Impact of renal impairment on short-term outcomes following endovascular thrombectomy for acute ischemic stroke: A systematic review and meta-analysis

Background: The impact of renal impairment on the outcomes of patients with acute ischemic stroke treated with endovascular thrombectomy was relatively limited and contradictory. We performed a systematic review and meta-analysis to investigate this. Aims: We registered a protocol in September 2020 and searched MEDLINE, EMBASE, and Google Scholar accordingly. Renal impairment was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m². Predefined outcomes included functional independence (defined as a modified Rankin Scale of 0, 1, or 2) at three months, successful reperfusion, mortality, and symptomatic intracerebral hemorrhage. Summary of review: Eleven studies involving 3453 patients were included. For the unadjusted outcomes, renal impairment was associated with fewer functional independence (odds ratio (OR), 0.49; 95% confidence interval (CI), 0.39–0.62) and higher mortality (OR, 2.55; 95% CI, 2.03–3.21). Renal impairment was not associated with successful reperfusion (OR, 0.80; 95% CI 0.63–1.00) and symptomatic intracerebral hemorrhage (OR, 1.41; 95% CI, 0.95–2.10). For the adjusted outcomes, results derived from a multivariate meta-analysis were consistent with the respective unadjusted outcomes: functional independence (OR, 0.59; 95% CI, 0.45–0.77), mortality (OR, 2.23, 95% CI, 1.45–3.43), and symptomatic intracerebral hemorrhage (OR, 1.34; 95% CI, 0.85–2.10). Conclusions: We presented the first systematic review to demonstrate that renal impairment is associated with fewer functional independence and higher mortality. Future endovascular thrombectomy studies should publish complete renal estimated glomerular filtration rate data to facilitate prognostic studies and permit estimated glomerular filtration rate to be analyzed in a continuous variable. Systematic Review Registration: PROSPERO CRD42020191309.