Safety of Desirudin Administered in the Immediate Postoperative Period Following Joint Replacement Surgery: An Observational Study
Authors: Jove Maurice , Maslanka Marc , Meyer James 
Published: October 2019

Abstract
INTRODUCTION. Desirudin is a recombinant direct thrombin inhibitor (DTI) approved in the US for the prophylaxis of deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE), in patients undergoing elective hip replacement surgery, and approved in the EU for the prevention of DVT in patients undergoing elective hip or knee replacement surgery. Evidence suggests that desirudin may possess a better safety profile in higher risk patients than other thromboprophylactic agents, and trials evaluating the safety of desirudin have indicated good tolerability without frequent adverse events. The most common adverse event associated with desirudin is hemorrhagic reactions. This observational study evaluated bleeding events and wound outcomes in patients receiving desirudin during the immediate postoperative period after total joint replacement surgery (hip and/or knee), followed by rivaroxaban for outpatient DVT prophylaxis.
METHODS. Patients undergoing total hip (THR) and/or total knee (TKR) replacement were eligible to participate in the study. Inpatient DVT prophylaxis was initiated with desirudin 15 mg BID the evening following the completion of surgery. At the discretion of the treating physician, DVT prophylaxis continued with rivaroxaban 10 mg on an outpatient basis following hospital discharge. The primary endpoints were (1) fall in hemoglobin (g/dL) and (2) degree of wound discharge at release from hospital. Wound discharge was rated on a 5-point scale of bruising ranging from 0 (negligible bruising) to 4 (bright red blood). Secondary endpoints included degree of wound discharge at the first postoperative follow-up visit. Endpoint assessments were conducted at hospital discharge, at the first postoperative visit, and at the staple-removal visit. All patients were required to follow-up with their surgeons in the clinic or via telephone between postoperative day 7 and postoperative day 14.
RESULTS. Patient demographic and baseline data are presented in Table 1. As shown, 151 patients participated in the study (THR, n=37; TKR, n=111; THR/TKR, n=2). Patients ranged between 37-98 years of age, with a mean age of 62 years. Almost 75% of the patients were female. It is also important to note that the overall patient population had a mean body mass index (BMI) of 35.9 kg/m2. Data for the primary endpoints (fall in hemoglobin and wound discharge at the time of release from the hospital) and the secondary endpoint of wound discharge at follow-up are shown in Table 2. There was a low incidence of wound discharge (score >0) at release (n=2; 1 patient had a score of 1, 1 patient had a score of 4); at follow-up, a higher incidence of wound discharge (score >0) was noted (n=44). There was also an average fall in hemoglobin in the range of approximately 3-4 g/dL across age, gender, type of surgery, and BMI.
CONCLUSION. The demographic characteristics of patients in this study suggest a patient population with a relatively high risk of venous thromboembolism (VTE) due to age and obesity. These data suggest that the use of desirudin in patients who may be at a higher risk for VTE due to age or obesity is not associated with adverse wound outcomes or increased bleeding risk.
TABLE 1 Demographic or Baseline Characteristics Patients (N=151) Median age, years (range) 62 (37-98) Mean weight, kg (SD) 100.59 (25.16) Mean BMI, kg/m2 (SD)a 35.96 (8.63) Age group, n (%) <65 years 90 (59.6) ≥65 years 61 (40.4) Sex, n (%)b Male 37 (24.5) Female 112 (74.2) Race/ethnicity, n (%)c White 86 (57) Black 54 (35.8) Latin American and Mexican 3 (2) Asian 2 (1.3) Native American 2 (1.3) Other 1 (0.7) Surgery type, n (%)a THR 37 (24.5) TKR 111 (73.5) THR/TKR 2 (1.3)
aData missing from 1 patient
bData missing from 2 patients
cData missing from 3 patients
TABLE 2 Population Wound Discharge at Release, Mean (SD) Wound Discharge at Follow-up, Mean (SD) Change in Hemoglobin, Mean (SD) Agea <65 (n=90) 0.07 (0.48) 0.43 (0.75) -4.13 (1.11) ≥65 (n=61) 0 (0) 0.27 (0.71) -3.85 (1.52) Genderb Male (n=37) 0.17 (0.75) 0.42 (0.81) -4.24 (1.29) Female (n=112) 0 (0) 0.41 (0.72) -3.93 (1.29) Type of Surgeryc THR (n=37) 0 (0) 0.25 (0.73) -3.98 (1.36) TKR (n=111) 0.06 (0.43) 0.45 (0.74) -4.04 (1.27) THR + TKR (n=2) 0 (0) 0.50 (0.71) -3.05 (2.19) BMIc, kg/m2 Nonobesed (n=40) 0 (0) 0.3 (0.64) -4.15 (1.49) Obesee (n=109) 0.1 (0.44) 0.4 (0.73) -3.97 (1.23)
aData missing from 7 patients
bData missing from 2 patients
cData missing from 1 patient
dNonobese defined as BMI≤30
eObese defined as BMI>30

Disclosures
Meyer: Marathon Pharma: Employment.