Enoxaparin ( Clexane, Lovenox ), a low molecular weight Heparin, is more effective in reducing serious ischaemic events than the traditionally used unfractionated Heparin ( UFH ), according to results from the ATOLL trial.

This is the first pure head-to-head comparison between two anticoagulants in primary PCI for STEMI ( ST segment elevation myocardial infarction ). The data have demonstrated that this approach, which is easier to use, is also more effective in reducing the most serious ischaemic complications of STEMI treated with primary PCI ( percutaneous coronary intervention ).

In the earlier STEEPLE study, performed in elective PCI, Enoxaparin was found to be associated with reductions in major bleeding when compared with unfractionated Heparin ( N Eng J M 2006 ). But to date only UFH has been used in primary PCI for STEMI.
Now, in this phase III investigator-initiated ATOLL study, Enoxaparin has been compared with UFH, both of which were administered intravenously in patients undergoing primary PCI for STEMI.
Although not a new drug, Enoxaparin has been recently reformulated for intravenous administration.

In this 43-site trial, 910 patients having primary PCI for STEMI were randomised to receive either Enoxaparin IV ( 0.5 mg/kg with or without GPIIb/IIIa ) or UFH IV ( 50-70 IU with GP IIb/IIIa, 70-100 IU without GPbIIb/IIIa ). Two-thirds of the patients in the study had radial access for primary PCI.

Results at 30 days have shown that the primary endpoint ( a composite of death, complications from myocardial infarction, procedure failure or major bleeds ) occurred in 33.7% receiving UFH and 28% receiving Enoxaparin ( p=0.07 ).
The main secondary endpoint looking at death, recurrent myocardial infarction / acute coronary syndrome or urgent revascularisation occurred in 11.3% receiving unfractionated Heparin and 6.7% receiving Enoxaparin ( p=0.01 ).

Death or complications of myocardial infarctions occurred in 12.4% receiving unfractionated Heparin and 7.8% receiving Enoxaparin ( p=0.02 ); while the triple ischemic endpoint ( death, re-myocardial infarction, or urgent revascularisation ) occurred in 8.5% receiving unfractionated Heparin and 5.1% receiving Enoxaparin ( p=0.04 ).

Additionally, the study has shown a 4.9% risk of non-CABG major bleeding in the unfractionated Heparin arm versus 4.5 % in the Enoxaparin arm, which was non-significant but may have been related to the high proportion of patients having radial access PCI.

Source: European Society of Cardiology Congress, 2010

XagenaMedicine2010


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