Identification of hypercoagulability with thrombelastography in patients with hip fracture receiving thromboprophylaxis

Identification of hypercoagulability with thrombelastography in patients with hip fracture receiving thromboprophylaxis

Can J Surg 2021;64(3):E324-E329 | PDF

Daniel You, MD; Leslie Skeith, MD, MHPE; Robert Korley, MD; Paul Cantle, MD, MBT; Adrienne Lee, MD; Paul McBeth, MD, MASc; Braedon McDonald, MD, PhD; Richard Buckley, MD; Paul Duffy, MD; C. Ryan Martin, MD; Andrea Soo, PhD; Prism Schneider, MD, PhD

Abstract

Background: Venous thromboembolism (VTE) is the second most common complication after hip fracture surgery. We used thrombelastography (TEG), a whole-blood, point-of-care test that can provide an overview of the clotting process, to determine the duration of hypercoagulability after hip fracture surgery.

Methods: In this prospective study, consecutive patients aged 51 years or more with hip fractures (trochanteric region or neck) amenable to surgical treatment who presented to the emergency department were eligible for enrolment. Thrombelastography, including calculation of the coagulation index (CI) (combination of 4 TEG parameters for an overall assessment of coagulation) was performed daily from admission until 5 days postoperatively, and at 2 and 6 weeks postoperatively. All patients received 28 days of thromboprophylaxis. We used single-sample t tests to compare mean maximal amplitude (MA) values (a measure of clot strength) to the hypercoagulable threshold of greater than 65 mm, a predictor of in-hospital VTE.

Results: Of the 35 patients enrolled, 11 (31%) were hypercoagulable on admission based on an MA value greater than 65 mm, and 29 (83%) were hypercoagulable based on a CI value greater than 3.0; the corresponding values at 6 weeks were 23 (66%) and 34 (97%). All patients had an MA value greater than 65 mm at 2 weeks. Patients demonstrated normal coagulation on admission (mean MA value 62.2 mm [standard deviation (SD) 6.3 mm], p = 0.01) but became significantly hypercoagulable at 2 weeks (mean 71.6 mm [SD 2.6 mm], p < 0.001). There was a trend toward persistent hypercoagulability at 6 weeks (mean MA value 66.2 mm [SD 3.8 mm], p = 0.06).

Conclusion: More than 50% of patients remained hypercoagulable 6 weeks after fracture despite thromboprophylaxis. Thrombelastography MA thresholds or a change in MA over time may help predict VTE risk; however, further study is needed.

Résumé

Contexte : La thromboembolie veineuse (TEV) est la deuxième complication la plus courante après une chirurgie pour fracture de la hanche. Nous avons eu recours à la thromboélastographie, un test de sang total effectué au point d’intervention et donnant une idée du processus de coagulation, pour évaluer la durée de l’hypercoagulabilité à la suite d’une chirurgie pour fracture de la hanche.

Méthodes : Cette étude prospective a été menée auprès de patients consécutifs admissibles de 51 ans et plus qui se sont présentés à l’urgence pour une fracture de la hanche (région trochantérienne ou col du fémur) pouvant faire l’objet d’un traitement chirurgical. Une thromboélastographie (TEG), qui comprenait le calcul de l’indice de coagulation (IC) [combinaison de 4 paramètres du TEG permettant une évaluation globale de la coagulation], a été réalisée chaque jour, de l’admission au cinquième jour postopératoire, de même qu’à 2 et à 6 semaines postopératoires. Tous les patients ont suivi une thromboprophylaxie de 28 jours. Nous avons réalisé des tests t pour échantillon unique afin de comparer l’amplitude maximale (AM) moyenne (une mesure de la résistance d’un caillot) au seuil d’hypercoagulabilité de plus de 65 mm, un prédicteur de TEV à l’hôpital.

Résultats : Des 35 patients recrutés, 11 (31 %) présentaient une hypercoagulabilité à l’admission selon une AM supérieure à 65 mm, et 29 (83 %) présentaient une hypercoagulabilité selon un IC supérieur à 3,0; les valeurs correspondantes à 6 semaines étaient de 23 (66 %) et de 34 (97 %), respectivement. Tous les patients avaient une AM de plus de 65 mm à 2 semaines. Dans l’ensemble, les patients avaient une coagulation normale à l’admission (AM moyenne 62,2 mm [écart type (E.T.) 6,3 mm], p = 0,01), mais présentaient une hypercoagulabilité importante à 2 semaines (moyenne 71,6 mm [E.T. 2,6 mm], p < 0,001). L'hypercoagulabilité avait tendance à persister à 6 semaines (AM moyenne 66,2 mm [E.T. 3,8 mm], p = 0,06).

Conclusion : Malgré la thromboprophylaxie, plus de 50 % des patients présentaient toujours une hypercoagulabilité 6 semaines après leur fracture. Les seuils d’AM à la thromboélastographie et les changements de l’AM au fil du temps pourraient aider à prédire le risque de TEV, mais d’autres études sur le sujet sont nécessaires.


Presented as a podium presentation at the 2019 Orthopaedic Trauma Association Annual Meeting, Sept. 25–28, 2019, Denver, Colo.; the 2019 Canadian Association of Chairs of Surgical Research Session, Canadian Surgery Forum, Sept. 5, 2019, Montréal, Que.; the 2019 Canadian Orthopaedic Residents’ Association Annual Meeting, June 19, 2019, Montréal, Que.; the 37th Annual University of Calgary Surgeon’s Research Day, June 14, 2019, Calgary, Alta.; and the 6th Annual McCaig Meeting on Musculoskeletal Diseases, May 17, 2019, Calgary, Alta.

Accepted June 8, 2020

Acknowledgements: The authors thank the University of Calgary Foothills Orthopaedic Trauma Research Team, including Aftab Akbari, Maria Beketskaia, Carolyn Gratton, Leah Kennedy, Karin Lienhard and Stephanie Yee, for their assistance with patient recruitment and data collection.

Affiliations: From the Division of Orthopaedic Surgery, University of Calgary, Calgary, Alta. (You, Korley, Buckley, Duffy, Martin, Schneider); the Division of Hematology & Hematological Malignancies, University of Calgary, Calgary, Alta. (Skeith, Lee); the Section of General Surgery, University of Calgary, Calgary, Alta. (Cantle, McBeth); the Section of Vascular Surgery, University of Calgary, Calgary, Alta. (Cantle); and the Department of Critical Care, University of Calgary, Calgary, Alta. (McBeth, McDonald, Soo).

Competing interests: Leslie Skeith reports research funding from CSL Behring and honoraria from LEO Pharma, outside the submitted work. Adrienne Lee reports research support from Bayer and speaker fees from Takeda, outside the submitted work. Ryan Martin consults for Smith & Nephew and DePuy Synthes. Prism Schneider reports honoraria from Amgen, Stryker and DePuy Synthes, outside the submitted work. No other competing interests were declared.

Contributors: All authors designed the study. D. You and P. Schneider acquired the data, which D. You, L. Skeith, R. Korley, A. Soo and P. Schneider analyzed. D. You and P. Schneider wrote the manuscript, which all authors critically revised. All authors gave final approval of the article to be published.

Content licence: This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY-NC-ND 4.0) licence, which permits use, distribution and reproduction in any medium, provided that the original publication is properly cited, the use is noncommercial (i.e., research or educational use), and no modifications or adaptations are made. See: https://creativecommons.org/licenses/by-nc-nd/4.0/

DOI: 10.1503/cjs.021019

Correspondence to: P. Schneider, Section of Orthopaedic Trauma, University of Calgary, McCaig Tower, 3134 Hospital Dr NW, Calgary AB T2N 5A1, prism.schneider@ahs.ca