Acute kidney injury negatively affects short and long-term outcomes of mechanical thrombectomy in acute ischaemic stroke.

Aim of study: We aimed to assess the impact of acute kidney injury (AKI) during hospitalisation on short- and long-term outcomes of mechanical thrombectomy (MT) in patients with acute ischaemic stroke (AIS).

Clinical rationale for study: AKI is a common complication in AIS patients treated with MT. Some studies examining its impact on prognosis have shown an association of AKI with worse MT outcomes, but observations exceeding three months are lacking.

Material and methods: To this observational cohort study, we included all AIS patients treated with MT in the University Hospital in Krakow from 2019 to 2021. AKI during hospitalisation was diagnosed based on serum creatinine concentration levels according to the KDIGO (Kidney Disease Improving Global Outcomes) guidelines. We compared patients with and without AKI in terms of mortality and functional outcome (assessed with modified Rankin scale, mRS) at discharge, and at 90 and at 365 days from stroke onset. Good functional outcome was defined as mRS 0-2. We identified factors associated with mortality and a good functional outcome using univariate logistic regression analysis, with statistically significant variables subsequently included into multivariate analyses.

Results: Among 593 MT-treated AIS patients, AKI was found in 12.6%. Patients with AKI had significantly higher mortality and worse functional outcome at discharge, and at 90, and at 365 days from stroke onset. AKI was an independent factor associated with mortality and worse functional outcome at discharge, and at 90, and at 365 days from stroke onset. AKI remained independently associated with a lower chance of a good functional outcome in a 365-day follow-up when the analysis was limited to patients who survived until discharge (OR = 0.244, 95% CI: 0.095-0.624, p = 0.003).

Conclusions and clinical implications: AKI during hospitalisation is an independent risk factor of short- and long-term mortality and poor functional outcome in patients with AIS undergoing MT. There is a need to create a protocol to monitor kidney function and ensure prompt AKI treatment in MT-treated AIS patients.