Effectiveness and cost of weekly recombinant tissue plasminogen activator hemodialysis catheter locking solution

Background and objectives Evidence to guide hemodialysis catheter locking solutions is limited. We aimed to assess effectiveness and cost of recombinant tissue plasminogen activator (rt-PA) once per week as a locking solution, compared with thrice weekly citrate or heparin, in patients at high risk of complications. Design, setting, participants, & measurements We used a prospective design and pre-post comparison in three sites across Canada. Pre-post comparisons were conducted using multilevel mixed effects regression models accounting for cluster with site and potential enrollment of patients more than once. In the pre period, catheter malfunction was managed as per site-specific standard of care. The intervention in the post period was once weekly rt-PA as a locking solution (with citrate or heparin used for other sessions). The primary outcome was rate of rt-PA use for treatment of catheter malfunction. Secondary outcomes included rates of bacteremia, management of catheter malfunction, and cost. Results There were 374 patients (mean age 68 years; 52% men) corresponding to 506 enrollments. Mean length of enrollment was 200 days (SD 119) in the pre period and 187 days (SD 101) in the post period. There was a significant decline in rate of rt-PA use for treatment of catheter malfunction in the post compared with pre period (adjusted incidence rate ratio, 0.39; 95% confidence interval, 0.30 to 0.52); however, there was no difference in the rate of bacteremia, or catheter stripping or removal/replacement. The increase in mean total health care cost in the post period was CAD$962 per enrollment, largely related to costs of rt-PA as a locking solution. Conclusions Once weekly rt-PA as a catheter locking solution was associated with a reduction in rt-PA use for treatment of catheter malfunction. Our results showing a reduction in rescue rt-PA use are consistent with a prior randomized trial, although we did not observe a reduction in bacteremia or catheter stripping/removal and did observe an increased incremental cost of this strategy primarily accounted for by the cost of the rt-PA.