Renal dysfunction increases the risk of recurrent stroke in patients with acute ischemic stroke

This study investigated risks of short-term (1 and 3 months) and long-term (1-year) recurrent stroke associated with glomerular filtration rate (eGFR) in patients with acute ischemic stroke.

From the Taiwan Stroke Registry data, we identified 45,876 acute ischemic stroke patients from April 2006 to April 2014 and classified them into 4 groups based on the eGFR at admission: ≥ 90, 60-89, 30-59, and <30 mL/min/1.73 m² or on dialysis. The risks of 1-month, 3-month and 1-year recurrent stroke related to the eGFR levels were investigated.

Both the risks of short-term and long-term recurrent stroke increased as the eGFR levels declined. The 1-month recurrent incidence rates increased steadily from 0.54 to 0.59, 0.84 and 0.89 per 1000 person-days, as the eGFR declined from ≥90 to 60-89, 30-59, and <30 mL/min/1.73 m² or on dialysis, respectively. Compared to patients with eGFR ≥90 mL/min/1.73 m², the adjusted subhazard ratio of 1-month recurrent stroke decreased from 1.69 (95% confidence interval (CI) = 1.24-2.31) for patients with eGFR < 30 mL/min/1.73 m² or on dialysis to 1.14 (95% CI = 0.91-1.43) for patients with eGFRs of 60-89 mL/min/1.73 m², considering the competing risk of deaths. Similar patterns were also observed for the adjusted HRs of 3-month and 1-year recurrent stroke, but with reduced hazard values, by the corresponding eGFR levels.

There is an independent graded association between an increased risk of recurrent stroke and declining eGFR levels in patients with acute ischemic stroke.