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Study breakdown

Rare Blood Clot Complication Linked to GLP-1 Drug: A Case of AV Fistula Thrombosis

evidence
The takeaway

A 55-year-old kidney transplant patient developed extensive arteriovenous fistula thrombosis after a GLP-1 agonist dose escalation, with no other identifiable cause — highlighting a rare but potentially serious thrombotic complication.

Extensive thrombosis

AV fistula, brachiocephalic vein, and both radial and ulnar arteries all thrombosed after GLP-1 dose escalation, with a completely negative hypercoagulability workup

What the researchers found

A 55-year-old African American female with a history of deceased donor renal transplantation developed:

• Extensive thrombosis of the left AV fistula

• Thrombosis extending to the brachiocephalic vein

• Thrombosis of both radial and ulnar arteries

• Symptoms: pain, swelling, erythema, fever, chills, and loss of palpable thrill over the fistula for approximately one week

Comprehensive prothrombotic workup (both inherited and acquired hypercoagulable states) was completely unremarkable. The only identifiable change was a recent dose escalation of her GLP-1 receptor agonist. After the drug was discontinued, no further thrombotic events occurred during follow-up, supporting a temporal and causal association.

Why it matters

With tens of millions of patients now taking GLP-1 drugs worldwide, even rare adverse events become clinically significant at scale. While GLP-1 agonists are generally cardiovascular-protective, this case adds to limited reports of thrombotic complications, particularly relevant for the growing population of kidney transplant and dialysis patients being prescribed these drugs for diabetes and obesity management.

How the study worked

Single patient case report documenting the clinical presentation, diagnostic workup (including venous and arterial Doppler ultrasound and comprehensive thrombophilia testing), treatment course, and follow-up outcome of a renal transplant patient who developed extensive AV fistula thrombosis temporally associated with GLP-1 agonist dose escalation.

What this study cannot tell us

Single case report — the lowest level of clinical evidence. Causation cannot be definitively established from temporal association alone. The patient had multiple risk factors for thrombosis (renal transplant, immunosuppression, AV fistula). The specific GLP-1 agonist and dose are not named in the abstract. Dehydration from reduced oral intake on GLP-1 therapy (a plausible contributing mechanism) is not discussed in the abstract.

How to read the evidence

Single case report representing the lowest level of clinical evidence. While the thorough negative workup and temporal association are suggestive, a single case cannot establish causality. It serves as a pharmacovigilance signal that may warrant further investigation in larger datasets.

When this study was published

Published in 2025, this case report is very recent and contributes to the evolving safety profile of GLP-1 agonists as their use expands rapidly across populations including kidney transplant recipients.

The bigger picture

GLP-1 agonists have demonstrated anti-atherosclerotic and cardiovascular benefits in large trials, but post-marketing surveillance continues to reveal rare adverse events. Thrombotic complications are particularly uncommon and counterintuitive given the class's vascular benefits. This case contributes to pharmacovigilance literature and raises the question of whether dehydration from GLP-1-induced appetite suppression or other mechanisms could promote clot formation in susceptible patients.

Questions still open

  • Could GLP-1 agonist-induced dehydration from reduced appetite contribute to thrombotic events in susceptible patients?
  • Should patients with AV fistulas or other vascular access devices be monitored more closely when starting or escalating GLP-1 therapy?
  • Is this thrombotic risk class-wide or specific to certain GLP-1 agonists?

Common questions

Can GLP-1 drugs cause blood clots?
This appears to be extremely rare. GLP-1 drugs are generally cardiovascular-protective and reduce heart disease events in large clinical trials. However, this case documents extensive blood clot formation that coincided with a GLP-1 dose increase in a kidney transplant patient. While a single case can't prove causation, it suggests clinicians should be aware of this possibility, especially in patients with additional clotting risk factors.
What is an AV fistula and why does thrombosis matter?
An arteriovenous (AV) fistula is a surgically created connection between an artery and vein, typically in the arm, used for dialysis access in kidney disease patients. When it clots (thromboses), it becomes unusable for dialysis and can cause pain, swelling, and potentially dangerous blood flow obstruction. In this patient, the clotting was extensive, affecting not just the fistula but also surrounding arteries and veins.

Read the original research

Extensive Arteriovenous Fistula Thrombosis With Glucagon-Like Peptide-1 Agonist.

Cureus, 17(7), e88015

Citation

Muneeb, Muhammad; Choi, Elizabeth; Rodriguez, Coralys; Goyal, Kanika; Bhura, Zainab; Hannoudi, Ghadeer. (2025). Extensive Arteriovenous Fistula Thrombosis With Glucagon-Like Peptide-1 Agonist.. Cureus, 17(7), e88015. https://doi.org/10.7759/cureus.88015