Association between estimated glomerular filtration rate, ankle-brachial index, and recurrent ischemic stroke in a Chinese population of ischemic stroke patients

Background: Very few studies have examined combined association of estimated glomerular filtration rate (eGFR) and ankle-brachial index (ABI) on recurrent ischemic stroke in patients with ischemic stroke in Chinese populations. Patients and methods: A Chinese population of 1219 ischemic stroke patients was followed up in this six-year prospective study. Results: 1080 ischemic stroke patients with complete follow-up data were included in the statistical analysis. A total of 245 ischemic stroke patients (22.7%) had recurrent ischemic stroke during follow-up. The Incidence of recurrent ischemic stroke was significantly increased with decreasing eGFR levels and that of patients with eGFR < 30 ml/min/1.73m(2) was the highest. Hazard ratio (HR) of eGFR <30 ml/min/1.73m2 to recurrent ischemic stroke was 2.633 (95% CI: 1.653 - 4.194) compared with that of eGFR 60 ml/min/1.73m2 after adjusting for other potential confounders using Cox regression analysis. Incidence of recurrent ischemic stroke was significantly increased with simultaneously decreasing eGFR and ABI. The highest percentage (71.4%) of patients with eGFR <30 ml/min/1.73m2 and ABI <= 0.4 simultaneously had recurrent ischemic stroke during follow-up. HR of eGFR <30 ml/min/1.73m2 and ABI 0.4 simultaneously with recurrent ischemic stroke was 9.415 (95% CI: 3.479 - 25.483) compared with that of eGFR 60 ml/min/1.73m2 and ABI > 1.0 to 1.4 respectively Conclusions: Low ABI and low eGFR together had synergistic effects on increasing recurrent ischemic stroke of ischemic stroke patients during a long-term follow-up.