深静脉血栓形成是有诱因的还是特发性的,是复发的重要决定因素。起始血凝块的范围和位置影响静脉炎后综合征的风险,而静脉炎后综合征是深静脉血栓形成的主要后遗症。深静脉血栓形成很少影响患者的总体预后。在深静脉血栓形成的患者中,是否有潜在恶性肿瘤和是否有潜在的内科疾病(如,肝病或慢性肾病)也是主要的预后决定因素。相比于无癌症患者,癌症患者的生存率较低。死于深静脉血栓形成的患者,原因通常是肺栓塞或抗凝治疗引起的大出血。
在一项系统性回顾研究中,抗凝治疗的前3个月,致死性静脉血栓复发率是0.4%,其中病死率为11.3%。致死性大出血事件发生率是0.2%,其中病死率为11.3%。抗凝治疗后,致死性深静脉血栓形成的复发率是0.3/100人年,其中病死率为3.6%。[118]Carrier M, Le Gal G, Wells PS, et al. Systematic review: case-fatality rates of recurrent venous thromboembolism and major bleeding events among patients treated for venous thromboembolism. Ann Intern Med. 2010;152:578-589.http://www.ncbi.nlm.nih.gov/pubmed/20439576?tool=bestpractice.com
社区队列研究中,60天内急性深静脉血栓形成复发率是25%到30%。急性复发的原因还不清楚,但可能是亚治疗量的抗凝治疗或者患者的依从性低导致的。[119]Spencer FA, Emery C, Joffe SW, et al. Incidence rates, clinical profile, and outcomes of patients with venous thromboembolism. The Worcester VTE study. J Thromb Thrombolysis. 2009;28:401-409.http://www.ncbi.nlm.nih.gov/pubmed/19629642?tool=bestpractice.com[120]Heit JA, Mohr DN, Silverstein MD, et al. Predictors of recurrence after deep vein thrombosis and pulmonary embolism: a population-based cohort study. Arch Intern Med. 2000;160:761-768.http://archinte.ama-assn.org/cgi/content/full/160/6/761http://www.ncbi.nlm.nih.gov/pubmed/10737275?tool=bestpractice.com
在一项急性深静脉血栓形成或肺栓塞患者入选的前瞻性队列研究中,5%的患者在抗凝治疗的前6个月发生静脉血栓栓塞复发,如果停止抗凝治疗,30%的患者会在初次发作的6个月到5年后出现静脉血栓栓塞复发。[121]Schulman S, Rhedin AS, Lindmarker P, et al. A comparison of six weeks with six months of oral anticoagulant therapy after a first episode of venous thromboembolism. Duration of Anticoagulation Trial Study Group. N Engl J Med. 1995;332:1661-1665.http://www.ncbi.nlm.nih.gov/pubmed/7760866?tool=bestpractice.com[122]Schulman S, Granqvist S, Holmström M, et al. The duration of oral anticoagulant therapy after a second episode of venous thromboembolism. The Duration of Anticoagulation Trial Study Group. N Engl J Med. 1997;336:393-398.http://www.ncbi.nlm.nih.gov/pubmed/9010144?tool=bestpractice.com
相比于没有血栓形成倾向缺陷的患者,有一项或多项缺陷的患者在华法林治疗期间复发率并没有升高。[115]Kearon C, Julian JA, Kovacs MJ, et al. Influence of thrombophilia on risk of recurrent venous thromboembolism while on warfarin: results from a randomized trial. Blood. 2008;112:4432-4436.http://bloodjournal.hematologylibrary.org/cgi/content/full/112/12/4432http://www.ncbi.nlm.nih.gov/pubmed/18791166?tool=bestpractice.com
抗凝治疗导致的有生命危险的大出血的发生率很低。
复发
共识指南建议,所有静脉血栓栓塞的患者,都应口服抗凝治疗3个月以预防复发。对于无诱因的或特发性静脉血栓栓塞的患者,需要在3个月后再次评估。[98]Louzada ML, Majeed H, Wells PS. Efficacy of low- molecular- weight- heparin versus vitamin K antagonists for long term treatment of cancer-associated venous thromboembolism in adults: a systematic review of randomized controlled trials. Thromb Res. 2009;123:837-844.http://www.ncbi.nlm.nih.gov/pubmed/18977517?tool=bestpractice.com特发性或无诱因的深静脉血栓形成的患者,应当考虑给予长期治疗。[123]Kearon C. Extended anticoagulation for unprovoked venous thromboembolism: a majority of patients should be treated. J Thromb Thrombolysis. 2011;31:295-300.http://www.ncbi.nlm.nih.gov/pubmed/21331558?tool=bestpractice.com
接受治疗的无诱因的深静脉血栓形成的患者中,已报道有大量个体因素和血栓栓塞低复发率有关,如女性、没有严重的血栓形成倾向缺陷(如,抗磷脂抗体综合征或抗凝血酶缺陷)、超声显示没有残余血栓、[124]Prandoni P, Prins MH, Lensing AW, et al. Residual thrombosis on ultrasonography to guide the duration of anticoagulation in patients with deep venous thrombosis: a randomized trial. Ann Intern Med. 2009;150:577-585.http://www.ncbi.nlm.nih.gov/pubmed/19414836?tool=bestpractice.com[125]Siragusa S, Malato A, Anastasio R, et al. Residual vein thrombosis to establish duration of anticoagulation after a first episode of deep vein thrombosis: the Duration of Anticoagulation based on Compression UltraSonography (DACUS) study. Blood. 2008;112:511-515.http://bloodjournal.hematologylibrary.org/cgi/content/full/112/3/511http://www.ncbi.nlm.nih.gov/pubmed/18497320?tool=bestpractice.com正常的凝血因子Ⅷ水平、正常的凝血酶以及停止华法林治疗1个月后正常的D-二聚体水平。[126]Cosmi B, Legnani C, Tosetto A, et al. Use of D-dimer testing to determine duration of anticoagulation, risk of cardiovascular events and occult cancer after a first episode of idiopathic venous thromboembolism: the extended follow-up of the PROLONG study. J Thromb Thrombolysis. 2009;28:381-388.http://www.ncbi.nlm.nih.gov/pubmed/19288181?tool=bestpractice.com[127]Cosmi B, Legnani C, Iorio A, et al. Residual venous obstruction, alone and in combination with D-dimer, as a risk factor for recurrence after anticoagulation withdrawal following a first idiopathic deep vein thrombosis in the prolong study. Eur J Vasc Endovasc Surg. 2010;39:356-365.http://www.ncbi.nlm.nih.gov/pubmed/20034816?tool=bestpractice.com这些危险因素以及它们的组合,应用于指导治疗的持续时间。[128]Meijer K, Schulman S. The absence of 'minor' risk factors for recurrent venous thromboembolism: a systematic review of negative predictive values and negative likelihood ratios. J Thromb Haemost. 2009;7:1619-1628.http://www.ncbi.nlm.nih.gov/pubmed/19624456?tool=bestpractice.com
一项研究显示,在无诱因的DVT的女性患者中,有多项发现与DVT的低复发率有关。有不超过以下一项危险因素的女性中,静脉血栓栓塞的复发率很低,包括:年龄小于65岁、BMI小于30、华法林治疗期间正常水平的D-二聚体或者患肢没有静脉血液瘀滞的皮肤改变(即,水肿、红斑、色素沉着)。然而,男性患者没有能区分静脉血栓栓塞复发风险高低的危险因素。[129]Rodger MA, Kahn SR, Wells PS, et al. Identifying unprovoked thromboembolism at low risk for recurrence who can discontinue anticoagulant therapy. CMAJ. 2008;179:417-426.http://www.cmaj.ca/content/179/5/417.fullhttp://www.ncbi.nlm.nih.gov/pubmed/18725614?tool=bestpractice.com其他风险评估模型还有D-二聚体、年龄、性别、激素水平(DASH)以及维也纳预测模型。然而,这些模型并没有被证明有效,也没有被临床常规使用。