High neutrophil-to-lymphocyte ratio (NLR) predicts poor response to intravenous thrombolysis in white Caucasian stroke patients

Objectives: Our aim was to investigate usefulness of the neutrophil-to-lymphocyte ratio (NLR) for predicting poor response to intravenous rtPA in white Caucasian ischemic stroke patients treated within 4.5 hours from the onset.Materials and methods: This retrospective analysis included all consecutive acute ischemic stroke patients (N = 344) treated with rtPA in a tertiary stroke center from 2011 to 2017. NLR was calculated from complete blood counts obtained on admission. The patients were classified into NLR terciles (T1 <1.75, T2<2.97, T3 >= 2.97). Significant neurological improvement was defined as an 8-point reduction in the NIHSS score or reaching the score of 0 to 1.Results: Compared to NLR T1, patients from NLR T3 were significantly older, more often disabled before stroke, and had longer onset-to-needle time. They less often achieved neurological improvement at day 7 (38% vs 59% p=0.002) and had higher 90-day mortality (27% vs 13%, p=0.020), with no differences in neurological improvement at 24 hours, occurrence of sICH and 7-day mortality. Each additional 4 units of NLR decreased unadjusted and adjusted odds for achieving favorable outcome at day 7 (OR 0.65, 95% CI: 0.46-0.92; aOR 0.62, 95% CI: 0.39-1.00), and increased the odds for death at 3 months (OR 1.60, 95% CI: 1.15-2.24; aOR 1.82, 95% CI:1.14-2.92)Conclusions: High NLR can predict poor response to intravenous rtPA in Caucasian patients with acute ischemic stroke, especially in terms of not achieving significant neurological improvement at day 7 and death at day 90. It encourages attempts to incorporate NLR in already validated scores.