#3643 Vascular access difficulties in patients of African descent—causes and consequences

Abstract Background and Aims In Portugal, many patients with end-stage renal disease (ESRD) are from Portuguese-speaking African countries and often experience worse vascular access (VA) outcomes for hemodialysis, potentially due to socioeconomic disparities and vascular characteristics. However, direct evidence addressing this issue is scarce. This study investigates the reasons behind these differences, focusing on vascular characteristics, comorbidities, sociodemographic factors, and clinical data. By comparing populations with and without African descent, we aim to identify factors contributing to disparities in hemodialysis access. Method This single-center observational study analyzed vascular ultrasound mapping and clinical data from advanced chronic kidney disease patients. Arterial and venous diameters and peak systolic velocities (PSV) were categorized as adequate or inadequate for VA creation, with continuous variables converted to binary form. Continuous variables are presented as means or medians and were compared using the Student's t-test, Welch test, or Mann-Whitney U test, depending on normality and variance. Categorical variables were compared using the Chi-square test. Multivariate logistic regression adjusted for age, sex, and comorbidities. Results The study included 304 patients (63 of African descent, 241 of non-African descent), with a mean follow-up of 401.1 days. No significant differences were observed in sex, diabetes, hypertension, heart failure, obesity, or cardiovascular disease. However, patients of African descent were younger (54 vs 75 years, P < 0.001), had lower tobacco use (14.3% vs 40.7%, P < 0.001), and lower rates of peripheral arterial disease (3.2% vs 11.2%, P = 0.011). Twenty two percent of patients were on HD, 58.4% were on pre-dialysis care, of which 19.9% started HD during follow-up. Univariate analysis (Fig. 1) revealed significant differences in vascular characteristics particularly in PSV and diameters of ulnar arteries, as well as in venous diameters of the cephalic and basilic veins. To further assess the suitability of VA creation, arterial and venous characteristics were analyzed as binary variables based on established adequacy thresholds, with the results summarized in Fig. 2. Multivariate analysis confirmed African descent as a strong independent predictor of worse vascular characteristics, namely in ulnar arteries diameter (P = 0.001), PSV in all arteries (P < 0.001) and venous forearm and arm cephalic and basilic veins (P = 0.016). Regarding VA feasibility, patients of African descent were more likely to require a prosthetic arteriovenous graft (AVG) due to inadequacy for autologous arteriovenous fistula (AVF) (17.5% vs 7.1%, P = 0.009) and most patients initiated hemodialysis via central venous catheter (58.7% vs fistulae 32.8%, P = 0.040), either at the beginning or during follow-up. Among these patients, 12.5% constructed radiocephalic AVF, 67.5% umerocephalic AVF, 5% umerobasilic AVF, and 15% AVG, with immediate patency rates of 97.4% and 83.3% at 3 months. Conclusion Patients of African descent have poorer vascular characteristics for dialysis access, resulting in increased dependence on AVGs and CVCs for hemodialysis initiation, with both short- and long-term clinical consequences that can be devastating. These findings highlight the need for proactive vascular care tailored to this population to ensure equitable access to optimal hemodialysis treatment and to explore new biological and genetic mechanisms underlying this phenomenon.