Arterio-Venous Fistula Calcifications-Risk Factors and Clinical Relevance.

(1) Background: Arterio-venous fistulas (AVFs) are considered the gold-standard vascular access (VA) in patients on maintenance hemodialysis (HD) therapy. AVF calcifications represent a less studied VA related complication, even though HD patients are at a higher risk for extraosseous calcifications. The aim of this study is to assess the prevalence and risk factors of AVF calcifications, as well as the 5-year impact on AVF functionality and on overall mortality. (2) Methods: We conducted a 5-year prospective study including 161 patients on maintenance HD therapy. At baseline, we collected data related to VA history, comorbidities, demographics, subjective global assessment scale (SGA), and biochemical parameters. All patients underwent a complete AVF ultrasound and we recorded AVF blood flow and the presence of AVF calcifications, stenoses, and aneurysms. (3) Results: In our study, we found an AVF calcification prevalence of 39%. In a univariate analysis, we found that patients with AVF calcifications were associated with other AVF complications as well (stenoses, aneurysms), had longer AVF and HD vintage, as well as higher serum calcium and PTH values. In a multivariate analysis, we found that patients with a longer HD vintage and higher calcium values were independently associated with AVF calcifications. AVF calcifications did not affect 5-year fistula patency, nor were they associated with a higher mortality risk in our group of patients. (4) Conclusions: AVF calcifications were a frequent finding in our analysis, but their presence does not seem to affect the 5-year AVF patency.