Kristina Shkirkova, BSc

Sheth SA, Lee S, Warach SJ, Gralla J, Jahan R, Goyal M, et al. Sex Differences in Outcome After Endovascular Stroke Therapy for Acute Ischemic Stroke. Stroke. 2019;50:2420-2427.

A recent publication by Sheth and colleagues examined the effect of sex on outcomes after endovascular stroke thrombectomy in acute ischemic stroke.

The study analyzed a pooled cohort of patients enrolled in the SWIFT (Solitaire FR With the Intention for Thrombectomy), STAR (Solitaire FR Thrombectomy for Acute Revascularization), and SWIFT PRIME (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment) Phase-III clinical trials. The study included a total of 389 patients treated with Solitaire stent retriever within 8 hours of stroke onset, who presented with occlusion of proximal cerebral arteries and moderate to severe neurological deficits. Patients with uncontrolled hypertension, sensitivity to contrast agents, and intracranial hemorrhage or major ischemic change in more than a third of the middle cerebral artery territory were excluded from the study. 

Among 389 included in this study, the average age was 67±3, and 55% were females. In the study cohort, females were significantly older than males (average age 69 vs 64 years old), less frequently smokers (11% vs 28%), less likely to be diagnosed with coronary disease (4% vs 9%), and more likely to be diagnosed with atrial fibrillation than males (45% vs 30%). The reperfusion rates between males and females were not significantly different.

On the logistic regression analysis adjusted for age, atrial fibrillation, premorbid modified Rankin Score (mRS), and baseline National Institute of Health Stroke Scale (NIHSS), 90-day mRS scores were not significantly different between males and females. Furthermore, on the logistic regression adjusted for baseline NIHSS, target occlusion location, ASPECTS, baseline serum glucose, prestroke mRS, atrial fibrillation, smoking status, and IV-tPA use, the likelihood of good neurological outcomes with advancing age was not different between males and females.

To establish an effect of sex on long-term stroke outcomes beyond 90 days, the authors used a calculated score of disability-adjusted life years (DALY). DALY score integrates disability and mortality after disease as a quantitative measure of disease burden and treatment benefits. To represent life expectancy adjusted for disability, DALYs gained were calculated individually by determining the patient’s poststroke life expectancy based on previously published data and adjusting it by disability weightings related to the patient’s 90-day modified Rankin Scale outcomes. When adjusted for age, stroke severity, prestroke function, presence of atrial fibrillation, smoking status, and use of IV-TPA, females poststroke disability outcomes were better than those of males. In this cohort, the study reports an advantage by 2 years of greater optimal life gained by females compared to males after endovascular therapy. It is important to note that because population-level data on poststroke mortality was used to calculate DALY scores, this data is prone to change over time. In the sensitivity analysis, where poststroke life expectancy for males and females were kept the same, the results were similar.

The authors conclude that despite presenting at older age and with atrial fibrillation more frequently than males, females with acute ischemic stroke did not differ in their functional outcomes from males and experienced 2 years of greater optimal life after endovascular therapy.