Mechanical thrombectomy for in-hospital stroke: data from the Italian Registry of Endovascular Treatment in Acute Stroke

Background: The benefit, safety, and time intervals of mechanical thrombectomy (MT) in patients with in-hospital stroke (IHS) are unclear. We sought to evaluate the outcomes and treatment times for IHS patients compared with out-of-hospital stroke (OHS) patients receiving MT. Methods: We analyzed data from the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) between 2015 and 2019. We compared the functional outcomes (modified Rankin Scale (mRS) scores) at 3 months, recanalization rates, and symptomatic intracranial hemorrhage (sICH) after MT. Time intervals from stroke onset-to-imaging, onset-to-groin, and onset-to-end MT were recorded for both groups, as were door-to-imaging and door-to-groin for OHS. A multivariate analysis was performed. Results: Of 5619 patients, 406 (7.2%) had IHS. At 3 months, IHS patients had a lower rate of mRS 0-2 (39% vs 48%, P<0.001) and higher mortality (30.1% vs 19.6%, P<0.001). Recanalization rates and sICH were similar. Time intervals (min, median (IQR)) from stroke onset-to-imaging, onset-to-groin, and onset-to-end MT were favorable for IHS (60 (34-106) vs 123 (89-188.5); 150 (105-220) vs 220 (168-294); 227 (164-303) vs 293 (230-370); all P<0.001), whereas OHS had lower door-to-imaging and door-to-groin times compared with stroke onset-to-imaging and onset-to-groin for IHS (29 (20-44) vs 60 (34-106), P<0.001; 113 (84-151) vs 150 (105-220); P<0.001). After adjustment, IHS was associated with higher mortality (aOR 1.77, 95% CI 1.33 to 2.35, P<0.001) and a shift towards worse functional outcomes in the ordinal analysis (aOR 1.32, 95% CI 1.06 to 1.66, P=0.015). Conclusion: Despite favorable time intervals for MT, IHS patients had worse functional outcomes than OHS patients. Delays in IHS management were detected.