OUP accepted manuscript

frailty has been shown to be a better predictor of clinical outcomes than age alone across many diseases. Few studies have examined the relationship between frailty, stroke and stroke interventions such as endovascular thrombectomy (EVT).we aimed to investigate the impact of frailty measured by clinical frailty scale (CFS) on clinical outcomes after EVT for acute ischemic stroke (AIS) in older patients ≥70 years.in this retrospective cohort study, we included all consecutive AIS patients age ≥ 70 years receiving EVT at a single comprehensive stroke centre. Patients with CFS of 1-3 were defined as not frail, and CFS > 3 was defined as frail. The primary outcome was modified Rankin Score (mRS) at 90 days. The secondary outcomes included duration of hospitalisation, in-hospital mortality, carer requirement, successful reperfusion, symptomatic intracranial haemorrhage and haemorrhagic transformation.a total of 198 patients were included. The mean age was 78.1 years and 52.0% were female. Frail patients were older, more likely to be female, had more co-morbidities. CFS was significantly associated with poor functional outcome after adjustment for age, NIHSS and time to intervention (adjusted odds ratio [aOR] 1.54, 95% confidence interval [CI] 1.04-2.28, P = 0.032). There was trend towards higher mortality rate in frail patients (frail: 18.3%; non-frail: 9.6%; P = 0.080). There were no significant differences in other secondary outcomes except increased carer requirement post discharge in frail patients (frail: 91.6%; non-frail: 72.8%; P = 0.002).frailty was associated with poorer functional outcome at 90 days post-EVT in patients ≥ 70 years.