A HARFORD1, D MISKULIN2, J GASSMAN3, R SCHRADER4, S PAINE4, P ZAGER1,4
1University of New Mexico, Albuquerque, New Mexico, United States; 2Tufts Medical Center, Boston, Massachusetts, United States; 3Cleveland Clinic, Cleveland, Ohio, United States; 4Dialysis Clinic, Inc., Albuquerque, New Mexico, United States
Aim: Assess the feasibility of using standardized predialysis blood pressure (SDUBP), home blood pressure (HBPM) or ambulatory blood pressure (ABPM) to drive therapy in a randomized, controlled trial (RCT) of intensive versus usual control of hypertension in hemodialysis patients.
Background: Since there are no RCTs powered for hard outcomes the optimal blood pressure target remains unknown. Moreover, there is evidence suggesting that HBPM and ABPM are superior to SDUBP in predicting outcomes.
Methods: We conducted a pilot study, which randomized 126 participants to a SDUBP of 110-140 or 155-165 mmHg. We used SDUBP to drive therapy but also collected data on adherence with prescribed weekly HBPM and quarterly ABPM during the 1-year intervention.
Results: Adherence with obtaining ≥4 SDUBP per month was excellent in months 1 (97%), 3 (96%), 6 (90%), 9 (88%) and 12 (75%). Adherence with obtaining ≥1 HBPM in months 1 (82%), 3 (72%), 6 (73%), 9 (64%) and 12 (62%) was modest but poor with ≥4 HBPM (36%, 28%, 34%, and 22%) in months 1, 3, 6, 9 and 12, respectively. We achieved sustained separation in both SDUBP and HBPM across study arms. Adherence with ABPM was only 20% in quarters 1, 2, 3, but surprisingly 60% in quarter 4.
Conclusions: Despite the putative advantages of HBPM and ABPM in predicting outcomes adherence with weekly HBPM and quarterly ABPM was poor. Adherence with ≥1 HBPM per month was good but this may not be frequent enough to safely drive therapy in a full-scale RCT. Use of HBPM or ABPM to drive therapy in a full-scale RCT will require great attention to ensure adequate adherence. Otherwise the trial should rely upon SDUBP.