Intravenous Thrombolysis Initiated Before Transfer for Endovascular Stroke Thrombectomy: A Systematic Review and Meta-analysis

Background and objective:The role of intravenous thrombolysis (IVT) in patients with large vessel occlusions (LVOs)administered prior to transferfrom a primary stroke center (PCS) to a comprehensive stroke center (CSC) is questioned.Methods:We included observational studies of patients with an LVO receiving IVT at a PCS prior to their EVT transfer compared to those receiving EVT alone. Efficacy outcomes included excellent or good functional outcomes [modified Rankin Scale (mRS) scores of 0-1or0-2, respectively] and reduced disability (mRS shift analysis) at three months. Safety outcomes included symptomatic intracranial hemorrhage (sICH) within 48 hours andthree-monthall-cause mortality. Associations are reported with crude odds ratios (ORs) and adjusted ORs (aOR).Results:We identified 6 studies, including 1723 participants (mean age: 71 years, 51% women; 53% treated with IVT at a PSC). The mean onset-to-groin puncture time did not differ between the two groups (mean difference:-20 min, 95%CI:-115.89,76.04). Patients receiving IVT prior to transfer had higher odds of three-month reduced disability (common OR=1.98; 95%CI:1.17-3.35), excellent (OR=1.70,95%CI:1.28-2.26) and good (OR=1.62,95%CI:1.15-2.29) functional outcomes, with no increased sICH (OR=0.87,95%CI:0.54-1.39) or mortality (OR=0.55,95%CI:0.37-0.83) risks. In the adjusted analyses patients receiving IVT at a PSC had higher odds of excellent functional outcome (aOR=1.32,95%CI:1.00-1.74) and lower probability for mortality (aOR=0.50,95%CI:0.27-0.93).Discussion:LVO patients receiving IVT at a PSC prior to an EVT transfer have higher likelihood of excellent functional recovery and lower odds of mortality, with no increase in sICH and onset-to-groin puncture times, compared tothose transferred for EVT without previously receiving IVT.