Twice-Weekly Hemodialysis with Adjuvant Pharmacotherapy and Conversion to Thrice-weekly Hemodialysis

Background: Almost all Americans with dialysis-dependent kidney disease (DDKD) initiated on treatment with maintenance hemodialysis (HD) are prescribed standard dialytic therapy of fixed frequency (thrice-weekly HD) and dose (dialysis single-pool Kt/V urea [spKt/V] ≥ 1.2, corresponding to standard Kt/V urea [stdKt/V] ≥ 2.1). However, this standard HD therapy disregards individual levels of residual kidney function, and a significant proportion of patients with DDKD who retain some level of residual kidney function (RKF) can likely be treated safely and effectively with twice-weekly HD at initiation until their RKF declines to such a level that thrice weekly HD becomes necessary. Previous retrospective studies suggest that this twice-weekly (incremental) approach to HD conferred similar or better patient outcomes and longer survival. The aim of this study was to access the feasibility of individual randomization to incremental vs conventional HD; and incorporation of participant clinical management and procedures related to serial measurement of residual kidney function into usual workflow at outpatient dialysis units. Preliminary evidence concerning intervention safety and clinical effectiveness was also obtained and is reported here.

Hypothesis: It is hypothesized that twice-weekly HD with adjuvant pharmacologic therapy will demonstrate differences from the standard thrice-weekly HD regime, yielding insight into the feasibility of a larger clinical trial. 

Methods: An individually randomized, open-label parallel-group pilot clinical trial was conducted with the primary objective of assessing the feasibility of a strategy of incremental HD in patients with incident DDKD and residual kidney function. Eligibility criteria included baseline estimated glomerular filtration rate ≥5 mL/min/1.73m2 and urine volume ≥500 mL/day. Participants were randomly assigned (1:1 ratio) to twice-weekly HD and adjuvant pharmacologic therapy (loop diuretics, sodium bicarbonate and/or patiromer) for 6 weeks followed by thrice-weekly HD (incremental HD group) or continued thrice-weekly HD (conventional HD group) at 14 outpatient dialysis units and 1 inpatient dialysis unit. The annual cumulative hospitalization rate, deaths, and adherence to study-specific assessments were recorded and analyzed for feasibility and safety. 

Results: 48 patients were enrolled (consent rate, 66%) and randomized to incremental HD (n=23) vs conventional HD (n=25). At mean follow-up of 284.9 days, adherence to the assigned HD schedule and serial timed urine collections was 96% and 100%, respectively, in both groups. Of those included in incremental-start HD, all received loop diuretics, 17% received patiromer, and 39% received sodium bicarbonate during the period of twice-weekly HD. The annual cumulative hospitalization rate was 1.06 and 1.84, respectively (P=0.05); and 7 deaths were recorded (1 in incremental HD group and 6 in conventional HD group). There were no events of urgent, unscheduled HD treatments in the incremental-start HD group. No significant differences were noted in pre-dialysis serum chemistry parameters related to metabolic and acid-base balance.  

Conclusions: The pilot trial demonstrates incremental-start HD is feasible and safe in a subpopulation of patients with incident DDKD. Larger multicenter clinical trials should be conducted to conclusively determine clinical effectiveness and safety of incremental HD.