Influence of blood pressure variations during hemodialysis on the prognosis of dialysis patients

Abstract

The prognosis of dialysis patients is poorer than that of the general population. The relationship between dialysis patients’ blood pressure (BP) and mortality is controversial. We investigated the relationships between mortality and (i) pre-dialysis BP and (ii) BP variation during hemodialysis in maintenance dialysis patients. We retroactively analyzed the cases of the 284 patients on hemodialysis (mean age 68 ± 13 years old) who had been regularly followed at Kokura Daiichi Hospital, Japan in 2018. We assessed the relationship between the patients’ BP components and risk of mortality over a 40-month follow-up. The patients’ average systolic/diastolic BP values before dialysis in 2018 were 145 ± 18/77 ± 11, and those after dialysis were 129 ± 17/71 ± 10 mmHg. The prevalence of intradialytic hypotension was 46.8%. During an average follow-up of 35 months, 72 patients died, including from infectious diseases (n = 41), cardiovascular diseases (n = 9), malignancies (n = 5), and others (n = 17). The mortality rate was 32.7% in the pre-dialysis SBP < 140 mmHg group, 20.6% in the 140–159 mmHg group, and 22.2% in ≥ 160 mmHg group. In a multivariable-adjusted analysis, the hazard ratio for mortality in the pre-dialysis SBP < 140 mmHg group with intradialytic hypotension was significantly higher than that in the 140–159 mmHg group. In dialysis patients, pre-dialysis SBP < 140 mmHg and intradialytic hypotension posed a significantly higher risk for mortality. Our findings suggest that not only lower pre-dialysis BP, but also intradialytic hypotension is associated with poor prognosis in dialysis patients.