Sidhu reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
Compared with enoxaparin, aspirin use resulted in higher rates of symptomatic venous thromboembolism within 90 days following total hip arthroplasty and total knee arthroplasty, according to published results.
Verinder S. Sidhu, MS, and colleagues from the CRISTAL study group analyzed 90-day outcomes of 5,416 patients who were randomized to receive 100 mg of aspirin orally for 35 days after THA and 14 days after TKA and 3,787 patients who were randomized to receive 40 mg of enoxaparin subcutaneously for the same time periods, with patients weighing less than 50 kg receiving only 20 mg of enoxaparin.
Enrollment included patients across 31 Australian hospitals from April 20, 2019, to Dec. 18, 2020. According to the study, outcome measures included symptomatic venous thromboembolism (VTE), pulmonary embolism and deep venous thrombosis above or below the knee.
At 90 days postoperatively, 256 patients experienced symptomatic VTE, including 79 cases of pulmonary embolism, 18 cases of above-knee DVT and 174 cases of below-knee DVT. Symptomatic VTE rates were 3.45% in the aspirin group and 1.82% in the enoxaparin group. Sidhu and colleagues noted the statistically significant superiority of enoxaparin compared with aspirin, as the difference in VTE rates did not meet the noninferiority margin of 1%.
“Although the study was designed as a noninferiority trial, the results demonstrated statistical superiority of enoxaparin compared with aspirin,” the researchers wrote in the study. “It is important to note that most of the difference in rates of VTE events between the enoxaparin and aspirin groups was due to differences in rates of below-knee DVT,” they added.