MyTEMP trial: Personalised cooler dialysate or standard for maintenance haemodialysis
While haemodialysis centres have typically used a standard dialysate temperature of 36.5°C or 37°C for maintenance dialysis, many have adopted a cooler dialysate (e.g. ≤36°C) for cardiovascular benefits. The evidence supporting dialysate cooling prior to this has been in the form of small trials and observational data, so a large outcome trial was welcome. The MyTEMP trial set out to assess whether personalised cooler dialysate reduced the risk of cardiovascular-related death or hospital admission compared with standard temperature dialysate, when implemented as centre-wide policy.
Centres in Ontario, Canada, were randomised to administer personalised cooler dialysate (0.5–0.9°C below pre-dialysis body temperature; n=42) or standard-temperature dialysate (36.5°C; n=42). During the 4-year trial, they provided maintenance haemodialysis to 15,413 patients (about 4.3 million treatments). The primary outcome (a composite of cardiovascular-related death or hospital admission with a major cardiovascular event) was recorded by medical coders unaware of the trial.
The primary outcome was reported in 1711 (21.4%) of 8000 patients in the cooler dialysate group versus 1658 (22.4%) of 7413 patients in the standard temperature group (adjusted HR, 1.00 [96% CI, 0.89–1.11; P=0.93]). Mean drops in intradialytic systolic blood pressure of 26.6 mmHg and 27.1 mmHg were reported in the cooler and standard dialysate groups, respectively (mean difference, –0.5 mmHg [99% CI, –1.4–0.4; P=0.14]).
The findings in this large, pragmatic trial that cooler dialysate did not significantly reduce major cardiovascular events, and that there was no meaningful difference in intradialytic systolic blood pressure between the groups, indicate that cooler dialysate should not be adopted as a centre-wide policy for all patients. However, the authors did not conclude that cooler dialysate should be abandoned altogether, but that its risks and benefits in some patients need to be investigated further.
