Intradialytic Hypertension Frequency and Short-Term Clinical Outcomes Among Individuals Receiving Maintenance Hemodialysis

Abstract

Background: Intradialytic hypertension occurs in 5-20% of hemodialysis treatments. Observational data support an association between intradialytic hypertension and long-term mortality. However, the short-term consequences of recurrent intradialytic hypertension are unknown.

Methods: Data were taken from a cohort of prevalent hemodialysis patients receiving treatment at a large United States dialysis organization on 1 January 2010. A retrospective cohort design with a 180-day baseline, 30-day exposure assessment, and 30-day follow-up period was used to estimate the associations between intradialytic hypertension frequency and 30-day outcomes. Intradialytic hypertension frequency was defined as the proportion of exposure period hemodialysis treatments with a predialysis to postdialysis systolic blood pressure rise >0 mm Hg. Multivariable Cox proportional hazards regression, adjusted for baseline clinical, laboratory, and dialysis treatment covariates, was used to estimate hazard ratios and 95% confidence intervals.

Results: Of the 37,094 study patients, 5,242 (14.1%), 17,965 (48.4%), 10,821 (29.2%), 3,066 (8.3%) had intradialytic hypertension in 0%, 1-32%, 33-66%, and ≥67% of exposure period treatments, respectively. More frequent intradialytic hypertension was associated with incremental increases in 30-day mortality and hospitalizations. Patients with intradialytic hypertension in ≥67% (vs. 0%) of exposure period treatments had the highest risk of all-cause death, hazard ratio [95% confidence interval]: 2.57 [1.68, 3.94]; cardiovascular (CV) death, 3.68 [1.89, 7.15]; all-cause hospitalizations, 1.42 [1.26, 1.62]; CV hospitalizations, 1.71 [1.36, 2.15]; and volume-related hospitalizations, 2.25 [1.25, 4.04].

Conclusions: Among prevalent hemodialysis patients, more frequent intradialytic hypertension was incrementally associated with increased 30-day morbidity and mortality. Intradialytic hypertension may be an important short-term risk marker in the hemodialysis population.

Keywords: blood pressure; hemodialysis; hospitalization; hypertension; intradialytic hypertension; mortality.