Safety And Effectiveness Of Dalteparin Versus Unfractionated Heparin During Elective Percutaneous Coronary Interventions

Backgroud: Percutaneous coronary intervention (PCI), as a new technology of reducing stenosis of coronary arterys, plays an important role in the treatment of coronary heart disease (CHD). It is minimally invasive and security, more and more patients adopt this treatment. However, many factors can activate blood coagulation cascade system during PCI, such as the rupture of coronary atherosclerotic plaques, foreign-body reaction, the injury of vascular endothelial cells and so on. Once an important blood vessel was blocked by a thrombus, disastrous consequences beyond imagination would happen. Thus, anticoagulation therapy become an important preventive and treatment measure during PCI. Conventionally, we use unfractionated heparin (UFH) during PCI. However, its therapeutic dose is indefinite, and its pharmacokinetics is unstable, people are constantly looking for a new anticoagulant to replace of it. Recently, more and more experiments have proved that low-molecular-weight heparin (LMWH) can be used safely and effectively as an alternative to UFH during PCI.Objective: The experiment is to explore the feasibility of LMWH as an alternative to UFH in elective PCI a step further by monitoring the changes of cardiac troponin T (cTnT) and creatine kinase MB(CKMB), the incidence of adverse cardiovascular events and bleeding after PCI, without monitoring its anticoagulant effect.Method: Consecutive patients who planned to undergo coronary angiography (CAG) or PCI were enrolled in our study. The number of the subjects is 273. All the subjects were randomized to LMWH group or UFH group, and had took aspirin at least 300 mg before PCI, similar to clopidogrel. In LMWH group, there were not any anticoagulant therapy within 12 h before PCI. Patients who were scheduled to undergo PCI after a successful coronary angiography were given dalteparin total 120IU/kg (LMWH goup) or unfractionated heparin total 120 IU/kg (UFH goup), including the dosage during the process of CAG. The radial arterial sheath were removed immediately after PCI in both groups. The femoral arterial sheath were removed about 2 hours after the last offer of dalteparin in LMWH group, whereas in UFH group, the removel of femoral arterial sheath was guided by APTT. Finally, 61 subjects were enrolled in this study, 30 in LMWH group and 31 in UFH group. Both of the two groups enrolled 1 subjects who only adopt percutaneous intraluminal coronary angioplasty respectively. Blood was sampled for CKMB and cTnT before and between 18 and 24 h after the procedure. Each patient was recorded detailedly, for example: their baseline characteristics, the operative parameters during PCI, the changes of cTnT and CKMB, the complications after PCI and so on. Statistical analysis was performed by SAS V 8.0 statistical software.Results: There were no side-branch occlusions, urgent target vessel revascularization, myocardial infarction, major bleeding and death in both groups. During hospitalization, 6 and 1 minor bleeding events were dected in LMWH goup and UFH group respectively. However, there were no statistical significance. No patient had abnormal cTnT or CKMB levels before the procedures, and no statistical diferences of cTnT and CKMB at baseline were observed between the two groups. There were 3 cTnT-positive patients and 3 CKMB-positive patients in UFH group. Whereas the CKMB and cTnT remained constantly normal in LMWH group, and there were no cTnT >3 times the upper reference limit in both groups. After PCI, 17and 15 patients'CKMB levels were higher in UFH group and LMWH group respectively than they were before the procedures, whereas 13 and 12 patients'cTnT levels were higher in UFH group and LMWH group respectively than they were before the procedures. After PCI, average increase of cTnT in LMWH group and UFH group were (0.009±0.0175) ng/ml and (0.025±0.064) ng/ml respectively, whereas CKMB were (0.3±6.075) U/l and (1.865±9.899)U/l respectively. All above, There were no statistical differences between the two groups (P > 0.05).Conclusion: LMWH is at least as efficacious and safe as UFH in patients undergoing elective PCI, when used intra-arterially, without monitoring. However, whether this conclusion can be extended to a more extensive extent still need to be testified by more experinents.