Areas of Uncertainty in Prophylaxis of Venous Thromboembolism in Unselected Subjects

In the last decade, parenteral anticoagulants have proven to be effective in the prevention of venous thromboembolism (VTE) in patients admitted to hospitals. Despite this, some registry studies have shown that pharmacological prophylaxis is still widely underused. We performed a literature search to identify important knowledge gaps in the use of VTE prophylaxis that were not addressed by previous published reports. MEDLINE and HighWire databases covering the years 1999-2009 were searched; only clinical trials of unselected adult subjects were included. Two reviewers independently selected studies and extracted data on inclusion and exclusion criteria, age, weight, comorbidities, study designs, and endpoints. Five of 113 relevant studies were identified from the literature search. Knowledge gaps were disclosed in subject inclusion, exclusion, and stratification regarding young age, under- and overweight, comorbidities, and the selection of clinically significant endpoints. Uncertainties in the dosage, risk stratification of subjects, and effect on hard endpoints as prevention of pulmonary embolism or reduction of mortality reduce the impact of VTE prevention clinical trials.