Interleukin-6 as an early predictor for one-year survival following an ischaemic stroke/transient ischaemic attack

Background: Early biomarkers for survival in an acute ischaemic stroke/transient ischaemic attack might serve as a useful tool for the clinician. Several studies have highlighted the role of inflammatory biomarkers as an early signal for acute ischaemic stroke prognosis. Aims: This study examines the potential advantage of using high-sensitivity interleukin-6 as a possible biomarker at the early stages of acute stroke for identifying patients at a high risk for 12-month mortality. Methods: Inflammatory biomarkers and neurological scores were determined in 250 patients following mild to moderate acute ischaemic stroke within 24 h of hospital admission. Outcome data on mortality were collected after 12 months. The signal detection methodology was used to identify subgroups that were at a high risk for 12-month mortality. Results: Twelve months following the event, 234 of the 250 stroke patients survived. Signal detection identified predictors that distinguished individuals likely to die from those with a better recovery prediction. Plasma interleukin-6 concentration emerged as the optimal predictor, with a cut point of 6·47 pg/ml, χ² (l, N=250)=20·5, P<0·001. Interleukin-6 above 6·47 pg/ml during the acute phase predicted subsequent non-survival (P=0·006, odds ratio 8·0). Conclusions: This study demonstrates the clinical potential of using high-sensitivity interleukin-6 as an early signal for acute ischaemic stroke survival and suggests a clear cut point for patients at a high risk who might benefit from closer clinical surveillance and/or administration of therapeutic interventions.