Prior thromboprophylaxis and outcome in patients experiencing acute venous thromboembolism after an acute medical illness

• Thromboprophylaxis decreases the VTE risk.
• Patients may present VTE despite prevention.
• Their prognosis is not worse than the others.

BackgroundEven despite the use of thromboprophylaxis, some patients with an acute medical illness develop symptomatic venous thromboembolism (VTE). It is unclear whether the outcome in these patients is different in those in whom prophylaxis was not prescribed.Patients and methodsWe used the RIETE (Registro Informatizado Enfermedad TromboEmbolica) database to compare the 3-month outcome (death, fatal pulmonary embolism, VTE recurrences, major bleeding) of patients with acute VTE after immobilization for an acute medical disease, according to the use of prophylaxis.ResultsThromboprophylaxis was prescribed in 1313 (37%) of the 3527 patients included in August 2014. Acute infection was the most frequent cause of immobilization. Patients who received prophylaxis were more frequently immobilized in hospital than at home (70% vs. 22%), and fewer patients were immobilized for cancer (13% vs. 22%). During the first 3 months of treatment, the rates of all-cause death (23 vs. 21%), fatal PE (2.6 vs. 3.1%), VTE recurrences (2.4% vs. 2.8%), and major bleeding (4.2% for both) did not differ between the two groups. Thromboprophylaxis was not associated with each outcome in multivariate analysis.ConclusionsThe outcome in patients with VTE provoked by medical immobilization was not influenced by the use of thromboprophylaxis during the period of immobility.