Is Continuation of Anti-platelet Treatment Safe for THA Patients?

Background: Discontinuation of anti-aggregation agents prior to total hip arthroplasty (THA) may reduce Peri-operative blood loss; while at the same time predispose patients to cardiovascular and cerebrovascular complications. In our practice, aspirin and clopidogrel are not discontinued prior to THA surgery. We compared peri-operative blood loss, complications and mortality of THA patients receiving aspirin or clopidogrel to patients having no anti-aggregation treatment.

Methods: A retrospective cohort of 843 consecutive patients who underwent total hip arthroplasty between 2011 and 2016 in a single medical center, after exclusion of patients receiving warfarin or other oral anticoagulation agents. Patients were assigned into three groups: no anti-aggregation agents (n=541), aspirin (n=257) or clopidogrel (n=45). All patients received post-operative thromboembolic prophylaxis with low-molecular-weight heparin. Outcomes included blood loss, rate of blood transfusion, wound drainage, peri prosthetic infection rate, revisions and readmissions, 30-day and one-year mortality rate. Multivariate analysis included adjustment for age, gender, socio-economic status, ASA score, duration of surgery and pre-operative hemoglobin levels.

Results: Perioperative blood loss was not significantly different between the "no anti-aggregation", "aspirin" and "clopidogrel" groups (3.75±3.21 g/dl, 3.50±1.98 g/dl and 2.68±1.64 g/dl, respectively; p>0.05). Percent of patients who required postoperative blood transfusions was highest in the clopidogrel group (17.8%), with significantly lower rates in aspirin (9.34%) and no anti-aggregation (6.65%)(p=0.02) groups. However, there were no significant differences between groups after multivariate adjustment. There were no differences between groups with respect to 30-day and one-year mortality rates.

Conclusions: Continued use of aspirin and clopidogrel perioperatively in patients undergoing THA was not associated with higher perioperative blood loss, complications or mortality. Based on the study results, withholding anti-aggregation use prior to surgery may not be justified.