Temporal Trends of Functional Outcome in Patients With Acute Ischemic Stroke Treated With Intravenous Thrombolysis
Authors: Marko Martha , Miksova Dominika , Ebner Johanna , Lang Marie , Serles Wolfgang , Sommer Peter , Sykora Marek , Lang Wilfried , Knoflach Michael , Kiechl Stefan , Greisenegger Stefan , Mutzenbach Johannes Sebastian , Bubel Nele , Zellner Thomas , Krstic Miroslav , Grandits Waltraud , Katzenschlager Regina , Vosko Milan R. , von Örzten Tim , Struhal Walter , Brunner Cornelia , Yilmaz-Kaymaz Nilguen , Hosseiny Omid , Krisper Eva , Säckl Felix , Baumgartner Christoph , Rumpl Elke , Pirker-Kees Agnes , Berger Otto , Beirer Sebastian , Komenda-Lett Martin , Weber Jörg R. , Höfner Elmar , Seiler Stephan , Berek Klaus , Mayr Markus , Haaser Stefan , Asenbaum-Nan Susanne , Heumesser Rebecca , Rumpl Barbara Almut , Rus Marc , Muellauer Barbara , Höger Franz , Lampl Christian , Bocksrucker Christof , Lackner Peter , Schlager Markus , Mayer Florian , Fertl Elisabeth , Steiner Sandrina , Koller Herbert , Doppler Wolfgang , Ferrari Julia , Krebs Stefan , Mitrovic Nenad , Salletmayr Thomas , Grunenberg Monika , Bancher Christian , Pinter Hajnalka , Karpat Frantisek , Sellner Johann , Wolf Thomas , Schnider Peter , Wallner-Blazek Mirja , Enzinger Christian , Gattringer Thomas , Poltrum Birgit , Böhme Christian , Mayer Lukas , Hofeneder Dominik , Daniel Gerhard , Kaniak Kitty , Grossmann Josef , Morgenstern Gabi , Wendlinger Nadja , Staykov Dimitre , Halilovic Almin , Frattner Michael , Waiß Christoph , Tinchon Alexander , Fischer Anna , Kapeller Peter , Luschin Gerda , Gasser Sibylle , Heine Martin , Wurzinger Harald , Wührer Susanne , Werner Philipp , Mayr Andrea , Matosevic Benjamin , Gollmer A. , Kern R. 
Published: August 2022

Background:
Intravenous thrombolysis improves functional outcome in patients with acute stroke and frequencies of r-tPA (recombinant tissue-type plasminogen activator) treatment have been increasing over time. We aimed to assess whether functional outcome in r-tPA–treated patients improved over time and to investigate the influence of clinical variables on functional outcome.

Methods:
We analyzed data of r-tPA–treated patients in the Austrian Stroke Unit Registry from 2006 to 2019. Favorable functional outcome was defined as modified Rankin Scale score of 0 to 2. Frequencies of modified Rankin Scale score of 0 to 2 were assessed for the overall population and in prespecified subgroups; multivariable logistic regression analysis was performed to assess associations of baseline characteristics including clinically relevant interactions, and outcome.

Results:
Overall, 4865 out of 9409 r-tPA–treated patients (51.7%) achieved favorable functional outcome 3 months post stroke. Between 2006 and 2019, frequencies of favorable functional outcome increased from 45.9% to 56.8%. In multivariable logistic regression analysis, year of treatment (adjusted odds ratio [adjOR], 1.08 [95% CI, 1.01–1.15]) was associated with favorable functional outcome. Stroke severity (National Institutes of Health Stroke Scale, adjOR, 0.86 [95% CI, 0.85–0.87]), age (61–70 years: adjOR, 0.67 [95% CI, 0.55–0.80], 71–80 years: adjOR, 0.42 [95% CI, 0.35–0.50], >80 years: adjOR, 0.16 [95% CI, 0.13–0.20]), female sex (adjOR, 0.89 [95% CI, 0.79–0.99]), and various comorbidities (eg, atrial fibrillation, prior stroke, diabetes) were negatively associated. Inclusion of interaction terms into the multivariable logistic regression model suggests a positive effect of year of treatment and endovascular treatment by increasing stroke severity on functional outcome (interaction between year of treatment and National Institutes of Health Stroke Scale: adjOR, 1.01 [95% CI, 1.00–1.02], interaction between National Institutes of Health Stroke Scale and endovascular treatment: adjOR, 1.02 [95% CI, 1.01–1.03]).

Conclusions:
Frequencies of favorable functional outcome in r-tPA–treated patients have been increasing over time, likely driven by improved outcome in patients with more severe strokes receiving endovascular treatment. However, some subgroups are still less likely to achieve functional independency and deserve particular attention.