Prevention of Deep Venous Thrombosis and Pulmonary Embolism

Prevention of DVT and PE remain important management issues in hospitalized patients. Ten percent of hospital deaths are considered to be due to PE and the prevention of DVT and PE is considered the most valuable of 79 preventative initiatives outlined by the Agency for Healthcare Research and Quality.85,86 NYHA Class III and IV HF is a major risk factor for DVT and acute hospitalization increases the risk of DVT several-fold.87,88 One million patients per year are admitted for acutely decompensated HF in both the US and Europe.89 With an in-hospital mortality for decompensated HF of approximately 4%, as many as 4000 patients deaths due to PE are potentially preventable yearly in both the US and Europe.90,91 Although no large randomized trial of DVT prophylaxis has been conducted solely in an acute decompensated HF population, several randomized trials conducted in hospitalized patients that have included a large percentage of patients admitted for decompensated HF.92-98 Prophylaxis with low dose UFH, LMWH, and fondaparinux have been shown to decrease the incidence of asymptomatic DVT and in some cases symptomatic DVT.92-98 Only one trial has independently demonstrated a benefit of anticoagulation prophylaxis on PE and that trial was conducted in patients with infectious diseases.99 Two meta-analyses have reported a significant benefit of either low dose UFH or LMWH on DVT and PE without an effect on mortality and with a non-significant increase in the risk of major bleeding.100,101 All but two of the studies in these meta-analyses included patients admitted with decompensated HF. The American College of Chest Physicians has given DVT prophylaxis with UFH or LMWH a 1A recommendation for acutely hospitalized patients with a high risk for DVT and NYHA Class III or IV HF is considered a high-risk category.85 Although no single trial has been conducted in only hospitalized patients with HF, a subgroup analyses of two large randomized trials demonstrates a significant benefit of LMWH on DVT in HF patients.102,103 No large study compares UFH to LMWH or fondaparinux, but a meta-analysis of all studies suggests a trend in favor of LMWH compared to low dose UFH for both reduction of DVT and PE with a trend for less bleeding.104

LMWH are renally excreted and should not be used in patients with a creatinine clearance <30 mL/min. LMWH should also be avoided in patients with HF who have undergone a recent surgical procedure, such as an ICD implantation.

Mechanical means of DVT prophylaxis, such as intermittent pneumatic compression devices or graded compression stockings, have not been subjected to randomized trials in medical patients and are reserved for patients with contraindications to anticoagulation.85 Graded compression stockings may be preferable if intermittent pneumatic compression devices limit patient mobility.104

At the time of admission, screening for venous thromboembolism is indicated when patients present with unilateral or asymmetric lower extremity edema, chest pain, or presyncope. Worsening right HF and pulmonary hypertension may also be signs of chronic pulmonary emboli.