Peut-on prédire la thrombose veineuse profonde par la clinique?

Transcription

1 Peut-on prédire la thrombose veineuse profonde par la clinique?

2 TVP et algorithme de prédiction clinique - 1 Médiocre sensibilité et spécificité des signes et symptômes cliniques Utilité démontrée de la combinaison de différents symptômes

3 TVP et APC - 2 Démarche implicite, empirique : Facteurs de risque Anomalies de l examen clinique Diagnostic différentiel Mais l expérience clinique comporte des biais : l intuition n est pas toujours raison!

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5 TVP et APC - 3 Le score de Wells : Wells PS, Anderson DR, Bormani J, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet 1997 ; 350 :

6 TVP et APC - 4

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8 APC, scores, : utiles? Identification d un sous groupe à faible risque démarche diagnostique allégée Cf étude princeps de Wells : Cohorte 593 patients Bonne valeur prédictive : Risque faible : 3% prévalence Risque moyen : 17% Risque élevé : 75%

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10 APC, scores, : inutiles? Estimation implicite de la probabilité clinique : valeur prédictive équivalente! cf Miron MJ, Perrier A Bounameaux H. Clinical probability of deep vein thrombosis : Comparison between a score and an empirical assessment. J Intern Med 2000 ; 247 :

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12 Les scores et leurs limites Items subjectifs reproductibilité? Généralisation à autres populations? Analyse multivariée exclut éléments rares mais potentiellement déterminants 10% de désaccord avec estimation implicite, qui détermine la décision

13 Les scores et leurs mérites Utilité didactique pour jeunes médecins : confrontation entre intuition et évaluation standardisée Si désaccord avec jugement empirique d un médecin expérimenté : discussion au cas par cas à la lumière des éléments explicite du score

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15 BMJ 2004;329:821 (9 October), doi: /bmj eb (published 21 September 2004) Combined use of rapid D-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review Tonya L Fancher, assistant professor1, Richard H White, professor of medicine1, Richard L Kravitz, professor of medicine and director2 1 Division of General Medicine, University of California at Davis, Patient Support Services Building, Suite 2400, Sacramento, California 95817, USA, 2 Center for Health Services Research in Primary Care, 2103 Stockton Blvd, Sacramento, CA 95817, USA

16 Utilité du dosage des D-dimères Score de Wells faible ou moyen + D-dimères (-) Incidence très faible de TVP : 0,4% (0,04% à 1,1%) dans les 3 mois

17 Evaluation of D-Dimer in the Diagnosis of Suspected Deep-Vein Thrombosis Wells, Philip S.; Anderson, David R.; Rodger, Marc; Forgie, Melissa; Kearon, Clive; Dreyer, Jonathan; Kovacs, George; Mitchell, Michael; Lewandowski, Bernard; Kovacs, Michael J. N Engl J Med 2003;349:

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19 Patient Outcomes Of the 1082 patients who completed follow-up, 83 (16.0 percent) in the control group and 87 (15.5 percent) in the D-dimer group had proximal deep-vein thrombosis or pulmonary embolism, for an overall prevalence of 15.7 percent. Four hundred ninety-five (45.7 percent) were categorized as likely to have deep-vein thrombosis; 138 of these patients (27.9 percent; 95 percent confidence interval, 23.9 to 31.8 percent) had proximal deep-vein thrombosis or pulmonary embolism. Five hundred eighty-seven (54.3 percent) were categorized as unlikely to have deep-vein thrombosis; 32 of these patients (5.5 percent; 95 percent confidence interval, 3.8 to 7.6 percent) had proximal deep-vein thrombosis or pulmonary embolism. These rates include events that occurred during the three-month follow-up.

20 This study confirms the validity of modifying our previous clinical model for the diagnosis of deep-vein thrombosis, which categorized patients into high-, moderate-, and low-probability groups, to one that categorizes patients as likely (>= 2) or unlikely (<2) to have deep-vein thrombosis. The addition to the scoring system of one point for a previous diagnosis of deep-vein thrombosis allows the model to be used in patients with previous thrombosis, a group we had excluded from earlier studies.

21 D-dimères et valeur prédictive Score Wells < 2 : Score Wells >= 2 : VPN = 99,1% VPN = 89,0% VPP = 14,1% VPP = 38,6% Pour tout le VPN groupe D-dimère = 96,1%

22 Conclusions: Deep-vein thrombosis can be ruled out in a patient who is judged clinically unlikely to have deep-vein thrombosis and who has a negative D-dimer test. Ultrasound testing can be safely omitted in such patients. N Engl J Med 2003;349: