LMWH superior to UFH for primary PCI patients
MedWire News: Low molecular weight heparin (LMWH) is associated with reduced mortality and bleeding compared with unfractionated heparin (UFH) in patients undergoing primary percutaneous coronary intervention (pPCI) for ST-elevation myocardial infarction (STEMI), research shows.
However, no such benefit was observed among patients undergoing PCI after thrombolysis, report Eliano Navarese (Nicolaus Copernicus University, Bydgoszcz, Poland) and colleagues in the Journal of Thrombosis and Thrombolysis.
The findings are derived from two separate meta-analyses, which the researchers conducted to compare LMWH and UFH treatment in STEMI patients treated with either pPCI or PCI after thrombolysis.
The team identified 10 studies, comprising 16,286 patients. The patients were followed-up for a median of 2 months for the primary endpoint of all-cause mortality. Major bleeding complications were recorded as a secondary endpoint.
The researchers report that LMWHs - most commonly enoxaparin - were associated with a significant 49% reduced risk for death and a significant 32% reduced risk for major bleeding compared with UFH in patients who underwent pPCI.
Furthermore, meta-regression showed that patients with higher baseline risk derived larger benefits from LMWH therapy than those with lower baseline risk.
In contrast, Navarese and colleagues found no clear evidence of an advantage of LMWH over UFH in patients who underwent PCI after thrombolysis with regard to mortality or major bleeding.
The researchers remark that these findings can potentially be explained by the fact that, in the setting of pPCI, LMWH is predominantly administered intravenously and for a short duration, whereas in the thrombolytic studies, they were generally given subcutaneously and for a prolonged period.
They add that "LMWHs have several pharmacological properties that may theoretically explain their greater efficacy." These include "greater activity against activated factor X that is crucial to promote the production of thrombin," and "a much more predictable anticoagulant response than UFH."
The team concludes: "Based on this meta-analysis, LMWHs may be considered as a preferred anticoagulant among STEMI patients undergoing pPCI."
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By Laura Dean