EPIDEMIOLOGY OF RENAL INFARCT: INCIDENCE AND RISK OF MORTALITY AND KIDN.EY FAILURE IN AN AUSTRALIAN LOCAL HEALTH DISTRICT
A/Prof. Hicham Cheikh Hassan1, Kelly Lambert2, Dr Karumathil Murali3, Professor Judy Mullan2
1Lebanese American University, Lebanon, 2University of Wollongong, Wollongong, Australia, 3Illawarra Shoalhaven Local Health District, Renal Department, Wollongong, Australia
Aim: To investigate renal infarction epidemiology within a local health district focusing on incidence, prevalence, mortality risk and kidney replacement therapy (KRT).
Background: Renal infarction is an uncommon cause of hospital presentation. The epidemiology of renal infarction has been poorly examined with poor insight on long term mortality or KRT risk.
Methods: Retrospective longitudinal cohort study of adult patients attending a health district facility (2008-2017). Data were linked to the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry to determined episodes of KRT. Variables included baseline demographics, comorbidities (international classification of disease [ICD10AM]) and creatinine to determine acute kidney injury (AKI) or chronic kidney disease (CKD). Exposure was a renal infarction, with the comparator group being patients with no renal infarction. Outcomes were mortality or KRT. Renal infarction crude incidence and prevalence were calculated in addition of Cox proportional hazard analysis for risk of outcome (hazard ratio [HR], 95% confidence interval [95%CI]).
Results: Of 140,890 patients followed over 638,306 patient-years a renal infarction occurred in 121 (0.1%) with an incidence of 1.89 per 10,000 patient-years. Renal infarction patients had a higher comorbidity burden compared to controls including hypertension (60% vs 6%), diabetes (26% vs 4%), arrythmias (43% vs 3%), cardiac disease (31% vs 2%), CKD (39% vs 8%) and AKI (41% vs 2%), P<0.05 for all. Mortality occurred in 19,434 patients (14%) and KRT in 364 (0.3%). Renal infarction was a significant risk factor for mortality (adjusted HR 1.5, 95%CI 1.1-2.1) and KRT (adjusted HR 7.7, 95%CI 2.9-21.2).
Conclusions: Renal infarction is an uncommon event but is associated with high comorbidity at baseline and is a significant risk factor for mortality and KRT.