How to measure accurately blood pressure in hemodialysis patients?

Objective : Blood pressure (BP) control in chronic hemodialysis (HD) patients is a major challenge and could explain the controversial results about its cardiovascular risk. Our study aimed to assess the contribution of two ambulatory techniques of measurements compared with office BP (OBP): ambulatory monitoring during a maximum of 44h interdialytic period (ABPM) and home blood pressure (HBPM) during a variable period of days in prevalent HD patients.

Methodology : 43 prevalent chronically HD patients (M=28; F=15), mean age 68.3±13 years were submitted to a 44h monitoring of BP (Spacelabs 90207) from the end of an HD session to 10 minutes before the next session, immediately followed by a 7days HBPM (Omron M6). Office BP was the mean of pre-dialysis BP or post-dialysis-BP recorded over 2 weeks (6 HD sessions). Hypertension was defined as BP equal or higher than 140/90 mmHg for pre-HD, 130/80 mmHg for post-HD, 130/80 mmHg for 44 h ABPM and 135/85 mmHg for HBPM.

Results : Good correlations were noted between ABPM and HBPM for the diagnosis of hypertension in HD patients. Both ambulatory techniques give the same proportion of masked hypertension and white coat hypertension compared with OBP (25%). The best diagnostic precision was noted for the longest periods of recordings (44h for ABPM and 7days for HBPM). Shorter periods were more practical for the patients but less precise for high BP identification. HBPM was more appreciated than ABPM by the patients

Conclusion : ABPM and HBPM identified a quarter of patients with a particular phenotype of hypertension not correctly classified by OBP. HBPM should be first recommended in HD (at least 1 week/month). As ABPM provides unique information for nocturnal BP, it could be proposed 1 time/year in all patients.