Development and validation of a risk score to prioritize patients for evaluation of access stenosis

Area of Science:

• Nephrology
• Vascular Surgery
• Biomedical Engineering

Background:

• Access flow dysfunction, often linked to stenosis, is a frequent complication in hemodialysis access, potentially leading to thrombosis.
• Early identification of accesses needing evaluation is crucial for maintaining access patency.
• The Vasc-Alert surveillance device offers potential for predicting interventions.

Purpose of the Study:

• To develop and validate a risk score using Vasc-Alert surveillance data to predict subsequent interventions in hemodialysis access.
• To assess the score's effectiveness in patients with arteriovenous fistulae (AVF) and arteriovenous grafts (AVG).

Main Methods:

• A risk score was developed using measurements from five factors over 28 days from 1.46 million hemodialysis treatments (6163 patients).
• The score's association with interventions within the subsequent 60 days was analyzed.
• Validation was performed on a separate dataset of 298,620 treatments (2641 patients).

Main Results:

• Interventions were significantly more common in patients with the highest risk score compared to the lowest for both AVF (36.2% vs. 11.0%) and AVG (43.2% vs. 21.1%).
• The score demonstrated excellent agreement for AVF (OR=2.67) and good agreement for AVG (OR=1.92) in validation datasets.

Conclusions:

• A straightforward risk score derived from surveillance data can effectively predict the need for interventions in hemodialysis access.
• This score can assist in prioritizing patients for physical examination and timely referral for intervention, thereby preserving access function.