Low-molecular-weight heparins demonstrated similar safety to unfractionated heparin in the setting of PCI and show promise as an antithrombotic agent across the spectrum of acute coronary syndromes.
Systematic Review
Do low-molecular-weight heparins improve efficacy and safety compared with unfractionated heparin or placebo in patients with acute coronary syndromes or undergoing PCI?
LMWHs show similar safety to unfractionated heparin in PCI and ACS, potentially serving as the antithrombotic agent of choice across the ACS spectrum.
CONTEXT: Low-molecular-weight heparins (LMWHs) possess several potential pharmacological advantages over unfractionated heparin as an antithrombotic agent. OBJECTIVE: To systematically summarize the clinical data on the efficacy and safety of LMWHs compared with unfractionated heparin across the spectrum of acute coronary syndromes (ACSs), and as an adjunct to percutaneous coronary intervention (PCI). DATA SOURCES: We searched MEDLINE for articles from 1990 to 2002 using the index terms heparin, enoxaparin, dalteparin, nadroparin, tinzaparin, low molecular weight heparin, myocardial infarction, unstable angina, coronary angiography, coronary angioplasty, thrombolytic therapy, reperfusion, and drug therapy, combination. Additional data sources included bibliographies of articles identified on MEDLINE, inquiry of experts and pharmaceutical companies, and data presented at recent national and international cardiology conferences. STUDY SELECTION: We selected for review randomized trials comparing LMWHs against either unfractionated heparin or placebo for treatment of ACS, as well as trials and registries examining clinical outcomes, pharmacokinetics, and/or phamacodynamics of LMWHs in the setting of PCI. Of 39 studies identified, 31 fulfilled criteria for analysis. DATA EXTRACTION: Data quality was determined by publication in the peer-reviewed literature or presentation at an official cardiology society-sponsored meeting. DATA SYNTHESIS: The LMWHs are recommended by the American Heart Association and the American College of Cardiology for treatment of unstable angina/non-ST-elevation myocardial infarction. Clinical trials have demonstrated similar safety with LMWHs compared with unfractionated heparin in the setting of PCI and in conjunction with glycoprotein IIb/IIIa inhibitors. Finally, LMWHs show promise as an antithrombotic agent for the treatment of ST-elevation myocardial infarction. CONCLUSIONS: The LMWHs could potentially replace unfractionated heparin as the antithrombotic agent of choice across the spectrum of ACSs. In addition, they show promise as a safe and efficacious antithrombotic agent for PCI. However, further study is warranted to define the benefit of LMWHs in certain high-risk subgroups before their use can be universally recommended.
Wong et al. (2003) conducted a systematic review in Acute coronary syndromes and percutaneous coronary intervention. Low-molecular-weight heparins (LMWHs) vs. Unfractionated heparin or placebo was evaluated on Clinical outcomes, efficacy, and safety. Low-molecular-weight heparins demonstrated similar safety to unfractionated heparin in the setting of PCI and show promise as an antithrombotic agent across the spectrum of acute coronary syndromes.