September 2, 2010

Lower Doses of Heparin Before a Coronary Procedure- Better or Worse for the Patient?

(Ivanhoe Newswire) "“ Many coronary procedures are done every year, and many involve the use of Heparin, an anticoagulant which prevents the blood from clotting and forming harmful bigger clots in the veins and arteries. It is typically used in lower doses for patients getting coronary procedures, but this study shows that using lower doses isn't more effective than using normal dosage.

Patients with acute coronary syndrome initially treated with Fondaparinux, an anticoagulant which prevents dangerous blood clots, who had a coronary procedure done (balloon angioplasty) and received lower dosages of Heparin, another anticoagulant, during surgery didn't have a lower rate of major bleeding or complications at the vascular access site, according to the study.

A previous study done showed that normal doses of Heparin used the time of percutaneous coronary intervention (PCI; procedures such as balloon angioplasty or stent replacement) was given to patients who had been taking Fondaparinux. The disagreement it about whether lower doses or normal doses of Heparin administered during a PCI are better at reducing risk of major bleeding and site complications.

The study evaluated the safety of two dose regimens of adjunctive intravenous unfractionated Heparin during a PCI in high risk patients. The randomized trial involved 179 hospitals in 18 countries and had 2,026 patients undergoing a PCI. All the patients were initially treated with Fondparinux. The researchers found that major and minor bleeding and vascual access site complications up to 48 hours after surgery occurred in 4.7 percent of patients in the low-dose group and 5.8 percent in the normal-dose group. There was a non-significant increase in death, heart attack, and target revascularization.

"The finding that adding ACT-guided unfractionated Heparin to fondaparinux while treating patients with acute coronary syndromes does not increase major bleeding is important in the context of modern PCI practice. Reducing bleeding is potentially important because several studies have suggested that moderate reductions in bleeding may lead to a reduction in longer term ischemic events, particularly mortality. In our study, there was no clinical benefit to using the experimental low-dose regimen, except for a reduction in minor bleeding alone (but not in the combination of major and minor bleeding)," Sanjit S. Jolly, M.D., of Hamilton Health Sciences and McMaster University, Hamilton, Ontario, Canada, and colleagues were quoted as saying "These findings support using the currently recommended standard ACT-guided dose of unfractionated heparin when performing PCI in patients with non-ST segment elevation acute coronary syndromes who are treated with fondaparinux."

SOURCE: JAMA, published online September 2010