A comparative effectiveness research study of the change in blood pressure during hemodialysis treatment and survival

Abstract

It is not clear to what extent changes in blood pressure (BP) during hemodialysis affect or predict survival. Studying comparative outcomes of BP changes during hemodialysis can have major clinical implications including the impact on management strategies in hemodialysis patients. Here we undertook a retrospective cohort study of 113,255 hemodialysis patients over a 5 year period to evaluate an association between change in BP during hemodialysis and mortality. The change in BP was defined as post- minus pre-hemodialysis BP and mean of BP change values during the hemodialysis session was used as a mortality predictor. The patients averaged 61 years old and consisted of 45% women, 32% African-Americans and 58% diabetics. Over a median follow-up of 2.2 years, a total of 53,461 (47.2%) all-cause and 21,548 (25.7%) cardiovascular deaths occurred. In fully adjusted Cox regression model with restricted cubic splines, there was a U-shaped association between change systolic BP and all-cause mortality. Post-dialytic drops in systolic BP between −30 to 0 mmHg were associated with greater survival, but large decreases of systolic BP (more than −30 mmHg) and any increase in systolic BP (over 0 mmHg) were related to increased mortality. Peak survival was found at a change in systolic BP of −14 mmHg. The U-shaped association was also found for cardiovascular mortality. Thus, modest declines in BP after hemodialysis are associated with the greatest survival, whereas any rise or large decline in BP is associated with worsened survival.

Intradialysis Hypertension in End-Stage Renal Disease Patients

“…Large intradialytic drops in SBP (ie, >30 mm Hg) and any elevation in SBP during dialysis were both associated with increased mortality risk. 13 In contrast to the US Renal Data System data, 3 the association of intradialytic hypertension with mortality was stronger for patients with predialysis SBP >120 mm Hg. 13 In the study by Inrig et al, 13 general linear modeling was applied, 3 whereas in the second Cox regression with restricted cubic splines was used, which is considered a more appropriate approach to detect nonlinear associations.…”

“…13 In contrast to the US Renal Data System data, 3 the association of intradialytic hypertension with mortality was stronger for patients with predialysis SBP >120 mm Hg. 13 In the study by Inrig et al, 13 general linear modeling was applied, 3 whereas in the second Cox regression with restricted cubic splines was used, which is considered a more appropriate approach to detect nonlinear associations. In general, the adjusted HR associated with intradialytic rises in BP is of just moderate degree (up to ≈1.6 for a 30-mm Hg rise in SBP in the largest study to date).…”

“…In general, the adjusted HR associated with intradialytic rises in BP is of just moderate degree (up to ≈1.6 for a 30-mm Hg rise in SBP in the largest study to date). 13 To add sufficient discrimination power over other risk factors for the identification of patients who will develop future events and to improve risk classification at individual level, risk factors should have a high HR for the outcome of interest.…”

Changes in Pulse Pressure during Hemodialysis Treatment and Survival in Maintenance Dialysis Patients

“…Therefore, they may be underpowered for detecting a U-shaped association of high mortality with either increases or decreases in PP (26). Both large declines and any rises in SBP during hemodialysis have been linked to increased mortality (27). The association between PP change during hemodialysis and mortality has not been sufficiently studied in large cohorts.…”

Intradialytic hypotension, blood pressure changes and mortality risk in incident hemodialysis patients

“…IDH has been associated with cardiovascular morbidity and mortality [1][2][3], myocardial stunning [4,5], myocardial infarct [6], arrhythmias [6], vascular access thrombosis [7] and inadequate dialysis dose [8]. IDH has also been suggested to contribute to brain atrophy and white matter ischemia among HD patients [9][10][11].…”