Bivalirudin vs Low-Dose Heparin in PCI: ARMYDA BIVALVE

April 15, 2011

April 13, 2011 (New Orleans, Louisiana)Bivalirudin was associated with lower bleeding complications than low-dose unfractionated heparin in PCI patients at high bleeding risk in the ARMYDA-BIVALVE study.

The study was presented by lead investigator Dr Giuseppe Patti (Campus Bio-Medical University of Rome, Italy) at last week's American College of Cardiology 2011 Scientific Sessions.

Patti noted that bivalirudin, a direct thrombin inhibitor, has been shown to be as effective as unfractionated heparin, with decreased bleeding risk, in patients with acute coronary syndromes undergoing PCI. But there has been no study specifically designed to evaluate effectiveness of bivalirudin vs heparin in patients at high risk of bleeding complications with PCI. This was therefore investigated in the ARMYDA-BIVALVE study.

Patti explained to heartwire that in previous studies comparing bivalirudin with heparin, such as HORIZONSACUITY,and REPLACE-2, the heparin group systematically received GP IIb/IIIa inhibitors, which may at least partially have contributed to the higher bleeding rate. "However, in ARMYDA-BIVALVE, we showed a reduction in bleeding complications without systematic use of GP IIb/IIIa inhibitors in the opposite arm."

He added that unlike ISAR-REACT 3, which used a heparin dose of 140 IU/kg as the control arm, ARMYDA-BIVALVE compared bivalirudin with a much lower dose of heparin (75 IU/kg) and still showed a reduced level of bleeding.

In the study, 401 patients at high bleeding risk (over 75 years of age, diabetes, reduced renal function) scheduled for PCI were randomized to bivalirudin (0.75 mg/kg bolus followed by 1.75 mg/kg per hour during the procedure) or unfractionated heparin (75 IU/kg). Provisional GP IIb/IIIa blockers were used in both groups.

The 30-day results showed that major adverse cardiac events (MACE)--death, MI, target vessel revascularization, or stent thrombosis--were similar in the two groups, but bleeding rates were vastly reduced in the bivalirudin group. Patti said this was essentially due to a reduction in hematoma at the entry site associated with the PCI femoral approach. The bleeding reduction was seen in both ACS and stable patients.

ARMYDA-BIVALVE: Major Results at 30 Days

Outcome Bivalirudin (%) Heparin (%) p
MACE 11.1 8.9 0.56
Bleeding (major, minor, and entry site) 1.5 9.9 0.0001

During the discussion of the study, one commentator suggested that it would now be desirable to compare bivalirudin with an even lower dose of heparin in such patients and in the context of a radial approach to PCI, which is associated with lower bleeding rates. It would also be interesting to look at whether the lowest-risk patients, rather than the highest, also derive any benefit of bivalirudin over heparin.

Cochair of the session, Dr Roxana Mehran (Mount Sinai Medical Center, New York, NY), said it would have been better if there had been more patients in the study to achieve more meaningful efficacy results.


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