The SOdium Lowering In Dialysate Trial

ANZ clinical trials registry number: 12611000975998

Principal Investigator: Dr Mark Marshall, Centre for Clinical Research and effective practice (CCRep), New Zealand
Clinical Project Manager: Lynda Mockett, Centre for Clinical Research and effective practice (CCRep), New Zealand

The primary aim of the SOLID trial is to assess whether low dialysate [Na+] improves left ventricular structure in patients receiving home haemodialysis (HD). The primary outcome is left ventricular mass index (LVMI) as measured by cardiac Magnetic Resonance Imaging (MRI). The secondary aims are to assess whether low dialysate [Na+] improves other surrogate cardiovascular outcomes and potential mechanistic factors: left ventricular function and haemodynamics, blood pressure, extra-cellular fluid volume status, thirst, and inter-dialytic weight gain. In addition, the SOLID trial will test low dialysate [Na+] in terms of tolerability and effect on health-related quality of life.

The trial will recruit 118 participants on home HD over the age of 18 years from five New Zealand centres. After baseline measurements including a cardiac MRI scan, participants will be randomised to receive low dialysate [Na+] of 135mM or conventional dialysate [Na+] of 140mM. Following randomisation, participants will undergo a supervised change in dialysate [Na+] by increments or decrements of 1mM/week until their target dialysate [Na+] has been achieved. Patients will be maintained on this dialysate setting until the 12 month follow-up.

The effect of low dialysate [Na+] on LVMI will be assessed by a repeat cardiac MRI scan at 12 months follow-up. Other outcomes will be assessed by blinded assessors at variably 3, 6, 9 and 12 months follow-up.

The trial is funded by the Health Research Council of New Zealand and endorsed by the Australasian Kidney Trials Network. It is being fully coordinated through the Centre for Clinical Research and effective practice (CCRep), Auckland, New Zealand.