Beyond the vascular access: unveiling the cardiovascular impact of dialysis access flow rates.

OBJECTIVE

To investigate the impact of arteriovenous fistula (AVF) and arteriovenous graft (AVG) flow rates on cardiac function and blood pressure in hemodialysis patients, comparing changes before and after vascular access creation and assessing differences between high and non-high flow access groups.

METHODS

This prospective, observational study included 80 hemodialysis patients (43 males), all of Iranian ethnicity, at a university-affiliated referral hospital in Tehran, Iran. Flow rates (Qa) of vascular accesses were measured using Color Doppler ultrasonography (Acuson Sequoia system). Echocardiographic parameters, including systolic blood pressure, ejection fraction (EF), and left ventricular end-diastolic dimension (LVEDD), were assessed at baseline and six months post-intervention. Data were analyzed using paired t-tests and Pearson correlation coefficients.

RESULTS

Following vascular access creation, a significant decrease in systolic blood pressure was observed (156.48 ± 18.04 mmHg to 141.42 ± 15.82 mmHg, p < 0.001), along with a notable decline in EF (57.18% ± 6.51 to 50.31% ± 4.99, p < 0.001), and an increase in LVEDD (4.43 ± 0.27 cm to 5.51 ± 0.26 cm, p < 0.001), suggesting potential cardiovascular burden in high-flow access patients. Patients with high-flow access exhibited greater cardiovascular burden, likely due to increased cardiac output demands and risk of high-output heart failure. No significant differences in cardiac outcomes were observed between proximal and distal AVFs or upper and lower limb AVGs.

CONCLUSIONS

These findings underscore the need for proactive cardiovascular monitoring, particularly in patients with high-flow vascular access, to prevent potential complications such as high-output cardiac failure. Routine Doppler ultrasonography and echocardiographic assessments should be integrated into clinical practice to identify high-risk patients and guide timely interventions.