Frailty and stroke thrombectomy outcomes-an observational cohort study

Introduction Mechanical thrombectomy (MT) can improve outcomes following ischaemic stroke. Patient selection for MT is predominantly based on physiological and imaging parameters. We assessed whether people living with pre-stroke frailty had differing outcomes following MT. Methods We included consecutive patients undergoing MT at a UK comprehensive stroke centre. We calculated a cumulative deficits frailty index to identify pre-stroke frailty in those patients presenting directly to the centre. Frailty was defined as an index score >= 0.24. We assessed univariable and multivariable association between pre-stroke frailty and stroke outcomes. Our primary outcomes were modified Rankin Scale (mRS) and mortality at 90 days. Results Of 175 patients who underwent MT (2014-2018), we identified frailty in 49 (28%). Frail and non-frail patients had similar rates of thrombolysis administration, successful recanalization and onset to recanalization times. Those with pre-stroke frailty had higher 24 hour National Institutes of Health Stroke Scale (12(IQR: 8-17) versus 3(IQR: 2-13); P = 0.001); were less likely to be independent (mRS 0-2: 18% versus 61%; P < 0.001) and more likely to die (47% versus 14%; P < 0.001) within 90 days. Adjusting for age, baseline NIHSS and thrombolysis, frailty remained a strong, independent predictor of poor clinical outcome at 90 days (Death OR: 3.12 (95% CI: 1.32-7.4); dependency OR: 3.04 (95%CI: 1.10-8.44). Age was no longer a predictor of outcome when adjusted for frailty. Conclusion Pre-stroke frailty is prevalent in real-world patients eligible for MT and is an important predictor of poor outcomes. Routine assessment of pre-stroke frailty could help decision-making around patient selection for MT.