Operative treatment of hip fractures in patients on clopidogrel: a case-control study

Clopidogrel, an inhibitor of ADP-induced platelet aggregation, is indicated for the reduction of atherosclerotic events in patients with atherosclerosis documented by recent stoke, myocardial infarction, acute coronary syndrome, and established peripheral arterial disease. In cardiovascular studies, clopidogrel has been associated with increased chest tube output, transfusion rates, and re-exploration rates. Few studies have addressed the possible complications of clopidogrel in hip fractures. Our study aims to assess the perioperative blood loss and transfusion rates in geriatric patients with hip fractures on clopidogrel. We hypothesize that patients on clopidogrel will have higher perioperative blood loss and transfusion rates.

A retrospective, case control study chart review over a five year span was conducted. Of the 2,766 geriatric hip fracture patients surgically treated, 52 patients taking clopidogrel upon admission to the hospital were compared to patients not on the drug. All of the patients in the study were taken to the operating room within two calendar days of admission. statistical analysis was performed using Wilcoxon's, Fisher exact, chi square, and logistic regression methods.

A total of 110 patients were included in the analysis, 52 (47%) were taking clopidogrel at the time of admission. these patients were compared to 58 (53%) patients not on the drug. No significant difference was found with respect to documented perioperative blood loss. Transfusion rates however, did vary. Patients who had been taking clopidogrel, prior to admission and subsequent surgery, had a transfusion rate of 56% while those patients not on the drug had a transfusion rate of 31%. Logistic regression analysis showed taking clopidogrel up to admission was significantly associated (p = .0121) with receiving a blood transfusion following surgical treatment of a hip fracture.

A growing body of evidence supports early (within 48 hrs) surgery for elderly patients with hip fractures. the pharmacokinetics of clopidogrel do not allow for bleeding time to return to normal until the drug has been discontinued for five days. Our study shows that patients taking clopidogrel upon admission for hip fracture are at increased risk of blood transfusions when surgery is performed within two calendar days of admis-sion. this risk must be balanced by the potential benefits of early surgery.