Percutaneous coronary intervention after subcutaneous enoxaparin pretreatment in patients with unstable angina pectoris

Background-Subcutaneous low-molecular-weight (LMW) heparins can effectively replace unfractionated heparin in patients with unstable angina or non-Q-w ave myocardial infarction, However, the optimal anticoagulation strategy fo r these patients when they require cardiac catheterization is still unclear . Therefore, we evaluated a new and simple strategy of anticoagulation in t hese patients. Methods and Results-A total of 451 consecutive patients with unstable angin a/non-Q-wave myocardial infarction were treated for at least 48 hours with subcutaneous injections of enoxaparin (1 mg [100 IU]/kg every 12 hours, cyc led at 6 AM and 6 PIM). Of this unselected population, 293 patients (65%) u nderwent a coronary angiography within 8 hours of the morning LMW heparin i njection, followed by immediate percutaneous coronary intervention (PCI) in 132 patients (28%). PCI was performed without any additional bolus of unfr actionated/LMW heparin and without coagulation monitoring. Anti-Xa activity at the time of catheterization was 0.98+/-0.03 IU/mL, was >0.5 IU/mL in 97 .6% of patients, and did not relate to the LMW heparin injection-to-cathete rization time. There were no in-hospital abrupt closures or urgent revascul arizations after PCI. The death/myocardial infarction rate at 30 days was 3 .0% in the PCI group (n=132) but 30-day major bleeding rate was 0.8% in the PCI group, which was comparable to that of patients without catheterizatio n (1.3%). Conclusions-PCI within 8 hours of the last enoxaparin subcutaneous injectio n seems to be safe and effective. The safety of subcutaneous LMW heparin in combination with platelet glycoprotein IIb/IIIa blockade awaits further st udy.