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 6·47pg/ml, χ2 (I, 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.