[Critical appraisal: Subcutaneous adjusted-dose unfractionated heparin vs fixed-dose low-molecular-weight heparin in the initial treatment of venous thromboembolism. Prandoni P, Carnovali M, Marchiori A, Galilei investigators. Arch Intern Med 2004; 164: 1077-83].
BACKGROUND
Few reports have addressed the value of unfractionated heparin (UFH) or low-molecular-weight heparin in treating the fill spectrum of patients with venous thromboembolism (VTE), including recurrent VTE and pulmonary embolism.


METHODS
In an open, multicenter clinical trial, 720 consecutive patients with acute symptomatic VTE, including 119 noncritically ill patients (16.5%) with pulmonary embolism and 102 (14.2%) with recurrent VTE, were randomly assigned to treatment with subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm (preceded by an intravenous loading dose), or fixed-dose (adjusted only to body weight) subcutaneous nadroparin calcium. Oral anticoagulant therapy was started concomitantly and continued for at least 3 months. We recorded the incidence of major bleeding during the initial heparin treatment and that of recurrent VTE and death during 3 months of follow-up.


RESULTS
Fifteen (4.2%) of the 360 patients assigned to UFH had recurrent thromboembolic events, as compared with 14 (3.9%) of the 360 patients assigned to nadroparin (absolute difference between rates, 0.3%; 95% confidence interval, -2.5% to 3.1%). Four patients assigned to UFH (1.1%) and 3 patients assigned to nadroparin (0.8%) had episodes of major bleeding (absolute difference between rates, 0.3%; 95% confidence interval, -1.2% to 1.7%). Overall mortality was 3.3% in each group.


CONCLUSIONS
Subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm is as effective and safe as fixed-dose nadroparin for the initial treatment of patients with VTE, including those with pulmonary embolism and recurrent VTE.
Burotto
Mauricio
M
Departamento de Medicina Interna, Pontificia Universidad Católica de Chile.
Gabrielli
Luigi
L
Crossley
Nicolás
N