Pre- or Intradialytic Low BP Tied to Vascular Thrombosis
Low predialysis systolic BP or frequent intradialytic hypotension tied to vascular access thrombosis
THURSDAY, Aug. 4 (HealthDay News) -- In patients on hemodialysis, frequent episodes of intradialytic hypotension and lower predialysis systolic blood pressure (BP) are associated with increased rates of vascular access thrombosis, according to a study published in the Aug. 1 issue of the Journal of the American Society of Nephrology.
Tara I. Chang, M.D., from the Stanford University School of Medicine in Palo Alto, Calif., and colleagues investigated whether intradialytic hypotension and/or lower predialysis systolic BP were associated with higher rates of vascular access thrombosis in 1,426 patients on hemodialysis. Participants were followed up for an average of 3.1 years. The number of vascular access thrombosis episodes occurring within a given six-month period was the main outcome measure.
The investigators identified 2005 episodes of vascular access thrombosis. Irrespective of the predialysis systolic BP and other covariates, patients in the highest quartile of intradialytic hypotension were at twice the relative risk of thrombosis of native arteriovenous fistulas than those in the lowest quartile. After multivariable adjustment, intradialytic hypotension had no significant association with prosthetic arteriovenous graft thrombosis. Irrespective of intradialytic hypotension and other covariates, higher predialysis systolic BP correlated with a lower rate of fistula and graft thrombosis.
"More frequent episodes of intradialytic hypotension and lower predialysis systolic BP associate with increased rates of vascular access thrombosis," the authors write.