LMWH feasible after heart valve surgery
MedWire News: Canadian researchers report that heart valve surgery patients who receive LMWH instead of UFH postoperatively have a lower risk for thrombosis, bleeding, and heparin induced thrombocytopenia (HIT).
"Although UFH is used routinely after heart valve surgery at many institutions, cardiovascular (CV) surgery patients have a particularly high risk for developing HIT," explain Claudia Bucci and colleagues from Sunnybrook Health Sciences Centre, in Toronto, Ontario.
Because of this increased risk for HIT, Bucci and team implemented an "avoid-heparin policy" for early anticoagulation after CV surgery at their institution in 2006. Instead, they chose to use LMWH, which confers a lower risk for HIT.
In the present study, they retrospectively evaluated the efficacy and safety of the two regimens by comparing CV surgery patients in whom the LMWH dalteparin (n=100) was used as the postoperative anticoagulant, with an earlier group of patients who received UFH (n=103).
Demographic and clinical characteristics were similar among the groups. The mean age was approximately 65 years and 68% of patients were men.
The researchers report that fewer thrombotic events occurred in the LMWH-treated group, at 4%, compared with the UFH group at 11%, indicating that LMWH had the greater efficacy of the two drugs. This difference in efficacy, however, was not statistically significant.
In addition, no cases of valve thrombosis occurred in the LMWH group compared with one case in the UFH group.
Patients who received LMWH also experienced a nonsignificantly lower rate of major bleeding events, most commonly pericardial bleeds, than those who received UFH, at 3% versus 10%.
Six patients in the UFH-treated group and three patients in the LMWH-treated group developed HIT, of whom four and one, respectively, also had thrombotic events.
There was one death in each group during hospitalization, both related to HIT.
Writing in the American Journal of Cardiology, Bucci and co-authors conclude that LMWH is a low-risk and effective regimen to use in patients who have undergone heart valve surgery.
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By Laura Dean