The effect of pre-stroke physical activity on the initial volume and growth of the brain infarct and the rate of recanalization: A post-hoc analysis of the rescue brain trial

– Pre-stroke physical activity is known to influence stroke severity and long-term outcomes. However, its effects on infarct volume and vascular recanalization remain unclear. Using data from the RESCUE BRAIN trial, we aimed to determine whether the beneficial effects of physical activity before stroke are associated with smaller infarct volumes at presentation, reduced infarct growth over 24 hours, and/or increased rates of arterial recanalization. – This study is a post-hoc analysis of the RESCUE BRAIN trial, a multicenter, randomized, open-label, controlled trial. Patients for whom information on activity habits was available at the time of randomization were included in this analysis. Hierarchical ascendant clustering was used to define physical activity clusters based on intensity (none, walking, walking and sports), frequency (0, 1, 1–3, > 3 times per week), and duration (0, 60 minutes). We examined the associations between physical activity clusters and baseline infarct volume and change in infarct volume over 24 hours, site of arterial occlusion, and successful recanalization (including intravenous thrombolysis and mechanical thrombectomy). – A total of 151 patients (mean ± standard deviation age 66.3 ± 15.9 years; 47.0% male) were included. Patients with high levels of pre-stroke physical activity were younger and had a lower prevalence of hypertension (p=0.02) and atrial fibrillation (p=0.03). At baseline, infarct volume was unexpectedly larger in the walking and sports cluster (p=0.01), but there was no significant difference between the three physical activity groups regarding the change in infarct volume at 24 hours. We also found no evidence of a difference in baseline cerebral artery occlusion or recanalization rates. – This study suggests that pre-stroke physical activity does not affect the change in infarct volume or recanalization rates, despite its impact on the initial infarct size. These findings may suggest that the effects of physical activity may not operate through reducing infarcts volume or improving reperfusion, but rather through other mechanisms.