Heparin Cuts VTE Risk, Not Inpatient Mortality

BY MARY ANN MOON

Both unfractionated heparin and low-molecular-weight heparin were found to reduce the risk of venous thromboembolism in hospitalized medical patients, according to researchers who reported on their meta-analysis of 36 randomized controlled clinical trials.

The pooled results of those trials that directly compared the two treament agents showed that the use of low-molecular-weight heparin was more effective than the use of unfractionated heparin in preventing the occurence of deep vein thrombosis, Lironne Wein and her associates reported.

The researchers performed the meta-analysis because thromboprophylaxis "is not widely practiced in the medical setting, even though medical patients represent most hospitalized patients, and at least 75% of fatal pulmonary embolisms occur in this group."

Pooled results of the 36 prospective trials showed that compared with placebo, both unfractionated heparin and low-molecular-weight heparin decreased the risk of thrombotic events, and the latter agent was more effective.

However, neither form of heparin was found to affect mortality, said Ms. Wein of the department of epidemiology and preventive medicine at Monash University, Melbourne, and her associates.

"It is therefore likely that a large proportion of patient deaths were attributable to causes other than VTE events," they said (Arch. Intern. Med. 2007;167:1476-86).

The study results indicate that routine prophylactic anticoagulation "has an important place in the medical setting," they concluded

'IT IS THEREFORE LIKELY THAT A LARGE PROPORTION OF PATIENT DEATHS WERE ATTRIBUTABLE TO CAUSES OTHER THAN VTE EVENTS.'