OBJECTIVEThe study was designed to compare the antithrombotic property and safety between nadroparin and unfractionated heparin during percutaneous coronary intervention (PCI).

METHODSA prospective, single blind, randomized study was performed. A total of 98 patients (aged 65.1 +/- 8.6 years, female, 28.6%, diabetes, 7.1%) undergoing selective PCI were randomized to be administered intravenously either nadroparin (0.075 ml/10 kg) or unfractionated heparin (100U/kg) for procedural anticoagulation, in whom stable angina was 42.9%, unstable angina, 27.6%, myocardial infarction, 29.6%, two or three-vessel disease, 23.5%, stent, 100%. Blood samples for anti-Xa level were assayed in the first 22 patients of the nadroparin group before and after administration at the following intervals: 8 min, 1 h, 2 h and 4 h. Bleeding complications were classified according to Thrombolysis In Myocardial Infarction (TIMI) criteria. The bleeding index (change in hemoglobin) was calculated. All patients were monitored for adverse clinical events (i.e. death, myocardial infarction, need for revascularization) during the period of 30 days after PCI.

RESULTS(1) There were no significant differences in baseline characteristics between the two randomized groups. (2) Plasma anti-Xa activities were 0.10 +/- 0.00 IU/ml at the time just before the administration of nadroparin, 1.89 +/- 0.24 IU/ml, 0.96 +/- 0.24 IU/ml, 0.47 +/- 0.13 IU/ml, and 0.30 +/- 0.12 IU/ml at the time of 8 min, 1 h, 2 h and 4 h after the use of nadroparin (and the rate of > 0.5 IU/ml were 100%, 100%, 45% and 9% patients), respectively. (3) There were no significant differences in the mean bleeding index, post-PCI hemoglobin and hematocrit between nadroparin and unfractionated heparin group [(1.16 +/- 5.80) g/L vs (0.90 +/- 6.50) g/L, P = 0.858; (129.5 +/- 13.6) g/L vs (125.5 +/- 14.9) g/L, P = 0.175; (39.0 +/- 3.9)% vs (37.9 +/- 4.6)%, P = 0.205]. (4) None of the patients in two randomized groups were observed hemorrhagic events, which including TIMI major or minor bleeding complications, gross or microscopic hematuria, melena, positive stool occult blood. There were no blood transfusions and no hematoma at the vascular access site in either of the group. (5) No death, no recurrent angina pectoris, and no urgent revascularization occurred within 30 days in both groups. One patient in nadroparin group was observed "no reflow" phenomenon that was accompanied with an elevated ST segment and a risen serum level of cTnI. This patient was diagnosed as non-Q-wave myocardial infarction. Though no myocardial infarction was found in unfractionated heparin group, there was no significant difference in the rate of myocardial infarction between the two groups of the study (P = 0.970).

CONCLUSIONSThe administration of nadroparin before PCI seems effective and safe. Compared with unfractionated heparin, nadroparin was associated with neither an excess of bleeding nor an increase of clinical complications in this study.