Rodger Marc A, Kahn Susan R, Wells Philip S, Anderson David A, Chagnon Isabelle, Le Gal Grégoire, Solymoss Susan, Crowther Mark, Perrier Arnaud, White Richard, Vickars Linda, Ramsay Tim, Betancourt Marisol T, Kovacs Michael J
Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa, Ottawa, Ont.
CMAJ. 2008 Aug 26;179(5):417-26. doi: 10.1503/cmaj.080493.
Whether to continue oral anticoagulant therapy beyond 6 months after an "unprovoked" venous thromboembolism is controversial. We sought to determine clinical predictors to identify patients who are at low risk of recurrent venous thromboembolism who could safely discontinue oral anticoagulants.
In a multicentre prospective cohort study, 646 participants with a first, unprovoked major venous thromboembolism were enrolled over a 4-year period. Of these, 600 participants completed a mean 18-month follow-up in September 2006. We collected data for 69 potential predictors of recurrent venous thromboembolism while patients were taking oral anticoagulation therapy (5-7 months after initiation). During follow-up after discontinuing oral anticoagulation therapy, all episodes of suspected recurrent venous thromboembolism were independently adjudicated. We performed a multivariable analysis of predictor variables (p < 0.10) with high interobserver reliability to derive a clinical decision rule.
We identified 91 confirmed episodes of recurrent venous thromboembolism during follow-up after discontinuing oral anticoagulation therapy (annual risk 9.3%, 95% CI 7.7%-11.3%). Men had a 13.7% (95% CI 10.8%-17.0%) annual risk. There was no combination of clinical predictors that satisfied our criteria for identifying a low-risk subgroup of men. Fifty-two percent of women had 0 or 1 of the following characteristics: hyperpigmentation, edema or redness of either leg; D-dimer > or = 250 microg/L while taking warfarin; body mass index > or = 30 kg/m(2); or age > or = 65 years. These women had an annual risk of 1.6% (95% CI 0.3%-4.6%). Women who had 2 or more of these findings had an annual risk of 14.1% (95% CI 10.9%-17.3%).
Women with 0 or 1 risk factor may safely discontinue oral anticoagulant therapy after 6 months of therapy following a first unprovoked venous thromboembolism. This criterion does not apply to men.
“不明原因”静脉血栓栓塞发生6个月后是否继续口服抗凝治疗存在争议。我们试图确定临床预测因素，以识别复发性静脉血栓栓塞低风险且可安全停用口服抗凝药的患者。
在一项多中心前瞻性队列研究中，4年间纳入了646例首次发生不明原因的严重静脉血栓栓塞的参与者。其中，600例参与者于2006年9月完成了平均18个月的随访。在患者接受口服抗凝治疗时（开始治疗5 - 7个月后），我们收集了69个复发性静脉血栓栓塞潜在预测因素的数据。在停用口服抗凝治疗后的随访期间，所有疑似复发性静脉血栓栓塞事件均由独立判定。我们对具有高观察者间可靠性的预测变量（p < 0.10）进行多变量分析，以得出临床决策规则。
在停用口服抗凝治疗后的随访期间，我们确定了91例确诊的复发性静脉血栓栓塞事件（年风险9.3%，95%CI 7.7% - 11.3%）。男性年风险为13.7%（95%CI 10.8% - 17.0%）。没有任何临床预测因素组合符合我们识别男性低风险亚组的标准。52%的女性具有以下特征中的0项或1项：双下肢色素沉着、水肿或发红；服用华法林时D - 二聚体≥250μg/L；体重指数≥30 kg/m²；或年龄≥65岁。这些女性年风险为1.6%（95%CI 0.3% - 4.6%）。有2项或更多这些表现的女性年风险为14.1%（95%CI 10.9% - 17.3%）。
首次不明原因静脉血栓栓塞后接受6个月治疗后，具有0项或1项风险因素的女性可安全停用口服抗凝治疗。该标准不适用于男性。
