EUROMAX Substudy: Bivalirudin Noninferior to Heparin Plus GPI for Myocardial Reperfusion

Results of a prespecified subanalysis of the EUROMAX trial presented Saturday at TCT 2014 show bivalirudin matches heparin plus glycoprotein IIb/IIIa inhibitor (GPI) use with regard to residual ST-segment deviation.

The findings reflect “comparable myocardial tissue reperfusion with the two strategies,” said investigator Jurrien M. ten Berg, MD, of St. Antonius Hospital in Nieuwegein, the Netherlands.

In the main EUROMAX trial, researchers at 65 European centers randomized 2,218 STEMI patients who were being transported for primary PCI to bivalirudin (0.75 mg/kg bolus followed by 1.75 mg/kg/h infusion) or to unfractionated heparin or enoxaparin (standard practice) with optional GPI use. They found that the bivalirudin strategy reduced short-term death and major non-CABG bleeding.

For the current analysis, ten Berg and colleagues looked at myocardial perfusion rates in the two study arms. Only patients from the nine hospitals that routinely used prehospital GPIs were included in the substudy.

Mean values for the primary endpoint of cumulative residual ST-segment elevation as measured by ECG at 1 hour post-procedure were 3.8 ± 4.9 mm in the bivalirudin group and 3.9 ± 5.2 mm in the heparin plus GPI group (P=.0019).

No differences in the degree of ST-segment resolution — whether none, partial or complete — were seen between the two groups (see Figure).

At 30 days, the combined rate of death and non-CABG major bleeding was lower for bivalirudin than for heparin plus GPI (3.5% vs. 6.3%; RR 0.55; 95% CI 0.30-1.01; P=.05). Protocol major non-CABG-related bleeding was 1.9% with bivalirudin and 5.2% with heparin plus GPI (RR 0.36; 95% CI 0.16-0.79; P=.008). Acute stent thrombosis rates were 8% and 2%, respectively (RR 4.10; 95% CI 0.88-19.21; P=.06). “We all know that primary PCI is the cause of reperfusion in patients with STEMI, but despite the success of primary PCI, there is microvascular damage in about one-third of these patients. Both antiplatelets and anticoagulants play a crucial role in preventing microvascular damage and improving myocardial tissue reperfusion,” ten Berg said.

In support of his data, ten Berg recounted the double-blind ON-TIME 2 study, published in 2008 in the Lancet, which showed better ST-segment resolution 1 hour after PCI in patients who were pretreated with high-dose tirofiban in the ambulance.

“This translated to better outcomes at 1 year and [the advantage] was especially true for patients who presented early. However, this trial was not powered to detect a difference in clinical outcome,” he said.