Affiliation:
1. Division of Renal Medicine, Department of Medicine Brigham and Women's Hospital Boston Massachusetts USA
2. Harvard Medical School Boston Massachusetts USA
3. Milken Institute School of Public Health The George Washington University Washington DC USA
4. Renal Section, Department of Medicine Boston University School of Medicine Boston Massachusetts USA
Abstract
AbstractIntroductionElevated N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) is a potent predictor of adverse outcomes in hemodialysis initiation. These patients often experience intradialytic hypotension, which may partially reflect cardiac dysfunction, but the association of NT‐proBNP with intradialytic hypotension is not clear.MethodsWe performed a post hoc analysis of a randomized trial that tested mannitol versus placebo in 52 patients initiating hemodialysis (NCT01520207). NT‐proBNP was measured prior to the first and third sessions (n = 87). Mixed‐effects models (adjusting for randomized treatment, sex, race, age, diabetes, heart failure, catheter use, pre‐dialysis systolic blood pressure, pre‐dialysis weight, ultrafiltration volume, serum sodium, bicarbonate, urea nitrogen, phosphate, albumin, hemoglobin, and session length) were fit to examine the association of NT‐proBNP with systolic blood pressure decline (pre‐dialysis minus nadir systolic blood pressure). Additionally, mixed‐effects Poisson models were fit to examine the association with intradialytic hypotension (≥20 mmHg decline in systolic blood pressure).FindingsMean age was 55 ± 16 years; 33% had baseline heart failure. The median NT‐proBNP was 5498 [25th‐75th percentile 2011, 14,790] pg/mL; 26 sessions (30%) were complicated by intradialytic hypotension. In adjusted models, each unit higher log‐NT‐proBNP was associated with 6.0 mmHg less decline in systolic blood pressure (95%CI −9.2 to −2.8). Higher pre‐dialysis NT‐proBNP, per log‐unit, was associated with a 52% lower risk of intradialytic hypotension (IRR 0.48, 95%CI 0.23–0.97), without evidence for effect modification by randomized treatment (P‐interaction = 0.17).DiscussionIn patients initiating hemodialysis, higher NT‐proBNP is associated with less decline in intradialytic systolic blood pressure and lower risk of intradialytic hypotension. Future studies should investigate if higher pre‐dialysis NT‐proBNP levels may identify patients who might tolerate more aggressive ultrafiltration.