Accuracy of Peridialytic, Intradialytic, and Scheduled Interdialytic Recordings in Detecting Elevated Ambulatory Blood Pressure in Hemodialysis Patients.

ABSTRACT Rationale and Objective Current recommendations suggest the use of ambulatory-BP-monitoring (ABPM) as the gold-standard for hypertension diagnosis and management in hemodialysis patients. This study assesses the accuracy of peridialytic, intradialytic, and scheduled interdialytic recordings in detecting abnormally elevated 44-h interdialytic BP. Study design Diagnostic test study. Settings and participants 242 Greek hemodialysis patients who successfully underwent ABPM. Tests Compared Ambulatory BP was used as reference to evaluate the accuracy of following BP metrics: pre- and post-dialysis, intradialytic, intradialytic plus pre/post-dialysis, and scheduled interdialytic BP at off-dialysis day at 8:00 am, 8:00 pm, and their average. Outcome 44-h ambulatory SBP/DBP ≥130/80 mmHg. Results 44-h SBP/DBP levels differed significantly from pre- and post-dialysis BP, but showed no or minor differences compared to the other BP metrics. Bland-Altman plots showed absence of systematic bias for all metrics, but large between-method difference and wider 95% limits of agreement for pre- and post-dialysis BP compared to intradialytic, intradialytic plus pre/post-dialysis and averaged scheduled interdialytic BP. The sensitivity/specificity and κ-statistic for diagnosing 44-h SBP≥130 mmHg were low for pre-dialysis (86.5%/38.6%, κ-statistic=0.27) and post-dialysis BP (63.1%/73.3%, κ-statistic=0.35), but better for intradialytic (77.3%/76.2%, κ-statistic=0.53), intradialytic plus pre/post-dialysis (76.6%/72.3%, κ-statistic=0.49), and scheduled interdialytic BP (87.9%/77.2%, κ-statistic=0.66). In ROC-analyses, the Areas-Under-the-Curve (AUC) of pre-dialysis (AUC 0.723) and post-dialysis SBP (AUC 0.746) were significantly lower than that of intradialytic (AUC 0.850), intradialytic plus pre/post-dialysis (AUC 0.850) and scheduled interdialytic SBP (AUC 0.917) (z-test, p Limitations Typical home BP data were not obtained and no assessment was obtained of reproducibility of examined metrics over time. Conclusions Intradialytic, intradialytic plus pre/post-dialysis, and scheduled interdialytic BP measurements were more accurate in detecting elevated 44-h BP than pre- and post-dialysis BP. Averaged intradialytic BP recordings or scheduled readings at the off-dialysis day appear to be promising approaches to the diagnosis of elevated BP in hemodialysis.