Retrospective Cohort Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jun 18, 2015; 6(5): 439-445
Published online Jun 18, 2015. doi: 10.5312/wjo.v6.i5.439
Variability of platelet aggregation in patients with clopidogrel treatment and hip fracture: A retrospective case-control study on 112 patients
Anna Clareus, Inga Fredriksson, Håkan Wallén, Max Gordon, André Stark, Olof Sköldenberg
Anna Clareus, Max Gordon, André Stark, Olof Sköldenberg, Division of Orthopaedics, Department of Clinical Sciences at Danderyd Hospital, Karolinska Institutet, 18288 Stockholm, Sweden
Inga Fredriksson, Division of Anesthesiology, Department of Clinical Sciences at Danderyd Hospital, Karolinska Institutet, 18288 Stockholm, Sweden
Håkan Wallén, Division of Cardiology, Department of Clinical Sciences at Danderyd Hospital, Karolinska Institute, 18288 Stockholm, Sweden
Author contributions: Clareus A collected data and wrote the manuscript; Fredriksson I interpreted the MEA analyses and wrote the manuscript; Wallén H initiated the study, interpreted the MEA analyses and wrote the manuscript; Stark A operated patients and wrote the manuscript; Gordon M operated patients, performed the statistical analysis and wrote the manuscript; Sköldenberg O initiated the study, performed the statistical analysis, operated patients, supervised Clareus A and wrote the manuscript.
Ethics approval: The study was granted ethical approval from the Ethics committee of the Karolinska institute, Stockholm, Sweden.
Informed consent: According to the Ethical approval, no informed consent was necessary from individual patients since all data were gathered retrospectively from medcial records.
Conflict-of-interest: No competing interests declared.
Data sharing: Technical appendix, statistical code, and available from the corresponding author at olof.skoldenberg@ki.se. The presented data are anonymized and risk of identification is negligible.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Olof Sköldenberg, MD, PhD, Consultant Orthopaedic Surgeon, Associate professor, Department of Clinical Sciences at Danderyd Hospital, Karolinska Institutet, Solnavägen 1, 18288 Stockholm, Sweden. olof.skoldenberg@ki.se
Telephone: +46-700-891253 Fax: +46-700-891253
Received: February 21, 2015
Peer-review started: February 22, 2015
First decision: March 20, 2015
Revised: April 14, 2015
Accepted: May 8, 2015
Article in press: May 11, 2015
Published online: June 18, 2015
Processing time: 118 Days and 14.2 Hours
Abstract

AIM: To identify the rate of non-responders to clopidogrel treatment in hip fracture patients and study how non-responders differ from controls.

METHODS: In a retrospective case-control study we included 28 cases of acute proximal femoral fracture with clopidogrel treatment 2011 to 2013. Eighty-four controls from the same time period were included. Data collected included response to clopidogrel measured with multiple electrode aggregometry (MEA), intraoperative bleeding, erythrocyte transfusion, time to surgery and the incidence of adverse events up to 3 mo after surgery.

RESULTS: Eight (29%) of the 28 cases were non-responders. The median intraoperative bleeding was 300 mL (range, 0-1500), and was lower for non-responders (50 mL) but did not reach statistical significance. Erythrocyte transfusions did not differ between responders, non-responders and controls. Forty-five (40%) of 112 patients had adverse events postoperatively but the rate did not differ between patients with and without clopidogrel treatment.

CONCLUSION: Almost one-third of patients with clopidogrel treatment and an acute proximal femoral fracture are non-responders to antiplatelet therapy and can be operated without delay.

Keywords: Proximal femoral fracture; Clopidogrel; Variability; Bleeding; Adverse events

Core tip: In this pilot study, almost one-third of patients with clopidogrel treatment and an acute proximal femoral fracture are non-responders to antiplatelet therapy. Analysis of variability in platelet aggregation can be used when fast tracking patients and we recommend this for emergency hospitals treating patients with acute proximal femoral fractures.