Feasibility of a Randomized Cluster Trial for Blood Pressure Targets in In-centre Hemodialysis Units

High blood pressure in people receiving hemodialysis is known to contribute to heart disease and heart-related death from strokes, heart failure, left ventricular hypertrophy (which is a thickening of the heart wall that makes it difficult for the heart to pump blood) and arrythmias (an irregular or abnormal heartbeat). In comparison, low blood pressure can lead to cramps, myocardial stunning, and cerebrovascular ischemia. However, despite, blood pressure management being an important component of hemodialysis care, the "best" blood pressure target for people on hemodialysis is unknown.

Finding the "right" blood pressure to target can have a major impact on patient lives. We are proposing a large, pragmatic, cluster randomized trial targeting a lower versus higher blood pressure target in in-centre hemodialysis units in Canada. Our initial steps towards this bigger trial are to run a smaller trial including 4 units, to evaluate whether it is feasible to conduct a larger trial. Our ultimate goal is to deliver the definitive randomized trial for blood pressure targets in the hemodialysis population.

Despite, blood pressure management being a cornerstone of multidisciplinary rounds, the optimal blood pressure target for people on hemodialysis is unknown. We plan to conduct a pilot study to determine if implementation of a pre-dialysis blood pressure protocol (as a unit-level policy) of a higher (150-170 mm Hg systolic) versus lower target (110-140 mm Hg systolic) in patients receiving chronic, in-centre hemodialysis is feasible?

This pilot study is a 4-centre pragmatic, two-arm, parallel-group, open-label cluster-randomized trial evaluating the feasibility of implementing a higher versus lower blood pressure target protocol. The intervention period will last 3 months, with check-ins at weeks 4 and 8 to see if clusters are able to meet their target blood pressures. If blood pressures are not at target at the week 4 check-in, a review between the study team and cluster will be conducted to determine how the target can be achieved.

Clusters will be randomized to a target pre-dialysis SBP of 110-140 mm Hg (the treatment arm) or 150-170 mm Hg (the standard arm). A 2-week average of standardized pre-dialysis systolic blood pressure readings measured in unknit will be used to define blood pressure targets and goals. Two weeks after a change to treatment has been made, SBP should be reassessed. If it is still above or below target range, another adjustment to course of treatment should be made. This interval allows for the effects of the change in treatment to be seen before any additional changes in treatment are made. The decision on how to adjust a participant's treatment in order to meet target blood pressure is up to the treating physician. This allows for more flexibility in treatment options and greater individuality in care. The treating physician can make treatment decisions based on individual needs, so as to better account for the participant's counter indication, comorbidities, and tolerances. Significant changes (both increases and decreases) in dry weight are not recommended. Changes in anti-hypertensive medication titration is the preferred option to adjust blood pressure before adjusting dry weight, sodium, and dialysis time.

Eligibility Criteria:
Inclusion Criteria:

* Age \> 18 years old
* Undergoing in-centre hemodialysis at least twice weekly
* \> 90 days since initiation of dialysis

Exclusion Criteria:

* Participation in another intervention study that may affect blood pressure other than other cluster RCTs of dialysate composition
* Inability to measure blood pressures in an upper arm
* Pregnancy, anticipated pregnancy, or breastfeeding
* Unmeasurable SBP (e.g., have left ventricular assist device)
* Life expectancy \< 4 months
* Planned transition to home dialysis within 3 months
* Planned move to a different dialysis unit within 3 months
* Anticipated living donor kidney transplant within 3 months
* Other reasons as determined by treating clinician, reasons will be recorded