Study: Aspirin Effective for Clot Prevention After Hip Replacement

Patients undergoing a major orthopedic surgery, such as hip replacement, stand at an increased risk of developing blood clots at some point following the procedure, medical experts say. As means of preventing blood clot formation, surgeons or doctors usually prescribe anticoagulants or blood-thinning medications, which primarily function by reducing the blood’s ability to clot. In comparing certain anti-clotting drugs, a group of researchers reportedly found that extended use of aspirin may be a safe, effective, convenient, and even inexpensive alternative to dalteparin in preventing venous thromboembolism (VTE) after total hip replacement.

Medical experts highlight that VTE is one of the most commonly occurring complications following joint replacement surgery.  It is a condition characterized by the formation of blood clots within a vein, manifesting through deep vein thrombosis (DVT) -- a blood clot which predominantly forms in deep, large veins, usually of the legs or pelvis.  In some cases, DVT may lead to pulmonary embolism, which occurs when a segment of a blood clot within a deep vein breaks off from a vessel and spreads to the lungs.

Canada-based researchers, spearheaded by Dr. David R. Anderson from Dalhousie University, set out on a study to find out if aspirin would be an effective alternative to extended use of low-molecular-weight heparin. In a multicenter randomized, controlled trial involving more than 770 hip replacement patients, study participants were initially administered a low-molecular-weight heparin called dalteparin via subcutaneous injection for 10 days. Patients were then randomly divided into two groups and were assigned to daily use of dalteparin injections and aspirin placebo tablets, or placebo injections and oral for 28 days.

During the 90-day follow-up period after randomization, 0.38 percent or one out of 386 participants from the aspirin group had a VTE event, according to the study featured at rheumatologynews.com. On the other hand, a VTE event was reported to occur in 1.3 percent or five out of 400 patients from the dalteparin group. Study findings, which were published online in the June edition of Annals of Internal Medicine, reportedly suggest that aspirin is neither inferior nor superior to dalteparin in VTE prevention.  Additionally, results showed that aspirin poses lesser risk of bleeding events than dalteparin, and is also effective from a cost perspective.