Abstract P632: The Blood Pressure in Dialysis (BID) Pilot Study

Background: The optimal blood pressure (BP) target for hypertensive hemodialysis (HD) patients is unknown. Current KDOQI guidelines have been extrapolated from data in the general population. The BID pilot, funded by NIDDK and DCI, is the first trial to randomize hypertensive HD patients to intensive (110-140 mm Hg) vs. usual (155-165 mm Hg) control of systolic blood pressure (SBP). The study’s goal is to assess the feasibility of conducting a full-scale trial.Methods: BID consortium consists of 5 clinical centers, a cardiac MRI reading center and a data coordinating center. Standardized predialysis SBP, measured in the dialysis unit in accord with AHA recommendations (SDUSBP), guide therapy. To be eligible for randomization patients needed a 2-week running mean SDUSBP ≥ 155 mm Hg. Home BP measurements (HBPM) are obtained twice on the day after the midweek dialysis. Ambulatory Blood Pressure Monitoring (ABPM) during a 44h interdialytic period is obtained quarterly. We compared SDUSBP, HBPM and ABPM.Results: We enrolled 281 and randomized 126 participants. Major reasons for drop out during the baseline period were 2-week mean SDUSBP u003c 155 mm Hg (40.6%), no cardiac MRI (13.0%) and perception of protocol as burdensome (11.2%). Adherence with prescribed SDUSBP was satisfactory. The percent of patients with ≥ 4, ≥ 8 and ≥12 SBP per month were 96, 88 and 57% in month 1 and 78, 68 and 37% in month 12. In a constant cohort of participants followed ≥ 330 days 2-week mean SDUSBP were 144 ± 17.4 and 156 ± 15.2 mm Hg in the intensive and usual arms, respectively. Major reasons that participants in the intensive arm did not achieve target SBP included large interdialytic weight gain (27.2%), non-adherence with medications or dialysis prescription (40.9%), and intradialytic hypotension (31.9%). Differences between the SDUSBP and both HBPM and ABPM were often ≥ 10 mm Hg. Optimal control of BP requires measurements in and out of the dialysis unit. Rates of adverse events were similar to those in other NIDDK funded ESRD studies.Conclusion: The difference in BP between arms was achieved and maintained throughout the study. It is feasible to conduct a full-scale clinical trial of intensive vs. usual treatment of hypertension in HD patients.