Pre-dialysis systolic blood pressure levels should be interpreted in the context of pre-dialysis fluid status, according to a recently published study. Researchers found patient outcomes were directly related to pre-dialysis systolic blood pressure and were dependent on fluid status.
“The primary objective of this study was to investigate whether the relation between pre-dialysis [systolic blood pressure] SBP and mortality differs in [hemodialysis] HD patients with pre-dialysis [fluid depletion] FD, [fluid overload] FO or [normovolemia] NV, assessed by pre-dialysis [multifrequency bioimpedance] MF-BIS, with traditional and novel statistical methods,” the authors wrote. “Next to this, we aimed to investigate if this association remains stable when inflammation is present and when accounting for higher ultrafiltration rate.”
Researchers studied patient information from the international Monitoring Dialysis Outcome Initiative database. According to the study, all patients who had a pre-dialysis MF-BIS measurement in 2011 were included.
Researchers noticed that when the association between pre-dialysis fluid status (FS) and SBP combined with outcome had been stratified by the patient’s inflammation status the effects had become more distinct in patients with inflammation.
“In the inflamed cohort, NV patients showed improved survival with low SBP [HR 0.37 (95% CI 0.15–0.93)],” the authors wrote. “[Whereas] in patients with altered pre-dialysis FS, the presence of low pre-SBP (<110 mmHg) was associated with increased mortality risks.”
However, researched found no association between pre-dialysis FS and ultrafiltration rate nor any associations to mortality between ultrafiltration rate with outcome and different FS subgroups.
Researchers found patients who presented pre-dialysis fluid overload, throughout all levels of pre-SBP, showed an increased mortality risk. Low SBP appeared to be harmful in fluid overload, as well as in patients with fluid depletion. However, this is not the case in patients with NV where low SBP was associated with increased survival.
“Therefore, we suggest that BP levels should be interpreted in the context of FS and not as an isolated risk marker,” the authors wrote. “Further, interventional studies should assess whether correction of pre-dialysis FO, as well as normalization of pre-dialysis FD in patients with low SBP is safe and associated with a survival benefit.”- by Scott Buzby
Disclosures: Please see the study for all authors’ relevant financial disclosures.