Hemodialysis Vascular Sound Index as a Diagnostic Tool for Vascular Access Stenosis: A Prospective Matched Observational Study

Background and objectives Vascular access (VA) monitoring is critical for hemodialysis patients. While vascular ultrasound (US) provides high diagnostic accuracy for VA stenosis, its reliance on specialized training limits its routine use. The Hemodialysis Vascular Sound Index (HVSI), derived from vascular murmur analysis, may provide a simple, objective alternative. This study evaluates the diagnostic performance of the HVSI in detecting VA stenosis and reduced flow volume (FV). Methods This prospective matched observational study included 202 hemodialysis patients (101 with stenosis in the study group, 101 in the control group). Participants were matched based on age, sex, dialysis duration, diabetes status, Kt/V, and blood data. HVSI was measured with an electronic stethoscope placed over the VA site. FV and resistance index (RI) were assessed by US. Stenosis was diagnosed by clinical criteria and confirmed by US. Diagnostic accuracy was determined from receiver operating characteristics, including sensitivity, specificity, and area under the curve (AUC). Multivariable logistic regression was performed to evaluate the independent association of HVSI with stenosis and FV reduction after adjustment for clinical covariates. Results HVSI showed significant correlations with FV (R² = 0.58) and RI (R² = 0.32). For FV thresholds ≤500, ≤400, and ≤350 mL/min, HVSI showed sensitivities of 86.3–94.4%, specificities of 78.7–82.9%, and AUCs of 0.90–0.94. Diagnostic accuracy was higher in non-bifurcated vessels. In multivariable models adjusting for age, sex, dialysis duration, diabetes, CRP, past VAIVT, and AVF type, HVSI remained independently associated with stenosis (per 100-unit increase: adjusted OR 0.44, 95% CI 0.33–0.57; p<0.001) and FV <400 mL/min (per 100-unit increase: adjusted OR 0.07, 95% CI 0.03–0.17; p<0.001). Discussion and Conclusion Thus, HVSI should be interpreted not as a replacement for vascular ultrasound, but as a simple screening adjunct to triage patients who require confirmatory ultrasound and/or VAIVT. In this prospective matched observational study, HVSI showed high diagnostic accuracy for reduced FV and VA stenosis, and may help to improve routine VA surveillance. Further studies should validate its applicability in diverse populations, particularly in consecutively enrolled real-world cohorts. Trial registration: UMIN000056433, retrospectively registered on 12/12/2024.