Diagnostic and prognostic yields of ambulatory blood pressure measurements in haemodialysis patients: a 6-year longitudinal study.

Background: Blood pressure (BP) control in haemodialysis (HD) patients is essential. Peri-dialytic BP levels do not accurately diagnose hypertension or predict the cardiovascular (CV) mortality.

Methods: In this study, we recruited 43 adult patients who had been on chronic HD for ≥3 months. Seven-day home BP monitoring (HBPM) (values of Day1 discarded) and 44-h interdialytic ambulatory BP monitoring (iABPM) were performed. Pre- and post-dialysis BP levels were measured during the 6 dialysis sessions prior to iABPM. A 6-year follow-up was carried out to assess all-cause and CV mortality.

Results: In patients considered as normotensive in pre-dialysis (n = 17), masked hypertension was found in 24% and 29% on the basis of iABPM and HBPM, respectively. Conversely, among hypertensive patients in pre-dialysis (n = 26), 'white-coat' hypertension was noted in 23% either by iABPM or HBPM. After a 6-year follow-up, 25 patients were deceased including 6 patients from CV causes. Day-time systolic BP measured by iABPM was associated with all-cause mortality in an adjusted model for age and gender (p = 0.045).

Conclusion: In chronic HD patients, 44-h iABPM and 6-day HBPM show a reliable concordance and help to re-classify ∼25% of cases miscategorised based on pre-dialysis measurements. Day-time systolic BP levels using iABPM were significantly associated with 6-year all-cause mortality.