Home bp monitoring improves the diagnosis of hypertension in hemodialysis patients

Objective: Although routine blood pressure (BP) measurements taken shortly before or after dialysis provide imprecise reflection of interdialytic ambulatory BP, this method continues to form the basis for the diagnosis of hypertension among patients on hemodialysis. Home BP monitoring (HBPM) is a guideline-recommended technique that may improve the diagnosis of hypertension in this population. Using 44-hour ambulatory BP monitoring (ABPM) as the reference-standard method, this study aimed to compare the diagnostic performance of home versus routine pre- and postdialysis BP recordings in hemodialysis patients. Design and method: In 70 stable patients with end-stage kidney disease receiving thrice-weekly hemodialysis, BP was assessed with the following methods: (i) routine predialysis and postdialysis BP measurements averaged over 2 weeks; (ii) HBPM for 7 days (dublicate morning and evening measurements, Microlife WatchBP Home N); (iii) ABPM (20 min intervals over an entire interdialytic interval - 44 hours, Microlife WatchBPO3). Results: The mean age of the patients was 65.3±13.3 years; 45 patients (64%) were males, and 62 (88.7%) had a known history of hypertension. The mean [95% confidence interval (CI)] of the difference between ambulatory systolic BP (SBP) and (i) predialysis SBP was 11.43 (8.24, 14.62) mmHg, (ii) postdialysis SBP was 3.9 (0.37, 7.56) mmHg, and (iii) home SBP was 8.61 (6.05, 11.17). The area under the receiver operating characteristic curve for the detection of an ambulatory daytime SBP equal or higher than 135 mmHg was significantly higher for home SBP measurements 0.934 (95% CI: 0.871-0.996) as compared to predialysis 0.778 (95% CI: 0.643-0.913) and postdialysis 0.766 (95% CI: 0.623-0.909) BP recordings (P = 0.02 for both comparisons). 1-week averaged home SBP at the cut-off point of 141.0 mmHg provided the best combination of high sensitivity (85.7%) and high specificity (92.9%) in diagnosing systolic ambulatory hypertension. Conclusions: The present study shows that among patients on hemodialysis, HBPM for 1 week provides greater accuracy than 2-week averaged routine pre- and postdialysis BP recordings in the diagnosis of hypertension confirmed by the reference-standard method of interdialytic ABPM.