Subcutaneous unfractionated heparin for the initial treatment of venous thromboembolism

A case of acute pulmonary embolism with severe haemoptysis

Haemoptysis is a potentially life-threatening symptom, which require immediate management. Haemoptysis is a challenging situation because the potential numerous causes lead to strongly different therapeutic options (medical, surgical, systematic embolization). When haemoptysis occurred at the acute phase of pulmonary embolism, anticoagulation should be stopped and inferior vena cava filter is justified. Based on a case report of massive haemoptysis related to pulmonary infarction (i.e., no other causes) in a patient with a unprovoked intermediate high-risk pulmonary embolism, we describe the dilemma set in the paradox between the need for stopping anticoagulation and the need to treat the cause of haemoptysis which is also anticoagulation. If anticoagulation should be stopped, however, the optimal management regarding the use of specific reversal agents or prothrombotic plasma concentrates remains uncertain and weakly documented. After haemoptysis has been resolved, there is also uncertainty on restarting anticoagulation modalities. Regarding long-term management, the decision to stop at three months or to prolong indefinitely based on international recommendation is also challenging in the case of unprovoked severe pulmonary embolism. In this particularly high risk situation, multidisciplinary expertise is essential.

Venous thromboembolism and mortality in breast cancer: cohort study with systematic review and meta-analysis

BACKGROUND

Breast cancer patients are at an increased risk of venous thromboembolism (VTE). However, current evidence as to whether VTE increases the risk of mortality in breast cancer patients is conflicting. We present data from a large cohort of patients from the UK and pool these with previous data from a systematic review.

METHODS

Using the Clinical Practice Research Datalink (CPRD) dataset, we identified a cohort of 13,202 breast cancer patients, of whom 611 were diagnosed with VTE between 1997 and 2006 and 12,591 did not develop VTE. Hazard ratios (HR) were used to compare mortality between the two groups. These were then pooled with existing data on this topic identified via a search of the MEDLINE and EMBASE databases (until January 2015) using a random-effects meta-analysis.

RESULTS

Within the CPRD, VTE was associated with increased mortality when treated as a time-varying covariate (HR = 2.42; 95% CI, 2.13-2.75), however, when patients were permanently classed as having VTE based on presence of a VTE event within 6 months of cancer diagnosis, no increased risk was observed (HR = 1.22; 0.93-1.60). The pooled HR from seven studies using the second approach was 1.69 (1.12-2.55), with no effect seen when restricted to studies which adjusted for key covariates.

CONCLUSION

A large HR for VTE in the time-varying covariate analysis reflects the known short-term mortality following a VTE. When breast cancer patients are fortunate to survive the initial VTE, the influence on longer-term mortality is less certain.

Subcutaneous unfractionated heparin for the initial treatment of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a prevalent and serious condition. Its medical treatment requires anticoagulation, usually with either unfractionated or low molecular weight heparin (LMWH). Administration of unfractionated heparin (UFH) is usually intravenous (IV) but can be subcutaneous as well. This is an update of a review first published in 2009.

OBJECTIVES

To assess the effects of subcutaneous UFH versus intravenous UFH, subcutaneous LMWH or any other anticoagulant drug for the initial treatment of venous thromboembolism.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (last searched 30 November 2016) and CENTRAL (2016, Issue 10). The Cochrane Vascular Information Specialist also searched trials registries for details of ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials comparing subcutaneous UFH to control, such as subcutaneous LMWH, continuous intravenous UFH or other anticoagulant drugs in participants with acute venous thromboembolism.

DATA COLLECTION AND ANALYSIS

Two review authors (JS and LR) independently extracted data and assessed the risk of bias in the trials. We used meta-analyses when we considered heterogeneity low. The primary outcomes were symptomatic recurrent venous thromboembolism (deep vein thrombosis and/or pulmonary embolism), VTE-related mortality, adverse effects of treatment including major bleeding, and all-cause mortality. We calculated all outcomes using an odds ratio (OR) with a 95% confidence interval (CI).

MAIN RESULTS

We included one additional study in this update, bringing the total number of studies in the review to 16 randomised controlled trials, with a total of 3593 participants (1745 participants in the intervention group and 1848 participants in the control group). Eight trials used intravenous UFH as the control treatment, seven trials used LMWH, and one trial had three arms with both drugs as the controls. We did not identify trials comparing subcutaneous UFH with other anticoagulant drugs. We downgraded the quality of the evidence to low due to lack of blinding in studies, which led to a risk of performance bias, and also for imprecision, as reflected by the wide confidence intervals.When comparing subcutaneous versus IV UFH, there was no difference in the incidence of symptomatic recurrent VTE at three months (odds ratio (OR) 1.66, 95% confidence interval (CI) 0.89 to 3.10; 8 studies; N = 965; low-quality evidence), symptomatic recurrent deep vein thrombosis (DVT) at three months (OR 3.29, 95% CI 0.64 to 17.06; 1 study; N = 115; low-quality evidence), pulmonary embolism (PE) at three months (OR 1.44, 95% CI 0.73 to 2.84; 9 studies; N = 1161; low-quality evidence), VTE-related mortality at three months (OR 0.98, 95% CI 0.20 to 4.88; 9 studies; N = 1168; low-quality evidence), major bleeding (OR 0.91, 95% CI 0.42 to 1.97; 4 studies; N = 583; low-quality evidence) or all-cause mortality (OR 1.74, 95% CI 0.67 to 4.51; 8 studies; N = 972; low-quality evidence). There were no episodes of asymptomatic VTE occurring within three months of the commencement of treatment.When comparing subcutaneous UFH versus LMWH, there was no difference in the incidence of recurrent VTE at three months (OR 1.01, 95% CI 0.63 to 1.63; 5 studies; N = 2156; low-quality evidence), recurrent DVT at three months (OR 1.38, 95% CI 0.73 to 2.63; 3 studies; N = 1566; low-quality evidence), PE (OR 0.84, 95% CI 0.36 to 1.96; 5 studies, N = 1819; low-quality evidence), VTE-related mortality (OR 0.53, 95% CI 0.17 to 1.67; 8 studies; N = 2469; low-quality evidence), major bleeding (OR 0.72, 95% CI 0.43 to 1.20; 5 studies; N = 2300; low-quality evidence) or all-cause mortality (OR 0.73, 95% CI 0.50 to 1.07; 7 studies; N = 2272; low-quality evidence). There were no episodes of asymptomatic VTE occurring within three months of the commencement of treatment.

AUTHORS' CONCLUSIONS

There is no evidence of a difference between subcutaneous versus intravenous UFH for preventing VTE recurrence, VTE-related or all-cause mortality, and major bleeding. According to GRADE criteria, the quality of the evidence was low. There is also no evidence of a difference between subcutaneous UFH and LMWH for preventing VTE recurrence, VTE-related or all-cause mortality or major bleeding.