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It has been almost 4 years since the publication of clinical-practice guidelines based on the Sixth American College of Chest Physicians (ACCP) Consensus Conference on Antithrombotic Therapy (2001). In that short amount of time, important new information on the management of thromboembolic disorders has become available from clinical trials, several new antithrombotic drugs have been approved for clinical use, and a number of new anticoagulants have been evaluated in phase III clinical trials, with additional research on the near horizon. Guidelines based on the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy, published in September 2004,¹ review the recent data, and provide new recommendations for the management of thromboembolic disorders.

In this expert commentary, Joseph A. Caprini, MD, discusses the clinical implications of important unresolved issues concerning thromboprophylaxis in surgical patients within the seventh ACCP guidelines.

According to Dr Caprini, some of these changes in the seventh ACCP guidelines are the acknowledgement of the benefits of extended prophylaxis in patients undergoing certain orthopedic procedures, shown by the results of recent trials with fondaparinux. There are new clinical-trial data with enoxaparin that underscore the efficacy of extended prophylaxis in patients undergoing surgery for abdominal cancers. And, there is a new emphasis on the efficacy and safety of thromboprophylaxis in seriously ill, hospitalized medical patients, based on clinical-trial data with enoxaparin, dalteparin, and fondaparinux.

Although Dr Caprini acknowledges the seventh ACCP guidelines, with their new “evidence-based” process and structure, as a significant improvement over the previous guidelines, several unresolved issues remain. Guideline statements that thromboprophylaxis is not recommended in patients undergoing certain outpatient procedures, such as arthroscopy and anterior cervical fusion, are then “qualified” by suggesting the decision to use prophylaxis may be reconsidered if there are “other risk factors.” Dr Caprini also takes issue with the continuing class 1A recommendation for the use of warfarin for thromboprophylaxis in orthopedic surgery despite comparative clinical trials that show greater efficacy with newer drugs, such as the low-molecular-weight heparins and fondaparinux.

Dr Caprini’s logical and authoritative commentary also addresses dosing issues of antithrombotic drugs for special patient populations, the importance of calf-vein thrombosis, and dilemmas posed by thromboprophylaxis in neurosurgery.

1. Hirsh J, Albers GW, Guyatt GH, Schünenmann HJ. The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: evidence-based guidelines. Chest. 2004;126:172S-173S.

Suggested Reading List

• Hull R, Raskob G, Pineo G, et al. A comparison of subcutaneous low-molecular-weight heparin with warfarin sodium for prophylaxis against deep-vein thrombosis after hip or knee implantation. N Engl J Med. 1993;329:1370-1376.
• Blättler W, Partsch H. Leg compression and ambulation is better than bed rest for the treatment of the symptoms of acute deep venous thrombosis. Int Angiol. 2003;22:393-400.
• Partsch H, Blättler W. Compression and walking versus bed-rest in the treatment of proximal deep venous thrombosis with low-molecular-weight heparin. J Vasc Surg. 2000;32:861-869.
• Lechler E, Schramm W, Flosbach CW. The venous thrombotic risk in non-surgical patients: epidemiological data and efficacy/safety profile of a low-molecular-weight heparin (enoxaparin). The Prime Study Group. Haemostasis. 1996;26 Suppl 2:49-56.