K TAN1,2,3, S MCDONALD4,5,6, W HOY1,2
1NHMRC CKD CRE and CKD.QLD, Brisbane, Australia, 2Faculty of medicine, University of Queensland, Brisbane, Australia, 3Renal unit, Logan hospital & Metro South health service, Brisbane, Australia, 4Faculty of medicine, Adelaide University, Adelaide, Australia, 5ANZDATA, Adelaide, Australia, 6Renal unit, CNAHS, Adelaide, Australia
Background: Diabetic patients with CKD have worse cardiovascular, kidney and mortality outcomes than those with neither and either condition alone. However, relationships between these 3 outcomes in patients receiving kidney specialist care remain unclear.
Aims: Determine the relationship between major adverse cardiovascular event (MACE), kidney failure (KF) and death using competing risk analysis.
Methods: CKD.QLD is a large Australian registry of patients with CKD not on KRT receiving kidney specialist care. Diabetic patients enrolled between 1/1/2011 and 31/12/2016 inclusive were studied. Follow-up was censored at death, KF, 1st MACE post enrolment, relocation of patient interstate/overseas, loss to follow-up or censor date of 31/12/2017. Competing risk analysis was performed with MACE, KF and death in turn as primary outcomes whilst the other 2 were competing risks. Co-variates examined were age, gender, ethnicity, incident status, access to services, biopsy, smoking, diabetes treatment, Hba1c, MACE prior to enrolment, eGFR, proteinuria, Hb, RAAS blocker and lipid lowering therapy.
Results: 2355 patients underwent 6608 patient-years follow-up (pyfu). The first event was MACE in 574 patients (24.4%), KF in 298 patients (12.7%) and death in 266 patients (11.3%), giving event rates of 87, 45 and 40 per 1000pyfu. 1217 patients (51.7%) experienced no event. The best-fit multivariate competing risk models revealed that only age, proteinuria and prior MACE predicted all 3 outcomes. Proteinuria positively predicted all 3 outcomes whilst age and prior MACE negatively predicted KF.
Conclusions: Even in the kidney specialist care setting, diabetic CKD patients are still nearly twice as likely to experience a MACE first then they are to die or develop KF. In competing risk analysis, proteinuria was a positive predictor for all 3 outcomes.
Nephrologist, Logan hospital and Metro South Nephrology and Transplant service.
Senior lecturer and PhD candidate, University of Queensland.