B SMYTH1,2, C CHAN3, S GRIEVE4,5,6, R PURANIK7,8, L ZUO9, D HONG10, N GRAY11,12, J DE ZOYSA13,14, A SCARIA1, M GALLAGHER1,4,15, V PERKOVIC1, M JARDINE1,15
1The George Institute for Global Health, UNSW, Sydney, Australia, 2Sydney School of Public Health, University of Sydney, Sydney, Australia, 3University Health Network, Toronto, Canada, 4Sydney Medical School, University of Sydney, Sydney, Australia, 5Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Sydney, Australia, 6Department of Radiology, Royal Prince Alfred Hospital, Sydney, Australia, 7Specialist Magnetic Resonance Imaging, Newtown, Australia, 8Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia, 9Peking University People’s Hospital, Beijing, China, 10Renal Department, Sichuan Provincial People’s Hospital, Chengdu, China, 11Sunshine Coast University Hospital, Birtinya, Australia, 12Sunshine Coast Clinical School, University of Queensland, , Australia, 13North Shore Hospital, Auckland, New Zealand, 14Department of Medicine, University of Auckland, Auckland, New Zealand, 15Renal Unit, Concord Repatriation General Hospital, Sydney, Australia
Aim: To determine predictors of change in left ventricular mass index (LVMI) in the ACTIVE Dialysis study.
Background: Extended hours dialysis was not associated with a significant reduction in LVMI in the ACTIVE Dialysis trial. Other factors, such as changes in fluid status and biochemical parameters, may predict regression of LV hypertrophy.
Methods: In the ACTIVE Dialysis study patients randomised to extended and standard dialysis, received median 24 and 12 haemodialysis hours per week respectively, predominantly delivered as three sessions per week. Ninety-five participants underwent cardiac magnetic resonance imaging (MRI) at baseline and 12 months. Predictors of change in LVMI were examined by multivariable linear regression in an observational analysis.
Results: In the overall MRI cohort, the change from baseline to 12 months in LVMI was -6.7g (95% confidence interval (CI) -11.2, -2.2; P=0.004) with non-significant reductions in mean normalised sessional ultrafiltration rate -1.0mL/kg/hr (95%CI -2.2, 0.24; P=0.114) and weekly total ultrafiltration -0.8L (95%CI -0.3, 2.0; P=0.165) and a significant reduction in systolic blood pressure (BP) -5.4mmHg (95%CI -8.8, -2.0; P=0.002). Baseline LVMI (P=0.003) was associated with improved LVMI in univariable analysis and this remained significant in the multivariable analysis (P=0.046). A non-significant improvement in LVMI was observed with longer dialysis vintage (P=0.137). There were no significant associations between changes in ultrafiltration rates and volumes, systolic and diastolic blood pressure, phosphate, and parathyroid hormone and change in LVMI.
Conclusions: Higher baseline LVMI, but not improvements in volume control, blood pressure or biochemical parameters, predicts regression of left ventricular hypertrophy over 12 months. Further study is warranted to identify predictors of change in this important treatment target.
Dr Smyth is a nphrologist and PhD candidate at The George Institute for Global Health. His research interests include dialysis, especially randomised controlled trial methodology and evidence as well as patient reported outcomes in dialysis patients.