Does cooled dialysate still have a role in reducing intradialytic stress? Implications of the MyTEMP trial

Abstract

Purpose of review: There is an excess of cardiovascular morbidity and mortality in the maintenance haemodialysis population. Targeting traditional risk factors (e.g. hypercholesterolaemia) do not improve cardiovascular outcomes. Repeated myocardial stunning during haemodialysis is an important nontraditional risk, resulting in pathological cardiac remodelling and fibrosis. This review explores dialysate cooling as a management strategy to promote haemodynamic stability, reduce myocardial injury, and improve cardiovascular disease outcomes for individuals receiving maintenance haemodialysis. Recent findings: Observational data and small interventional studies demonstrate dialysate cooling has the potential to reduce end-organ damage and provide cardioprotection, renal protection and neuroprotection compared with standard care. These data are limited by the small sample sizes, short follow-up times and lack of long-term patient important outcomes. The MyTEMP study, a multicentre pragmatic randomized controlled trial, demonstrated cooled dialysate (0.5°C below body temperature) vs. standard care did not improve cardiovascular outcomes for prevalent haemodialysis patients. Summary: Dialysate cooling has been widely adopted into routine clinical practice; the MyTEMP study challenges the unit-level approach to implementing dialysate cooling. Due to methodological limitations, the absence of other important patient outcome measures, and lack of granularity of patient-level data, dialysate cooling should not be hastily removed from all dialysis care and warrants further research.