Periprocedural Intravenous Heparin During Endovascular Treatment for Ischemic Stroke
Authors: van de Graaf Rob A. , Chalos Vicky , van Es Adriaan C.G.M. , Emmer Bart J. , Lycklama à Nijeholt Geert J. , van der Worp H. Bart , Schonewille Wouter J. , van der Lugt Aad , Dippel Diederik W.J. , Lingsma Hester F. , Roozenbeek Bob ,   on behalf of the MR CLEAN Registry Investigators, Majoie Charles , Roos Yvo , van Oostenbrugge Robert , van Zwam Wim , Boiten Jelis , Albert Vos Jan , Jansen Ivo , Mulder Maxim , Goldhoorn Robert-Jan , Compagne Kars , Kappelhof Manon , Albert Vos Jan , Majoie Charles , Coutinho Jonathan , Wermer Marieke , van Walderveen Marianne , Staals Julie , van Zwam Wim , Hofmeijer Jeannette , Martens Jasper M. , Boiten Jelis , de Bruijn Sebastiaan , van Dijk Lukas , Lo Rob , van Dijk Ewoud , Boogaarts Hieronymus , de Kort Paul , Peluso Jo , van den Berg Jan , van Hasselt Boudewijn , Aerden Leo , Dallinga René , Uyttenboogaart Maarten , Eshghi Omid , Schreuder Tobien , Heijboer Roel , Keizer Koos , Yo Lonneke , den Hertog Heleen , Sturm Emiel , Majoie Charles , van Zwam Wim , van Walderveen Marianne , Sprengers Marieke , Jenniskens Sjoerd , van den Berg René , Yoo Albert , Beenen Ludo , Postma Alida , Roosendaal Stefan , van der Kallen Bas , van den Wijngaard Ido , Emmer Bart , Martens Jasper , Yo Lonneke , Albert Vos Jan , Bot Joost , van Doormaal Pieter-Jan , Majoie Charles , Roos Yvo , van Oostenbrugge Robert , van Zwam Wim , Boiten Jelis , Albert Vos Jan , Hofmeijer Jeannette , Martens Jasper , Lo Rob , van Oostenbrugge Robert , Hofmeijer Jeannette , Flach Zwenneke , Ghannouti Naziha el , Sterrenberg Martin , Puppels Corina , Pellikaan Wilma , Sprengers Rita , Elfrink Marjan , de Meris Joke , Vermeulen Tamara , Geerlings Annet , van Vemde Gina , Simons Tiny , van Rijswijk Cathelijn , Messchendorp Gert , Bongenaar Hester , Bodde Karin , Kleijn Sandra , Lodico Jasmijn , Droste Hanneke , Wollaert M. , Jeurrissen D. , Bos Ernas , Drabbe Yvonne , Aaldering Nicoline , Zweedijk Berber , Khalilzada Mostafa , Venema Esmee , Geuskens Ralph , van Straaten Tim , Ergezen Saliha , Harmsma Roger , Muijres Daan , de Jong Anouk , Hinseveld Wouter , Berkhemer Olvert , Boers Anna , Huguet J. , Groot P. , Mens Marieke , van Kranendonk Katinka , Treurniet Kilian , Tolhuijsen Manon , Alves Heitor 
Published: July 2019

Background and Purpose—
Intravenous administration of heparin during endovascular treatment for ischemic stroke may improve outcomes. However, risks and benefits of this adjunctive therapy remain uncertain. We aimed to evaluate periprocedural intravenous heparin use in Dutch stroke intervention centers and to assess its efficacy and safety.

Methods—
Patients registered between March 2014 and June 2016 in the MR CLEAN Registry (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke), including all patients treated with endovascular treatment in the Netherlands, were analyzed. The primary outcome was functional outcome (modified Rankin Scale) at 90 days. Secondary outcomes were successful recanalization (extended Thrombolysis in Cerebral Infarction ≥2B), symptomatic intracranial hemorrhage, and mortality at 90 days. We used multilevel regression analysis to evaluate the association of periprocedural intravenous heparin on outcomes, adjusted for center effects and prognostic factors. To account for possible unobserved confounding by indication, we analyzed the effect of center preference to administer intravenous heparin, defined as percentage of patients treated with intravenous heparin in a center, on functional outcome.

Results—
One thousand four hundred eighty-eight patients from 16 centers were analyzed, of whom 398 (27%) received intravenous heparin (median dose 5000 international units). There was substantial between-center variability in the proportion of patients treated with intravenous heparin (range, 0%–94%). There was no significant difference in functional outcome between patients treated with intravenous heparin and those without (adjusted common odds ratio, 1.17; 95% CI, 0.87–1.56), successful recanalization (adjusted odds ratio, 1.24; 95% CI, 0.89–1.71), symptomatic intracranial hemorrhage (adjusted odds ratio, 1.13; 95% CI, 0.65–1.99), or mortality (adjusted odds ratio, 0.95; 95% CI, 0.66–1.38). Analysis at center level showed that functional outcomes were better in centers with higher percentages of heparin administration (adjusted common odds ratio, 1.07 per 10% more heparin, 95% CI, 1.01–1.13).

Conclusions—
Substantial between-center variability exists in periprocedural intravenous heparin use during endovascular treatment, but the treatment is safe. Centers using heparin more often had better outcomes. A randomized trial is needed to further study these effects.