Report helps orthopedists select best VTE prophylaxis for TJR, hip fracture cases
Despite the tradeoffs between different venous thromboprophylaxis treatments used for total joint replacement and hip fracture surgery, an updated Agency for Healthcare Research and Quality Effective Health Care Program report showed use of low-molecular-weight heparin resulted in less major bleeding and deep vein thrombosis and lower venous thromboembolic outcomes after total hip and knee replacement.
For the report, researchers compared interventions used in 127 randomized controlled trials and 15 nonrandomized comparative studies that examined VTE, major bleeding and other adverse events after total hip replacement, total knee replacement and hip fracture surgery.
VTE prophylaxis outcomes
Results showed a lower risk of various VTE outcomes and major bleeding with low-molecular-weight heparin (LMWH) compared with unfractionated heparin for THR. Low-molecular-weight heparin had less major bleeding than direct thrombin inhibitors, vitamin K antagonists and factor Xa inhibitors, according to the results. However, direct thrombin inhibitors had lower DVT risks.
Researchers noted there were similar risks of total pulmonary embolism, symptomatic DVT and major bleeding with both LMWH and aspirin.
Compared with mechanical devices, researchers found a lower proximal DVT risk with vitamin K antagonists. In addition, a longer duration of LMWH use led to a lower risk of various VTE outcomes and a higher dose of LMWH led to a lower risk of total DVT, but more major bleeding, researchers noted. Results showed a lower total risk of VTE with higher-dose factor Xa inhibitors.
For TKR, while LMWH led to lower DVT risks vs. vitamin K antagonists, researchers noted vitamin K antagonists had less major bleeding. Compared with LMWH, results showed a lower risk of various venous thromboembolic outcomes with factor Xa inhibitors; however, LMWH had less major bleeding and more study-defined serious adverse events. A higher-dose direct thrombin inhibitor led to lower rates of DVT, but more major bleeding; while a lower risk of various VTE outcomes was found with a higher-dose factor Xa inhibitor.
Researchers also found a lower DVT risk with LMWH used in hip fracture surgery vs. factor Xa inhibitor. However, they either had insufficient evidence to assess both benefits and harms or inconsistent findings to make hip fracture surgery and other intervention comparisons.
More research needed
This systematic review provides orthopedic surgeons with the available evidence behind prophylactic options for patients, Laura L. Pincock, PharmD, MPH, Captain, U.S. Public Health Service, Pharmacist Officer of the Evidence-based Practice Center Program, noted. However, she said, more research is needed in several areas due to incomplete and unclear evidence when comparing these prophylactic options to the extent that they will prevent VTE and harms, such as major bleeding, in patients who undergo orthopedic surgery.
“None of our key questions were fully and adequately addressed because these areas could definitely benefit with additional studies,” Pincock told Orthopedics Today.
She noted most studies the researchers included reviewed the use of LMWH alone, which made it difficult to make comparisons when most of the studies investigated a single drug. Larger studies, studies that compare drugs head-to-head for treatment effect, studies not funded by the pharmaceutical industry and studies that look at different subgroups of patients with differing conditions are needed, according to Pincock. – by Casey Tingle
- Balk EM, et al. Venous thromboembolism prophylaxis in major orthopedic surgery: Systematic review update. Available at: www.effectivehealthcare.ahrq.gov/index.cfm/search-for-guides-reviews-and-reports/?pageaction=displayproduct&productid=2480. Accessed: June 28, 2017.
- For more information:
- Laura L. Pincock, PharmD, MPH, can be reached at Agency for Healthcare Research and Quality, 5600 Fishers Lane, Rockville, MD 20857; email: email@example.com.
Disclosure: Pincock reports no relevant financial disclosures.