Sex differences in the Norwegian Tenecteplase Trial (NOR-TEST)

Sex differences in acute ischemic stroke is of increasing interest in the era of precision medicine. We aimed to explore sex disparities in baseline characteristics, management and outcomes in patients treated with intravenous thrombolysis included in the Norwegian Tenecteplase trial (NOR-TEST).

NOR-TEST was an open-label, randomized, blinded endpoint trial, performed from 2012 to 2016, comparing treatment with tenecteplase to treatment with alteplase within 4.5 h after acute ischemic stroke symptom onset. Sex differences at baseline, treatment and outcomes were compared using multivariable logistic regression models. Heterogeneity in treatment was evaluated by including an interaction term in the model.

Of 1100 patients enrolled, 40% were women, and in patients aged >80 years, the proportion of women was greater than men (19% vs. 14%; p = 0.02). Women had a lower burden of cardiovascular risk factors, such as diabetes mellitus (11% vs. 15%; p = 0.05) and a higher mean high-density lipoprotein cholesterol level (1.7 ± 0.6 mmol/L vs. 1.3 ± 0.4 mmol/L; p < 0.001), and a higher proportion of women had never smoked (45% vs. 33%; p < 0.001) compared with men. While there was no sex difference in time from onset of symptoms to admission, door to needle time or in-hospital workup, women were admitted with more severe stroke (National Institutes of Health Stroke Scale [NIHSS] score 6.2 ± 5.6 vs. 5.3 ± 5.1; p = 0.01). Stroke mimic diagnosis was more common in women (21% vs. 15%; p = 0.01). There were no significant sex differences in clinical outcome, measured by the NIHSS, the modified Rankin Scale, intracranial hemorrhage and mortality.

Women were underrepresented in number in NOR-TEST. The included women had a lower cardiovascular risk factor burden and more severe strokes.