Secondary Prevention of Venous Thromboembolism: A Role for Low-Molecular-Weight Heparin

Abstract

Background: After a short initial course of heparin therapy, patients with venous thrombo-embolism (VTE) require continuing anticoagulant therapy for several months after hospital discharge. At present, two small-scale studies have compared the efficacy and safety of low-molecular-weight heparin (LMWH) with warfarin in the secondary prevention of VTE. Patients and Methods: We studied 654 consecutive patients, 202 with pulmonary embolism (PE) and 452 patients with deep vein thrombosis (DVT) of the lower limbs. 220/654 patients (34%) were considered to have some contraindications to coumarin, and were discharged on LMWH (dalteparin, Fragmin^®, 10,000 IU s.c. once daily). The remaining 434/654 patients were asked to choose between either coumarin or LMWH: 190 patients preferred LMWH and 244 coumarin. Patients were followed up for a 3-month (DVT patients) or 6-month (PE patients) period. Results: 14/654 patients (2%) developed recurrent VTE while on anticoagulant therapy. One in every three recurrent episodes was PE (which was fatal in 2/5 patients), and half of the recurrent DVT were located in the contralateral leg. We failed to find any differences between patients receiving LMWH and those on coumarin therapy, but recurrences were more common in patients with cancer (hazard ratio: 17.15; 95% CI: 4.0–73.5; p < 0.001). 21 patients (3.3%) bled (major bleeding 5 patients; minor bleeding 16). Bleeding was more common in patients on coumarin therapy (hazard ratio: 3.14; 95% CI: 1.20–8.22; p = 0.02). Conclusions: Long-term LMWH therapy proved to be both effective and safe in the long-term treatment of VTE. Thus, we suggest long-term LMWH therapy should be considered for patients with contraindications to coumarin, or those with difficulties in coming to laboratory control.

Benchmark for Time in Therapeutic Range in Venous Thromboembolism: A Systematic Review and Meta-Analysis

“…In total, 40 studies [8], [9], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51] reporting the TTR in 26064 patients treated with VKA for VTE were included in the analyses.…”

“…Two studies [9], [20] reported the TTR in the first month since the start of treatment, thirteen studies [14], [18], [19], [21], [25], [29], [31], [34], [36], [40], [46], [48], [49] reported the TTR measured in months 1 to 3, four studies [20], [28], [32], [44] measured the TTR in months 2 to 3, fifteen studies [8], [9], [17], [22], [23], [26], [33], [35], [37], [38], [41], [45], [47], [50], [51] in months 1 to a minimum of 6 months and four studies [15], [16], [27], [30] reported the TTR in months 4 to at least 12 months since the start of treatment. Twenty (50%) studies [15], [16], [17], [18], [19], [25], [27], [28], [29], [30], [31], [33], [35], [37], [41], [45], [47], [48], [49], [50] reported that they calculated the TTR by using linear interpolation [52]. The method used for calculating TTR was not mentioned in 1...…”

Management of Venous Thromboembolism: A Clinical Practice Guideline from the American College of Physicians and the American Academy of Family Physicians

“…33 The EPC identifi ed 19 studies that evaluated treatment of VTE during pregnancy, but after they excluded studies that evaluated prophylaxis only, very small studies, and those without clinical outcomes, only 11 studies-all observational-remained for review. [34][35][36][37][38][39][40][41][42][43][44] There is not adequate evidence for defi nitive recommendations for management of VTE in pregnancy. Clinicians should avoid vitamin K antagonists in pregnant women because these drugs cross the placenta and are associated with embryopathy between 6 and 12 weeks' gestation, as well as with fetal bleeding (including intracranial hemorrhage) at delivery.…”

Fixed‐dose low‐molecular‐weight heparin for secondary prevention of venous thromboembolism in patients with disseminated cancer: a prospective cohort study

“…In a previous trial we found long‐term treatment with fixed‐dose 5000 IU dalteparin twice daily to be a good alternative in patients with VTE and contraindications to vitamin K antagonists [3]. In a latter, prospective cohort study with a large series of patients with VTE 10 000 IU dalteparin once daily was as effective and safe as coumarin [4]. In the present study we evaluated the effectiveness and safety of the same dose dalteparin in a series of consecutive patients with VTE and disseminated cancer.…”