Among permanent vascular access options for hemodialysis, arteriovenous grafts carry a higher risk for venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, compared with arteriovenous fistulas.
Using information from the 2010-2015 US Renal Data System, investigators compared 17,763 new recipients of arteriovenous grafts and 60,329 recipients of arteriovenous fistulas. Over 3 years, 10.8 vs 5.3 VTE events per 100 person-years occurred in the arteriovenous grafts vs arteriovenous fistulas groups, respectively. After adjustment for potential confounders, arteriovenous grafts were significantly associated with a 74% higher risk for VTE compared with arteriovenous fistulas, Nicholas S. Roetker, PhD, MS, of Hennepin Healthcare Research Institute in Minneapolis, Minnesota, and colleagues reported in Kidney Medicine. The investigators also observed excess VTE risks among arteriovenous graft users in subgroup analyses of patients without a baseline history of VTE, those who switched from a catheter to permanent vascular access, and prevalent users of arteriovenous grafts and arteriovenous fistulas.
The groups did not differ significantly in their risk for major bleeding. None of the patients were receiving oral anticoagulants.
The investigators found a significant 9% increased risk for cardiovascular death among the arteriovenous grafts group.
“It appears, at least in the case of older patients, that neither the risk of major bleeding nor major cardiovascular events are important factors in this calculus,” the authors wrote.
“However, a nearly 2-fold increase in the risk of venous thromboembolism associated with the use of [arteriovenous grafts] provides a basis for discussion about the risks incurred by [arteriovenous graft] users compared with [arteriovenous fistula] users when attempting to select an optimal access for a given patient.”
Dr Roetker’s team did not find unique properties of arteriovenous grafts that would make them more prothrombotic. Differences in vasculature between patients selected for arteriovenous grafts vs arteriovenous fistulas is one possible reason for excess VTE risk. Virchow’s triad is another.
They pointed out that clinicians and patients should also consider adverse events that may occur during access maturation when choosing between arteriovenous grafts vs arteriovenous fistulas. Recent guidelines emphasize individualized selection of the right vascular access for the right patient.
Disclosure: This research was supported by Merck & Co, Inc. Please see the original reference for a full list of disclosures.
Roetker NS, Guo H, Rosen Ramey D, McMullan CJ, Atkins GB, Wetmore JB. Hemodialysis vascular access and risk of major bleeding, thrombosis, and cardiovascular events: a cohort study. Kidney Med. 2022 Mar 24;4(6):100456. doi:10.1016/j.xkme.2022.100456