Lack of effect of a low-molecular-weight heparin (nadroparin) on mortality in bedridden medical in-patients: a prospective randomised double-blind study

Abstract

Background: Hospitalised medical patients are at significant risk of venous thromboembolic disease through fatal pulmonary embolism; low-molecular-weight heparins have been proved efficient in preventing deep venous thrombosis in surgical and medical patients, but their effect on mortality in bedridden medical patients remains unknown.

Methods: In a multi-centre, randomised, double-blind, placebo-controlled study, 2,474 consecutive patients aged over 40 years admitted to internal medicine departments in the last 24 h and unable to move alone were randomised to receive 0.3 ml nadroparin (7,500 anti-Xa units) or placebo for up to 21 days. The primary end-point was overall mortality at day 21.

Results: There were no significant differences between the patients' characteristics. Overall mortality between the two groups was not statistically different [10.08% (124 of 1,230) versus 10.29% (128 of 1,244), respectively, in the nadroparin and in the placebo groups; relative risk reduction 0.02, CI (-0.27, +0.25), P=0.89]. An autopsy was performed in 123 of the 252 patients who died (49%). Pulmonary embolism was discovered at autopsy in 10 of 63 patients in the nadroparin group and in 17 of 60 in the placebo group [relative risk reduction 0.38, CI (-0.27, +0.70), P=0.13].

Conclusion: Nadroparin does not have a significant effect on mortality in bedridden medical patients, based on the study results. The study provides no data suggesting that low-molecular-weight heparins might reduce the incidence of thromboembolic in-patients hospitalised for an acute medical disease.