Association between estimated glomerular filtration rate and clinical outcomes in patients with acute ischaemic stroke: results from China National Stroke Registry

Background: the impact of estimated glomerular filtration rate (eGFR) on stroke clinical outcomes remains controversial. We examined the association between eGFR and all-cause mortality, recurrent stroke, and stroke disability in patients with acute ischaemic stroke. Methods: we analysed 8865 patients with acute ischaemic stroke in the China National Stroke Registry (CNSR) between September 2007 and August 2008. Multivariate logistic regression analysis was used to evaluate the association between eGFR and 1-year all-cause mortality, recurrent stroke, and stroke disability. Low eGFR was defined as < 45 ml/min/1.73 m(2). Results: of 8865 acute ischaemic stroke patients included in the analysis, eGFR of < 45 ml/min/1.73 m(2) occurred in 394 (4.4%), eGFR of 45-59 ml/min/1.73 m(2) in 675 (7.6%), eGFR of 60-89 ml/min/1.73 m(2) in 3533 (39.9%), and eGFR of a parts per thousand yen90 ml/min/1.73 m(2) in 4263 (48.1%) at baseline. Patients with reduced renal function were more likely to die, experience recurrent stroke or have stroke disability than patients with preserved renal function. After adjusting for both demographic and clinical risk factors, an eGFR of < 45 ml/min/1.73 m(2) was independently associated with 1-year all-cause mortality (OR: 2.65; 95% CI: 1.95-3.59) and recurrent stroke (OR: 1.97; 95% CI: 1.51-2.56) but not for stroke disability defined as modified Rankin Score of 2-6 (OR: 1.26; 95% CI: 0.95-1.67). These results were consistent in stratified analyses by age, diabetes or hypertension. Conclusions: a low eGFR was associated with increased risks of all-cause mortality and recurrent stroke independent of the traditional vascular risk factors in Chinese stroke patients.