Can enoxaparin safely replace unfractionated heparin during coronary intervention in acute coronary syndromes?

Enoxaparin has gained wide acceptance in patients with acute coronary syndromes. However, there is uncertainty regarding management of patients who require coronary intervention while on enoxaparin. Some physicians withhold the morning dose of enoxaparin prior to coronary intervention while others switch patients to unfractionated heparin. Both methods do not provide optimal anticoagulation in the hours preceding intervention. There are no published controlled data to assess the safety of coronary intervention using enoxaparin alone in patients with acute coronary syndromes.

We prospectively compared enoxaparin to unfractionated heparin during coronary angiography and intervention. Sixty four patients admitted to the coronary care unit (CCU) were given enoxaparin twice daily, including on the morning of procedure. Coronary angiography and intervention were performed without additional unfractionated heparin. The control group comprised of 52 patients admitted to Internal Medicine for an acute coronary syndrome. These were also given enoxaparin but the morning dose was withheld and unfractionated heparin was used during procedure.

Patients in both groups had similar baseline characteristics. No significant differences were observed between the two groups in procedural success rate, complications or bleeding. One year follow up showed similar rates of hospitalization and mortality.

Enoxaparin seems to offer safe and effective procedural anticoagulation in patients undergoing percutaneous intervention for acute coronary syndromes. Patients given enoxaparin can probably have coronary intervention without interruption of enoxaparin treatment and without additional procedural anticoagulation. These findings require confirmation in larger, randomized trials.