The significance of preventing deep vein thrombosis (DVT) following surgery for proximal femoral fractures (PFF) has come under renewed scrutiny, particularly concerning the use of aspirin as a prophylactic agent. A recent study conducted in Japan found no evidence supporting the effectiveness of aspirin for preventing venous thromboembolism (VTE) in elderly patients who experienced hip fractures.
Venous thromboembolism poses considerable risks, with rates ranging between 11% to 40% post-operatively. While guidelines from organizations like the American College of Chest Physicians endorse aspirin for preventing VTE, its adoption is hampered by the lack of supportive studies specific to the Japanese population. The Japanese Orthopaedic Association, for example, does not recommend aspirin for this purpose, yet many patients continue to take aspirin for cardiovascular protection.
To address the knowledge gap surrounding aspirin’s role, researchers analyzed patient data from surgeries conducted between January 2010 and December 2023. They classified patients aged 65 years or older based on their aspirin intake—those continuing aspirin preoperatively were compared against patients who did not receive any antithrombotic therapy.
Among the cohort of 1,064 patients, 161 were on aspirin therapy. Following propensity score matching to equalize baseline characteristics, 128 patients were analyzed. The results revealed no statistically significant differences—in terms of DVT incidence—between the aspirin group and control group, with the rates being 54 and 60, respectively.
"This study demonstrates aspirin is not effective for preventing VTE in patients with PFF in Japan," the study emphasizes. Subgroup analyses also indicated aspirin did not improve outcomes among patients who were not prescribed postoperative antithrombotic therapy.
Interestingly, aspirin's mechanism—primarily inhibiting platelet aggregation—does not translate well to venous conditions, which often involve slower blood flow and fibrin-rich clots rather than platelet-rich ones. The biological rationale for aspirin’s efficacy in arterial thrombosis does not apply to venous thrombi, and this fundamental difference could explain the study's findings.
The study's conclusions add to the complex discourse on DVT prophylaxis, which remains inconsistent across different countries. "Aspirin is widely recommended due to its lower risk of bleeding and cost-effectiveness," concluded the authors, highlighting the need for potential clinical reconsiderations and guiding future research efforts.
Given these findings and the standard practices globally, the authors stress the urgent requirement for high-quality randomized controlled trials within Japan to truly ascertain aspirin's role, if any, as a preventative measure for VTE standings post-surgery.
While the current study did not find support for aspirin as effective against DVT following hip surgeries, the necessity for alternative and perhaps more effective prophylactic strategies remains evident.