Presentation on theme: "Brian M. Johnson, MD CCRMC PBL 11/7/12"— Presentation transcript:
1 Brian M. Johnson, MD CCRMC PBL 11/7/12 Deep Vein ThrombosisBrian M. Johnson, MDCCRMC PBL11/7/12
2 Case 1Mrs. 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? DVT2. Cellulitis3. Baker’s cyst4. Lymphedema5. FracturePost-thrombotic syndromeVenous insufficiencyScorpions? Or bee stings?ToxinsMassTrauma / Compartment syndrome
4 What are risk factors for DVT? HospitalizationLong-term immobilityOCPSmokingAgeSurgeryCancerCHFRenal diseaseCirrhosisPregnancyAnti-psychoticsThrombophiliasObesityRestrictive clothingGenderLupus (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 Clinical featureScore*Active cancer within 6 mo1Paralysis, paresis, or cast of lower extremityRecently bedridden >3 d or major surgery within 4 wkLocalized tenderness along distribution of deep vein systemCalf diameter >3 cm larger than opposite leg†Pitting edemaCollateral superficial veins (nonvaricose)Alternative diagnosis as likely or greater than that of DVTClinical model for predicting pretest probability for DVT*Interpretation: 0 = low probability = 3% frequency of DVT; 1-2 = medium probability= 17% frequency of DVT; ≥3 = high probability = 75% frequency of DVT.†Measured 10 cm below tibial tuberosity.-2
8 How would a d-dimer help? StatisticallySensitive not Specific (useful if it’s negative)High false positive rateBiomedicallymeasures level of coagulation process in the body
9 Case 2Ms. 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)
13 Remember: the superficial femoral vein is a deep vein
14 Operating characteristics of diagnostic tests for proximal DVT Operating characteristics of diagnostic tests for proximal DVT* Black et al.*Diagnostic testSensitivity, %Specificity, %Positive LRNegative LRVenography~100InfinityDuplex ultrasonography95190.05Impedence plethysmography80160.21Iodine 125 fibrinogen scan79622.10.34D-Dimer level88-10055-80LR = likelihood ratio.
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? YesNeed immediate anticoagulation (i.e. Lovenox) then can bridge to warfarinNoObesityCacheticRenal failure (GFR <40)High bleeding riskComplicated medical historyPoor resources
17 For how long?Unprovoked 6 months?Provoked 6 months?
18 What’s a provoked DVT and why does it matter? Risk factorsMajor: Cancer, Major Surgery, Major traumaMinor: Preg., long flight, OCP, smoking, minor trauma, minor surgery
19 Risk of VTE recurrence after stopping anticoagulation Risk factor1st yearNext 5 yearsDistal DVT3%<10%Major transient10%Minor transient5-6%15%UnprovokedAt least 10%30%Recurrent>10%>30%This is why duration of therapy is based on provoked vs. unprovokedKearon, American Society Hematology Dec. 2004
20 Is longer anticoagulation better in idiopathic DVT? TRIALDurationRecurrenceTHRIVE3mo7.6/ 100pt yrs2.1 yrs2.6/100pt yrsPREVENT6mo12.6%18 mo2.8%PREVENT: Idiopathic DVTTHRIVESchulman et al. N Engl J Med 2003Ridker et al. N Engl J Med. 2003
21 Do the experts agree with the ACCP recommendations? 8th ACCP guidelineBritish Thoracic SocietyRecent recommendationsFirst VTE,Provoked3 months4-6 weeks3 months if distal or upper extremity; 6 if proximal DVT or PEIdiopathicAt least 3 months, evaluate for indefinite txIndefiniteSamuel Z. Goldhaber
23 Incidence of recurrent VTE Christensen et al. JAMA 2005. Patient group (total 474 pt)Recurrence of VTE/yearWith 1 thrombophilia2.5%Initial VTE provoked1.8%Initial VTE idiopathic3.3%Idiopathic with thrombophilia3.4%Idiopathic without thrombophilia3.2%Total group2.6%So basically having a thombophilia is much less predictive of recurrence than having an idiopathic VTE. But this is a small study that didn’t separate out the thrombophilias individually. Later they do comment that APLA does increase risk of recurrence. Based on this data, both the author of the above study and the author of a recent article in the american journal of medicine (2008) suggests that thrombophilia work up is almost never useful after a first event. They do recommend testing for APLA as it does have a significant impact on risk of recurrence.
24 How can I determine who’s at risk for recurrent clot? ThrombophiliaMale genderActive cancer (i.e. ongoing risk factors)Recurrent dvtProximal over distalMorbidity from DVTRepeat studies (US and ddimer)
25 Algorithm for Determining Duration of Treatment After 3m CHECK U/S assess bleeding risk (& discuss indefinite tx if pt with PE, Male or thrombophilia)Female: No residual clot. Clinical risk rule <1, stop ACMale: No residual clot, stop AC, measure d-dimer after 30d and stop if normal.Evidence of residual clot, continue AC and repeat U/S
26 REFERENCESBates 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):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: 611–618Ofri D Diagnosis and treatment of deep vein thrombosisWest J Med 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):1425Rodger et al. Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy. CMAJ August 26, 2008 vol. 179 no. 5Schulman 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: