Deep Vein Thrombosis

1. Deep Vein Thrombosis Brian M. Johnson, MD CCRMC PBL 11/7/12

2. Case 1 Mrs. Z, a 44-year-old woman without significant PMH, presents for an urgent visit with left leg swelling of two days duration. She takes no medications and reports moderate leg pain but no chest pain, shortness of breath, or palpitations.

3. What is the differential diagnosis of unilateral leg swelling? • DVT 2. Cellulitis 3. Baker’s cyst 4. Lymphedema 5. Fracture • Post-thrombotic syndrome • Venous insufficiency • Scorpions? Or bee stings? • Toxins • Mass • Trauma / Compartment syndrome

4. What are risk factors for DVT? • Hospitalization • Long-term immobility • OCP • Smoking • Age • Surgery • Cancer • CHF • Renal disease • Cirrhosis • Pregnancy • Anti-psychotics • Thrombophilias • Obesity • Restrictive clothing • Gender • Lupus (and other autoimmune diseases) • Sickle Cell

5. Case Continued… • She reports that she has no family history of blood clots to her knowledge and that she is not pregnant. She denies any “warning signs” of cancer and is up to date on her cancer screening (mammogram, Pap smear; no colorectal cancer screening, but she denies family history of colorectal cancer so she is not yet due). She denies recent immobilization or trauma. • Her exam is significant for a minimally swollen right calf. To ensure a reliable assessment of circumference, you mark off 10cm below each tibial tuberosity and measure the circumference at that level. You find that the right calf measures 1cm larger in circumference than the left. There is no edema or skin changes; no masses/cords are palpable. The thighs are symmetric, and no superficial veins are noted.

6. How could you determine the probability of the DVT in this patient?

7. What is the probability that this patient has a DVT? Modified Wells

8. How would a d-dimer help? Statistically • Sensitive not Specific (useful if it’s negative) • High false positive rate Biomedically • measures level of coagulation process in the body

9. Case 2 Ms. W, comes with the exact same presenting complaint and past medical history. The only difference in the presentation of Ms. W. is that she does report that she had the “flu” about one week ago and was in bed for four to five days. Additionally, her exam is significant for a swollen and tender right calf, measuring 4 cm wider in circumference than the left. There is pitting edema on the right lower extremity, extending to the inferior calf. There is no change in the skin, and no masses/cords are palpable. The thighs are symmetric, and no superficial veins are noted.

10. What’s the probability this patient has a DVT? 75%!!High, with wells score greater than 3

11. What’s the value of doing a d-dimer? • If high probability 21% still positive for DVT even with negative D-dimer

12. What other test could you preform? • Venous Doppler • (venography)

14. Operating characteristics of diagnostic tests for proximal DVT*Black et al. *

15. U/S negative. End of story? • With high probability clinical exam but NEGATIVE U/S: • Consider other imaging, repeat study or obtain D-dimer. • Consider treatment

16. U/S positive. Can she be treated as an outpatient? • Yes • Need immediate anticoagulation (i.e. Lovenox) then can bridge to warfarin • No • Obesity • Cachetic • Renal failure (GFR <40) • High bleeding risk • Complicated medical history • Poor resources

17. For how long? • Unprovoked 6 months? • Provoked 6 months?

18. What’s a provoked DVT and why does it matter? • Risk factors • Major: Cancer, Major Surgery, Major trauma • Minor: Preg., long flight, OCP, smoking, minor trauma, minor surgery

19. Risk of VTE recurrence after stopping anticoagulation Kearon, American Society Hematology Dec. 2004

20. Is longer anticoagulation better in idiopathic DVT? Schulman et al. N Engl J Med 2003 Ridker et al. N Engl J Med. 2003

21. Do the experts agree with the ACCP recommendations?

22. Should I do the thrombophilia work up?

23. Incidence of recurrent VTEChristensen et al. JAMA 2005.

24. How can I determine who’s at risk for recurrent clot? Thrombophilia Male gender Active cancer (i.e. ongoing risk factors) Recurrent dvt Proximal over distal Morbidity from DVT Repeat studies (US and ddimer)

25. Algorithm for Determining Duration of Treatment

26. REFERENCES Bates SM, Kearon C, Crowther M, et al. A diagnostic strategy involving a quantitative latex D-dimer assay reliably excludes deep venous thrombosis. Annals of Internal Medicine. 2003;138(10):787-794. Black ER, Bordley DR, Tape TG, Panzer RJ. Diagnostic Strategies for Common Medical Problems. Philadelphia: American College of Physicians; 1999. Bruinstoop, E., Klok, F. A.,Van de Ree, M. A., Oosterwijk, F. L. and Huisman, M. V., Elevated d-dimer levels predict recurrence in patients with idiopathic venous thromboembolism: a meta-analysis. Journal of Thrombosis and Haemostasis, 2009;7: 611–618 Ofri D Diagnosis and treatment of deep vein thrombosis West J Med. 2000 September; 173(3): 194–197. Ridker PM, Goldhaber SZ, Danielson E, Rosenberg Y, Eby CS, Deitcher SR, Cushman M, Moll S, Kessler CM, Elliott CG, Paulson R, Wong T, Bauer KA, Schwartz BA, Miletich JP, Bounameaux H, Glynn RJ, PREVENT Investigators N Engl J Med. 2003;348(15):1425 Rodger et al. Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy. CMAJ August 26, 2008 vol. 179 no. 5 Schulman S, Wåhlander K, Lundström T, Clason SB, Eriksson H. Secondary prevention of venous thromboembolism with the oral direct thrombin inhibitor ximelagatran.. N Engl J Med 2003 Oct 30;349:1713-21