Prophylaxis guidelines for venous thromboembolism (VTE) issued by the AAOS and the American College of Chest Physicians (ACCP) have been at odds regarding whether aspirin should qualify as an acceptable prophylactic option. This difference in philosophy has had an impact on the Surgical Care Improvement Project (SCIP) measures, which are based on the ACCP guidelines, because aspirin was not recommended by the ACCP for prophylaxis in total joint arthroplasty patients.

But when revised SCIP measures regarding VTE prophylaxis go into effect on Jan. 1, 2014, aspirin will join the list of acceptable prophylactic agents—compared to no prophylaxis at all—under the SCIP measures, thus bringing the AAOS and ACCP guidelines and the SCIP measures into better alignment regarding VTE prophylaxis.

“To comply with current SCIP measures—and until the new measures go into effect next year—if orthopaedic surgeons choose to use aspirin and mechanical compression as VTE prophylaxis for total hip arthroplasty patients, they need to document it in the patient’s chart with a note saying that they selected this specific prophylaxis regimen because they have a concern about bleeding,” said Jay R. Lieberman, MD, AAOS representative to SCIP. “As of Jan. 1, 2014, that notation will not be required anymore.”

SCIP measures
The revised SCIP measures that go into effect next year include the following quality measure related to VTE prophylaxis:

• SCIP-VTE-2: Surgery patients who received appropriate venous thromboembolism prophylaxis within 24 hours prior to surgery to 24 hours after surgery

The measures will also list the types of orthopaedic surgery and the corresponding agents for VTE prophylaxis that will be acceptable for each procedure, as follows:

• Elective total knee or total hip replacement
• Low molecular weight heparin (LMWH)
• Factor Xa inhibitor
• Oral factor Xa inhibitor
• Vitamin K antagonist (Warfarin)
• Intermittent pneumatic compression devices (IPCD)
• Venous foot pump (VFP)
• Low-dose unfractionated heparin (LDUH)
• Aspirin
• Hip fracture surgery
• LDUH
• LMWH
• Factor Xa inhibitor
• Warfarin
• IPCD
• Aspirin

Evolution of the CPGs
Clinical practice guidelines (CPGs) issued by the AAOS and ACCP must be updated every 5 years, as required by the National Guideline Clearinghouse. The CPGs issued by each of these organizations have changed over time, as more evidence related to VTE prophylaxis has become available and the approach to guideline development has evolved.

In 2008, the ACCP published the eighth edition of its evidence-based CPG on the prevention of VTE in patients undergoing orthopaedic surgery. According to Dr. Lieberman, because VTE after total joint arthroplasty or hip fracture surgery is quite rare, it is difficult to conduct large, randomized trials evaluating the efficacy of different prophylaxis regimens and chemoprophylaxis agents in preventing symptomatic events. Thus, the 2008 version of the ACCP guidelines was based on surrogate outcomes derived from venographic screening of asymptomatic events, rather than on data from symptomatic events.

The ACCP guidelines—which included a grade 1A recommendation against the use of aspirin and upon which the current SCIP measures are based—caused concern among some orthopaedic surgeons who thought the ACCP guidelines focused more on efficacy than on patient safety.

“Orthopaedic surgeons who prefer to use aspirin combined with a mechanical device for prophylaxis were concerned about increased bleeding rates that have been associated with LMWH and other chemoprophylaxis agents,” said Dr. Lieberman, who noted that these ACCP guidelines conflicted with AAOS VTE prophylaxis guidelines issued in 2007.

Reaching greater consensus
In 2011, as controversy continued regarding the conflicting guidelines, the AAOS published its CPG on the prevention of venous thromboembolic disease (VTED) in patients undergoing elective hip or knee arthroplasty. One of the 10 recommendations (“moderate” rating )suggests “the use of pharmacologic agents and/or mechanical compressive devices for the prevention of venous thromboembolism in patients undergoing elective hip or knee arthroplasty, and who are not at elevated risk beyond that of the surgery itself for venous thromboembolism or bleeding.” Based on the underlying research used by the study group, however, the guidelines could not make any recommendations with respect to the most effective prophylaxis agents.

The following year, ACCP issued the ninth edition of its guidelines on antithrombotic therapy and prevention of thrombosis. These new guidelines recommended that, instead of no prophylaxis at all, patients undergoing total hip or knee arthroplasty receive one of a list of prophylactic regimens for at least 10 to 14 days following surgery. One of the listed prophylactics is aspirin.

“The ACCP guidelines issued in 2012 recommend against screening with duplex ultrasonography before hospital discharge,” Dr. Lieberman noted. “In addition, they recommend starting LMWH prophylaxis either 12 hours preoperatively or postoperatively, rather than 4 hours before or after surgery, due to concerns about increasing bleeding.”

Because the new SCIP measures will be based upon the 2012 ACCP guidelines, the recommendations will provide flexibility regarding the use of different prophylactic regimens, although this clinical flexibility is the result of different study methodologies.

“The inclusion of aspirin as an alternative to no antithrombotic prophylaxis—based on the results of the Pulmonary Embolism Prevention trial, the results of which were published in 2000—represents a major change because the previous ACCP guidelines included a grade 1A recommendation against its use,” continued Dr. Lieberman. “Evidence suggests that aspirin may not be as effective an anticoagulation agent as other chemoprophylaxis drugs, but it seems to have a better safety profile, which makes its use as a prophylactic agent appealing to some orthopaedic surgeons.”

According to AAOS President Joshua J. Jacobs, MD, chair of the AAOS workgroup that developed the Academy’s 2011 CPG on VTED, the convergence of the ACCP and AAOS guidelines and the SCIP measures is a “very positive development.”

“In its latest guideline, the ACCP took into account some of the important safety outcomes for surgeons—such as wound complications due to bleeding—that it may not have considered in previous iterations of its guidelines,” said Dr. Jacobs. “Even though much of the literature supporting the ACCP’s previous guidelines involved evidence from clinical trials whose end point was typically asymptomatic DVT detected radiographically or ultrasonographically, both the AAOS and the ACCP have acknowledged that the presence of an asymptomatic DVT, particularly if it is distal to the knee, in and of itself is not necessarily of much consequence to the patient. And considering only the critical outcomes as defined by the AAOS guideline—major bleeding, pulmonary embolism, and all-cause mortality—the evidence base is much weaker to guide the physician regarding optimal prophylaxis.

“Dr. Lieberman, as the AAOS liaison to SCIP, emphasized the rigor of the process the AAOS used to develop its latest CPGs,” added Dr. Jacobs. “The new alignment among the AAOS and ACCP guidelines and the SCIP measures points to the importance of AAOS involvement in the guideline process.”

“When the new SCIP measures take effect in 2014,” concluded Dr. Lieberman, “orthopaedic surgeons will be able to find a balance between safety and efficacy without being concerned about meeting the quality measures set forth by SCIP for their hospital.”

Jennie McKee is a senior science writer for AAOS Now. She can be reached at mckee@aaos.org

More about SCIP
The Surgical Care Improvement Project (SCIP) is a national quality partnership of organizations interested in improving surgical care by significantly reducing surgical complications. SCIP measures are listed in the Specifications Manual for National Inpatient Quality Measures, a collaborative effort of the Joint Commission and the Centers for Medicare & Medicaid Services (CMS) to publish a uniform set of national hospital quality measures.

Although guidelines issued by the AAOS and the ACCP are valuable resources on the use of VTE prophylaxis, only the SCIP VTE prophylaxis measures are tied to CMS pay-for-performance programs. Thus, hospitals must ensure that they conform to the SCIP measures for VTE prophylaxis to qualify for bonus payments.

To learn more about SCIP, visit the Joint Commission online at www.jointcommission.org or visit www.qualitynet.org

Additional Information:

• AAOS Guideline on Preventing Venous Thromboembolic Disease in Patients Undergoing Total Hip or Total Knee Arthroplasty
• Prevention of VTE in orthopedic surgery patients: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines
• SCIP guidelines
• Joint Commission