Abstract: TH-PO0519
Predictors of Filter and Circuit Clotting in Incident Hemodialysis Patients
Session Information
- Dialysis: Novel Therapeutics and Medication Management
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Banine, Amine, McGill University Health Centre, Montreal, Quebec, Canada
- Baroz, Frederic, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Mavrakanas, Thomas A., Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
Background
Frequent circuit clotting during maintenance hemodialysis (HD) compromises treatment adequacy. While anticoagulation is routinely used to mitigate this risk, it is often limited by bleeding events. Alternatives such as citrate or saline flushes are costly or less effective. Data to guide evidence-based practice remain scarce. We evaluated the link between circuit/filter clotting and anticoagulation use, vascular access, and blood flow.
Methods
We conducted a retrospective cohort study of incident HD patients from 2017 to 2022. Data were extracted from the dialysis information system. Predictors included the use anticoagulation, access type, blood flow, age, and HD vintage. Clotting was graded using a standardized 4-point scale; grade 4 indicated a fully clotted circuit. We used multivariate mixed-effects ordinal logistic regression and reported odds ratios for higher clotting severity. A secondary binary model assessed the odds of full circuit clotting (grade 4) versus any other grade.
Results
We included 409 patients and 172,103 treatments. Median age was 63 years and 64% were male. Anticoagulation was used in 78% of treatments. Clotting severity was distributed as follows: 42% grade 1, 46% grade 2, 11% grade 3, and 0.63% grade 4. Anticoagulation was associated with significantly lower odds of higher clotting severity (Odds Ratio [OR] = 0.82, 95% Confidence Interval [CI]: 0.80–0.85) and full circuit clotting (OR = 0.40, 95% CI: 0.34–0.48) (Figure). Access type, particularly arteriovenous grafts, was significantly associated with higher clotting severity (OR = 1.21, 95% CI: 1.01–1.46), but not with full circuit clotting, suggesting an effect limited to less severe forms.
Conclusion
Although full circuit clotting was rare, absence of anticoagulation significantly increased the odds of both higher clotting severity and complete clotting. Access type may contribute to milder forms and affect adequacy. These findings add to a sparse body of evidence and may inform practice by prompting intentional consideration of appropriate anticoagulation.
Effect of Selected Predictors on the Risk of Clotting
Funding
- Government Support – Non-U.S.