Results of the PCI-ExTRACT-TIMI 25 study has announced at the World Congress of Cardiology-European Society of Cardiology 2006 in Barcelona, showed that among patients with ST-segment elevation myocardial infarction (STEMI) who initially received fibrinolytic therapy and adjunctive antithrombotic therapy with either enoxaparin or unfractionated heparin and subsequently underwent PCI, the enoxaparin strategy reduced the risk of death or recurrent heart attacks during the treatment phase before PCI and this benefit persisted after PCI for up to 30 days. Fewer patients in the enoxaparin group had to undergo PCI compared to those in the UFH group.

These advantages of enoxaparin were observed without an increase in the risk of major bleeding between the enoxaparin and UFH groups (1.4 per cent and 1.6per cent respectively).

The PCI-ExTRACT-TIMI 25 study was a pre-planned prospective analysis of the subgroup of the 4,676 patients in the ExTRACT-TIMI 25 (Enoxaparin and Thrombosis Reperfusion for Acute Myocardial InfarCtion treatment, Thrombosis In Myocardial Infarction study (25) trial?. The ExTRACT-TIMI 25 trial was a randomized controlled clinical study of 20,479 patients in 48 countries between October 2002 and October 2005.

Patients in the PCI-ExTRACT-TIMI 25 study received adjunctive anticoagulation therapy with either enoxaparin or UFH in a blinded fashion during fibrinolysis and underwent subsequent PCI. Anticoagulation treatment was continued in those patients who had PCI. The aim of the study was to determine whether enoxaparin was associated with superior efficacy and safety compared to UFH in the PCI setting. The main outcomes were death or repeat heart attacks through 30 days (10.7 per cent of the enoxaparin and 13.8 per cent of the UFH patients, 0.77 relative risk, 95 per cent CI 10 per cent 34 per cent; p=0.001).

Secondary outcomes included stroke and bleeding rates. There were fewer strokes both before and after PCI among patients treated with enoxaparin compared with those who received UHF (0.3 per cent vs 0.9 per cent, RR0.30, p=0.006).

"We believe that these results are important because they show that enoxaparin is a more effective treatment for STEMI patients undergoing PCI compared to UFH, the current standard treatment of care. These results indicate that adding enoxaparin for anticoagulation supports a practice pattern in which PCI is performed at some time following fibrinolytic administration. As the use of enoxaparin Antman EM et al. N Eng J Med 2006; 354:1477-88 2/4 both delays the onset and reduces the occurrence of repeat heart attacks, the window of opportunity to perform PCI following fibrinolytic administration is larger than that with UFH, "stated C. Michael Gibson, MS, MD of the TIMI Study Group, Harvard Medical School, Boston Massachusetts. "Moreover, not only does enoxaparin provide a seamless transition to the catheterisation laboratory without the need for additional antithrombin inhibition, it also removes the need for monitoring in the catheterisation laboratory, thereby offering an attractive and more practical alternative to the cumbersome and uncertain administration requirements of UFH anticoagulation." added Dr Gibson.

With more than 1 million PCI procedures now performed worldwide each year, the PCI ExTRACTTIMI 25 results are timely to address unmet needs in medical therapy in the contemporary era of PCI. Unfractionated heparin has been the mainstay anticoagulant during PCI procedures, despite its limitations. The PCI-ExTRACT-TIMI 25 study confirms that enoxaparin is an effective, safe, and easy to use antithrombin in patients undergoing PCI for ST-elevation heart attack. These results, consistent with the results of the STEEPLE study showing the superior safety profile of enoxaparin versus UFH in patients undergoing elective PCI, contribute to building a more complete picture of the use of enoxaparin in all thrombosis settings, and further add to the 50,000 patients who have participated in cardiovascular trials of enoxaparin to date.