A randomized placebo controlled trial of dalteparin for the prevention of venous thromboembolism in 3706 acutely Ill medical patients: the PREVENT medical thromboprophylaxis study
Abstract number: OC396
Leizorovicz* A., Cohen A. T., Turpie A. G. G., Olsson§ C. G., Vaitkus¶ P. T., Goldhaber** S. Z.
**Brigham & Women's Hospital, Boston, USA Guy's King's & St Thomas's School of Medical, London, UK; McMaster University, Hamilton, Canada; *Université Claude Bernard Lyon, France; §University Hospital of Lund, Sweden; ¶University of Illinois at Chicago, USA;
Venous thromboembolism (VTE) is a major cause of morbidity and mortality in hospitalized patients, including those with acute medical illnesses. Approximately three-fourths of VTE occur among these acutely ill nonsurgical patients. Nevertheless, thromboprophylaxis use is low in medical patients, even though they are at high risk for VTE. Therefore, we undertook a large international study in acutely ill medical patients to assess the efficacy of dalteparin, administered in a fixed dose of 5000 units daily, for prevention of proximal deep vein thrombosis (DVT), symptomatic VTE, or sudden death.
PREVENT was a randomized, double-blind, placebo-controlled trial of hospitalized medical patients at moderately high risk of VTE. Patients received 14 days of dalteparin (5000 IU qd) or matching placebo. The primary endpoint was clinically important VTE defined as objectively verified symptomatic DVT, pulmonary embolism, sudden death, and objectively verified asymptomatic proximal DVT. Compression ultrasound was performed in all patients who had not reached an endpoint by day 21.
A total of 3706 patients were enrolled at 219 centers in 26 countries. The most common reasons for inclusion were congestive heart failure, acute respiratory failure, or infectious disease. One-third of patients were 75 years of age or more. The incidence of the composite primary outcome was 2.77% (42/1518 patients) in the dalteparin group and 4.96% (73/1473 patients) in the placebo group, a risk reduction of 45% (95% confidence interval 2062%) (P = 0.0015). The incidence of proximal deep vein thrombosis by day 21 was lower among the patients receiving dalteparin than in those receiving placebo, 29 vs. 60 patients. Two patients in the placebo group had fatal pulmonary embolism by day 21 compared with none in the dalteparin group. By day 21, major bleeding had occurred in 12 patients, 9 (0.49%) of whom were receiving dalteparin and 3 (0.16%) receiving placebo (P = 0.15).
This large randomized, controlled trial of thromboprophylaxis in medically ill patients showed that dalteparin 5000 IU daily reduced clinically important venous thromboembolism with a low risk of bleeding. These findings should encourage more widespread and routine thromboprophylaxis of medically ill patients who are hospitalized and should lower the incidence of venous thromboembolism in this large group of patients, resulting in improved clinical outcomes.
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Journal of Thrombosis and Haemostasis 2003; 1 Supplement 1 July: abstract number
|Subject:||Clinical trials: heparins/LMWH|
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