Are we improving? Temporal trends in outcomes for mechanical thrombectomy for stroke: A systematic review and meta-analysis of randomized trials

Background In 2015, mechanical thrombectomy (MT) was deemed the standard of care for acute ischemic stroke (AIS) in the anterior circulation due to large vessel occlusion (LVO). To determine if outcomes in patients treated with MT have changed, we conducted a systematic review and meta-analysis of published randomized controlled trials (RCTs). Methods A systematic literature review of the English language literature was conducted using PubMed. We included RCTs that focused on patients with AIS treated with MT. The primary outcome of interest was good functional outcome defined as modified Rankin Scale (mRS) 0-2 at 90 days. Safety outcomes included rates of symptomatic intracranial hemorrhage (sICH) and mortality at 90 days. Using Joinpoint Regression Analysis Program, we calculated the average annual percent change (AAPC) for the outcomes of interest. Results We included 23 RCTs with 5784 patients. The years of mid-enrollment among the included RCTs ranged from 2012-2020. There was an AAPC of +3.82% between 2012 and 2020 (95% CI 0.4 to 7.3; P-value = 0.033) in rates of good functional outcome. There was an AAPC of +6.98% between 2012 and 2020 (95% CI 0.5 to 13.9; P-value = 0.039) in rates of sICH. There was an AAPC of -0.49% between 2012 and 2020 (95% CI -4.4 to 3.5; P-value = 0.77) in rates of mortality. Conclusion Between 2012 and 2020, rates of good functional outcome and sICH increased, while rates of mortality remained consistent in RCTs investigating MT for AIS. Multiple factors likely influenced our results, including increased use of MT and utilization of adjunctive therapies alongside MT.