen monitoring in CDT and underscore the need for more reliable tools to guide therapy.”

Nguyen, who is entering her final year of medical school, is interested in pursuing this subject further while in residency, such as launching a larger trial to directly compare outcomes between patients managed with or without fibrinogen monitoring—ideally one “stratified by thrombolytic dosing regimens and patient-specific risk factors.” In addition, Nguyen is interested in identifying more reliable biomarkers for hemorrhagic risk during CDT.

Nguyen will present her findings on Monday, March 31, at 3 p.m. during the Pulmonary Embolism session.