Age dependent impact of estimated glomerular filtration rate on long-term survival after ischaemic stroke

Low estimated glomerular filtration rate (eGFR) is associated with high mortality after stroke. However, ageing can influence eGFR directly and limit this burden impact. We investigated if low eGFR can be a predictor of death in different age groups after ischaemic stroke.

We evaluated and followed for 22 ± 14 months 871 unselected consecutive survivor patients more than 30 days after ischaemic stroke (55% men, mean age of 66 ± 13 years) recruited in a prospective Brazilian cohort study from March 2005 to December 2007. Traditional cardiovascular risk factors and eGFR by The Chronic Kidney Disease Epidemiology Collaboration formula were analyzed as predictors of mortality for the whole cohort population and stratified by age (younger or older than 65 years old) in a Cox proportional hazards regression model.

There were 119 (14%) deaths during follow up. The mean eGFR was 74 ± 23 mL/min per 1.73 m(2). Three hundred and sixteen patients (36%) presented eGFR lower than 60 mL/min per 1.73 m(2). For the whole population, eGFR lower than 60 mL/min per 1.73 m(2) was independently associated with death after stroke in the multivariate analysis. When stratified by age groups, low eGFR was the single and independent predictor of death just for individuals younger than 65 years-old, as for older people just chronic atrial fibrillation, previous stroke and increase of age were associated with death.

Low eGFR measured at the first day of hospital admission can be a simple and trustful predictor of death after ischaemic stroke in people younger than 65 years old.