Optimal strategy for administering enoxaparin to patients undergoing coronary angiography without angioplasty for acute coronary syndromes.

The optimal strategy for administration of low molecular weight heparin in patients with acute coronary syndrome (ACS) undergoing coronary angiography without percutaneous coronary intervention remains unclear. We studied postangiographic vascular complications in 325 consecutive patients (210 men and 115 women, mean age 63 years) with ACS undergoing diagnostic coronary angiography via a femoral approach followed by immediate sheath removal. At the time of angiography, 44 patients were on intravenous unfractionated heparin (UFH), 229 on subcutaneous enoxaparin, and 52 on no heparin. Enoxaparin was withheld on the morning of angiography in 181 of 229 patients: the no A.M. dose group. Vascular complications were audited, including hematoma development at angiographic puncture sites; these complications were considered significant if >25 cm(2). Major vascular complications requiring transfusion or surgical interventions were infrequent in all groups. Patients receiving enoxaparin on the morning of angiography had a twofold increase in significant hematoma rate compared with the no A.M. dose group (31% vs 16%; p = 0.015). The no A.M. dose group had hematoma rates similar to UFH (20%; p = NS) and no anticoagulation (13.5%; p = NS). No significant increase in ischemic episodes occurred as a result of withholding enoxaparin in the no A.M. dose group. We conclude that omission of enoxaparin on the morning of cardiac catheterization results in vascular complications rates comparable to that of UFH without precipitating rebound ischemia. This is a practical, safe strategy for patients with ACS undergoing coronary angiography, allowing early mobilization for most patients who do not proceed to immediate percutaneous coronary intervention.